logo RSS Rabbit quadric
News that matters, fast.
Good luck, have news.
Happy scrolling!

Categories



Date/Time of Last Update: Wed Aug 10 03:00:35 2022 UTC




********** CLIMATE **********
return to top



What Could Keep Climate Change From Becoming Catastrophic?
Tue, 09 Aug 2022 11:00:00 +0000
WIRED’s editor in chief weighs the merits and detriments of carbon capture and storage, plus more thoughts on this month’s headlines.
Match ID: 0 Score: 30.00 source: www.wired.com age: 0 days
qualifiers: 15.00 climate change, 15.00 carbon

Lawmakers in India pass energy conservation bill
Tue, 9 Aug 2022 21:39:33 EDT
The Indian government took another step toward its climate goals by passing a conservation bill through parliament’s lower house, which makes it easier to put a price on carbon emissions and encourages the use of non-fossil fuel sources to generate power across the country
Match ID: 1 Score: 15.00 source: www.washingtonpost.com age: 0 days
qualifiers: 15.00 carbon

Trillions of dollars at risk because central banks’ climate models not up to scratch
Tue, 09 Aug 2022 17:30:30 GMT

Climate research finds modelling used cannot predict localised extreme weather, leading to poor estimations of risk

Trillions of dollars may be misallocated to deal with the wrong climate threats around the world because the models used by central banks and regulators aren’t fit for purpose, a leading Australian climate researcher says.

Prof Andy Pitman, director of the Australian Research Council’s Centre of Excellence for Climate Extremes, said regulators were relying on models that are good at forecasting how average climates will change as the planet warms, but were less likely to be of use for predicting how extreme weather will imperil individual localities such as cities.

The concerns, detailed in a report in the journal Environmental Research: Climate, were underscored by the Australian Prudential Regulation Authority’s release on Monday of its corporate plan 2022-23. Apra plans to “continue to ensure regulated institutions are well-prepared for the risks and opportunities presented by climate change”.

Sign up to receive an email with the top stories from Guardian Australia every morning

Continue reading...
Match ID: 2 Score: 15.00 source: www.theguardian.com age: 0 days
qualifiers: 15.00 climate change

Humanity's Biggest Problems Require a Whole New Media Mode
Tue, 09 Aug 2022 12:00:00 +0000
In this era of climate change and crisis, it's time for formats as varied, animal, and leafy as the world they seek to represent.
Match ID: 3 Score: 15.00 source: www.wired.com age: 0 days
qualifiers: 15.00 climate change

This Laser-Firing Truck Could Help Make Hot Cities More Livable
Tue, 09 Aug 2022 11:00:00 +0000
Scientists are driving around in a specialized observatory to better understand how urban heat varies not only block to block, but door to door.
Match ID: 4 Score: 15.00 source: www.wired.com age: 0 days
qualifiers: 15.00 climate change

The Democrats Finally Deliver
Tue, 09 Aug 2022 00:10:41 +0000
The Senate’s passage of a sweeping, if imperfect, climate-change-and-health-care bill is a landmark moment in U.S. policymaking.
Match ID: 5 Score: 15.00 source: www.newyorker.com age: 1 day
qualifiers: 15.00 climate change

It’s possible no electric vehicles will qualify for the new tax credit
Mon, 08 Aug 2022 22:11:19 +0000
There is no grace period, so credits effectively end once the bill is signed.
Match ID: 6 Score: 15.00 source: arstechnica.com age: 1 day
qualifiers: 15.00 climate change

US Senate passes sweeping climate, tax and healthcare package
Mon, 08 Aug 2022 22:02:37 GMT
The bill seeks to lower the cost of medicines, increase corporate taxes and reduce carbon emissions.
Match ID: 7 Score: 15.00 source: www.bbc.co.uk age: 1 day
qualifiers: 15.00 carbon

New EV Prototype Leaves Range Anxiety in the Dust
Mon, 08 Aug 2022 16:13:15 +0000


Not long ago, a 300-mile range seemed like a healthy target for electric cars. More recently, the 520-mile (837-kilometer) Lucid Air became the world’s longest-range EV. But that record may not stand for long.

The Mercedes-Benz Vision EQXX, and its showroom-bound tech, looks to banish range anxiety for good: In April, the sleek prototype sedan completed a 621-mile (1,000-km) trek through the Alps from Mercedes’s Sindelfingen facility to the Côte d’Azur in Cassis, France, with battery juice to spare. It built on that feat in late May, when the prototype covered a world-beating, bladder-busting 747 miles (1,202 km) in a run from Germany to the Formula One circuit in Silverstone, England.

This wasn’t your usual long-distance, college-engineering project, a single-seat death trap made from Kleenex and balsa wood, with no amenities or hope of being certified for use on public roads. Despite modest power, a futuristic teardrop shape, and next-gen tech, the EQXX—developed in just 18 months—is otherwise a familiar, small Mercedes luxury sedan. That includes a dramatic sci-fi display and human-machine interface that spans the full dashboard. To underline real-world intent, Mercedes vows that the EQXX’s power train will reach showrooms by 2024. An initial showroom model, and surely more to come, will be built on the company’s new Mercedes Modular Architecture platform, designed for smaller “entry-luxury” models such as the A-Class and the CLA Coupe. While Mercedes was refining its one-off tech showpiece, it even used a current EQB model as a test mule for the power train.

“The car is an R&D project, but we’re feeding it into the development of our next compact car platform,” says Conrad Sagert, an engineer at Mercedes who is developing electric drive systems.

The engineering team included specialists with the Mercedes-EQ Formula E team, drawing from their well of electric racing experience. Developed in just 18 months, the rear-drive Vision EQXX is powered by a single radial-flux electric motor—developed entirely in-house—fed by a battery pack with just under 100 kilowatt-hours of usable energy. Inside, environmentally conscious materials include trim panels sourced from cacti, mushroom-based seat inserts and bamboo-fiber shag floor mats, all previewing potential use in showroom cars. One thing that won’t reach production by 2024 is the EQXX’s high-silicon battery anode, which Sagert says is closer to four years from showrooms. Such silicon-rich anodes, which can squeeze more range from batteries, are widely expected to be popularized over the next decade.

A 241-horsepower output delivers a reasonable 7-second trip from 0 to 60 miles per hour. But from a feathery (for an electric vehicle) 3,900-pound curb weight to wind-cheating aerodynamics, the carbon-fiber-bodied EQXX is designed for pure efficiency, not winning stoplight races. The Benz sipped electrons at 8.7 miles per kilowatt-hour on its Côte d'Azur run, nearly double the roughly 4.5 kWh of the Lucid (the current high for global EVs) and 7.5 miles per kilowatt-hour on the trip to the United Kingdom. If that electric math still seems esoteric, the England-bound Benz delivered the equivalent of 262 miles per gallon, nearly double the 141 mpg of the industry-leading Tesla Model 3 Standard Range.

A roof panel with 117 solar cells lessens the burden by powering a conventional 12-volt system to run accessories, including lighting, an audio system, and the display screens worthy of Minority Report. On the cloudy April trip to southern France, with plenty of tunnel passages, the panels saved 13 km of range. On the sunnier May drive to the U.K., the solar roof saved 43 km of range.

Roof of a car with solar panels with a beach in the background. The Vision EQXX’s roof panel has 117 solar cells.Mercedes-Benz

Aerodynamics naturally play an essential role, including a tiny frontal area and dramatic Kamm tail whose active rear diffuser extends nearly 8 inches at speeds above 23 mph. The sidewalls of specially designed Bridgestone tires sit flush with the body and 20-inch magnesium wheels, aiding a claimed drag coefficient of 0.17, which exceeds any current production car. Surprisingly for such a slippery design, the EQXX features traditional yet aerodynamic exterior mirrors: Mercedes says the camera-based “mirrors” used on many concept cars drew too much electricity to generate a tangible benefit.

Defying today’s EV norms, the battery and motor are entirely air cooled. Eliminating liquid-cooling circuits, pumps, and fluids set off a spiral of savings in weight and packaging. To cool the battery, a smoothly shaped underbody acts as a heat sink. The design reversed the usual engineering challenge in EVs and internal combustion engine cars alike: The problem was getting heat into the system to bring battery and motor to optimal operating temperature. Active front shutters can open to boost airflow when necessary.

“We don’t get enough waste heat, so we had to insulate the electric motor. It’s still about heat management, but the other way around,” Sagert says.

Add it up and the EQXX transfers a claimed 95 percent of electric energy into forward motion, up from 90 percent for Mercedes’s current models such as the EQS. If that doesn’t sound like much gain to nonengineers, Sagert puts it another way: The EQXX reduces typical EV energy losses by 50 percent.

“We’re always hoping for this magical thing, but it’s really the sum of the details,” Sagert says.

That obsession with tiny details paid off. Based on computer and dynamometer simulations, engineers saw a 1,000-km run as a challenging target, and plotted a Mediterranean road trip to Cassis, France. Instead, the car blew away those conservative projections. Pulling into Cassis, the EQXX had 140 km of remaining range.

“We thought about waving and just driving on, but we weren’t allowed,” Sagert says, not least because Mercedes board member and chief technology officer Markus Schäfer was waiting to greet them. Mercedes then set its sights higher, and chose Silverstone and its Formula One track, ideal for a team meetup.

“We started thinking, can we do a longer run?” Sagert says. “We always wished to visit our colleagues in Formula E, who did so much for the project. But again we thought, ‘This will be really tough.’ ”

To make the runs legit, Mercedes was determined to drive at real-world speeds and conditions, not “hypermile” their way to some illusory record. The car averaged 83 kilometers per hour on its U.K. run, and 87 km/h to Cassis. Test drivers even ran the air conditioning for 8 hours of the two-day, 14 hour-and-30-minute trip to Silverstone, and encountered an autobahn road closure and snarled traffic around London.

The sleek sedan capped off the record-breaking trek with an energy-guzzling flourish: Despite some misgivings, the team handed their precious prototype to a Formula E team driver, Nyck de Vries. The Type-A racer forgot all about efficiency and pushed the car to its limits on the Silverstone F1 circuit, watched by nervous engineers. Where long-distance drivers had relied almost exclusively on regenerative braking (with four adjustable levels) during their runs, de Vries got to test the car’s novel aluminum brake rotors. Those ultralight rotors are possible because the Benz so rarely needs to use its foot-operated mechanical brakes, as telemetry readings from the track showed.

“In three laps, de Vries burned more energy using the mechanical brakes than we did on two entire runs” through Europe, Sagert says. “But it was a good feeling, that this wasn’t some show car, and that you could give it to a race driver and not have it fall apart.”

Some of this prototype tech won’t be feasible on coming production models—a carbon-fiber body, for one, is the stuff of supercars, not small-and-affordable Mercedes. Still, the EQXX offers a tantalizing taste of what’s to come, including all-day range to savor.

“This range anxiety is not a problem anymore,” Sagert says. “If your range isn’t enough today, wait two years, and the step will be big.”


Match ID: 8 Score: 15.00 source: spectrum.ieee.org age: 1 day
qualifiers: 15.00 carbon

How Clean Is ‘Clean’ Hydrogen?
Mon, 08 Aug 2022 11:00:00 +0000
Batteries and renewable energy alone can’t decarbonize industries, and recent proposals for a “hydrogen economy” could bridge those gaps.
Match ID: 9 Score: 15.00 source: www.wired.com age: 1 day
qualifiers: 15.00 carbon

Extreme Heat Is Becoming More Dangerous for Farmworkers
Sat, 06 Aug 2022 12:00:00 +0000
Sweltering temperatures and humidity threaten the health of outdoor laborers, and there are few standards to protect them from working when it’s too hot.
Match ID: 10 Score: 12.86 source: www.wired.com age: 3 days
qualifiers: 12.86 climate change

Solar-to-Jet-Fuel System Readies for Takeoff
Wed, 03 Aug 2022 17:00:00 +0000


As climate change edges from crisis to emergency, the aviation sector looks set to miss its 2050 goal of net-zero emissions. In the five years preceding the pandemic, the top four U.S. airlines—American, Delta, Southwest, and United—saw a 15 percent increase in the use of jet fuel. Despite continual improvements in engine efficiencies, that number is projected to keep rising.

A glimmer of hope, however, comes from solar fuels. For the first time, scientists and engineers at the Swiss Federal Institute of Technology (ETH) in Zurich have reported a successful demonstration of an integrated fuel-production plant for solar kerosene. Using concentrated solar energy, they were able to produce kerosene from water vapor and carbon dioxide directly from air. Fuel thus produced is a drop-in alternative to fossil-derived fuels and can be used with existing storage and distribution infrastructures, and engines.

Fuels derived from synthesis gas (or syngas)—an intermediate product that is a specific mixture of carbon monoxide and hydrogen—is a known alternative to conventional, fossil-derived fuels. Syngas is produced by Fischer-Tropsch (FT) synthesis, in which chemical reactions convert carbon monoxide and water vapor into hydrocarbons. The team of researchers at ETH found that a solar-driven thermochemical method to split water and carbon dioxide using a metal oxide redox cycle can produce renewable syngas. They demonstrated the process in a rooftop solar refinery at the ETH Machine Laboratory in 2019.

Close-up of a spongy looking material Reticulated porous structure made of ceria used in the solar reactor to thermochemically split CO2 and H2O and produce syngas, a specific mixture of H2 and CO.ETH Zurich

The current pilot-scale solar tower plant was set up at the IMDEA Energy Institute in Spain. It scales up the solar reactor of the 2019 experiment by a factor of 10, says Aldo Steinfeld, an engineering professor at ETH who led the study. The fuel plant brings together three subsystems—the solar tower concentrating facility, solar reactor, and gas-to-liquid unit.

First, a heliostat field made of mirrors that rotate to follow the sun concentrates solar irradiation into a reactor mounted on top of the tower. The reactor is a cavity receiver lined with reticulated porous ceramic structures made of ceria (or cerium(IV) oxide). Within the reactor, the concentrated sunlight creates a high-temperature environment of about 1,500 °C which is hot enough to split captured carbon dioxide and water from the atmosphere to produce syngas. Finally, the syngas is processed to kerosene in the gas-to-liquid unit. A centralized control room operates the whole system.

Fuel produced using this method closes the fuel carbon cycle as it only produces as much carbon dioxide as has gone into its manufacture. “The present pilot fuel plant is still a demonstration facility for research purposes,” says Steinfeld, “but it is a fully integrated plant and uses a solar-tower configuration at a scale that is relevant for industrial implementation.”

“The solar reactor produced syngas with selectivity, purity, and quality suitable for FT synthesis,” the authors noted in their paper. They also reported good material stability for multiple consecutive cycles. They observed a value of 4.1 percent solar-to-syngas energy efficiency, which Steinfeld says is a record value for thermochemical fuel production, even though better efficiencies are required to make the technology economically competitive.

Schematic of the solar tower fuel plant.  A heliostat field concentrates solar radiation onto a solar reactor mounted on top of the solar tower. The solar reactor cosplits water and carbon dioxide and produces a mixture of molecular hydrogen and carbon monoxide, which in turn is processed to drop-in fuels such as kerosene.ETH Zurich

“The measured value of energy conversion efficiency was obtained without any implementation of heat recovery,” he says. The heat rejected during the redox cycle of the reactor accounted for more than 50 percent of the solar-energy input. “This fraction can be partially recovered via thermocline heat storage. Thermodynamic analyses indicate that sensible heat recovery could potentially boost the energy efficiency to values exceeding 20 percent.”

To do so, more work is needed to optimize the ceramic structures lining the reactor, something the ETH team is actively working on, by looking at 3D-printed structures for improved volumetric radiative absorption. “In addition, alternative material compositions, that is, perovskites or aluminates, may yield improved redox capacity, and consequently higher specific fuel output per mass of redox material,” Steinfeld adds.

The next challenge for the researchers, he says, is the scale-up of their technology for higher solar-radiative power inputs, possibly using an array of solar cavity-receiver modules on top of the solar tower.

To bring solar kerosene into the market, Steinfeld envisages a quota-based system. “Airlines and airports would be required to have a minimum share of sustainable aviation fuels in the total volume of jet fuel that they put in their aircraft,” he says. This is possible as solar kerosene can be mixed with fossil-based kerosene. This would start out small, as little as 1 or 2 percent, which would raise the total fuel costs at first, though minimally—adding “only a few euros to the cost of a typical flight,” as Steinfeld puts it

Meanwhile, rising quotas would lead to investment, and to falling costs, eventually replacing fossil-derived kerosene with solar kerosene. “By the time solar jet fuel reaches 10 to 15 percent of the total jet-fuel volume, we ought to see the costs for solar kerosene nearing those of fossil-derived kerosene,” he adds.

However, we may not have to wait too long for flights to operate solely on solar fuel. A commercial spin-off of Steinfeld’s laboratory, Synhelion, is working on commissioning the first industrial-scale solar fuel plant in 2023. The company has also collaborated with the airline SWISS to conduct a flight solely using its solar kerosene.


Match ID: 11 Score: 12.86 source: spectrum.ieee.org age: 6 days
qualifiers: 6.43 climate change, 6.43 carbon

Massive Quantities of PFAS Waste Go Unreported to EPA
Fri, 05 Aug 2022 11:00:21 +0000

US Ecology failed to report more than 11 million pounds of PFAS-contaminated waste at its facility in Beatty, Nevada.

The post Massive Quantities of PFAS Waste Go Unreported to EPA appeared first on The Intercept.


Match ID: 12 Score: 10.71 source: theintercept.com age: 4 days
qualifiers: 10.71 toxic

Rhode Island’s Renewable Energy Goal Is a Beacon for Other States
Thu, 04 Aug 2022 18:14:33 +0000


Early in July, Rhode Island’s governor signed legislation mandating that the state acquire 100 percent of its electricity from renewable sources by 2033. Among the state’s American peers, there’s no deadline more ambitious.

“Anything more ambitious, and I would start being a little skeptical that it would be attainable,” says Seaver Wang, a climate and energy researcher at the Breakthrough Institute.

It is true that Rhode Island is small. It is also true that the state’s conditions make it riper for such a timeframe than most of the country. But watching this tiny state go about its policy business, analysts say, might show other states how to light their own ways into a renewable future.

Rhode Island’s 2033 deadline comes in the form of a renewable-energy standard, setting a goal that electricity providers must meet by collecting a certain number of certificates. Electricity providers can earn those certificates by generating electricity from renewable sources themselves; alternatively, they can buy certificates from other providers. (Numerous other states have similar standards—Rhode Island’s current standard is actually an upgrade to an older standard—and policy wonks have mooted a national standard.)

Today, it might seem a bit optimistic to pin hopes for renewable energy on a state that still gets 89 percent of its electricity from natural gas. Much of the meager wind power that does exist comes either from other states or from the 30-megawatt Block Island Wind Farm—the first offshore wind farm in the United States—which consists of just five turbines and only came online in 2016.

But Rhode Island plans to fill the gap with as much as 600 megawatts of new wind power. To aid this effort, it has partnered with Ørsted, which could bring a critical mass of turbine expertise from Europe, where the sector is far more advanced. “I think that adds greatly to the likelihood of [Rhode Island’s] success,” says Morgan Higman, a clean-energy researcher at the Center for Strategic and International Studies, in Washington, D.C.

The policies in the package are, indeed, quite specific to Rhode Island’s position. Not only is it one of the least populous states in the United States, it already has about the lowest per capita energy consumption in the country. Moreover, powering a service-oriented economy, Rhode Island’s grid doesn’t have to accommodate many energy-intensive manufacturing firms. That makes that 2033 goal all the more achievable.

“It’s better to have attainable goals and focus on a diverse portfolio of policies to promote clean energy advancement, rather than sort of rush to meet what is essentially…a bit of a PR goal,” says Wang.

That Rhode Island is going all-in on something this maritime state might have in abundance—offshore wind—offers another lesson. Higman says it’s a good example of using a state’s own potential resources. Moreover, the partnership with Ørsted might help the state harness helpful expertise.

In similar fashion, Texans could choose to double down on that state’s own wind-power portfolio. New Mexico could potentially shape a renewable-energy supply from its bountiful sunlight. Doing this sort of thing, Higman says, “is the fastest way that we see states accelerate renewable-energy deployment.”

Rhode Island’s policy does leave some room for improvement. Its focus on renewables looks past New England’s largest source of carbon-free energy: fission. Just two nuclear power plants (Millstone in Connecticut and Seabrook in New Hampshire) pump out more than a fifth of the region’s electricity. A more inclusive policy might take note and incentivize nuclear power, too.

Perhaps most important, any discussion of energy policy should note that Rhode Island’s grid doesn’t exist in a vacuum; it’s linked in with the grids of its surrounding states in New England, New York, and beyond. (Indeed, it has repeatedly partnered on setting goals and building new offshore wind power.)

If neighboring states implement similarly aggressive standards without actually building new energy capacity, then there’s a chance that when all the renewable energy certificates are bought out, some states won’t have any renewable energy left.

But analysts are optimistic that Rhode Island can do the job. “Rhode Island does deserve some kudos for this policy,” says Wang.

“It’s really tempting to applaud states for their goals. This is a useful example of where setting a goal is not very meaningful,” adds Higman. “Identifying the means and strategies and technologies to achieve that goal is the most important thing. And Rhode Island has done that.”


Match ID: 13 Score: 8.57 source: spectrum.ieee.org age: 5 days
qualifiers: 8.57 carbon

Satellite Imagery for Everyone
Sat, 19 Feb 2022 16:00:00 +0000


Every day, satellites circling overhead capture trillions of pixels of high-resolution imagery of the surface below. In the past, this kind of information was mostly reserved for specialists in government or the military. But these days, almost anyone can use it.

That’s because the cost of sending payloads, including imaging satellites, into orbit has dropped drastically. High-resolution satellite images, which used to cost tens of thousands of dollars, now can be had for the price of a cup of coffee.

What’s more, with the recent advances in artificial intelligence, companies can more easily extract the information they need from huge digital data sets, including ones composed of satellite images. Using such images to make business decisions on the fly might seem like science fiction, but it is already happening within some industries.


This image shows are variety of blue and green hues, interwoven in a geometrically intriguing way.

These underwater sand dunes adorn the seafloor between Andros Island and the Exuma islands in the Bahamas. The turquoise to the right reflects a shallow carbonate bank, while the dark blue to the left marks the edge of a local deep called Tongue of the Ocean. This image was captured in April 2020 using the Moderate Resolution Imaging Spectroradiometer on NASA’s Terra satellite.

Joshua Stevens/NASA Earth Observatory


Here’s a brief overview of how you, too, can access this kind of information and use it to your advantage. But before you’ll be able to do that effectively, you need to learn a little about how modern satellite imagery works.

The orbits of Earth-observation satellites generally fall into one of two categories: GEO and LEO. The former is shorthand for geosynchronous equatorial orbit. GEO satellites are positioned roughly 36,000 kilometers above the equator, where they circle in sync with Earth’s rotation. Viewed from the ground, these satellites appear to be stationary, in the sense that their bearing and elevation remain constant. That’s why GEO is said to be a geostationary orbit.

Such orbits are, of course, great for communications relays—it’s what allows people to mount satellite-TV dishes on their houses in a fixed orientation. But GEO satellites are also appropriate when you want to monitor some region of Earth by capturing images over time. Because the satellites are so high up, the resolution of that imagery is quite coarse, however. So these orbits are primarily used for observation satellites designed to track changing weather conditions over broad areas.

Being stationary with respect to Earth means that GEO satellites are always within range of a downlink station, so they can send data back to Earth in minutes. This allows them to alert people to changes in weather patterns almost in real time. Most of this kind of data is made available for free by the U.S. National Oceanographic and Atmospheric Administration.


This black-and-white image shows a narrow waterway blocked by a large ship. The resolution of the image is sufficient to make out individual shipping containers on its deck, as well as the tugboats arrayed around it.

In March 2021, the container ship Ever Given ran aground, blocking the Suez Canal for six days. This satellite image of the scene, obtained using synthetic-aperture radar, shows the kind resolution that is possible with this technology.

Capella Space


The other option is LEO, which stands for low Earth orbit. Satellites placed in LEO are much closer to the ground, which allows them to obtain higher-resolution images. And the lower you can go, the better the resolution you can get. The company Planet, for example, increased the resolution of its recently completed satellite constellation, SkySat, from 72 centimeters per pixel to just 50 cm—an incredible feat—by lowering the orbits its satellites follow from 500 to 450 km and improving the image processing.

The best commercially available spatial resolution for optical imagery is 25 cm, which means that one pixel represents a 25-by-25-cm area on the ground—roughly the size of your laptop. A handful of companies capture data with 25-cm to 1-meter resolution, which is considered high to very high resolution in this industry. Some of these companies also offer data from 1- to 5-meter resolution, considered medium to high resolution. Finally, several government programs have made optical data available at 10-, 15-, 30-, and 250-meter resolutions for free with open data programs. These include NASA/U.S. Geological Survey Landsat, NASA MODIS (Moderate Resolution Imaging Spectroradiometer), and ESA Copernicus. This imagery is considered low resolution.

Because the satellites that provide the highest-resolution images are in the lowest orbits, they sense less area at once. To cover the entire planet, a satellite can be placed in a polar orbit, which takes it from pole to pole. As it travels, Earth rotates under it, so on its next pass, it will be above a different part of Earth.

Many of these satellites don’t pass directly over the poles, though. Instead, they are placed in a near-polar orbit that has been specially designed to take advantage of a subtle bit of physics. You see, the spinning Earth bulges outward slightly at the equator. That extra mass causes the orbits of satellites that are not in polar orbits to shift or (technically speaking) to precess. Satellite operators often take advantage of this phenomenon to put a satellite in what’s called a sun-synchronous orbit. Such orbits allow the repeated passes of the satellite over a given spot to take place at the same time of day. Not having the pattern of shadows shift between passes helps the people using these images to detect changes.




It usually takes 24 hours for a satellite in polar orbit to survey the entire surface of Earth. To image the whole world more frequently, satellite companies use multiple satellites, all equipped with the same sensor and following different orbits. In this way, these companies can provide more frequently updated images of a given location. For example, Maxar’s Worldview Legion constellation, launching later this year, includes six satellites.

After a satellite captures some number of images, all that data needs to be sent down to Earth and processed. The time required for that varies.

DigitalGlobe (which Maxar acquired in 2017) recently announced that it had managed to send data from a satellite down to a ground station and then store it in the cloud in less than a minute. That was possible because the image sent back was of the parking lot of the ground station, so the satellite didn’t have to travel between the collection point and where it had to be to do the data “dumping,” as this process is called.

In general, Earth-observation satellites in LEO don’t capture imagery all the time—they do that only when they are above an area of special interest. That’s because these satellites are limited to how much data they can send at one time. Typically, they can transmit data for only 10 minutes or so before they get out of range of a ground station. And they cannot record more data than they’ll have time to dump.

Currently, ground stations are located mostly near the poles, the most visited areas in polar orbits. But we can soon expect distances to the nearest ground station to shorten because both Amazon and Microsoft have announced intentions to build large networks of ground stations located all over the world. As it turns out, hosting the terabytes of satellite data that are collected daily is big business for these companies, which sell their cloud services (Amazon Web Services and Microsoft’s Azure) to satellite operators.

For now, if you are looking for imagery of an area far from a ground station, expect a significant delay—maybe hours—between capture and transmission of the data. The data will then have to be processed, which adds yet more time. The fastest providers currently make their data available within 48 hours of capture, but not all can manage that. While it is possible, under ideal weather conditions, for a commercial entity to request a new capture and get the data it needs delivered the same week, such quick turnaround times are still considered cutting edge.


The best commercially available spatial resolution is 25 centimeters for optical imagery, which means that one pixel represents something roughly the size of your laptop.


I’ve been using the word “imagery,” but it’s important to note that satellites do not capture images the same way ordinary cameras do. The optical sensors in satellites are calibrated to measure reflectance over specific bands of the electromagnetic spectrum. This could mean they record how much red, green, and blue light is reflected from different parts of the ground. The satellite operator will then apply a variety of adjustments to correct colors, combine adjacent images, and account for parallax, forming what’s called a true-color composite image, which looks pretty much like what you would expect to get from a good camera floating high in the sky and pointed directly down.

Imaging satellites can also capture data outside of the visible-light spectrum. The near-infrared band is widely used in agriculture, for example, because these images help farmers gauge the health of their crops. This band can also be used to detect soil moisture and a variety of other ground features that would otherwise be hard to determine.

Longer-wavelength “thermal” IR does a good job of penetrating smoke and picking up heat sources, making it useful for wildfire monitoring. And synthetic-aperture radar satellites, which I discuss in greater detail below, are becoming more common because the images they produce aren’t affected by clouds and don’t require the sun for illumination.

You might wonder whether aerial imagery, say, from a drone, wouldn’t work at least as well as satellite data. Sometimes it can. But for many situations, using satellites is the better strategy. Satellites can capture imagery over areas that would be difficult to access otherwise because of their remoteness, for example. Or there could be other sorts of accessibility issues: The area of interest could be in a conflict zone, on private land, or in another place that planes or drones cannot overfly.

So with satellites, organizations can easily monitor the changes taking place at various far-flung locations. Satellite imagery allows pipeline operators, for instance, to quickly identify incursions into their right-of-way zones. The company can then take steps to prevent a disastrous incident, such as someone puncturing a gas pipeline while construction is taking place nearby.


\u200bThis satellite image shows a snow-covered area. A tongue of darker material is draped over the side of a slope, impinging on a nearby developed area with buildings.

This SkySat image shows the effect of a devastating landslide that took place on 30 December 2020. Debris from that landslide destroyed buildings and killed 10 people in the Norwegian village of Ask.

SkySat/Planet



The ability to compare archived imagery with recently acquired data has helped a variety of industries. For example, insurance companies sometimes use satellite data to detect fraudulent claims (“Looks like your house had a damaged roof when you bought it…”). And financial-investment firms use satellite imagery to evaluate such things as retailers’ future profits based on parking-lot fullness or to predict crop prices before farmers report their yields for the season.

Satellite imagery provides a particularly useful way to find or monitor the location of undisclosed features or activities. Sarah Parcak of the University of Alabama, for example, uses satellite imagery to locate archaeological sites of interest. 52Impact, a consulting company in the Netherlands, identified undisclosed waste dump sites by training an algorithm to recognize their telltale spectral signature. Satellite imagery has also helped identify illegal fishing activities, fight human trafficking, monitor oil spills, get accurate reporting on COVID-19 deaths, and even investigate Uyghur internment camps in China—all situations where the primary actors couldn’t be trusted to accurately report what’s going on.

Despite these many successes, investigative reporters and nongovernmental organizations aren’t yet using satellite data regularly, perhaps because even the small cost of the imagery is a deterrent. Thankfully, some kinds of low-resolution satellite data can be had for free.

The first place to look for free satellite imagery is the Copernicus Open Access Hub and EarthExplorer. Both offer free access to a wide range of open data. The imagery is lower resolution than what you can purchase, but if the limited resolution meets your needs, why spend money?

If you require medium- or high-resolution data, you might be able to buy it directly from the relevant satellite operator. This field recently went through a period of mergers and acquisitions, leaving only a handful of providers, the big three in the West being Maxar and Planet in the United States and Airbus in Germany. There are also a few large Asian providers, such as SI Imaging Services in South Korea and Twenty First Century Aerospace Technology in Singapore. Most providers have a commercial branch, but they primarily target government buyers. And they often require large minimum purchases, which is unhelpful to companies looking to monitor hundreds of locations or fewer.

Expect the distance to the nearest ground station to shorten because both Amazon and Microsoft have announced intentions to build large networks of ground stations located all over the world.

Fortunately, approaching a satellite operator isn’t the only option. In the past five years, a cottage industry of consultants and local resellers with exclusive deals to service a certain market has sprung up. Aggregators and resellers spend years negotiating contracts with multiple providers so they can offer customers access to data sets at more attractive prices, sometimes for as little as a few dollars per image. Some companies providing geographic information systems—including Esri, L3Harris, and Safe Software—have also negotiated reselling agreements with satellite-image providers.

Traditional resellers are middlemen who will connect you with a salesperson to discuss your needs, obtain quotes from providers on your behalf, and negotiate pricing and priority schedules for image capture and sometimes also for the processing of the data. This is the case for Apollo Mapping, European Space Imaging, Geocento, LandInfo, Satellite Imaging Corp., and many more. The more innovative resellers will give you access to digital platforms where you can check whether an image you need is available from a certain archive and then order it. Examples include LandViewer from EOS and Image Hunter from Apollo Mapping.

More recently, a new crop of aggregators began offering customers the ability to programmatically access Earth-observation data sets. These companies work best for people looking to integrate such data into their own applications or workflows. These include the company I work for, SkyWatch, which provides such a service, called EarthCache. Other examples are UP42 from Airbus and Sentinel Hub from Sinergise.

While you will still need to talk with a sales rep to activate your account—most often to verify you will use the data in ways that fits the company’s terms of service and licensing agreements—once you’ve been granted access to their applications, you will be able to programmatically order archive data from one or multiple providers. SkyWatch is, however, the only aggregator allowing users to programmatically request future data to be collected (“tasking a satellite”).

While satellite imagery is fantastically abundant and easy to access today, two changes are afoot that will expand further what you can do with satellite data: faster revisits and greater use of synthetic-aperture radar (SAR).

This image shows a sprawling compound of dozens of large buildings located in a desert area.

This image shows a race-track shaped structure with a tall chimney in the middle, built in an area where the ground is a distinctly reddish hue. Satellite images have helped to reveal China’s treatment of its Muslim Uyghur minority. About a million Uyghurs (and other ethnic minorities) have been interned in prisons or camps like the one shown here [top], which lies to the east of the city of Ürümqi, the capital of China’s Xinjiang Uyghur Autonomous Region. Another satellite image [bottom] shows the characteristic oval shape of a fixed-chimney Bull’s trench kiln, a type widely used for manufacturing bricks in southern Asia. This one is located in Pakistan’s Punjab province. This design poses environmental concerns because of the sooty air pollution it generates, and such kilns have also been associated with human-rights abuses.Top: CNES/Airbus/Google Earth; Bottom: Maxar Technologies/Google Earth

The first of these developments is not surprising. As more Earth-observation satellites are put into orbit, more images will be taken, more often. So how frequently a given area is imaged by a satellite will increase. Right now, that’s typically two or three times a week. Expect the revisit rate soon to become several times a day. This won’t entirely address the challenge of clouds obscuring what you want to view, but it will help.

The second development is more subtle. Data from the two satellites of the European Space Agency’s Sentinel-1 SAR mission, available at no cost, has enabled companies to dabble in SAR over the last few years.

With SAR, the satellite beams radio waves down and measures the return signals bouncing off the surface. It does that continually, and clever processing is used to turn that data into images. The use of radio allows these satellites to see through clouds and to collect measurements day and night. Depending on the radar band that’s employed, SAR imagery can be used to judge material properties, moisture content, precise movements, and elevation.

As more companies get familiar with such data sets, there will no doubt be a growing demand for satellite SAR imagery, which has been widely used by the military since the 1970s. But it’s just now starting to appear in commercial products. You can expect those offerings to grow dramatically, though.

Indeed, a large portion of the money being invested in this industry is currently going to fund large SAR constellations, including those of Capella Space, Iceye, Synspective, XpressSAR, and others. The market is going to get crowded fast, which is great news for customers. It means they will be able to obtain high-resolution SAR images of the place they’re interested in, taken every hour (or less), day or night, cloudy or clear.

People will no doubt figure out wonderful new ways to employ this information, so the more folks who have access to it, the better. This is something my colleagues at SkyWatch and I deeply believe, and it’s why we’ve made it our mission to help democratize access to satellite imagery.

One day in the not-so-distant future, Earth-observation satellite data might become as ubiquitous as GPS, another satellite technology first used only by the military. Imagine, for example, being able to take out your phone and say something like, “Show me this morning’s soil-moisture map for Grover’s Corners High; I want to see whether the baseball fields are still soggy.”

This article appears in the March 2022 print issue as “A Boom with a View.”

Editor's note: The original version of this article incorrectly stated that Maxar's Worldview Legion constellation launched last year.


Match ID: 14 Score: 7.86 source: spectrum.ieee.org age: 171 days
qualifiers: 5.71 air pollution, 2.14 carbon

Climate change: More studies needed on possibility of human extinction
Mon, 01 Aug 2022 19:09:08 GMT
New research says it could be "fatally foolish" not to think the unthinkable on climate change.
Match ID: 15 Score: 2.14 source: www.bbc.co.uk age: 8 days
qualifiers: 2.14 climate change

UK's 40C heatwave 'basically impossible' without climate change
Fri, 29 Jul 2022 03:51:01 GMT
Human-caused climate change made the high temperatures last week much more likely, say scientists.
Match ID: 16 Score: 2.14 source: www.bbc.co.uk age: 11 days
qualifiers: 2.14 climate change

Climate change: UK sea level rise speeding up - Met Office
Thu, 28 Jul 2022 09:16:40 GMT
The Met Office's annual look at our climate says higher temperatures are the new normal.
Match ID: 17 Score: 2.14 source: www.bbc.co.uk age: 12 days
qualifiers: 2.14 climate change

The art of cutting carbon - how new technologies can help
Tue, 26 Jul 2022 23:09:05 GMT
With the 'de-printer' specially coated sheets of paper can be used 10 times over.
Match ID: 18 Score: 2.14 source: www.bbc.co.uk age: 14 days
qualifiers: 2.14 carbon

Climate change: How to talk to a denier
Sat, 23 Jul 2022 23:14:38 GMT
Tips about how to engage with people who think climate change is a "hoax".
Match ID: 19 Score: 2.14 source: www.bbc.co.uk age: 17 days
qualifiers: 2.14 climate change

Inside the Universe Machine: The Webb Space Telescope’s Staggering Vision
Wed, 06 Jul 2022 13:00:00 +0000


For a deep dive into the engineering behind the James Webb Space Telescope, see our collection of posts here.

“Build something that will absolutely, positively work.” This was the mandate from NASA for designing and building the James Webb Space Telescope—at 6.5 meters wide the largest space telescope in history. Last December, JWST launched famously and successfully to its observing station out beyond the moon. And now according to NASA, as soon as next week, the JWST will at long last begin releasing scientific images and data.

Mark Kahan, on JWST’s product integrity team, recalls NASA’s engineering challenge as a call to arms for a worldwide team of thousands that set out to create one of the most ambitious scientific instruments in human history. Kahan—chief electro-optical systems engineer at Mountain View, Calif.–based Synopsys—and many others in JWST’s “pit crew” (as he calls the team) drew hard lessons from three decades ago, having helped repair another world-class space telescope with a debilitating case of flawed optics. Of course the Hubble Space Telescope is in low Earth orbit, and so a special space-shuttle mission to install corrective optics ( as happened in 1993) was entirely possible.

Not so with the JWST.

The meticulous care NASA demanded of JWST’s designers is all the more a necessity because Webb is well out of reach of repair crews. Its mission is to study the infrared universe, and that requires shielding the telescope and its sensors from both the heat of sunlight and the infrared glow of Earth. A good place to do that without getting too far from Earth is an empty patch of interplanetary space 1.5 million kilometers away (well beyond the moon’s orbit) near a spot physicists call the second Lagrange point, or L2.

The pit crew’s job was “down at the detail level, error checking every critical aspect of the optical design,” says Kahan. Having learned the hard way from Hubble, the crew insisted that every measurement on Webb’s optics be made in at least two different ways that could be checked and cross-checked. Diagnostics were built into the process, Kahan says, so that “you could look at them to see what to kick” to resolve any discrepancies. Their work had to be done on the ground, but their tests had to assess how the telescope would work in deep space at cryogenic temperatures.

Three New Technologies for the Main Mirror

Superficially, Webb follows the design of all large reflecting telescopes. A big mirror collects light from stars, galaxies, nebulae, planets, comets, and other astronomical objects—and then focuses those photons onto a smaller secondary mirror that then ultimately directs the light to instruments that record images and spectra.

Webb’s 6.5-meter primary mirror is the first segmented mirror to be launched into space. All the optics had to be made on the ground at room temperature but were deployed in space and operated at 30 to 55 degrees above absolute zero. “We had to develop three new technologies” to make it work, says Lee D. Feinberg of the NASA Goddard Space Flight Center, the optical telescope element manager for Webb for the past 20 years.

The longest wavelengths that Hubble has to contend with were 2.5 micrometers, whereas Webb is built to observe infrared light that stretches to 28 μm in wavelength. Compared with Hubble, whose primary mirror is a circle of an area 4.5 square meters, “[Webb’s primary mirror] had to be 25 square meters,” says Feinberg. Webb also “needed segmented mirrors that were lightweight, and its mass was a huge consideration,” he adds. No single-component mirror that could provide the required resolution would have fit on the Ariane 5 rocket that launched JWST. That meant the mirror would have to be made in pieces, assembled, folded, secured to withstand the stress of launch, then unfolded and deployed in space to create a surface that was within tens of nanometers of the shape specified by the designers.

Images of the James Webb Space Telescope and Hubble Space Telescope to scale, compared to a human figure, who is dwarfed by their size The James Webb Space Telescope [left] and the Hubble Space Telescope side by side—with Hubble’s 2.4-meter-diameter mirror versus Webb’s array of hexagonal mirrors making a 6.5-meter-diameter light-collecting area. NASA Goddard Space Flight Center

NASA and the U.S. Air Force, which has its own interests in large lightweight space mirrors for surveillance and focusing laser energy, teamed up to develop the technology. The two agencies narrowed eight submitted proposals down to two approaches for building JWST’s mirrors: one based on low-expansion glass made of a mixture of silicon and titanium dioxides similar to that used in Hubble and the other the light but highly toxic metal beryllium. The most crucial issue came down to how well the materials could withstand temperature changes from room temperature on the ground to around 50 K in space. Beryllium won because it could fully release stress after cooling without changing its shape, and it’s not vulnerable to the cracking that can occur in glass. The final beryllium mirror was a 6.5-meter array of 18 hexagonal beryllium mirrors, each weighing about 20 kilograms. The weight per unit area of JWST’s mirror was only 10 percent of that in Hubble. A 100-nanometer layer of pure gold makes the surface reflect 98 percent of incident light from JWST’s main observing band of 0.6 to 28.5 μm. “Pure silver has slightly higher reflectivity than pure gold, but gold is more robust,” says Feinberg. A thin layer of amorphous silica protects the metal film from surface damage.

In addition, a wavefront-sensing control system keeps mirror segment surfaces aligned to within tens of nanometers. Built on the ground, the system is expected to keep mirror alignment stabilized throughout the telescope’s operational life. A backplane kept at a temperature of 35 K holds all 2.4 tonnes of the telescope and instruments rock-steady to within 32 nm while maintaining them at cryogenic temperatures during observations.

Metal superstructure of cages and supports stands on a giant platform in a warehouse-sized clean-room. A man in a cleanroom suit watches the operations. The JWST backplane, the “spine” that supports the entire hexagonal mirror structure and carries more than 2,400 kg of hardware, is readied for assembly to the rest of the telescope. NASA/Chris Gunn

Hubble’s amazing, long-exposure images of distant galaxies are possible through the use of gyroscopes and reaction wheels. The gyroscopes are used to sense unwanted rotations, and reaction wheels are used to counteract them.

But the gyroscopes used on Hubble have had a bad track record and have had to be replaced repeatedly. Only three of Hubble’s six gyros remain operational today, and NASA has devised plans for operating with one or two gyros at reduced capability. Hubble also includes reaction wheels and magnetic torquers, used to maintain its orientation when needed or to point at different parts of the sky.

Webb uses reaction wheels similarly to turn across the sky, but instead of using mechanical gyros to sense direction, it uses hemispherical resonator gyroscopes, which have no moving parts. Webb also has a small fine-steering mirror in the optical path, which can tilt over an angle of just 5 arc seconds. Those very fine adjustments of the light path into the instruments keep the telescope on target. “It’s a really wonderful way to go,” says Feinberg, adding that it compensates for small amounts of jitter without having to move the whole 6-tonne observatory.

Instruments

Other optics distribute light from the fine-steering mirror among four instruments, two of which can observe simultaneously. Three instruments have sensors that observe wavelengths of 0.6 to 5 μm, which astronomers call the near-infrared. The fourth, called the Mid-InfraRed Instrument (MIRI), observes what astronomers call the mid-infrared spectrum, from 5 to 28.5 μm. Different instruments are needed because sensors and optics have limited wavelength ranges. (Optical engineers may blanch slightly at astronomers’ definitions of what constitutes the near- and mid-infrared wavelength ranges. These two groups simply have differing conventions for labeling the various regimes of the infrared spectrum.)

Mid-infrared wavelengths are crucial for observing young stars and planetary systems and the earliest galaxies, but they also pose some of the biggest engineering challenges. Namely, everything on Earth and planets out to Jupiter glow in the mid-infrared. So for JWST to observe distant astronomical objects, it must avoid recording extraneous mid-infrared noise from all the various sources inside the solar system. “I have spent my whole career building instruments for wavelengths of 5 μm and longer,” says MIRI instrument scientist Alastair Glasse of the Royal Observatory, in Edinburgh. “We’re always struggling against thermal background.”

Mountaintop telescopes can see the near-infrared, but observing the mid-infrared sky requires telescopes in space. However, the thermal radiation from Earth and its atmosphere can cloud their view, and so can the telescopes themselves unless they are cooled far below room temperature. An ample supply of liquid helium and an orbit far from Earth allowed the Spitzer Space Telescope’s primary observing mission to last for five years, but once the last of the cryogenic fluid evaporated in 2009, its observations were limited to wavelengths shorter than 5 μm.

Webb has an elaborate solar shield to block sunlight, and an orbit 1.5 million km from Earth that can keep the telescope to below 55 K, but that’s not good enough for low-noise observations at wavelengths longer than 5 μm. The near-infrared instruments operate at 40 K to minimize thermal noise. But for observations out to 28.5 μm, MIRI uses a specially developed closed-cycle, helium cryocooler to keep MIRI cooled below 7 K. “We want to have sensitivity limited by the shot noise of astronomical sources,” says Glasse. (Shot noise occurs when optical or electrical signals are so feeble that each photon or electron constitutes a detectable peak.) That will make MIRI 1,000 times as sensitive in the mid-infrared as Spitzer.

Another challenge is the limited transparency of optical materials in the mid-infrared. “We use reflective optics wherever possible,” says Glasse, but they also pose problems, he adds. “Thermal contraction is a big deal,” he says, because the instrument was made at room temperature but is used at 7 K. To keep thermal changes uniform throughout MIRI, they made the whole structure of gold-coated aluminum lest other metals cause warping.

Detectors are another problem. Webb’s near-infrared sensors use mercury cadmium telluride photodetectors with a resolution of 2,048 x 2,048 pixels. This resolution is widely used at wavelengths below 5 μm, but sensing at MIRI’s longer wavelengths required exotic detectors that are limited to offering only 1,024 x 1,024 pixels.

Glasse says commissioning “has gone incredibly well.” Although some stray light has been detected, he says, “we are fully expecting to meet all our science goals.”

NIRcam Aligns the Whole Telescope

The near-infrared detectors and optical materials used for observing at wavelengths shorter than 5 μm are much more mature than those for the mid-infrared, so the Near-Infrared Camera (NIRcam) does double duty by both recording images and aligning all the optics in the whole telescope. That alignment was the trickiest part of building the instrument, says NIRcam principal investigator Marcia Rieke of the University of Arizona.

Alignment means getting all the light collected by the primary mirror to get to the right place in the final image. That’s crucial for Webb, because it has 18 separate segments that have to overlay their images perfectly in the final image, and because all those segments were built on the ground at room temperature but operate at cryogenic temperatures in space at zero gravity. When NASA recorded a test image of a single star after Webb first opened its primary mirror, it showed 18 separate bright spots, one from each segment. When alignment was completed on 11 March, the image from NIRcam showed a single star with six spikes caused by diffraction.

Image of a star with six-pointed spikes caused by diffraction Even when performing instrumental calibration tasks, JWST couldn’t help but showcase its stunning sensitivity to the infrared sky. The central star is what telescope technicians used to align JWST’s mirrors. But notice the distant galaxies and stars that photobombed the image too!NASA/STScI

Building a separate alignment system would have added to both the weight and cost of Webb, Rieke realized, and in the original 1995 plan for the telescope she proposed designing NIRcam so it could align the telescope optics once it was up in space as well as record images. “The only real compromise was that it required NIRcam to have exquisite image quality,” says Rieke, wryly. From a scientific point, she adds, using the instrument to align the telescope optics “is great because you know you’re going to have good image quality and it’s going to be aligned with you.” Alignment might be just a tiny bit off for other instruments. In the end, it took a team at Lockheed Martin to develop the computational tools to account for all the elements of thermal expansion.

Escalating costs and delays had troubled Webb for years. But for Feinberg, “commissioning has been a magical five months.” It began with the sight of sunlight hitting the mirrors. The segmented mirror deployed smoothly, and after the near-infrared cameras cooled, the mirrors focused one star into 18 spots, then aligned them to put the spots on top of each other. “Everything had to work to get it to [focus] that well,” he says. It’s been an intense time, but for Feinberg, a veteran of the Hubble repair mission, commissioning Webb was “a piece of cake.”

NASA announced that between May 23rd and 25th, one segment of the primary mirror had been dinged by a micrometeorite bigger than the agency had expected when it analyzed the potential results of such impacts. “Things do degrade over time,” Feinberg said. But he added that Webb had been engineered to minimize damage, and NASA said the event had not affected Webb’s operation schedule.


Correction 26-28 July 2022: The story was updated a) to reflect the fact that the Lagrange point L2 where Webb now orbits is not that of the "Earth-moon system" (as the story had originally reported) but rather the Earth-sun system
and b) to correct misstatements in the original posting about Webb's hardware for controlling its orientation.


Match ID: 20 Score: 2.14 source: spectrum.ieee.org age: 34 days
qualifiers: 2.14 toxic

City heat extremes
Wed, 06 Jul 2022 13:30:00 +0200
Land-surface temperature in Milan on 18 June 2022

With air temperatures in excess of 10°C above the average for the time of year in parts of Europe, the United States and Asia, June 2022 has gone down as a record breaker. The fear is that these extreme early-season heatwaves are a taste of what could soon be the norm as climate change continues to take hold. For those in cities, the heat dissipates slower creating ‘urban heat islands’, which make everyday life even more of a struggle.

An instrument, carried on the International Space Station, has captured the recent land-surface temperature extremes for some European cities, including Milan, Paris and Prague.


Match ID: 21 Score: 2.14 source: www.esa.int age: 34 days
qualifiers: 2.14 climate change

NASA to Industry: Let’s Develop Flight Tech to Reduce Carbon Emissions
Wed, 29 Jun 2022 14:25 EDT
NASA announced Wednesday the agency is seeking partners to develop technologies needed to shape a new generation of lower-emission, single-aisle airliners that passengers could see in airports in the 2030s.
Match ID: 22 Score: 2.14 source: www.nasa.gov age: 41 days
qualifiers: 2.14 carbon

NASA, FEMA Release Comprehensive Climate Action Guide
Wed, 08 Jun 2022 12:37 EDT
NASA and the Federal Emergency Management Agency (FEMA) have released a guide which provides resources for adapting to and mitigating impacts of climate change.
Match ID: 23 Score: 2.14 source: www.nasa.gov age: 62 days
qualifiers: 2.14 climate change

Why is climate 'doomism' going viral – and who's fighting it?
Sun, 22 May 2022 23:16:59 GMT
Climate "doomers" believe it’s far too late to do anything about climate change - but they're wrong.
Match ID: 24 Score: 2.14 source: www.bbc.co.uk age: 79 days
qualifiers: 2.14 climate change

U.N. Kills Any Plans to Use Mercury as a Rocket Propellant
Tue, 19 Apr 2022 18:00:01 +0000


A recent United Nations provision has banned the use of mercury in spacecraft propellant. Although no private company has actually used mercury propellant in a launched spacecraft, the possibility was alarming enough—and the dangers extreme enough—that the ban was enacted just a few years after one U.S.-based startup began toying with the idea. Had the company gone through with its intention to sell mercury propellant thrusters to some of the companies building massive satellite constellations over the coming decade, it would have resulted in Earth’s upper atmosphere being laced with mercury.

Mercury is a neurotoxin. It’s also bio-accumulative, which means it’s absorbed by the body at a faster rate than the body can remove it. The most common way to get mercury poisoning is through eating contaminated seafood. “It’s pretty nasty,” says Michael Bender, the international coordinator of the Zero Mercury Working Group (ZMWG). “Which is why this is one of the very few instances where the governments of the world came together pretty much unanimously and ratified a treaty.”

Bender is referring to the 2013 Minamata Convention on Mercury, a U.N. treaty named for a city in Japan whose residents suffered from mercury poisoning from a nearby chemical factory for decades. Because mercury pollutants easily find their way into the oceans and the atmosphere, it’s virtually impossible for one country to prevent mercury poisoning within its borders. “Mercury—it’s an intercontinental pollutant,” Bender says. “So it required a global treaty.”

Today, the only remaining permitted uses for mercury are in fluorescent lighting and dental amalgams, and even those are being phased out. Mercury is otherwise found as a by-product of other processes, such as the burning of coal. But then a company hit on the idea to use it as a spacecraft propellant.

In 2018, an employee at Apollo Fusion approached the Public Employees for Environmental Responsibility (PEER), a nonprofit that investigates environmental misconduct in the United States. The employee—who has remained anonymous—alleged that the Mountain View, Calif.–based space startup was planning to build and sell thrusters that used mercury propellant to multiple companies building low Earth orbit (LEO) satellite constellations.

Four industry insiders ultimately confirmed that Apollo Fusion was building thrusters that utilized mercury propellant. Apollo Fusion, which was acquired by rocket manufacturing startup Astra in June 2021, insisted that the composition of its propellant mixture should be considered confidential information. The company withdrew its plans for a mercury propellant in April 2021. Astra declined to respond to a request for comment for this story.

Apollo Fusion wasn’t the first to consider using mercury as a propellant. NASA originally tested it in the 1960s and 1970s with two Space Electric Propulsion Tests (SERT), one of which was sent into orbit in 1970. Although the tests demonstrated mercury’s effectiveness as a propellant, the same concerns over the element’s toxicity that have seen it banned in many other industries halted its use by the space agency as well.

“I think it just sort of fell off a lot of folks’ radars,” says Kevin Bell, the staff counsel for PEER. “And then somebody just resurrected the research on it and said, ‘Hey, other than the environmental impact, this was a pretty good idea.’ It would give you a competitive advantage in what I imagine is a pretty tight, competitive market.”

That’s presumably why Apollo Fusion was keen on using it in their thrusters. Apollo Fusion as a startup emerged more or less simultaneously with the rise of massive LEO constellations that use hundreds or thousands of satellites in orbits below 2,000 kilometers to provide continual low-latency coverage. Finding a slightly cheaper, more efficient propellant for one large geostationary satellite doesn’t move the needle much. But doing the same for thousands of satellites that need to be replaced every several years? That’s a much more noticeable discount.

Were it not for mercury’s extreme toxicity, it would actually make an extremely attractive propellant. Apollo Fusion wanted to use a type of ion thruster called a Hall-effect thruster. Ion thrusters strip electrons from the atoms that make up a liquid or gaseous propellant, and then an electric field pushes the resultant ions away from the spacecraft, generating a modest thrust in the opposite direction. The physics of rocket engines means that the performance of these engines increases with the mass of the ion that you can accelerate.

Mercury is heavier than either xenon or krypton, the most commonly used propellants, meaning more thrust per expelled ion. It’s also liquid at room temperature, making it efficient to store and use. And it’s cheap—there’s not a lot of competition with anyone looking to buy mercury.

Bender says that ZMWG, alongside PEER, caught wind of Apollo Fusion marketing its mercury-based thrusters to at least three companies deploying LEO constellations—One Web, Planet Labs, and SpaceX. Planet Labs, an Earth-imaging company, has at least 200 CubeSats in low Earth orbit. One Web and SpaceX, both wireless-communication providers, have many more. One Web plans to have nearly 650 satellites in orbit by the end of 2022. SpaceX already has nearly 1,500 active satellites aloft in its Starlink constellation, with an eye toward deploying as many as 30,000 satellites before its constellation is complete. Other constellations, like Amazon’s Kuiper constellation, are also planning to deploy thousands of satellites.

In 2019, a group of researchers in Italy and the United States estimated how much of the mercury used in spacecraft propellant might find its way back into Earth’s atmosphere. They figured that a hypothetical LEO constellation of 2,000 satellites, each carrying 100 kilograms of propellant, would emit 20 tonnes of mercury every year over the course of a 10-year life span. Three quarters of that mercury, the researchers suggested, would eventually wind up in the oceans.

That amounts to 1 percent of global mercury emissions from a constellation only a fraction of the size of the one planned by SpaceX alone. And if multiple constellations adopted the technology, they would represent a significant percentage of global mercury emissions—especially, the researchers warned, as other uses of mercury are phased out as planned in the years ahead.

Fortunately, it’s unlikely that any mercury propellant thrusters will even get off the ground. Prior to the fourth meeting of the Minamata Convention, Canada, the European Union, and Norway highlighted the dangers of mercury propellant, alongside ZMWG. The provision to ban mercury usage in satellites was passed on 26 March 2022.

The question now is enforcement. “Obviously, there aren’t any U.N. peacekeepers going into space to shoot down” mercury-based satellites, says Bell. But the 137 countries, including the United States, who are party to the convention have pledged to adhere to its provisions—including the propellant ban.

The United States is notable in that list because as Bender explains, it did not ratify the Minamata Convention via the U.S. Senate but instead deposited with the U.N. an instrument of acceptance. In a 7 November 2013 statement (about one month after the original Minamata Convention was adopted), the U.S. State Department said the country would be able to fulfill its obligations “under existing legislative and regulatory authority.”

Bender says the difference is “weedy” but that this appears to mean that the U.S. government has agreed to adhere to the Minamata Convention’s provisions because it already has similar laws on the books. Except there is still no existing U.S. law or regulation banning mercury propellant. For Bender, that creates some uncertainty around compliance when the provision goes into force in 2025.

Still, with a U.S. company being the first startup to toy with mercury propellant, it might be ideal to have a stronger U.S. ratification of the Minamata Convention before another company hits on the same idea. “There will always be market incentives to cut corners and do something more dangerously,” Bell says.

Update 19 April 2022: In an email, a spokesperson for Astra stated that the company's propulsion system, the Astra Spacecraft Engine, does not use mercury. The spokesperson also stated that Astra has no plans to use mercury propellant and that the company does not have anything in orbit that uses mercury.

Updated 20 April 2022 to clarify that Apollo Fusion was building thrusters that used mercury, not that they had actually used them.


Match ID: 25 Score: 2.14 source: spectrum.ieee.org age: 112 days
qualifiers: 2.14 toxic

Ahrefs vs SEMrush: Which SEO Tool Should You Use?
Tue, 01 Mar 2022 12:16:00 +0000
semrush vs ahrefs


SEMrush and Ahrefs are among the most popular tools in the SEO industry. Both companies have been in business for years and have thousands of customers per month.

If you're a professional SEO or trying to do digital marketing on your own, at some point you'll likely consider using a tool to help with your efforts. Ahrefs and SEMrush are two names that will likely appear on your shortlist.

In this guide, I'm going to help you learn more about these SEO tools and how to choose the one that's best for your purposes.

What is SEMrush?

semrush

SEMrush is a popular SEO tool with a wide range of features—it's the leading competitor research service for online marketers. SEMrush's SEO Keyword Magic tool offers over 20 billion Google-approved keywords, which are constantly updated and it's the largest keyword database.

The program was developed in 2007 as SeoQuake is a small Firefox extension

Features

  • Most accurate keyword data: Accurate keyword search volume data is crucial for SEO and PPC campaigns by allowing you to identify what keywords are most likely to bring in big sales from ad clicks. SEMrush constantly updates its databases and provides the most accurate data.
  • Largest Keyword database: SEMrush's Keyword Magic Tool now features 20-billion keywords, providing marketers and SEO professionals the largest database of keywords.

  • All SEMrush users receive daily ranking data, mobile volume information, and the option to buy additional keywords by default with no additional payment or add-ons needed
  • Most accurate position tracking tool: This tool provides all subscribers with basic tracking capabilities, making it suitable for SEO professionals. Plus, the Position Tracking tool provides local-level data to everyone who uses the tool.
  • SEO Data Management: SEMrush makes managing your online data easy by allowing you to create visually appealing custom PDF reports, including Branded and White Label reports, report scheduling, and integration with GA, GMB, and GSC.
  • Toxic link monitoring and penalty recovery: With SEMrush, you can make a detailed analysis of toxic backlinks, toxic scores, toxic markers, and outreach to those sites.
  • Content Optimization and Creation Tools: SEMrush offers content optimization and creation tools that let you create SEO-friendly content. Some features include the SEO Writing Assistant, On-Page SEO Check, er/SEO Content Template, Content Audit, Post Tracking, Brand Monitoring.

Ahrefs

ahrefs


Ahrefs is a leading SEO platform that offers a set of tools to grow your search traffic, research your competitors, and monitor your niche. The company was founded in 2010, and it has become a popular choice among SEO tools. Ahrefs has a keyword index of over 10.3 billion keywords and offers accurate and extensive backlink data updated every 15-30 minutes and it is the world's most extensive backlink index database.

Features

  • Backlink alerts data and new keywords: Get an alert when your site is linked to or discussed in blogs, forums, comments, or when new keywords are added to a blog posting about you.
  • Intuitive interface: The intuitive design of the widget helps you see the overall health of your website and search engine ranking at a glance.
  • Site Explorer: The Site Explorer will give you an in-depth look at your site's search traffic.
  • Domain Comparison
  • Reports with charts and graphs
  • JavaScript rendering and a site audit can identify SEO issues.
  • A question explorer that provides well-crafted topic suggestions

Direct Comparisons: Ahrefs vs SEMrush

Now that you know a little more about each tool, let's take a look at how they compare. I'll analyze each tool to see how they differ in interfaces, keyword research resources, rank tracking, and competitor analysis.

User Interface

Ahrefs and SEMrush both offer comprehensive information and quick metrics regarding your website's SEO performance. However, Ahrefs takes a bit more of a hands-on approach to getting your account fully set up, whereas SEMrush's simpler dashboard can give you access to the data you need quickly.

In this section, we provide a brief overview of the elements found on each dashboard and highlight the ease with which you can complete tasks.

AHREFS

ahrefs interface


The Ahrefs dashboard is less cluttered than that of SEMrush, and its primary menu is at the very top of the page, with a search bar designed only for entering URLs.

Additional features of the Ahrefs platform include:

  • You can see analytics from the dashboard, including search engine rankings to domain ratings, referring domains, and backlink
  • Jumping from one tool to another is easy. You can use the Keyword Explorer to find a keyword to target and then directly track your ranking with one click.
  • The website offers a tooltip helper tool that allows you to hover your mouse over something that isn't clear and get an in-depth explanation.

SEMRUSH

semrush domain overview


When you log into the SEMrush Tool, you will find four main modules. These include information about your domains, organic keyword analysis, ad keyword, and site traffic.

You'll also find some other options like

  • A search bar allows you to enter a domain, keyword, or anything else you wish to explore.
  • A menu on the left side of the page provides quick links to relevant information, including marketing insights, projects, keyword analytics, and more.
  • The customer support resources located directly within the dashboard can be used to communicate with the support team or to learn about other resources such as webinars and blogs.
  • Detailed descriptions of every resource offered. This detail is beneficial for new marketers, who are just starting.

WHO WINS?

Both Ahrefs and SEMrush have user-friendly dashboards, but Ahrefs is less cluttered and easier to navigate. On the other hand, SEMrush offers dozens of extra tools, including access to customer support resources.

When deciding on which dashboard to use, consider what you value in the user interface, and test out both.

Rank Tracking

If you're looking to track your website's search engine ranking, rank tracking features can help. You can also use them to monitor your competitors.

Let's take a look at Ahrefs vs. SEMrush to see which tool does a better job.

Ahrefs

ahrefs rank tracking


The Ahrefs Rank Tracker is simpler to use. Just type in the domain name and keywords you want to analyze, and it spits out a report showing you the search engine results page (SERP) ranking for each keyword you enter.

Rank Tracker looks at the ranking performance of keywords and compares them with the top rankings for those keywords. Ahrefs also offers:

You'll see metrics that help you understand your visibility, traffic, average position, and keyword difficulty.

It gives you an idea of whether a keyword would be profitable to target or not.

SEMRUSH

semrush position tracking


SEMRush offers a tool called Position Tracking. This tool is a project tool—you must set it up as a new project. Below are a few of the most popular features of the SEMrush Position Tracking tool:

All subscribers are given regular data updates and mobile search rankings upon subscribing

The platform provides opportunities to track several SERP features, including Local tracking.

Intuitive reports allow you to track statistics for the pages on your website, as well as the keywords used in those pages.

Identify pages that may be competing with each other using the Cannibalization report.

WHO WINS?

Ahrefs is a more user-friendly option. It takes seconds to enter a domain name and keywords. From there, you can quickly decide whether to proceed with that keyword or figure out how to rank better for other keywords.

SEMrush allows you to check your mobile rankings and ranking updates daily, which is something Ahrefs does not offer. SEMrush also offers social media rankings, a tool you won't find within the Ahrefs platform. Both are good which one do you like let me know in the comment.

Keyword Research

Keyword research is closely related to rank tracking, but it's used for deciding which keywords you plan on using for future content rather than those you use now.

When it comes to SEO, keyword research is the most important thing to consider when comparing the two platforms.

AHREFS



The Ahrefs Keyword Explorer provides you with thousands of keyword ideas and filters search results based on the chosen search engine.

Ahrefs supports several features, including:

  • It can search multiple keywords in a single search and analyze them together. At SEMrush, you also have this feature in Keyword Overview.
  • Ahrefs has a variety of keywords for different search engines, including Google, YouTube, Amazon, Bing, Yahoo, Yandex, and other search engines.
  • When you click on a keyword, you can see its search volume and keyword difficulty, but also other keywords related to it, which you didn't use.

SEMRUSH



SEMrush's Keyword Magic Tool has over 20 billion keywords for Google. You can type in any keyword you want, and a list of suggested keywords will appear.

The Keyword Magic Tool also lets you to:

  • Show performance metrics by keyword
  • Search results are based on both broad and exact keyword matches.
  • Show data like search volume, trends, keyword difficulty, and CPC.
  • Show the first 100 Google search results for any keyword.
  • Identify SERP Features and Questions related to each keyword
  • SEMrush has released a new Keyword Gap Tool that uncovers potentially useful keyword opportunities for you, including both paid and organic keywords.

WHO WINS?

Both of these tools offer keyword research features and allow users to break down complicated tasks into something that can be understood by beginners and advanced users alike.

If you're interested in keyword suggestions, SEMrush appears to have more keyword suggestions than Ahrefs does. It also continues to add new features, like the Keyword Gap tool and SERP Questions recommendations.

Competitor Analysis

Both platforms offer competitor analysis tools, eliminating the need to come up with keywords off the top of your head. Each tool is useful for finding keywords that will be useful for your competition so you know they will be valuable to you.

AHREFS



Ahrefs' domain comparison tool lets you compare up to five websites (your website and four competitors) side-by-side.it also shows you how your site is ranked against others with metrics such as backlinks, domain ratings, and more.

Use the Competing Domains section to see a list of your most direct competitors, and explore how many keywords matches your competitors have.

To find more information about your competitor, you can look at the Site Explorer and Content Explorer tools and type in their URL instead of yours.

SEMRUSH



SEMrush provides a variety of insights into your competitors' marketing tactics. The platform enables you to research your competitors effectively. It also offers several resources for competitor analysis including:

Traffic Analytics helps you identify where your audience comes from, how they engage with your site, what devices visitors use to view your site, and how your audiences overlap with other websites.

SEMrush's Organic Research examines your website's major competitors and shows their organic search rankings, keywords they are ranking for, and even if they are ranking for any (SERP) features and more.

The Market Explorer search field allows you to type in a domain and lists websites or articles similar to what you entered. Market Explorer also allows users to perform in-depth data analytics on These companies and markets.

WHO WINS?

SEMrush wins here because it has more tools dedicated to competitor analysis than Ahrefs. However, Ahrefs offers a lot of functionality in this area, too. It takes a combination of both tools to gain an advantage over your competition.

Pricing

Ahrefs

  • Lite Monthly: $99/month
  • Standard Monthly: $179/month
  • Annually Lite: $990/year
  • Annually Standard: $1790/year

SEMRUSH

  • Pro Plan: $119.95/month
  • Guru Plan:$229.95/month
  • Business Plan: $449.95/month

Which SEO tool should you choose for digital marketing?

When it comes to keyword data research, you will become confused about which one to choose.

Consider choosing Ahrefs if you

  • Like friendly and clean interface
  • Searching for simple keyword suggestions

  • Want to get more keywords for different search engines like Amazon, Bing, Yahoo, Yandex, Baidu, and more

 

Consider SEMrush if you:

  • Want more marketing and SEO features
  • Need competitor analysis tool
  • Need to keep your backlinks profile clean
  • Looking for more keyword suggestions for Google

Both tools are great. Choose the one which meets your requirements and if you have any experience using either Ahrefs or SEMrush let me know in the comment section which works well for you.

 

 


Match ID: 26 Score: 2.14 source: www.crunchhype.com age: 161 days
qualifiers: 2.14 toxic

Eviation’s Maiden Flight Could Usher in Electric Aviation Era
Mon, 07 Feb 2022 19:01:19 +0000


The first commercial all-electric passenger plane is just weeks away from its maiden flight, according to its maker Israeli startup Eviation. If successful, the nine-seater Alice aircraft would be the most compelling demonstration yet of the potential for battery-powered flight. But experts say there’s still a long way to go before electric aircraft makes a significant dent in the aviation industry.

The Alice is currently undergoing high-speed taxi tests at Arlington Municipal Airport close to Seattle, says Eviation CEO Omer Bar-Yohay. This involves subjecting all of the plane’s key systems and fail-safe mechanisms to a variety of different scenarios to ensure they are operating as expected before its first flight. The company is five or six good weather days away from completing those tests, says Bar-Yohay, after which the plane should be cleared for takeoff. Initial flights won’t push the aircraft to its limits, but the Alice should ultimately be capable of cruising speeds of 250 knots (463 kilometers per hour) and a maximum range of 440 nautical miles (815 kilometers).

Electric aviation has received considerable attention in recent years as the industry looks to reduce its carbon emissions. And while the Alice won’t be the first all-electric aircraft to take to the skies, Bar-Yohay says it will be the first designed with practical commercial applications in mind. Eviation plans to offer three configurations—a nine-seater commuter model, a six-seater executive model for private jet customers, and a cargo version with a capacity of 12.74 cubic meters. The company has already received advance orders from logistics giant DHL and Massachusetts-based regional airline Cape Air.

“It’s not some sort of proof-of-concept or demonstrator,” says Bar-Yohay. “It’s the first all-electric with a real-life mission, and I think that’s the big differentiator.”

Getting there has required a major engineering effort, says Bar-Yohay, because the requirements for an all-electric plane are very different from those of conventional aircraft. The biggest challenge is weight, thanks to the fact that batteries provide considerably less mileage to the pound compared to energy-dense jet fuels.

That makes slashing the weight of other components a priority and the plane features lightweight composite materials “where no composite has gone before,”’, says Bar-Yohay. The company has also done away with the bulky mechanical systems used to adjust control surfaces on the wings, and replaced them with a much lighter fly-by-wire system that uses electronic actuators controlled via electrical wires.

The company’s engineers have had to deal with a host of other complications too, from having to optimize the aerodynamics to the unique volume and weight requirements dictated by the batteries to integrating brakes designed for much heavier planes. “There is just so much optimization, so many specific things that had to be solved,” says Bar-Yohay. “In some cases, there are just no components out there that do what you need done, which weren’t built for a train, or something like that.”

Despite the huge amount of work that’s gone into it, Bar-Yohay says the Alice will be comparable in price to similar sized turboprop aircraft like the Beechcraft King Air and cheaper than small business jets like the Embraer Phenom 300. And crucially, he adds, the relative simplicity of electrical motors and actuators compared with mechanical control systems and turboprops or jets means maintenance costs will be markedly lower.

Aircraft in the sky with white clouds below it This is a conceptual rendering of Eviation's Alice, the first commercial all-electric passenger plane, in flight.Eviation

Combined with the lower cost of electricity compared to jet fuel, and even accounting for the need to replace batteries every 3,000 flight hours, Eviation expects Alice’s operating costs to be about half those of similar sized aircraft.

But there are question marks over whether the plane has an obvious market, says aviation analyst Richard Aboulafia, managing director at AeroDynamic Advisory. It’s been decades since anyone has built a regional commuter with less than 70 seats, he says, and most business jets typically require more than the 440 nautical mile range the Alice offers. Scaling up to bigger aircraft or larger ranges is also largely out of the company’s hands as it will require substantial breakthroughs in battery technology. “You need to move on to a different battery chemistry,” he says. “There isn’t even a 10-year road map to get there.”

An aircraft like the Alice isn’t meant to be a straight swap for today’s short-haul aircraft though, says Lynette Dray, a research fellow at University College London who studies the decarbonization of aviation. More likely it would be used for short intercity hops or for creating entirely new route networks better suited to its capabilities.

This is exactly what Bar-Yohay envisages, with the Alice’s reduced operating costs opening up new short-haul routes that were previously impractical or uneconomical. It could even make it feasible to replace larger jets with several smaller ones, he says, allowing you to provide more granular regional travel by making use of the thousands of runways around the country currently used only for recreational aviation.

The economics are far from certain though, says Dray, and if the ultimate goal is to decarbonize the aviation sector, it’s important to remember that aircraft are long-lived assets. In that respect, sustainable aviation fuels that can be used by existing aircraft are probably a more promising avenue.

Even if the Alice’s maiden flight goes well, it still faces a long path to commercialization, says Kiruba Haran, a professor of electrical and computer engineering at the University of Illinois at Urbana-Champaign. Aviation’s stringent safety requirements mean the company must show it can fly the aircraft for a long period, over and over again without incident, which has yet to be done with an all-electric plane at this scale.

Nonetheless, if the maiden flight goes according to plan it will be a major milestone for electric aviation, says Haran. “It’s exciting, right?” he says. “Anytime we do something more than, or further than, or better than, that’s always good for the industry.”

And while battery-powered electric aircraft may have little chance of disrupting the bulk of commercial aviation in the near-term, Haran says hybrid schemes that use a combination of batteries and conventional fuels (or even hydrogen) to power electric engines could have more immediate impact. The successful deployment of the Alice could go a long way to proving the capabilities of electric propulsion and building momentum behind the technology, says Haran.

“There are still a lot of skeptics out there,” he says. “This kind of flight demo will hopefully help bring those people along.”


Match ID: 27 Score: 2.14 source: spectrum.ieee.org age: 183 days
qualifiers: 2.14 carbon

Spin Me Up, Scotty—Up Into Orbit
Fri, 21 Jan 2022 16:34:49 +0000


At first, the dream of riding a rocket into space was laughed off the stage by critics who said you’d have to carry along fuel that weighed more than the rocket itself. But the advent of booster rockets and better fuels let the dreamers have the last laugh.

Hah, the critics said: To put a kilogram of payload into orbit we just need 98 kilograms of rocket plus rocket fuel.

What a ratio, what a cost. To transport a kilogram of cargo, commercial air freight services typically charge about US $10; spaceflight costs reach $10,000. Sure, you can save money by reusing the booster, as Elon Musk and Jeff Bezos are trying to do, but it would be so much better if you could dispense with the booster and shoot the payload straight into space.

The first people to think along these lines used cannon launchers, such as those in Project HARP (High Altitude Research Project), in the 1960s. Research support dried up after booster rockets showed their mettle. Another idea was to shoot payloads into orbit along a gigantic electrified ramp, called a railgun, but that technology still faces hurdles of a basic scientific nature, not least the need for massive banks of capacitors to provide the jolt of energy.

Imagine a satellite spinning in a vacuum chamber at many times the speed of sound. The gates of that chamber open up, and the satellite shoots out faster than the air outside can rush back in—creating a sonic boom when it hits the wall of air.

Now SpinLaunch, a company founded in 2015 in Long Beach, Calif., proposes a gentler way to heave satellites into orbit. Rather than shoot the satellite in a gun, SpinLaunch would sling it from the end of a carbon-fiber tether that spins around in a vacuum chamber for as long as an hour before reaching terminal speed. The tether lets go milliseconds before gates in the chamber open up to allow the satellite out.

“Because we’re slowly accelerating the system, we can keep the power demands relatively low,” David Wrenn, vice president for technology, tells IEEE Spectrum. “And as there’s a certain amount of energy stored in the tether itself, you can recapture that through regenerative braking.”

The company reports they've raised about $100 million. Among the backers are the investment arms of Airbus and Google and the Defense Innovation Unit, part of the U.S. Department of Defense.

SpinLaunch began with a lab centrifuge that measures about 12 meters in diameter. In November, a 33-meter version at Space Port America test-launched a payload thousands of meters up. Such a system could loft a small rocket, which would finish the job of reaching orbit. A 100-meter version, now in the planning stage, should be able to handle a 200-kg payload.

Wrenn answers all the obvious questions. How can the tether withstand the g-force when spinning at hypersonic speed? “A carbon-fiber cable with a cross-sectional area of one square inch (6.5 square centimeters) can suspend a mass of 300,000 pounds (136,000 kg),” he says.

How much preparation do you need between shots? Not much, because the chamber doesn’t have to be superclean. If the customer wants to loft a lot of satellites—a likely desideratum, given the trend toward massive constellations of small satellites–the setup could include motors powerful enough to spin up in 30 minutes. “Upwards of 10 launches per day are possible,” Wrenn says.

How tight must the vacuum be? A “rough” vacuum suffices, he says. SpinLaunch maintains the vacuum with a system of airlocks operated by those millisecond-fast gates.

Most parts, including the steel for the vacuum chamber and carbon fiber, are off-the-shelf, but those gates are proprietary. All Wrenn will say is that they’re not made of steel.

So imagine a highly intricate communications satellite, housed in some structure, spinning at many times the speed of sound. The gates open up, the satellite shoots out far faster than the air outside can rush back in. Then the satellite hits the wall of air, creating a sonic boom.

No problem, says Wrenn. Electronic systems have been hurtling from vacuums into air ever since the cannon-launching days of HARP, some 60 years ago. SpinLaunch has done work already on engineering certain satellite components to withstand the ordeal—“deployable solar panels, for example,” he says.

After the online version of this article appeared, several readers objected to the SpinLaunch system, above all to the stress it would put on the liquid-fueled rocket at the end of that carbon-fiber tether.

“The system has to support up to 8,000 gs; most payloads at launch are rated at 6 or 10 gs,” said John Bucknell, a rocket scientist who heads the startup Virtus Solis Technologies, which aims to collect solar energy in space and beam it to earth.

Keith Lostrom, a chip engineer, went even further. “Drop a brick onto an egg—that is a tiny fraction of the damage that SpinLaunch’s centripedal acceleration would do to a liquid-fuel orbital launch rocket,” he wrote, in an emailed message.

Wrenn denies that the g-force is a dealbreaker. For one thing, he argues, the turbopumps in liquid-fuel rockets spin at over 30,000 rotations per minute, subjecting the liquid oxygen and fuel to “much more aggressive conditions than the uniform g-force that SpinLaunch has.”

Besides, he says, finite element analysis and high-g testing in the company’s 12-meter accelerator “has led to confidence it’s not a fundamental issue for us. We’ve already hot-fired our SpinLaunch-compatible upper-stage engine on the test stand.”

SpinLaunch says it will announce the site for its full-scale orbital launcher within the next five months. It will likely be built on a coastline, far from populated areas and regular airplane service. Construction costs would be held down if the machine can be built up the side of a hill. If all goes well, expect to see the first satellite slung into orbit sometime around 2025.

This article was updated on 24 Feb. 2022 to include additional perspectives on the technology.


Match ID: 28 Score: 2.14 source: spectrum.ieee.org age: 200 days
qualifiers: 2.14 carbon

12 Exciting Engineering Milestones to Look for in 2022
Thu, 30 Dec 2021 16:00:00 +0000


Psyche’s Deep-Space Lasers


An illustration of a satellite holding a ray gun in a cartoon style hand. MCKIBILLO

In August, NASA will launch the Psyche mission, sending a deep-space orbiter to a weird metal asteroid orbiting between Mars and Jupiter. While the probe’s main purpose is to study Psyche’s origins, it will also carry an experiment that could inform the future of deep-space communications. The Deep Space Optical Communications (DSOC) experiment will test whether lasers can transmit signals beyond lunar orbit. Optical signals, such as those used in undersea fiber-optic cables, can carry more data than radio signals can, but their use in space has been hampered by difficulties in aiming the beams accurately over long distances. DSOC will use a 4-watt infrared laser with a wavelength of 1,550 nanometers (the same used in many optical fibers) to send optical signals at multiple distances during Psyche’s outward journey to the asteroid.


The Great Electric Plane Race


An illustration of a battery with wings and a spinning propeller. MCKIBILLO

For the first time in almost a century, the U.S.-based National Aeronautic Association (NAA) will host a cross-country aircraft race. Unlike the national air races of the 1920s, however, the Pulitzer Electric Aircraft Race, scheduled for 19 May, will include only electric-propulsion aircraft. Both fixed-wing craft and helicopters are eligible. The competition will be limited to 25 contestants, and each aircraft must have an onboard pilot. The course will start in Omaha and end four days later in Manteo, N.C., near the site of the Wright brothers’ first flight. The NAA has stated that the goal of the cross-country, multiday race is to force competitors to confront logistical problems that still plague electric aircraft, like range, battery charging, reliability, and speed.

6-Gigahertz Wi-Fi Goes Mainstream

An illustration of the wifi signal and an arrow near the word \u201c6Ghz.\u201d MCKIBILLO

Wi-Fi is getting a boost with 1,200 megahertz of new spectrum in the 6-gigahertz band, adding a third spectrum band to the more familiar 2.4 GHz and 5 GHz. The new band is called Wi-Fi 6E because it extends Wi-Fi’s capabilities into the 6-GHz band. As a rule, higher radio frequencies have higher data capacity, but a shorter range. With its higher frequencies, 6-GHz Wi-Fi is expected to find use in heavy traffic environments like offices and public hotspots. The Wi-Fi Alliance introduced a Wi-Fi 6E certification program in January 2021, and the first trickle of 6E routers appeared by the end of the year. In 2022, expect to see a bonanza of Wi-Fi 6E–enabled smartphones.

3-Nanometer Chips Arrive

An illustration of a chip dancing and holding a hat with \u201c3nm\u201d at the center. MCKIBILLO

Taiwan Semiconductor Manufacturing Co. (TSMC) plans to begin producing 3-nanometer semiconductor chips in the second half of 2022. Right now, 5-nm chips are the standard. TSMC will make its 3-nm chips using a tried-and-true semiconductor structure called the FinFET (short for “fin field-effect transistor”). Meanwhile, Samsung and Intel are moving to a different technique for 3 nm called nanosheet. (TSMC is eventually planning to abandon FinFETs.) At one point, TSMC’s sole 3-nm chip customer for 2022 was Apple, for the latter’s iPhone 14, but supply-chain issues have made it less certain that TSMC will be able to produce enough chips—which promise more design flexibility—to fulfill even that order.

Seoul Joins the Metaverse

An illustration of a building MCKIBILLO

After Facebook (now Meta) announced it was hell-bent on making the metaverse real, a host of other tech companies followed suit. Definitions differ, but the basic idea of the metaverse involves merging virtual reality and augmented reality with actual reality. Also jumping on the metaverse bandwagon is the government of the South Korean capital, Seoul, which plans to develop a “metaverse platform” by the end of 2022. To build this first public metaverse, Seoul will invest 3.9 billion won (US $3.3 million). The platform will offer public services and cultural events, beginning with the Metaverse 120 Center, a virtual-reality portal for citizens to address concerns that previously required a trip to city hall. Other planned projects include virtual exhibition halls for school courses and a digital representation of Deoksu Palace. The city expects the project to be complete by 2026.

IBM’s Condors Take Flight

An illustration of a bird made up of squares. MCKIBILLO

In 2022, IBM will debut a new quantum processor—its biggest yet—as a stepping-stone to a 1,000-qubit processor by the end of 2023. This year’s iteration will contain 433 qubits, three times as much as the company’s 127-qubit Eagle processor, which was launched last year. Following the bird theme, the 433- and 1,000-qubit processors will be named Condor. There have been quantum computers with many more qubits; D-Wave Systems, for example, announced a 5,000-qubit computer in 2020. However, D-Wave’s computers are specialized machines for optimization problems. IBM’s Condors aim to be the largest general-purpose quantum processors.

New Dark-Matter Detector

An illustration of two dotted arrow headed lines and two circles with the letter \u201cp\u201d on them. MCKIBILLO

The Forward Search Experiment (FASER) at CERN is slated to switch on in July 2022. The exact date depends on when the Large Hadron Collider is set to renew proton-proton collisions after three years of upgrades and maintenance. FASER will begin a hunt for dark matter and other particles that interact extremely weakly with “normal” matter. CERN, the fundamental physics research center near Geneva, has four main detectors attached to its Large Hadron Collider, but they aren’t well-suited to detecting dark matter. FASER won’t attempt to detect the particles directly; instead, it will search for the more strongly interacting Standard Model particles created when dark matter interacts with something else. The new detector was constructed while the collider was shut down from 2018 to 2021. Located 480 meters “downstream” of the ATLAS detector, FASER will also hunt for neutrinos produced in huge quantities by particle collisions in the LHC loop. The other CERN detectors have so far failed to detect such neutrinos.

Pong Turns 50

An illustration of the pong game with the numbers \u201c6\u201d and \u201c9\u201d on top. MCKIBILLO

Atari changed the course of video games when it released its first game, Pong, in 1972. While not the first video game—or even the first to be presented in an upright, arcade-style cabinet—Pong was the first to be commercially successful. The game was developed by engineer Allan Alcorn and originally assigned to him as a test after he was hired, before he began working on actual projects. However, executives at Atari saw potential in Pong’s simple game play and decided to develop it into a real product. Unlike the countless video games that came after it, the original Pong did not use any code or microprocessors. Instead, it was built from a television and transistor-transistor logic.

The Green Hydrogen Boom

An illustration of a generator with large, circular blades. MCKIBILLO

Utility company Energias de Portugal (EDP), based in Lisbon, is on track to begin operating a 3-megawatt green hydrogen plant in Brazil by the end of the year. Green hydrogen is hydrogen produced in sustainable ways, using solar or wind-powered electrolyzers to split water molecules into hydrogen and oxygen. According to the International Energy Agency, only 0.1 percent of hydrogen is produced this way. The plant will replace an existing coal-fired plant and generate hydrogen—which can be used in fuel cells—using solar photovoltaics. EDP’s roughly US $7.9 million pilot program is just the tip of the green hydrogen iceberg. Enegix Energy has announced plans for a $5.4 billion green hydrogen plant in the same Brazilian state, Ceará, where the EDP plant is being built. The green hydrogen market is predicted to generate a revenue of nearly $10 billion by 2028, according to a November 2021 report by Research Dive.

A Permanent Space Station for China

An illustration of a space station MCKIBILLO

China is scheduled to complete its Tiangong (“Heavenly Palace”) space station in 2022. The station, China’s first long-term space habitat, was preceded by the Tiangong-1 and Tiangong-2 stations, which orbited from 2011 to 2018 and 2016 to 2019, respectively. The new station’s core module, the Tianhe, was launched in April 2021. A further 10 missions by the end of 2022 will deliver other components and modules, with construction to be completed in orbit. The final station will have two laboratory modules in addition to the core module. Tiangong will orbit at roughly the same altitude as the International Space Station but will be only about one-fifth the mass of the ISS.

A Cool Form of Energy Storage

An illustration of a lightning bolt in an ice cube. MCKIBILLO

Cryogenic energy-storage company Highview Power will begin operations at its Carrington plant near Manchester, England, this year. Cryogenic energy storage is a long-term method of storing electricity by cooling air until it liquefies (about –196 °C). Crucially, the air is cooled when electricity is cheaper—at night, for example—and then stored until electricity demand peaks. The liquid air is then allowed to boil back into a gas, which drives a turbine to generate electricity. The 50-megawatt/250-megawatt-hour Carrington plant will be Highview Power’s first commercial plant using its cryogenic storage technology, dubbed CRYOBattery. Highview Power has said it plans to build a similar plant in Vermont, although it has not specified a timeline yet.

Carbon-Neutral Cryptocurrency?

An illustration of a coin with stars around it. MCKIBILLO

Seattle-based startup Nori is set to offer a cryptocurrency for carbon removal. Nori will mint 500 million tokens of its Ethereum-based currency (called NORI). Individuals and companies can purchase and trade NORI, and eventually exchange any NORI they own for an equal number of carbon credits. Each carbon credit represents a tonne of carbon dioxide that has already been removed from the atmosphere and stored in the ground. When exchanged in this way, a NORI is retired, making it impossible for owners to try to “double count” carbon credits and therefore seem like they’re offsetting more carbon than they actually have. The startup has acknowledged that Ethereum and other blockchain-based technologies consume an enormous amount of energy, so the carbon it sequesters could conceivably originate in cryptocurrency mining. However, 2022 will also see Ethereum scheduled to switch to a much more energy-efficient method of verifying its blockchain, called proof-of-stake, which Nori will take advantage of when it launches.


Match ID: 29 Score: 2.14 source: spectrum.ieee.org age: 222 days
qualifiers: 2.14 carbon

Filter efficiency 96.068 (30 matches/763 results)


********** TRAVEL **********
return to top



Rep. Scott Perry says the FBI seized his phone while he was traveling
Tue, 9 Aug 2022 20:30:09 EDT
FBI agents reportedly seized the cellphone of Trump ally Rep. Scott Perry.
Match ID: 0 Score: 35.00 source: www.washingtonpost.com age: 0 days
qualifiers: 35.00 travel(|ing)

Ukraine round-up: Blasts in Crimea and travel dispute
Tue, 09 Aug 2022 19:20:16 GMT
Explosions rock a Russian military airfield in Crimea and travel may get yet harder for Russians.
Match ID: 1 Score: 35.00 source: www.bbc.co.uk age: 0 days
qualifiers: 35.00 travel(|ing)

Kremlin sharply critical of Ukraine’s call for travel ban on Russians
Tue, 9 Aug 2022 11:05:32 EDT
Ukrainian President Volodymyr Zelensky called on other countries to ban all Russian travelers to help stop Moscow from annexing any more Ukrainian territory.
Match ID: 2 Score: 35.00 source: www.washingtonpost.com age: 0 days
qualifiers: 35.00 travel(|ing)

The simple life: tips for easy outdoor cooking | Kitchen aide
Tue, 09 Aug 2022 13:00:29 GMT

Don’t have a snazzy camping grill? No problem. You just need a campfire and unfussy foods with their own natural wrapping – corn on the cob, shell-on prawns, baked spuds – or stuff you can stick on a skewer

• Got a culinary dilemma? Email feast@theguardian.com

What can I cook outdoors – on a barbecue or campfire – that’s easy and requires minimal equipment?
Josh, Norwich

When playing with fire, home or away, chef Itamar Srulovich suggests staying “in the realm of wrapped food”. And the simplest solution is whole sweetcorn. “It’s the ultimate summer food, and I can’t get enough of it,” says the co-founder of Honey & Co. Make sure you get corn with the husk on, mind: “Grill them directly on the barbecue and the kernels will steam inside – it’s like their own little cooking vessel.” Once the corn is cooked and cool enough to handle, remove the husks and pop them back on the barbie, “to give a little smokiness”, then brush with chilli butter and honey: “It’s so good.”

Continue reading...
Match ID: 3 Score: 35.00 source: www.theguardian.com age: 0 days
qualifiers: 35.00 travel(|ing)

Bournemouth residents: share your views on an abortion clinic buffer zone
Tue, 09 Aug 2022 11:00:48 GMT

We’d like to hear from people in Bournemouth about council plans for a buffer zone outside an abortion clinic

Bournemouth council have launched consultation over plans for a buffer zone outside an abortion clinic. Local residents are being encouraged to respond to the consultation on whether to implement a buffer zone outside the BPAS clinic in Bournemouth.

Bournemouth Council said the aim of the buffer zone would be “to protect the staff and visitors who have been affected by the behaviour of those who congregate, hold vigils and protest outside”. This includes anti-abortion protesters.

Continue reading...
Match ID: 4 Score: 35.00 source: www.theguardian.com age: 0 days
qualifiers: 35.00 travel(|ing)

Coronavirus tally: Chinese authorities close Tibet's Potala Palace over small COVID outbreak
Tue, 09 Aug 2022 10:19:57 GMT

Chinese authorities have closed Tibet's Potala Palace after a small outbreak of COVID cases in the Himalayan region, the Associated Press reported. The action underscores China's continued adherence to its "zero-COVID" policy, mandating lockdowns, routine testing, quarantines and travel restrictions, even while most other countries have reopened. Meanwhile, more than 80,000 travelers remain stranded on the southern resort island of Hainan under requirements that they consistently test negative for the virus in coming days before being allowed to leave. In the U.S., the daily average for new cases continued its recent decline, but not all data are being captured as many people are testing at home. The average stood at 108,261 on Monday, according to a New York Times tracker, down 16% from two weeks ago. The daily average for hospitalizations was down 1% at 43,070, while the daily average for deaths is up 10% to 483. Globally, the confirmed case tally rose above 585.4 million on Tuesday, according to data aggregated by Johns 2Hopkins, while the death toll is above 6.42 million with the U.S. leading the world with 92.2 million cases and 1,034,021 deaths.

Market Pulse Stories are Rapid-fire, short news bursts on stocks and markets as they move. Visit MarketWatch.com for more information on this news.


Match ID: 5 Score: 35.00 source: www.marketwatch.com age: 0 days
qualifiers: 35.00 travel(|ing)

Spirit Airlines revenue rises above pre-pandemic levels, beats expectations amid 'robust' leisure travel demand
Tue, 09 Aug 2022 10:18:19 GMT

Spirit Airlines Inc. reported Tuesday a narrower-than-expected second-quarter loss and revenue that topped pre-pandemic 2019 levels, amid increased flight volume and higher revenue per seat as demand for leisure travel was "robust" during the peak summer season. The discount air carrier, that agreed in late July to merge with JetBlue Airways Corp. in a $3.8 billion deal, said net losses narrowed to $52.4 million, or 48 cents a share, from $287.9 million, or $2.73 a share, in the year-ago period, but compared with net income of $114.5 million, or $1.67 a share, in the same period in 2019. Excluding nonrecurring items, the adjusted per-share loss of 30 cents beat the FactSet loss consensus of 46 cents. Revenue jumped 59.0% from last year to $1.37 billion, and was 34.9% higher than the same period in 2019, to beat the FactSet consensus of $1.35 billion. Total revenue per available seat mile (TRASM) was 11.54 cents, up 22.8% from 2019. Capacity was up 0.9% when compared with 2019 and load factor was up 1.0 percentage point to 86.0. The average fuel cost per gallon more than doubled from a year ago, to $4.30 from $1.95, and from $2.16 in 2019, but is expected to decline to $3.55 to $3.60 in the third quarter. The stock, which was still inactive in premarket trading, has soared 46.6% over the past three months while the S&P 500 has gained 3.7%.

Market Pulse Stories are Rapid-fire, short news bursts on stocks and markets as they move. Visit MarketWatch.com for more information on this news.


Match ID: 6 Score: 35.00 source: www.marketwatch.com age: 0 days
qualifiers: 35.00 travel(|ing)

Australia calls for ‘return to calm’ amid Taiwan drills as Beijing demands Canberra ‘respect China’s core interests’
Tue, 09 Aug 2022 09:41:29 GMT

China’s foreign ministry said Australia should ‘respect China’s core interests’ and ‘avoid creating new obstacles for China-Australia ties’

Australia has again called for an end to China’s military drills near Taiwan, and a “return to calm”, as China has demanded that Australia stop interfering in its affairs.

China has been conducting live-fire drills near Taiwan in the wake of a visit from the US house speaker, Nancy Pelosi. Australia does not recognise Taiwan as a country under the One China policy, but maintains unofficial ties. The US recognises the One China policy without agreeing with it.

Sign up to receive an email with the top stories from Guardian Australia every morning

Continue reading...
Match ID: 7 Score: 35.00 source: www.theguardian.com age: 0 days
qualifiers: 35.00 travel(|ing)

Quinta-ssential Portugal: a campervan tour of farms, villages and flavours
Tue, 09 Aug 2022 06:00:19 GMT

A new website for campervanners puts Portugal’s superb country food and wine on your doorstep – and you only pay for the welcome basket

As we pull up at the gate of Lavoura da Bouça, a huge but friendly mastiff is there to meet us. Behind him waddle a gaggle of noisy geese, followed by a scattering of sheep. In the back of our brightly coloured rental van, my two sons and their school friend look doubtful. Have we come to the right place?

Admittedly, the stone farmhouse with its animals and apple orchard does not look like your usual edge-of-town campervan stopover joint. There are no other vans, no facilities (other than a very clean compost toilet), and no illumination other than the stars.

I assure them this rustic spot, an hour-and-a-half’s drive from Porto, is where the EasyCamp website has directed us and so, while it looks like someone’s private home, it must indeed be our destination. Then, as if on cue, Aurora and José, the farm’s cheerful owners, appear from behind a large fruit tree and usher us through the gate.

Continue reading...
Match ID: 8 Score: 35.00 source: www.theguardian.com age: 0 days
qualifiers: 35.00 travel(|ing)

Russia suspends US inspections of its nuclear weapons arsenal
Tue, 09 Aug 2022 00:10:44 GMT

Moscow blames Ukraine war sanctions for preventing mutual inspection of its nuclear arms under New Start treaty

Russia has suspended an arrangement that allowed US and Russian inspectors to visit each other’s nuclear weapons sites under the 2010 New Start treaty, in a new blow to arms control.

Mutual inspections had been suspended as a health precaution since the start of the Covid pandemic, but a foreign ministry statement on Monday added another reason Russia is unwilling to restart them. It argued that US sanctions imposed because of the invasion of Ukraine stopped Russian inspectors travelling to the US.

Continue reading...
Match ID: 9 Score: 35.00 source: www.theguardian.com age: 1 day
qualifiers: 35.00 travel(|ing)

Should Doctors Break the Law?
Sat, 06 Aug 2022 11:00:49 +0000

As abortion bans compel them to endanger patients, some are considering civil disobedience.

The post Should Doctors Break the Law? appeared first on The Intercept.


Match ID: 10 Score: 30.00 source: theintercept.com age: 3 days
qualifiers: 30.00 travel(|ing)

Lobbying Blitz Pushed Fertilizer Prices Higher, Fueling Food Inflation
Wed, 03 Aug 2022 22:59:20 +0000

Emails show fertilizer producer Mosaic lobbied heavily for tariffs under Trump, then used them to dominate the market.

The post Lobbying Blitz Pushed Fertilizer Prices Higher, Fueling Food Inflation appeared first on The Intercept.


Match ID: 11 Score: 15.00 source: theintercept.com age: 6 days
qualifiers: 15.00 travel(|ing)

Solar-to-Jet-Fuel System Readies for Takeoff
Wed, 03 Aug 2022 17:00:00 +0000


As climate change edges from crisis to emergency, the aviation sector looks set to miss its 2050 goal of net-zero emissions. In the five years preceding the pandemic, the top four U.S. airlines—American, Delta, Southwest, and United—saw a 15 percent increase in the use of jet fuel. Despite continual improvements in engine efficiencies, that number is projected to keep rising.

A glimmer of hope, however, comes from solar fuels. For the first time, scientists and engineers at the Swiss Federal Institute of Technology (ETH) in Zurich have reported a successful demonstration of an integrated fuel-production plant for solar kerosene. Using concentrated solar energy, they were able to produce kerosene from water vapor and carbon dioxide directly from air. Fuel thus produced is a drop-in alternative to fossil-derived fuels and can be used with existing storage and distribution infrastructures, and engines.

Fuels derived from synthesis gas (or syngas)—an intermediate product that is a specific mixture of carbon monoxide and hydrogen—is a known alternative to conventional, fossil-derived fuels. Syngas is produced by Fischer-Tropsch (FT) synthesis, in which chemical reactions convert carbon monoxide and water vapor into hydrocarbons. The team of researchers at ETH found that a solar-driven thermochemical method to split water and carbon dioxide using a metal oxide redox cycle can produce renewable syngas. They demonstrated the process in a rooftop solar refinery at the ETH Machine Laboratory in 2019.

Close-up of a spongy looking material Reticulated porous structure made of ceria used in the solar reactor to thermochemically split CO2 and H2O and produce syngas, a specific mixture of H2 and CO.ETH Zurich

The current pilot-scale solar tower plant was set up at the IMDEA Energy Institute in Spain. It scales up the solar reactor of the 2019 experiment by a factor of 10, says Aldo Steinfeld, an engineering professor at ETH who led the study. The fuel plant brings together three subsystems—the solar tower concentrating facility, solar reactor, and gas-to-liquid unit.

First, a heliostat field made of mirrors that rotate to follow the sun concentrates solar irradiation into a reactor mounted on top of the tower. The reactor is a cavity receiver lined with reticulated porous ceramic structures made of ceria (or cerium(IV) oxide). Within the reactor, the concentrated sunlight creates a high-temperature environment of about 1,500 °C which is hot enough to split captured carbon dioxide and water from the atmosphere to produce syngas. Finally, the syngas is processed to kerosene in the gas-to-liquid unit. A centralized control room operates the whole system.

Fuel produced using this method closes the fuel carbon cycle as it only produces as much carbon dioxide as has gone into its manufacture. “The present pilot fuel plant is still a demonstration facility for research purposes,” says Steinfeld, “but it is a fully integrated plant and uses a solar-tower configuration at a scale that is relevant for industrial implementation.”

“The solar reactor produced syngas with selectivity, purity, and quality suitable for FT synthesis,” the authors noted in their paper. They also reported good material stability for multiple consecutive cycles. They observed a value of 4.1 percent solar-to-syngas energy efficiency, which Steinfeld says is a record value for thermochemical fuel production, even though better efficiencies are required to make the technology economically competitive.

Schematic of the solar tower fuel plant.  A heliostat field concentrates solar radiation onto a solar reactor mounted on top of the solar tower. The solar reactor cosplits water and carbon dioxide and produces a mixture of molecular hydrogen and carbon monoxide, which in turn is processed to drop-in fuels such as kerosene.ETH Zurich

“The measured value of energy conversion efficiency was obtained without any implementation of heat recovery,” he says. The heat rejected during the redox cycle of the reactor accounted for more than 50 percent of the solar-energy input. “This fraction can be partially recovered via thermocline heat storage. Thermodynamic analyses indicate that sensible heat recovery could potentially boost the energy efficiency to values exceeding 20 percent.”

To do so, more work is needed to optimize the ceramic structures lining the reactor, something the ETH team is actively working on, by looking at 3D-printed structures for improved volumetric radiative absorption. “In addition, alternative material compositions, that is, perovskites or aluminates, may yield improved redox capacity, and consequently higher specific fuel output per mass of redox material,” Steinfeld adds.

The next challenge for the researchers, he says, is the scale-up of their technology for higher solar-radiative power inputs, possibly using an array of solar cavity-receiver modules on top of the solar tower.

To bring solar kerosene into the market, Steinfeld envisages a quota-based system. “Airlines and airports would be required to have a minimum share of sustainable aviation fuels in the total volume of jet fuel that they put in their aircraft,” he says. This is possible as solar kerosene can be mixed with fossil-based kerosene. This would start out small, as little as 1 or 2 percent, which would raise the total fuel costs at first, though minimally—adding “only a few euros to the cost of a typical flight,” as Steinfeld puts it

Meanwhile, rising quotas would lead to investment, and to falling costs, eventually replacing fossil-derived kerosene with solar kerosene. “By the time solar jet fuel reaches 10 to 15 percent of the total jet-fuel volume, we ought to see the costs for solar kerosene nearing those of fossil-derived kerosene,” he adds.

However, we may not have to wait too long for flights to operate solely on solar fuel. A commercial spin-off of Steinfeld’s laboratory, Synhelion, is working on commissioning the first industrial-scale solar fuel plant in 2023. The company has also collaborated with the airline SWISS to conduct a flight solely using its solar kerosene.


Match ID: 12 Score: 15.00 source: spectrum.ieee.org age: 6 days
qualifiers: 15.00 travel(|ing)

Border Patrol Agents Are Trashing Sikh Asylum-Seekers’ Turbans
Tue, 02 Aug 2022 17:45:44 +0000

“The turban is sacred.” At least 64 Sikh men have had their headwear confiscated and discarded by Yuma’s Border Patrol.

The post Border Patrol Agents Are Trashing Sikh Asylum-Seekers’ Turbans appeared first on The Intercept.


Match ID: 13 Score: 10.00 source: theintercept.com age: 7 days
qualifiers: 10.00 travel(|ing)

Should Premier League football clubs travel so far for pre-season?
Tue, 02 Aug 2022 08:05:17 GMT
BBC Sport examines the climate impact of the Premier League's globe-trotting pre-season tours.
Match ID: 14 Score: 10.00 source: www.bbc.co.uk age: 7 days
qualifiers: 10.00 travel(|ing)

Turing Award Winner On His Pioneering Algorithms
Wed, 27 Jul 2022 18:00:00 +0000


Jack Dongarra’s dream job growing up was to teach science at a public high school in Chicago.

“I was pretty good in math and science, but I wasn’t a particularly good student,” Dongarra says, laughing.

After he graduated high school, there was only one university he wanted to attend: Chicago State. That’s because, he says, it was known for “churning out teachers.” Chicago State accepted his application, and he decided to major in mathematics.


His physics professor suggested that Dongarra apply for an internship at the Argonne National Laboratory, in Lemont, Ill., a nearby U.S. Department of Energy science and engineering research center. For 16 weeks he worked with a group of researchers designing and developing EISPACK, a package of Fortran routines that compute the eigenvalues and eigenvectors of matrices—calculations common in scientific computing.

Dongarra acknowledges he didn’t have a background in or knowledge of eigenvalues and eigenvectors—or of linear algebra—but he loved what he was doing. The experience at Argonne, he says, was transformative. He had found his passion.

“I thought it was a cool thing to do,” he says, “so I kept pursuing it.”

About Jack Dongarra


Employer: University of Tennessee, Knoxville

Title: Professor emeritus, computer science

Member grade: Life Fellow

Alma mater: Chicago State University

The IEEE Life Fellow has since made pioneering contributions to numerical algorithms and libraries for linear algebra, which allowed software to make good use of high-performance hardware. His open-source software libraries are used in just about every computer, from laptops to the world’s fastest supercomputers.

The libraries include basic linear algebra subprograms (BLAS), the linear-algebra package LAPACK, parallel virtual machines (PVMs), automatically tuned linear algebra software (ATLAS), and the high-performance conjugate gradient (HPCG) benchmark.

For his work, he was honored this year with the 2021 A.M. Turing Award from the Association for Computing Machinery. He received US $1 million as part of the award, which is known as the Nobel Prize of computing.

“When I think about previous Turing Award recipients, I’m humbled to think about what I’ve learned from their books and papers,” Dongarra says. “Their programming languages, theorems, techniques, and standards have helped me develop my algorithms.

“It’s a tremendous honor to be this year’s recipient. The award is a recognition by the computer-science community that the contributions we are making in high-performance computing are important and have an impact in the broader computer-science community and science in general.”

Dongarra didn’t end up teaching science to high school students. Instead, he became a professor of electrical engineering and computer science at the University of Tennessee in Knoxville, where he taught for 33 years. The university recently named him professor emeritus.

Entrepreneurial Spirit

After graduating from Chicago State in 1972 with a bachelor’s degree in mathematics, Dongarra went on to pursue a master’s degree in computer science at the Illinois Institute of Technology, also in Chicago. While there he worked one day a week for Argonne with the same team of researchers. After he got his degree in 1973, the lab hired him full time as a researcher.

With encouragement from his colleagues to pursue a Ph.D., he left the lab to study applied mathematics at the University of New Mexico in Albuquerque. He honed his knowledge of linear algebra there and began working out algorithms and writing software.

He returned to Argonne after getting his doctorate in 1980 and worked there as a senior scientist until 1989, when he got the opportunity to fulfill his dream of teaching.

He was offered a joint position teaching computer science at the University of Tennessee and conducting research at the nearby Oak Ridge National Laboratory which, like Argonne, is a Department of Energy facility.

“It was time for me to try out some new things,” he says. “I was ready to try my hand at academia.”

He says Oak Ridge operated in a similar way to Argonne, and the culture there was more or less the same.

“The challenge,” he says, “was becoming a university professor.”

"The Turing Award is a recognition by the computer science community that the contributions we are making in high-performance computing are important, and have an impact in the broader computer science community and science in general.”

University culture is very different from that at a government laboratory, he says, but he quickly fell into the rhythm of the academic setting.

Although he loved teaching, he says, he also was attracted to the opportunity the university gave its instructors to work on technology they are passionate about.

“You follow your own path and course of research,” he says. “I’ve prospered in that environment. I interact with smart people, I have the ability to travel around the world, and I have collaborations going on with people in many countries.

“Academia gives you this freedom to do things and not be constrained by a company’s drive or its motivation. Rather, I get to work on what motivates me. That’s why I’ve stayed in academia for so many years.”

Man with glasses and checkered shirt sitting in front of a Tektronix computer. In 1980, Dongarra worked as a senior scientist at Argonne National Laboratory, in Lemont, Ill.Jack Dongarra

Dongarra founded the university’s Innovative Computing Laboratory, whose mission is to provide tools for high-performance computing to the scientific community. He also directs the school’s Center for Information Technology Research.

He is now a distinguished researcher at Oak Ridge, which he calls “a wonderful place, with its state-of-the-art equipment and the latest computers.”

Software for Supercomputers

It was working in creative environments that led Dongarra to come up with what many describe as world-changing software libraries, which have contributed to the growth of high-performance computing in many areas including artificial intelligence, data analytics, genomics, and health care.

“The libraries we designed have basic components that are needed in many areas of science so that users can draw on those components to help them solve their computational problems,” he says. “That software is portable and efficient. It has all the attributes that we want in terms of being understandable and providing reliable results.”

He’s currently working on creating a software library for the world’s fastest supercomputer, Frontier, which recently was installed at the Oak Ridge lab. It is the first computer that can process more than 1 quintillion operations per second.

Computer-Science Recognition

Dongarra has been an IEEE member for more than 30 years.

“I enjoy interacting with the community,” he says in explaining why he continues to belong. “Also I enjoy reading IEEE Spectrum and journals that are relevant to my specific field.”

He has served as an editor for several IEEE journals including Proceedings of the IEEE, IEEE Computer Architecture Letters, and IEEE Transactions on Parallel and Distributed Systems.

Dongarra says he’s a big promoter of IEEE meetings and workshops, especially the International Conference for High Performance Computing, Networking, Storage, and Analysis, sponsored by ACM and the IEEE Computer Society, of which he is a member. He’s been attending the event every year since 1988. He has won many awards at the conference for his papers.

“That conference is really a homecoming for the high-performance computing community,” he says, “and IEEE plays a major role.”

IEEE is proud of Dongarra’s contributions to computing and has honored him over the years. In 2008 he received the first IEEE Medal of Excellence in Scalable Computing. He also received the 2020 Computer Pioneer Award, the 2013 ACM/IEEE Ken Kennedy Award, the 2011 IEEE Charles Babbage Award and the 2003 Sidney Fernbach Award.

“I’m very happy and proud to be a member of IEEE,” he says. “I think it provides a valuable service to the community.”


Match ID: 15 Score: 5.00 source: spectrum.ieee.org age: 13 days
qualifiers: 5.00 travel(|ing)

Interstate Travel Post-Roe Isn’t as Secure as You May Think
Mon, 25 Jul 2022 11:00:00 +0000
Despite the DOJ vowing to protect people's ability to travel out of state for abortion care, legal experts warn not to take that freedom for granted.
Match ID: 16 Score: 5.00 source: www.wired.com age: 15 days
qualifiers: 5.00 travel(|ing)

X-Rays Could Carry Quantum Signals Across the Stars
Mon, 18 Jul 2022 15:07:14 +0000


Quantum signals may possess a number of advantages over regular forms of communication, leading scientists to wonder if humanity was not alone in discovering such benefits. Now a new study suggests that, for hypothetical extraterrestrial civilizations, quantum transmissions using X-rays may be possible across interstellar distances.

Quantum communication relies on a quantum phenomenon known as entanglement. Essentially, two or more particles such as photons that get “linked” via entanglement can, in theory, influence each other instantly no matter how far apart they are.

Entanglement is essential to quantum teleportation, in which data can essentially disappear one place and reappear someplace else. Since this information does not travel across the intervening space, there is no chance the information will be lost.

To accomplish quantum teleportation, one would first entangle two photons. Then, one of the photons—the one to be teleported—is kept at one location while the other is beamed to whatever destination is desired.

Next, the photon at the destination's quantum state—which defines its key characteristics—is analyzed, an act that also destroys its quantum state. Entanglement will lead the destination photon to prove identical to its partner. For all intents and purposes, the photon at the origin point “teleported” to the destination point—no physical matter moved, but the two photons are physically indistinguishable.

And to be clear, quantum teleportation cannot send information faster than the speed of light, because the destination photon must still be transmitted via conventional means.

One weakness of quantum communication is that entanglement is fragile. Still, researchers have successfully transmitted entangled photons that remained stable or “coherent” enough for quantum teleportation across distances as great as 1,400 kilometers.

Such findings led theoretical physicist Arjun Berera at the University of Edinburgh to wonder just how far quantum signals might stay coherent. First, he discovered quantum coherence might survive interstellar distances within our galaxy, and then he and his colleagues found quantum coherence might survive intergalactic distances.

“If photons in Earth’s atmosphere don’t decohere to 100 km, then in interstellar space where the medium is much less dense then our atmosphere, photons won’t decohere up to even the size of the galaxy,” Berera says.

In the new study, the researchers investigated whether and how well quantum communication might survive interstellar distances. Quantum signals might face disruption from a number of factors, such as the gravitational pull of interstellar bodies, they note.

The scientists discovered the best quantum communication channels for interstellar messages are X-rays. Such frequencies are easier to focus and detect across interstellar distances. (NASA has tested deep-space X-ray communication with its XCOM experiment.) The researchers also found that the optical and microwave bands could enable communication across large distances as well, albeit less effectively than X-rays.

Although coherence might survive interstellar distances, Berera does note quantum signals might lose fidelity. “This means the quantum state is sustained, but it can have a phase shift, so although the quantum information is preserved in these states, it has been altered by the effect of gravity.” Therefore, it may “take some work at the receiving end to account for these phase shifts and be able to assess the information contained in the original state.”

Why might an interstellar civilization transmit quantum signals as opposed to regular ones? The researchers note that quantum communication may allow greater data compression and, in some cases, exponentially faster speeds than classical channels. Such a boost in efficiency might prove very useful for civilizations separated by interstellar distances.

“It could be that quantum communication is the main communication mode in an extraterrestrial's world, so they just apply what is at hand to send signals into the cosmos,” Berera says.

The scientists detailed their findings online 28 June in the journal Physical Review D.


Match ID: 17 Score: 5.00 source: spectrum.ieee.org age: 22 days
qualifiers: 5.00 travel(|ing)

The Webb Space Telescope’s Profound Data Challenges
Fri, 08 Jul 2022 18:03:45 +0000


For a deep dive into the engineering behind the James Webb Space Telescope, see our collection of posts here.

When the James Webb Space Telescope (JWST) reveals its first images on 12 July, they will be the by-product of carefully crafted mirrors and scientific instruments. But all of its data-collecting prowess would be moot without the spacecraft’s communications subsystem.

The Webb’s comms aren’t flashy. Rather, the data and communication systems are designed to be incredibly, unquestionably dependable and reliable. And while some aspects of them are relatively new—it’s the first mission to use Ka-band frequencies for such high data rates so far from Earth, for example—above all else, JWST’s comms provide the foundation upon which JWST’s scientific endeavors sit.


As previous articles in this series have noted, JWST is parked at Lagrange point L2. It’s a point of gravitational equilibrium located about 1.5 million kilometers beyond Earth on a straight line between the planet and the sun. It’s an ideal location for JWST to observe the universe without obstruction and with minimal orbital adjustments.

Being so far away from Earth, however, means that data has farther to travel to make it back in one piece. It also means the communications subsystem needs to be reliable, because the prospect of a repair mission being sent to address a problem is, for the near term at least, highly unlikely. Given the cost and time involved, says Michael Menzel, the mission systems engineer for JWST, “I would not encourage a rendezvous and servicing mission unless something went wildly wrong.”

According to Menzel, who has worked on JWST in some capacity for over 20 years, the plan has always been to use well-understood K a-band frequencies for the bulky transmissions of scientific data. Specifically, JWST is transmitting data back to Earth on a 25.9-gigahertz channel at up to 28 megabits per second. The Ka-band is a portion of the broader K-band (another portion, the Ku-band, was also considered).

The Lagrange points are equilibrium locations where competing gravitational tugs on an object net out to zero. JWST is one of three craft currently occupying L2 (Shown here at an exaggerated distance from Earth).IEEE Spectrum

Both the data-collection and transmission rates of JWST dwarf those of the older Hubble Space Telescope. Compared to Hubble, which is still active and generates 1 to 2 gigabytes of data daily, JWST can produce up to 57 GB each day (although that amount is dependent on what observations are scheduled).

Menzel says he first saw the frequency selection proposals for JWST around 2000, when he was working at Northrop Grumman. He became the mission systems engineer in 2004. “I knew where the risks were in this mission. And I wanted to make sure that we didn’t get any new risks,” he says.

IEEE Spectrum

Besides, K a-band frequencies can transmit more data than X-band (7 to 11.2 GHz) or S-band (2 to 4 GHz), common choices for craft in deep space. A high data rate is a necessity for the scientific work JWST will be undertaking. In addition, according to Carl Hansen, a flight systems engineer at the Space Telescope Science Institute (the science operations center for JWST), a comparable X-band antenna would be so large that the spacecraft would have trouble remaining steady for imaging.

Although the 25.9-GHz K a-band frequency is the telescope’s workhorse communication channel, it also employs two channels in the S-band. One is the 2.09-GHz uplink that ferries future transmission and scientific observation schedules to the telescope at 16 kilobits per second. The other is the 2.27-GHz, 40-kb/s downlink over which the telescope transmits engineering data—including its operational status, systems health, and other information concerning the telescope’s day-to-day activities.

Any scientific data the JWST collects during its lifetime will need to be stored on board, because the spacecraft doesn’t maintain round-the-clock contact with Earth. Data gathered from its scientific instruments, once collected, is stored within the spacecraft’s 68-GB solid-state drive (3 percent is reserved for engineering and telemetry data). Alex Hunter, also a flight systems engineer at the Space Telescope Science Institute, says that by the end of JWST’s 10-year mission life, they expect to be down to about 60 GB because of deep-space radiation and wear and tear.

The onboard storage is enough to collect data for about 24 hours before it runs out of room. Well before that becomes an issue, JWST will have scheduled opportunities to beam that invaluable data to Earth.

JWST will stay connected via the Deep Space Network (DSN)—a resource it shares with the Parker Solar Probe, Transiting Exoplanet Survey Satellite, the Voyager probes, and the entire ensemble of Mars rovers and orbiters, to name just a few of the other heavyweights. The DSN consists of three antenna complexes: Canberra, Australia; Madrid, Spain; and Barstow, Calif. JWST needs to share finite antenna time with plenty of other deep-space missions, each with unique communications needs and schedules.

IEEE Spectrum

Sandy Kwan, a DSN systems engineer, says that contact windows with spacecraft are scheduled 12 to 20 weeks in advance. JWST had a greater number of scheduled contact windows during its commissioning phase, as instruments were brought on line, checked, and calibrated. Most of that process required real-time communication with Earth.

All of the communications channels use the Reed-Solomon error-correction protocol—the same error-correction standard as used in DVDs and Blu-ray discs as well as QR codes. The lower data-rate S-band channels use binary phase-shift key modulation—involving phase shifting of a signal’s carrier wave. The K-band channel, however, uses a quadrature phase-shift key modulation. Quadrature phase-shift keying can double a channel’s data rate, at the cost of more complicated transmitters and receivers.

JWST’s communications with Earth incorporate an acknowledgement protocol—only after the JWST gets confirmation that a file has been successfully received will it go ahead and delete its copy of the data to clear up space.

The communications subsystem was assembled along with the rest of the spacecraft bus by Northrop Grumman, using off-the-shelf components sourced from multiple manufacturers.

JWST has had a long and often-delayed development, but its communications system has always been a bedrock for the rest of the project. Keeping at least one system dependable means it’s one less thing to worry about. Menzel can remember, for instance, ideas for laser-based optical systems that were invariably rejected. “I can count at least two times where I had been approached by people who wanted to experiment with optical communications,” says Menzel. “Each time they came to me, I sent them away with the old ‘Thank you, but I don’t need it. And I don’t want it.’”


Match ID: 18 Score: 5.00 source: spectrum.ieee.org age: 32 days
qualifiers: 5.00 travel(|ing)

Lochs, camera, action: a tour of Scotland’s stunning film and TV locations
Fri, 01 Jul 2022 12:22:39 GMT

Scotland’s cinematic landscapes and historic cities have provided the backdrop for countless on-screen tales – and there’s no better way to celebrate its Year of Stories 2022 than to take a tour round these real-life locations

Scotland has long been a source of inspiration for film-makers around the world, who look to the country’s immense landscapes and unique history to aid their storytelling. Whether it’s tales of love and romance or epic battles based on actual events, Scotland has played a central role in numerous productions on both the big and small screen.

One of the most popular settings for film-making that places emphasis on stunning scenic shots is the Scottish Highlands, which will likely bring to mind a range of characters including Thomasina the cat, William Wallace in Braveheart, Harry Potter and even James Bond. The Jacobite steam train, which travels from Fort William to Mallaig along the West Highland line, plays a starring role as the Hogwarts Express in all eight Harry Potter films, thanks to the now iconic shots of the magical train crossing the stunning Glenfinnan viaduct. Meanwhile, Sam Mendes’s Skyfall has 007 returning to his Scottish roots, with much of the action taking place in Glencoe, where Bond grew up. Scenes from the film were shot in dramatic locations such as Glen Etive, near the peaks of Buachaille Etive Mor and Buachaille Etive Beag.

Continue reading...
Match ID: 19 Score: 5.00 source: www.theguardian.com age: 39 days
qualifiers: 5.00 travel(|ing)

Defending the Amazon: retracing Dom Phillips and Bruno Pereira's fatal journey - video
Fri, 01 Jul 2022 07:32:11 GMT

Organized crime in the remote Javari valley region of the Amazon is rampant. Drug trafficking, illegal fishing, mining and logging now go by almost unchecked, making it a frontline in the war on nature. It is this violence that cost journalist Dom Phillips and Indigeneous activist Bruno Pereira their lives. The Guardian's Oliver Laughland travels to the small riverside town of Atalaia do Norte, to retrace part of the journey Dom and Bruno took before they were killed.

Continue reading...
Match ID: 20 Score: 5.00 source: www.theguardian.com age: 39 days
qualifiers: 5.00 travel(|ing)

Pentagon Aims to Demo a Nuclear Spacecraft Within 5 Years
Thu, 09 Jun 2022 16:44:41 +0000


In the latest push for nuclear power in space, the Pentagon’s Defense Innovation Unit (DIU) awarded a contract in May to Seattle-based Ultra Safe Nuclear to advance its nuclear power and propulsion concepts. The company is making a soccer ball–size radioisotope battery it calls EmberCore. The DIU’s goal is to launch the technology into space for demonstration in 2027.

Ultra Safe Nuclear’s system is intended to be lightweight, scalable, and usable as both a propulsion source and a power source. It will be specifically designed to give small-to-medium-size military spacecraft the ability to maneuver nimbly in the space between Earth orbit and the moon. The DIU effort is part of the U.S. military’s recently announced plans to develop a surveillance network in cislunar space.

Besides speedy space maneuvers, the DIU wants to power sensors and communication systems without having to worry about solar panels pointing in the right direction or batteries having enough charge to work at night, says Adam Schilffarth, director of strategy at Ultra Safe Nuclear. “Right now, if you are trying to take radar imagery in Ukraine through cloudy skies,” he says, “current platforms can only take a very short image because they draw so much power.”

Radioisotope power sources are well suited for small, uncrewed spacecraft, adds Christopher Morrison, who is leading EmberCore’s development. Such sources rely on the radioactive decay of an element that produces energy, as opposed to nuclear fission, which involves splitting atomic nuclei in a controlled chain reaction to release energy. Heat produced by radioactive decay is converted into electricity using thermoelectric devices.

Radioisotopes have provided heat and electricity for spacecraft since 1961. The Curiosity and Perseverance rovers on Mars, and deep-space missions including Cassini, New Horizons, and Voyager all use radioisotope batteries that rely on the decay of plutonium-238, which is nonfissile—unlike plutonium-239, which is used in weapons and power reactors.

For EmberCore, Ultra Safe Nuclear has instead turned to medical isotopes such as cobalt-60 that are easier and cheaper to produce. The materials start out inert, and have to be charged with neutrons to become radioactive. The company encapsulates the material in a proprietary ceramic for safety.

Cobalt-60 has a half-life of five years (compared to plutonium-238’s 90 years), which is enough for the cislunar missions that the DOD and NASA are looking at, Morrison says. He says that EmberCore should be able to provide 10 times as much power as a plutonium-238 system, providing over 1 million kilowatt-hours of energy using just a few pounds of fuel. “This is a technology that is in many ways commercially viable and potentially more scalable than plutonium-238,” he says.

One downside of the medical isotopes is that they can produce high-energy X-rays in addition to heat. So Ultra Safe Nuclear wraps the fuel with a radiation-absorbing metal shield. But in the future, the EmberCore system could be designed for scientists to use the X-rays for experiments. “They buy this heater and get an X-ray source for free,” says Schilffarth. “We’ve talked with scientists who right now have to haul pieces of lunar or Martian regolith up to their sensor because the X-ray source is so weak. Now we’re talking about a spotlight that could shine down to do science from a distance.”

Ultra Safe Nuclear’s contract is one of two awarded by the DIU—which aims to speed up the deployment of commercial technology through military use—to develop nuclear power and propulsion for spacecraft. The other contract was awarded to Avalanche Energy, which is making a lunchbox-size fusion device it calls an Orbitron. The device will use electrostatic fields to trap high-speed ions in slowly changing orbits around a negatively charged cathode. Collisions between the ions can result in fusion reactions that produce energetic particles.

Both companies will use nuclear energy to power high-efficiency electric propulsion systems. Electric propulsion technologies such as ion thrusters, which use electromagnetic fields to accelerate ions and generate thrust, are more efficient than chemical rockets, which burn fuel. Solar panels typically power the ion thrusters that satellites use today to change their position and orientation. Schilffarth says that the higher power from EmberCore should give a greater velocity change of 10 kilometers per second in orbit than today’s electric propulsion systems.

Ultra Safe Nuclear is also one of three companies developing nuclear fission thermal propulsion systems for NASA and the Department of Energy. Meanwhile, the Defense Advanced Research Projects Agency (DARPA) is seeking companies to develop a fission-based nuclear thermal rocket engine, with demonstrations expected in 2026.

This article appears in the August 2022 print issue as “Spacecraft to Run on Radioactive Decay.”


Match ID: 21 Score: 5.00 source: spectrum.ieee.org age: 61 days
qualifiers: 5.00 travel(|ing)

NASA Leadership to Advocate for Agency Missions at ESA Council Meeting
Wed, 08 Jun 2022 13:33 EDT
NASA Administrator Bill Nelson and Deputy Administrator Pam Melroy will travel to Noordwijk, Netherlands, to participate in the ESA (European Space Agency) Council Meeting on Wednesday, June 15.
Match ID: 22 Score: 5.00 source: www.nasa.gov age: 62 days
qualifiers: 5.00 travel(|ing)

How Flyback Rocket Boosters Got Off the Ground
Mon, 21 Mar 2022 20:27:59 +0000


In the popular conception of a technological breakthrough, a flash of genius is followed quickly by commercial or industrial success, public acclaim, and substantial wealth for a small group of inventors and backers. In the real world, it almost never works out that way.

Advances that seem to appear suddenly are often backed by decades of development. Consider steam engines. Starting in the second quarter of the 19th century they began powering trains, and they soon revolutionized the transportation of people and goods. But steam engines themselves had been invented at the beginning of the 18th century. For 125 years they had been used to pump water out of mines and then to power the mills of the Industrial Revolution.


Lately we’ve become accustomed to seeing rocket boosters return to Earth and then land vertically, on their tails, ready to be serviced and flown again. (Much the same majestic imagery thrilled sci-fi moviegoers in the 1950s.) Today, both SpaceX and Blue Origin are using these techniques, and a third startup, Relativity Space, is on the verge of joining them. Such reusable rocketry is already cutting the cost of access to space and, with other advances yet to come, will help make it possible for humanity to return to the moon and eventually to travel to Mars.

Vertical landings, too, have a long history, with the same ground being plowed many times by multiple research organizations. From 1993 to 1996 a booster named DCX, for Delta Clipper Experimental, took off and landed vertically eight times at White Sands Missile Range. It flew to a height of only 2,500 meters, but it successfully negotiated the very tricky dynamics of landing a vertical cylinder on its end.

The key innovations that made all this possible happened 50 or more years ago. And those in turn built upon the invention a century ago of liquid-fueled rockets that can be throttled up or down by pumping more or less fuel into a combustion chamber.

In August 1954 the Rolls-Royce Thrust Measuring Rig, also known as the “flying bedstead,” took off and landed vertically while carrying a pilot. The ungainly contraption had two downward-pointing Rolls-Royce jet engines with nozzles that allowed the pilot to vector the thrust and control the flight. By 1957 another company, Hawker Siddeley, started work on turning this idea into a vertical take-off and landing (VTOL) fighter jet. It first flew in 1967 and entered service in 1969 as the Harrier Jump Jet, with new Rolls-Royce engines specifically designed for thrust vectoring. Thrust vectoring is a critical component of control for all of today’s reusable rocket boosters.

During the 1960s another rig, also nicknamed the flying bedstead, was developed in the United States for training astronauts to land on the moon. There was a gimbaled rocket engine that always pointed directly downward, providing thrust equal to five-sixths of the vehicle and the pilot’s weight, simulating lunar gravity. The pilot then controlled the thrust and direction of another rocket engine to land the vehicle safely.

It was not all smooth flying. Neil Armstrong first flew the trainer in March 1967, but he was nearly killed in May 1968 when things went awry and he had to use the ejection seat to rocket to safety. The parachute deployed and he hit the ground just 4 seconds later. Rocket-powered vertical descent was harder than it looked.

Vertical rocket landings have a long history, with the same ground being plowed many times by multiple research organizations.

Nevertheless, between 1969 and 1972, Armstrong and then five other astronauts piloted lunar modules to vertical landings on the moon. There were no ejection seats, and these have been the only crewed rocket-powered landings on a spaceflight. All other humans lofted into space have used Earth’s atmosphere to slow down, combining heat shields with either wings or parachutes.

In the early days of Blue Origin, the company returned to the flying-bedstead approach, and its vehicle took off and landed successfully in March 2005. It was powered by four jet engines, once again from Rolls-Royce, bought secondhand from the South African Air Force. Ten years later, in November 2015, Blue Origin’s New Shepard booster reached an altitude of 100 kilometers and then landed vertically. A month later SpaceX had its first successful vertical landing of a Falcon-9 booster.

Today’s reusable, or flyback, boosters also use something called grid fins, those honeycombed panels sticking out perpendicularly from the top of a booster that guide the massive cylinder as it falls through the atmosphere unpowered. The fins have an even longer history, as they have been part of every crewed Soyuz launch since the 1960s. They guide the capsule back to Earth if there’s an abort during the climb to orbit. They were last used in October 2018 when a Soyuz failed at 50 km up. The cosmonaut and astronaut who were aboard landed safely and had a successful launch in another Soyuz five months later.

The next big accomplishment will be crewed vertical landings, 50 years after mankind's last one, on the moon. It will almost certainly happen before this decade is out.

I’m less confident that we’ll see general-purpose quantum computers and abundant electricity from nuclear fusion in that time frame. But I’m pretty sure we’ll eventually get there with both. The arc of technology development is often long. And sometimes, the longer it is, the more revolutionary it is in the end.

This article appears in the April 2022 print issue as “The Long Road to Overnight Success .”


Match ID: 23 Score: 5.00 source: spectrum.ieee.org age: 141 days
qualifiers: 5.00 travel(|ing)

To Catch a Falling Satellite
Mon, 14 Mar 2022 16:55:14 +0000


It is the fate of many a dead satellite to spend its last years tumbling out of control. A fuel line may burst, or solar wind may surge, or there may be drag from the outer reaches of the atmosphere—and unless a spacecraft has been designed in some way that keeps it naturally stable, chances are good that it will begin to turn end over end.

That’s a problem, because Earth orbit is getting more and more crowded. Engineers would like to corral old pieces of space junk, but they can’t safely reach them, especially if they’re unstable. The European Space Agency says there are about 30,000 “debris objects” now being tracked in Earth orbit—derelict satellites, spent rocket stages, pieces sent flying from collisions in space. There may also be 900,000 smaller bits of orbital debris—everything from loose bolts to flecks of paint to shards of insulation. They may be less than 10 centimeters long, but they can still destroy a healthy satellite if they hit at orbital speeds.

“With more satellites being launched, we might encounter more situations where we have a defunct satellite that’s occupying a valuable orbit,” says Richard Linares, an assistant professor of aeronautics and astronautics at MIT. He’s part of an American-German project, called TumbleDock/ROAM, researching ways to corral and stabilize tumbling satellites so they can be deorbited or, in some cases, perhaps even refueled or repaired.

Engineers have put up with orbital debris for decades, but Linares says the picture is changing. For one thing, satellite technology is becoming more and more affordable—just look at SpaceX, which has been launching 40 satellites a week so far this year. For another, he says, the economic benefits those satellites offer—high-speed internet, GPS, climate and crop monitoring and other applications—will be threatened if the risk of impacts keeps growing.

“I think in the next few years we’ll have the technology to do something about space debris,” says Linares. “And there are economic drivers that will incentivize companies to do this.”

The TumbleDock/ROAM team has just finished a series of tests in the cabin of the International Space Station, using NASA robots called Astrobees to stand in for a tumbling satellite and a “chaser” spacecraft sent to catch it. The goal: to figure out algorithms so that a chaser can find its target, determine its tumble rates, and calculate the safest and most efficient approach to it.

Astrobee robot experiment aboard the ISS to reach a tumbling target in space. www.youtube.com

“There’s a massive amount of large debris out there,” says Keenan Albee, a Ph.D. student on the team at MIT. “Look at some of them, with large solar panels that are ready to whack you if you don’t do the approach correctly.”

The researchers decided early on that a chase vehicle needs enough autonomy to close in on a disabled satellite on its own. Even the largest satellites are too distant for ground-based tracking stations to track their attitude with any precision. A chaser, perhaps equipped with navigation cameras, lidar, and other sensors, will need to do the job in real time.

“The tumbling motion of a satellite can be quite complex,” says Roberto Lampariello, the principal investigator on the project at the German Aerospace Center, or DLR. “And if you want to be sure you are not going to collide with any appendages while approaching the mating point, having an autonomous method of guidance is, I think, very attractive.”

The Astrobee tests on the space station showed that it can be done, at least in principle. Each Astrobee robot is a cube, about 30 centimeters on a side, with navigation cameras, compressed-air thrusters, and Snapdragon processors much like what you would find in a smartphone. For the latest test, last month, NASA astronaut Mark Vande Hei set up two Astrobees a couple of meters apart. They then took their commands from Albee on the ground. He started the test runs, with one robot tumbling and the other trying to rendezvous with it. There have been glitches; the Astrobees needed help determining their precise location relative to the station walls. But the results of the tests were promising.

A next step, say the researchers, is to determine how best for a chase spacecraft to grapple its target, which is especially difficult if it’s a piece of debris with no docking mechanism. Other plans over the years have involved big nets or lasers; TumbleDock/ROAM team members say they’re intrigued by grippers that use van der Waals forces between atoms, the kinds that help a gecko cling to a sheer surface.

The larger question is how to turn experiments like these into actual solutions to a growing, if lofty, problem. Low Earth orbit has been crowded enough, for long enough, that satellite makers add shielding to their vehicles and space agencies continuously scan the skies to prevent close calls. No space travelers have been killed, and there have only been a few cases in which satellites were actually pulverized. But the problem has become increasingly expensive and, in some cases, dangerous. SpaceX has launched 2,000 Starlink Internet satellites so far, may launch 30,000 more, and has other companies (like Amazon) racing to keep up. They see profits up there.

MIT’s Linares says that, in fact, is why it’s worth figuring out the space-junk problem. “There’s a reason why those orbits are valuable,” he says. Companies may spend billions to launch new satellites—and don’t want them threatened by old satellites.

“If your company’s benefiting from an orbit band,” he says, “then you’d probably better get someone to clean it up for you.”


Match ID: 24 Score: 5.00 source: spectrum.ieee.org age: 148 days
qualifiers: 5.00 travel(|ing)

Satellite Imagery for Everyone
Sat, 19 Feb 2022 16:00:00 +0000


Every day, satellites circling overhead capture trillions of pixels of high-resolution imagery of the surface below. In the past, this kind of information was mostly reserved for specialists in government or the military. But these days, almost anyone can use it.

That’s because the cost of sending payloads, including imaging satellites, into orbit has dropped drastically. High-resolution satellite images, which used to cost tens of thousands of dollars, now can be had for the price of a cup of coffee.

What’s more, with the recent advances in artificial intelligence, companies can more easily extract the information they need from huge digital data sets, including ones composed of satellite images. Using such images to make business decisions on the fly might seem like science fiction, but it is already happening within some industries.


This image shows are variety of blue and green hues, interwoven in a geometrically intriguing way.

These underwater sand dunes adorn the seafloor between Andros Island and the Exuma islands in the Bahamas. The turquoise to the right reflects a shallow carbonate bank, while the dark blue to the left marks the edge of a local deep called Tongue of the Ocean. This image was captured in April 2020 using the Moderate Resolution Imaging Spectroradiometer on NASA’s Terra satellite.

Joshua Stevens/NASA Earth Observatory


Here’s a brief overview of how you, too, can access this kind of information and use it to your advantage. But before you’ll be able to do that effectively, you need to learn a little about how modern satellite imagery works.

The orbits of Earth-observation satellites generally fall into one of two categories: GEO and LEO. The former is shorthand for geosynchronous equatorial orbit. GEO satellites are positioned roughly 36,000 kilometers above the equator, where they circle in sync with Earth’s rotation. Viewed from the ground, these satellites appear to be stationary, in the sense that their bearing and elevation remain constant. That’s why GEO is said to be a geostationary orbit.

Such orbits are, of course, great for communications relays—it’s what allows people to mount satellite-TV dishes on their houses in a fixed orientation. But GEO satellites are also appropriate when you want to monitor some region of Earth by capturing images over time. Because the satellites are so high up, the resolution of that imagery is quite coarse, however. So these orbits are primarily used for observation satellites designed to track changing weather conditions over broad areas.

Being stationary with respect to Earth means that GEO satellites are always within range of a downlink station, so they can send data back to Earth in minutes. This allows them to alert people to changes in weather patterns almost in real time. Most of this kind of data is made available for free by the U.S. National Oceanographic and Atmospheric Administration.


This black-and-white image shows a narrow waterway blocked by a large ship. The resolution of the image is sufficient to make out individual shipping containers on its deck, as well as the tugboats arrayed around it.

In March 2021, the container ship Ever Given ran aground, blocking the Suez Canal for six days. This satellite image of the scene, obtained using synthetic-aperture radar, shows the kind resolution that is possible with this technology.

Capella Space


The other option is LEO, which stands for low Earth orbit. Satellites placed in LEO are much closer to the ground, which allows them to obtain higher-resolution images. And the lower you can go, the better the resolution you can get. The company Planet, for example, increased the resolution of its recently completed satellite constellation, SkySat, from 72 centimeters per pixel to just 50 cm—an incredible feat—by lowering the orbits its satellites follow from 500 to 450 km and improving the image processing.

The best commercially available spatial resolution for optical imagery is 25 cm, which means that one pixel represents a 25-by-25-cm area on the ground—roughly the size of your laptop. A handful of companies capture data with 25-cm to 1-meter resolution, which is considered high to very high resolution in this industry. Some of these companies also offer data from 1- to 5-meter resolution, considered medium to high resolution. Finally, several government programs have made optical data available at 10-, 15-, 30-, and 250-meter resolutions for free with open data programs. These include NASA/U.S. Geological Survey Landsat, NASA MODIS (Moderate Resolution Imaging Spectroradiometer), and ESA Copernicus. This imagery is considered low resolution.

Because the satellites that provide the highest-resolution images are in the lowest orbits, they sense less area at once. To cover the entire planet, a satellite can be placed in a polar orbit, which takes it from pole to pole. As it travels, Earth rotates under it, so on its next pass, it will be above a different part of Earth.

Many of these satellites don’t pass directly over the poles, though. Instead, they are placed in a near-polar orbit that has been specially designed to take advantage of a subtle bit of physics. You see, the spinning Earth bulges outward slightly at the equator. That extra mass causes the orbits of satellites that are not in polar orbits to shift or (technically speaking) to precess. Satellite operators often take advantage of this phenomenon to put a satellite in what’s called a sun-synchronous orbit. Such orbits allow the repeated passes of the satellite over a given spot to take place at the same time of day. Not having the pattern of shadows shift between passes helps the people using these images to detect changes.




It usually takes 24 hours for a satellite in polar orbit to survey the entire surface of Earth. To image the whole world more frequently, satellite companies use multiple satellites, all equipped with the same sensor and following different orbits. In this way, these companies can provide more frequently updated images of a given location. For example, Maxar’s Worldview Legion constellation, launching later this year, includes six satellites.

After a satellite captures some number of images, all that data needs to be sent down to Earth and processed. The time required for that varies.

DigitalGlobe (which Maxar acquired in 2017) recently announced that it had managed to send data from a satellite down to a ground station and then store it in the cloud in less than a minute. That was possible because the image sent back was of the parking lot of the ground station, so the satellite didn’t have to travel between the collection point and where it had to be to do the data “dumping,” as this process is called.

In general, Earth-observation satellites in LEO don’t capture imagery all the time—they do that only when they are above an area of special interest. That’s because these satellites are limited to how much data they can send at one time. Typically, they can transmit data for only 10 minutes or so before they get out of range of a ground station. And they cannot record more data than they’ll have time to dump.

Currently, ground stations are located mostly near the poles, the most visited areas in polar orbits. But we can soon expect distances to the nearest ground station to shorten because both Amazon and Microsoft have announced intentions to build large networks of ground stations located all over the world. As it turns out, hosting the terabytes of satellite data that are collected daily is big business for these companies, which sell their cloud services (Amazon Web Services and Microsoft’s Azure) to satellite operators.

For now, if you are looking for imagery of an area far from a ground station, expect a significant delay—maybe hours—between capture and transmission of the data. The data will then have to be processed, which adds yet more time. The fastest providers currently make their data available within 48 hours of capture, but not all can manage that. While it is possible, under ideal weather conditions, for a commercial entity to request a new capture and get the data it needs delivered the same week, such quick turnaround times are still considered cutting edge.


The best commercially available spatial resolution is 25 centimeters for optical imagery, which means that one pixel represents something roughly the size of your laptop.


I’ve been using the word “imagery,” but it’s important to note that satellites do not capture images the same way ordinary cameras do. The optical sensors in satellites are calibrated to measure reflectance over specific bands of the electromagnetic spectrum. This could mean they record how much red, green, and blue light is reflected from different parts of the ground. The satellite operator will then apply a variety of adjustments to correct colors, combine adjacent images, and account for parallax, forming what’s called a true-color composite image, which looks pretty much like what you would expect to get from a good camera floating high in the sky and pointed directly down.

Imaging satellites can also capture data outside of the visible-light spectrum. The near-infrared band is widely used in agriculture, for example, because these images help farmers gauge the health of their crops. This band can also be used to detect soil moisture and a variety of other ground features that would otherwise be hard to determine.

Longer-wavelength “thermal” IR does a good job of penetrating smoke and picking up heat sources, making it useful for wildfire monitoring. And synthetic-aperture radar satellites, which I discuss in greater detail below, are becoming more common because the images they produce aren’t affected by clouds and don’t require the sun for illumination.

You might wonder whether aerial imagery, say, from a drone, wouldn’t work at least as well as satellite data. Sometimes it can. But for many situations, using satellites is the better strategy. Satellites can capture imagery over areas that would be difficult to access otherwise because of their remoteness, for example. Or there could be other sorts of accessibility issues: The area of interest could be in a conflict zone, on private land, or in another place that planes or drones cannot overfly.

So with satellites, organizations can easily monitor the changes taking place at various far-flung locations. Satellite imagery allows pipeline operators, for instance, to quickly identify incursions into their right-of-way zones. The company can then take steps to prevent a disastrous incident, such as someone puncturing a gas pipeline while construction is taking place nearby.


\u200bThis satellite image shows a snow-covered area. A tongue of darker material is draped over the side of a slope, impinging on a nearby developed area with buildings.

This SkySat image shows the effect of a devastating landslide that took place on 30 December 2020. Debris from that landslide destroyed buildings and killed 10 people in the Norwegian village of Ask.

SkySat/Planet



The ability to compare archived imagery with recently acquired data has helped a variety of industries. For example, insurance companies sometimes use satellite data to detect fraudulent claims (“Looks like your house had a damaged roof when you bought it…”). And financial-investment firms use satellite imagery to evaluate such things as retailers’ future profits based on parking-lot fullness or to predict crop prices before farmers report their yields for the season.

Satellite imagery provides a particularly useful way to find or monitor the location of undisclosed features or activities. Sarah Parcak of the University of Alabama, for example, uses satellite imagery to locate archaeological sites of interest. 52Impact, a consulting company in the Netherlands, identified undisclosed waste dump sites by training an algorithm to recognize their telltale spectral signature. Satellite imagery has also helped identify illegal fishing activities, fight human trafficking, monitor oil spills, get accurate reporting on COVID-19 deaths, and even investigate Uyghur internment camps in China—all situations where the primary actors couldn’t be trusted to accurately report what’s going on.

Despite these many successes, investigative reporters and nongovernmental organizations aren’t yet using satellite data regularly, perhaps because even the small cost of the imagery is a deterrent. Thankfully, some kinds of low-resolution satellite data can be had for free.

The first place to look for free satellite imagery is the Copernicus Open Access Hub and EarthExplorer. Both offer free access to a wide range of open data. The imagery is lower resolution than what you can purchase, but if the limited resolution meets your needs, why spend money?

If you require medium- or high-resolution data, you might be able to buy it directly from the relevant satellite operator. This field recently went through a period of mergers and acquisitions, leaving only a handful of providers, the big three in the West being Maxar and Planet in the United States and Airbus in Germany. There are also a few large Asian providers, such as SI Imaging Services in South Korea and Twenty First Century Aerospace Technology in Singapore. Most providers have a commercial branch, but they primarily target government buyers. And they often require large minimum purchases, which is unhelpful to companies looking to monitor hundreds of locations or fewer.

Expect the distance to the nearest ground station to shorten because both Amazon and Microsoft have announced intentions to build large networks of ground stations located all over the world.

Fortunately, approaching a satellite operator isn’t the only option. In the past five years, a cottage industry of consultants and local resellers with exclusive deals to service a certain market has sprung up. Aggregators and resellers spend years negotiating contracts with multiple providers so they can offer customers access to data sets at more attractive prices, sometimes for as little as a few dollars per image. Some companies providing geographic information systems—including Esri, L3Harris, and Safe Software—have also negotiated reselling agreements with satellite-image providers.

Traditional resellers are middlemen who will connect you with a salesperson to discuss your needs, obtain quotes from providers on your behalf, and negotiate pricing and priority schedules for image capture and sometimes also for the processing of the data. This is the case for Apollo Mapping, European Space Imaging, Geocento, LandInfo, Satellite Imaging Corp., and many more. The more innovative resellers will give you access to digital platforms where you can check whether an image you need is available from a certain archive and then order it. Examples include LandViewer from EOS and Image Hunter from Apollo Mapping.

More recently, a new crop of aggregators began offering customers the ability to programmatically access Earth-observation data sets. These companies work best for people looking to integrate such data into their own applications or workflows. These include the company I work for, SkyWatch, which provides such a service, called EarthCache. Other examples are UP42 from Airbus and Sentinel Hub from Sinergise.

While you will still need to talk with a sales rep to activate your account—most often to verify you will use the data in ways that fits the company’s terms of service and licensing agreements—once you’ve been granted access to their applications, you will be able to programmatically order archive data from one or multiple providers. SkyWatch is, however, the only aggregator allowing users to programmatically request future data to be collected (“tasking a satellite”).

While satellite imagery is fantastically abundant and easy to access today, two changes are afoot that will expand further what you can do with satellite data: faster revisits and greater use of synthetic-aperture radar (SAR).

This image shows a sprawling compound of dozens of large buildings located in a desert area.

This image shows a race-track shaped structure with a tall chimney in the middle, built in an area where the ground is a distinctly reddish hue. Satellite images have helped to reveal China’s treatment of its Muslim Uyghur minority. About a million Uyghurs (and other ethnic minorities) have been interned in prisons or camps like the one shown here [top], which lies to the east of the city of Ürümqi, the capital of China’s Xinjiang Uyghur Autonomous Region. Another satellite image [bottom] shows the characteristic oval shape of a fixed-chimney Bull’s trench kiln, a type widely used for manufacturing bricks in southern Asia. This one is located in Pakistan’s Punjab province. This design poses environmental concerns because of the sooty air pollution it generates, and such kilns have also been associated with human-rights abuses.Top: CNES/Airbus/Google Earth; Bottom: Maxar Technologies/Google Earth

The first of these developments is not surprising. As more Earth-observation satellites are put into orbit, more images will be taken, more often. So how frequently a given area is imaged by a satellite will increase. Right now, that’s typically two or three times a week. Expect the revisit rate soon to become several times a day. This won’t entirely address the challenge of clouds obscuring what you want to view, but it will help.

The second development is more subtle. Data from the two satellites of the European Space Agency’s Sentinel-1 SAR mission, available at no cost, has enabled companies to dabble in SAR over the last few years.

With SAR, the satellite beams radio waves down and measures the return signals bouncing off the surface. It does that continually, and clever processing is used to turn that data into images. The use of radio allows these satellites to see through clouds and to collect measurements day and night. Depending on the radar band that’s employed, SAR imagery can be used to judge material properties, moisture content, precise movements, and elevation.

As more companies get familiar with such data sets, there will no doubt be a growing demand for satellite SAR imagery, which has been widely used by the military since the 1970s. But it’s just now starting to appear in commercial products. You can expect those offerings to grow dramatically, though.

Indeed, a large portion of the money being invested in this industry is currently going to fund large SAR constellations, including those of Capella Space, Iceye, Synspective, XpressSAR, and others. The market is going to get crowded fast, which is great news for customers. It means they will be able to obtain high-resolution SAR images of the place they’re interested in, taken every hour (or less), day or night, cloudy or clear.

People will no doubt figure out wonderful new ways to employ this information, so the more folks who have access to it, the better. This is something my colleagues at SkyWatch and I deeply believe, and it’s why we’ve made it our mission to help democratize access to satellite imagery.

One day in the not-so-distant future, Earth-observation satellite data might become as ubiquitous as GPS, another satellite technology first used only by the military. Imagine, for example, being able to take out your phone and say something like, “Show me this morning’s soil-moisture map for Grover’s Corners High; I want to see whether the baseball fields are still soggy.”

This article appears in the March 2022 print issue as “A Boom with a View.”

Editor's note: The original version of this article incorrectly stated that Maxar's Worldview Legion constellation launched last year.


Match ID: 25 Score: 5.00 source: spectrum.ieee.org age: 171 days
qualifiers: 5.00 travel(|ing)

Following the Money in the Air-Taxi Craze
Tue, 08 Feb 2022 15:04:00 +0000


When entrepreneur JoeBen Bevirt launched Joby Aviation 12 years ago, it was just one of a slew of offbeat tech projects at his Sproutwerx ranch in the Santa Cruz mountains. Today, Joby has more than 1,000 employees and it’s backed by close to US $2 billion in investments, including $400 million from Toyota Motor Corporation along with big infusions from Uber and JetBlue.

Having raked in perhaps 30 percent of all the money invested in electrically-powered vertical takeoff and landing (eVTOL) aircraft so far, Joby is the colossus in an emerging class of startups working on these radical, battery-powered commercial flyers. All told, at least 250 companies worldwide are angling to revolutionize transportation in and around cities with a new category of aviation, called urban air mobility or advanced air mobility. With Joby at the apex, the category’s top seven companies together have hauled in more than $5 billion in funding—a figure that doesn’t include private firms, whose finances haven’t been disclosed.

But with some of these companies pledging to start commercial operations in 2024, there is no clear answer to a fundamental question: Are we on the verge of a stunning revolution in urban transportation, or are we witnessing, as aviation analyst Richard Aboulafia puts it, the “mother of all aerospace bubbles”?

Even by the standards of big-money tech investment, the vision is giddily audacious. During rush hour, the skies over a large city, such as Dubai or Madrid or Los Angeles, would swarm with hundreds, and eventually thousands, of eVTOL “air taxis.” Each would seat between one and perhaps half a dozen passengers, and would, eventually, be autonomous. Hailing a ride would be no more complicated than scheduling a trip on a ride-sharing app.

“We’re going to have to get the consumer used to thinking about flying in a small aircraft without a pilot on board. I have reservations about the general public’s willingness to accept that vision.”
—Laurie Garrow, Georgia Tech

And somehow, the cost would be no greater, either. In a discussion hosted by the Washington Post last July, Bevirt declared, “Our initial price point would be comparable to the cost of a taxi or an Uber, but our target is to move quickly down to the cost of what it costs you to drive your own car. And we believe that's the critical unlock to making this transformative to the world and for people’s daily lives.” Asked to put some dollar figures on his projection, Bevirt said, “Our goal is to launch this service [in 2024] at an average price of around $3 a mile and to move that down below $1 a mile over time.” The cost of an Uber varies by city and time of day, but it’s usually between $1 and $2 per mile, not including fees.

Industry analysts tend to have more restrained expectations. With the notable exception of China, they suggest, limited commercial flights will begin with eVTOL aircraft flown by human pilots, a phase that is expected to last six to eight years at least. Costs will be similar to those of helicopter trips, which tend to be in the range of $6 to $10 per mile or more. Of the 250+ startups in the field, only three—Kittyhawk, Wisk Aero (a joint venture of Kittyhawk and Boeing), and Ehang—plan to go straight to full autonomy without a preliminary phase involving pilots, says Chris Anderson, Chief Operating Officer at Kittyhawk.

To some, the autonomy issue is the heart of whether this entire enterprise can succeed economically. “When you figure in autonomy, you go from $3 a mile to 50 cents a mile,” says Anderson, citing studies done by his company. “You can’t do that with a pilot in the seat.”

Laurie A. Garrow, a professor at the Georgia Institute of Technology, agrees. “For the large-scale vision, autonomy will be critical,” she says. “In order to get to the vision that people have, where this is a ubiquitous mode of transportation with a high market share, the only way to get that is by… eliminating the pilot.” Garrow, a civil engineer who co-directs the university’s Center for Urban and Regional Air Mobility, adds that autonomy presents challenges beyond technology: “We’re going to have to get the consumer used to thinking about flying in a small aircraft without a pilot on board. I have reservations about the general public’s willingness to accept that vision, especially early on.”

“The technical problems are, if not solved, then solvable. The main limiters are laws and regulations.”
—Chris Anderson, COO, Kittyhawk

Some analysts have much more fundamental doubts. Aboulafia, managing director at the consultancy AeroDynamic Advisory, says the figures simply don’t add up. eVTOL startups are counting on mass-manufacturing techniques to reduce the costs of these exotic aircraft, but such techniques have never been applied to producing aircraft on the scale specified in the projections. Even the anticipated lower operating costs, Aboulafia adds, won’t compensate. “If I started a car service here in Washington, D.C., using Rolls Royces, you’d think I was out of my mind, right?,” he asks. “But if I put batteries in those Rolls Royces, would you think I was any less crazy?”

What everyone agrees on is that achieving even a modest amount of success for eVTOLs will require surmounting entire categories of challenges, including regulations and certification, technology development, and the operational considerations of safely flying large numbers of aircraft in a small airspace.

To some, certification will be the highest hurdle. “The technical problems are, if not solved, then solvable,” says Anderson. “The main limiters are laws and regulations.”

There are dozens of aviation certification agencies in the world. But the three most important ones for these new aircraft are the Federal Aviation Administration (FAA) in the U.S., the European Union Aviation Safety Agency (EASA), and the Civil Aviation Administration of China (CAAC). Of the three, the FAA is considered the most challenging, for several reasons. One is that, to deal with eVTOLs, the agency has chosen to adapt its existing certification rules. That gives some observers pause, because the FAA does not have a body of knowledge and experience for certifying aircraft that fly by means of battery systems and electric motors. The EASA, on the other hand, has created an entirely new set of regulations tailored for eVTOL aircraft and related technology, according to Erin Rivera, senior associate for regulatory affairs at Lilium.

To clear an aircraft for commercial flight, the FAA actually requires three certifications: one for the aircraft itself, one for its operations, and one for its manufacturing. For the aircraft, the agency designates different categories, or “parts,” for different kinds of fliers. For eVTOLs (other than multicopters), the applicable category seems to be Title 14 Code of Federal Regulations, Part 23, which covers “normal, utility, acrobatic, and commuter category airplanes.” The certification process itself is performance based, meaning that the FAA establishes performance criteria that an aircraft must meet, but does not specify how it must meet them.

Because eVTOLs are so novel, the FAA is expected to lean on industry-developed standards referred to as Means of Compliance (MOC). The proposed MOCs must be acceptable to the FAA. Through a certification scheme known as the “issue paper process,” the applicant begins by submitting what’s known as a G1 proposal, which specifies the applicable certification standards and special conditions that must be met to achieve certification. The FAA reviews and then either approves or rejects the proposal. If it’s rejected, the applicant revises the proposal to address the FAA’s concerns and tries again.

“If very high levels of automation are critical to scaling, that will be very difficult to certify. How do you certify all the algorithms?”
—Matt Metcalfe, Deloitte Consulting

Some participants are wary. When he was the chief executive of drone maker 3D Robotics, Anderson participated in an analogous experiment in which the FAA had pledged to work more closely with industry to expedite certification of drone aircraft such as multicopters. “That was five years ago, and none of the drones have been certified,” Anderson points out. “It was supposed to be agile and streamlined, and it has been anything but.”

Nobody knows how many eVTOL startups have started the certification process with the FAA, although a good guess seems to be one or two dozen. Joby is furthest along in the process, according to Mark Moore, CEO of Whisper Aero, a maker of advanced electric propulsor systems in Crossville, Tenn. The G1 certification proposals are not public, but when the FAA accepts one (presumably Joby’s), it will become available through the U.S. Federal Register for public comment. Observers expect that to happen any day now.

This certification phase of piloted aircraft is fraught with unknowns because of the novelty of the eVTOL craft themselves. But experts say a greater challenge lies ahead, when manufacturers seek to certify the vehicles for autonomous flight. “If very high levels of automation are critical to scaling, that will be very difficult to certify,” says Matt Metcalfe, a managing director in Deloitte Consulting's Future of Mobility and Aviation practice. “That’s a real challenge, because it’s so complicated. How do you certify all the algorithms?”

“It’s a matter of, how do you ensure that autonomous technology is going to be as safe as a pilot?,” says an executive at one of the startups. “How do you certify that it’s always going to be able to do what it says? With true autonomous technology, the system itself can make an undetermined number of decisions, within its programming. And the way the current certification regulations work, is that they want to be able to know the inputs and outcome of every decision that the aircraft system makes. With a fully autonomous system, you can’t do that.”

Perhaps surprisingly, most experts contacted for this story agreed with Kittyhawk's Anderson that the technical challenges of building the aircraft themselves are solvable. Even autonomy—certification challenges aside—is within reach, most say. The Chinese company EHang has already offered fully autonomous, trial flights of its EH216 multicopter to tourists in the northeastern port city of Yantai and is now building a flight hub in its home city of Guangzhou. Wisk, Kittyhawk, Joby, and other companies have collectively conducted thousands of flights that were at least partially autonomous, without a pilot on board.

Experts foresee eVTOLs largely replacing helicopters for niche applications. There’s less agreement on whether middle-class people will ever be routinely whisked around cities for pennies a mile.

A more imposing challenge, and one likely to determine whether the grand vision of urban air mobility comes to pass, is whether municipal and aviation authorities can solve the challenges of integrating large numbers of eVTOLs into the airspace over major cities. Some of these challenges are, like the aircraft themselves, totally new. For example, most viable scenarios require the construction of “vertiports” in and around cities. These would be like mini airports where the eVTOLs would take off and land, be recharged, and take on and discharge passengers. Right now, it’s not clear who would pay for these. “Manufacturers probably won’t have the money to do it,” says Metcalfe at Deloitte.

As Georgia Tech's Garrow sees it, “vertiports may be one of the greatest constraints on scalability of UAM.” Vertiports, she explains, will be the “pinch points,” because at urban facilities, space will likely be limited to accommodating several aircraft at most. And yet at such a facility, room will be needed during rush hours to accommodate dozens of aircraft needing to land, be charged, take on passengers, and take off. “So the scalability of operations at the vertiports, and the amount of land space required to do that, are going to be two major challenges.”

Despite all the challenges, Garrow, Metcalfe, and others are cautiously optimistic that air mobility will eventually become part of the urban fabric in many cities. They foresee an initial period in which the eVTOLs largely replace helicopters in a few niche applications, such as linking downtown transportation depots to airports for those who can afford it, taking tourists on sightseeing tours, and transporting organs and high-risk patients among hospitals. There’s less agreement on whether middle-class people will ever be routinely whisked around cities for pennies a mile. Even some advocates think that’s more than 10 years away, if it happens at all.

If it does happen, a few studies have predicted that travel times and greenhouse-gas and pollutant emissions could all be reduced. A 2020 study published by the U.S. National Academy of Sciences found a substantial reduction in overall energy use for transportation under “optimistic” scenarios for urban air mobility. And a 2021 study at the University of California, Berkeley, found that in the San Francisco Bay area, overall travel times could be reduced with as few as 10 vertiports. The benefits went up as the number of vertiports increased and as the transfer times at the vertiports went down. But the study also warned that “vertiport scheduling and capacity may become bottlenecks that limit the value of UAM.”

Metacalfe notes that ubiquitous modern conveniences like online shopping have already unleashed tech-based revolutions on a par with the grand vision for UAM. “We tend to look at this through the lens of today,” he says. “And that may be the wrong way to look at it. Ten years ago we never would have thought we’d be getting two or three packages a day. Similarly, the way we move people and goods in the future could be very, very different from the way we do it today.”

This article appears in the March 2022 print issue as “What’s Behind the Air-Taxi Craze.”


Match ID: 26 Score: 5.00 source: spectrum.ieee.org age: 182 days
qualifiers: 5.00 travel(|ing)

Eviation’s Maiden Flight Could Usher in Electric Aviation Era
Mon, 07 Feb 2022 19:01:19 +0000


The first commercial all-electric passenger plane is just weeks away from its maiden flight, according to its maker Israeli startup Eviation. If successful, the nine-seater Alice aircraft would be the most compelling demonstration yet of the potential for battery-powered flight. But experts say there’s still a long way to go before electric aircraft makes a significant dent in the aviation industry.

The Alice is currently undergoing high-speed taxi tests at Arlington Municipal Airport close to Seattle, says Eviation CEO Omer Bar-Yohay. This involves subjecting all of the plane’s key systems and fail-safe mechanisms to a variety of different scenarios to ensure they are operating as expected before its first flight. The company is five or six good weather days away from completing those tests, says Bar-Yohay, after which the plane should be cleared for takeoff. Initial flights won’t push the aircraft to its limits, but the Alice should ultimately be capable of cruising speeds of 250 knots (463 kilometers per hour) and a maximum range of 440 nautical miles (815 kilometers).

Electric aviation has received considerable attention in recent years as the industry looks to reduce its carbon emissions. And while the Alice won’t be the first all-electric aircraft to take to the skies, Bar-Yohay says it will be the first designed with practical commercial applications in mind. Eviation plans to offer three configurations—a nine-seater commuter model, a six-seater executive model for private jet customers, and a cargo version with a capacity of 12.74 cubic meters. The company has already received advance orders from logistics giant DHL and Massachusetts-based regional airline Cape Air.

“It’s not some sort of proof-of-concept or demonstrator,” says Bar-Yohay. “It’s the first all-electric with a real-life mission, and I think that’s the big differentiator.”

Getting there has required a major engineering effort, says Bar-Yohay, because the requirements for an all-electric plane are very different from those of conventional aircraft. The biggest challenge is weight, thanks to the fact that batteries provide considerably less mileage to the pound compared to energy-dense jet fuels.

That makes slashing the weight of other components a priority and the plane features lightweight composite materials “where no composite has gone before,”’, says Bar-Yohay. The company has also done away with the bulky mechanical systems used to adjust control surfaces on the wings, and replaced them with a much lighter fly-by-wire system that uses electronic actuators controlled via electrical wires.

The company’s engineers have had to deal with a host of other complications too, from having to optimize the aerodynamics to the unique volume and weight requirements dictated by the batteries to integrating brakes designed for much heavier planes. “There is just so much optimization, so many specific things that had to be solved,” says Bar-Yohay. “In some cases, there are just no components out there that do what you need done, which weren’t built for a train, or something like that.”

Despite the huge amount of work that’s gone into it, Bar-Yohay says the Alice will be comparable in price to similar sized turboprop aircraft like the Beechcraft King Air and cheaper than small business jets like the Embraer Phenom 300. And crucially, he adds, the relative simplicity of electrical motors and actuators compared with mechanical control systems and turboprops or jets means maintenance costs will be markedly lower.

Aircraft in the sky with white clouds below it This is a conceptual rendering of Eviation's Alice, the first commercial all-electric passenger plane, in flight.Eviation

Combined with the lower cost of electricity compared to jet fuel, and even accounting for the need to replace batteries every 3,000 flight hours, Eviation expects Alice’s operating costs to be about half those of similar sized aircraft.

But there are question marks over whether the plane has an obvious market, says aviation analyst Richard Aboulafia, managing director at AeroDynamic Advisory. It’s been decades since anyone has built a regional commuter with less than 70 seats, he says, and most business jets typically require more than the 440 nautical mile range the Alice offers. Scaling up to bigger aircraft or larger ranges is also largely out of the company’s hands as it will require substantial breakthroughs in battery technology. “You need to move on to a different battery chemistry,” he says. “There isn’t even a 10-year road map to get there.”

An aircraft like the Alice isn’t meant to be a straight swap for today’s short-haul aircraft though, says Lynette Dray, a research fellow at University College London who studies the decarbonization of aviation. More likely it would be used for short intercity hops or for creating entirely new route networks better suited to its capabilities.

This is exactly what Bar-Yohay envisages, with the Alice’s reduced operating costs opening up new short-haul routes that were previously impractical or uneconomical. It could even make it feasible to replace larger jets with several smaller ones, he says, allowing you to provide more granular regional travel by making use of the thousands of runways around the country currently used only for recreational aviation.

The economics are far from certain though, says Dray, and if the ultimate goal is to decarbonize the aviation sector, it’s important to remember that aircraft are long-lived assets. In that respect, sustainable aviation fuels that can be used by existing aircraft are probably a more promising avenue.

Even if the Alice’s maiden flight goes well, it still faces a long path to commercialization, says Kiruba Haran, a professor of electrical and computer engineering at the University of Illinois at Urbana-Champaign. Aviation’s stringent safety requirements mean the company must show it can fly the aircraft for a long period, over and over again without incident, which has yet to be done with an all-electric plane at this scale.

Nonetheless, if the maiden flight goes according to plan it will be a major milestone for electric aviation, says Haran. “It’s exciting, right?” he says. “Anytime we do something more than, or further than, or better than, that’s always good for the industry.”

And while battery-powered electric aircraft may have little chance of disrupting the bulk of commercial aviation in the near-term, Haran says hybrid schemes that use a combination of batteries and conventional fuels (or even hydrogen) to power electric engines could have more immediate impact. The successful deployment of the Alice could go a long way to proving the capabilities of electric propulsion and building momentum behind the technology, says Haran.

“There are still a lot of skeptics out there,” he says. “This kind of flight demo will hopefully help bring those people along.”


Match ID: 27 Score: 5.00 source: spectrum.ieee.org age: 183 days
qualifiers: 5.00 travel(|ing)

Taking Cosmology to the Far Side of the Moon
Wed, 19 Jan 2022 16:08:15 +0000


A team of Chinese researchers are planning to use the moon as a shield to detect otherwise hard-to-observe low frequencies of the electromagnetic spectrum and open up a new window on the universe. The Discovering the Sky at the Longest Wavelengths (DSL) mission aims to seek out faint, low-frequency signals from the early cosmos using an array of 10 satellites in lunar orbit. If it launches in 2025 as planned, it will offer one of the very first glimpses of the universe through a new lens.

Nine “sister” spacecraft will make observations of the sky while passing over the far side of the moon, using our 3,474-kilometer-diameter celestial neighbor to block out human-made and other electromagnetic interference. Data collected in this radio-pristine environment will, according to researchers, be gathered by a larger mother spacecraft and transmitted to Earth when the satellites are on the near side of the moon and in view of ground stations.

The mission aims to map the sky and catalog the major sources of long-wavelength signals—the last, largely undiscovered area of the electromagnetic spectrum—according to a paper on the DSL mission by Xuelei Chen and others at the National Astronomical Observatories and the National Space Science Center, two institutions under the Chinese Academy of Sciences.

“A mission like this being in lunar orbit could make a scientific impact, particularly on cosmic dawn and dark ages science,” says Marc Klein Wolt, managing director of the Radboud Radio Lab in the Netherlands and a member of the Netherlands-China Low Frequency Explorer (NCLE), aboard the Chinese Queqiao relay satellite.

“When you open up a new window on the universe, you’re going to make new discoveries, things that you don’t know about yet—the unknown unknowns.”
—Marc Klein Wolt, Radboud Radio Lab, Netherlands

Detecting the cosmic dark ages (the time before the first stars formed and began to shine) and the cosmic dawn (when the first stars and galaxies formed) requires making observations of frequencies between 10 and 50 megahertz. Signals emitted by hydrogen atoms during these early cosmic eras have been stretched out over cosmic timescales to much longer wavelengths across 13 billion years of travel time. Radio astronomy of this kind is extremely difficult on Earth as the ionosphere interferes with or completely blocks such ultralong wavelengths.

“To measure the 'cosmic dawn' signal, or even the 'dark ages' signal, which is even more difficult, you have to be in a really quiet environment,” Wolt notes.

The satellites could, over time, measure the primordial distributions of hydrogen at several different epochs in the early life of the universe, says Wolt. Learning how the distributions changed and evolved over time and grew into bigger clusters of matter to form stars and galaxies would be an important contribution to astronomy.

Heliophysics, space weather, exoplanets, the interstellar medium, and extragalactic radio sources are just some of the other areas in which DSL’s long-wavelength astronomy could make additional new contributions.

“When you open up a new window on the universe, you're going to make new discoveries, things that you don't know about yet,” says Wolt. “The unknown unknowns.”

Astronomers in the United States and elsewhere have proposed setting up telescopes on the far side of the moon to benefit from the radio quiet to make unprecedented observations. Over billions of years, the Earth’s gravity has slowed the rotation of the moon, making it “tidally locked,” meaning the lunar far side now never faces Earth and is shielded from any electromagnetic noise created by terrestrial sources.

The DSL mission will, however, avoid the much greater cost and complexity of needing to land and set up on the moon, nor will it be required to carry radioisotope heating systems to keep electronics warm during frigid two-week-long lunar nights. On the other hand, being in orbit limits the duration of the observations the satellites can make while shielded by the moon.

Yet there are other benefits, too.

“With the train of satellites, you're able to do interferometry observations, so you combine the measurements of the various instruments together. And as they orbit around the moon, they can cover most of the sky every month,” says Wolt.

The mission presents a number of challenges, such as maintaining the satellites orbiting in a precise configuration. It would also be an early example of using small satellites for space science in deep space.

China previously attempted to test interferometry in lunar orbit with two small satellites that launched along with the Queqiao relay satellite in 2018 to support China’s Chang’e-4 lunar far side landing mission, but one of the spacecraft was lost after the burn to take them from Earth into translunar orbit. This next attempt would be much more ambitious.

The DSL team has recently completed the intensive study into the mission and is now applying for entering the engineering phase, according to Chen, targeting a launch in 2025. While the “dark side of the moon” is a misnomer, the silence (and thus at least radio darkness) on the lunar far side could offer unprecedented insight into cosmic mysteries.

Correction 19 Jan. 2022: A previous version of this post stated the DSL mission was Chinese and European. There was a proposal for a similar Sino-European effort, but another team was ultimately selected. The present mission is a Chinese one.


Match ID: 28 Score: 5.00 source: spectrum.ieee.org age: 202 days
qualifiers: 5.00 travel(|ing)

Psyche: NASA Mission to a Metal World
Mon, 27 Dec 2021 16:00:00 +0000


When our solar system was very young, there were no planets—only a diffuse disk of gas and dust circled the sun. But within a few million years, that churning cloud of primordial material collapsed under its own gravity to form hundreds, or maybe thousands, of infant planets. Some of those planetesimals, as astronomers call them, grew to be hundreds of kilometers across as they swept up more dust and gas within the swirling solar nebula.

Once they had attained such a size, heat from the decay of the radioactive elements within them became trapped, raising temperatures enough to melt their insides. The denser components of that melt—iron and other metals—settled to the center, leaving lighter silicates to float up toward the surface. These lighter materials eventually cooled to form mantles of silicate rock around heavy metallic cores. In this way, vast amounts of iron and nickel alloys were trapped deep inside these planetesimals, forever hidden from direct scrutiny.

Or were they?


At this time, the solar system was still relatively crowded despite its vast size. And over the next 20 million or so years, many planetesimals crossed paths and collided. Some merged and grew into even larger protoplanets, eventually forming what became the familiar planets we know today.

In each of those protoplanet collisions, the metallic cores were battered and remixed with silicate mantle material, later separating again after being melted by the heat of accretion. Some collisions had enough energy to completely obliterate a protoplanet, leaving behind debris that contributed to the asteroid belt that now exists between the orbits of Mars and Jupiter.

But a few protoplanets may have escaped either of these fates. Astronomers hypothesize that a series of “hit and run” impacts caused these bodies to lose most of their mantles, leaving behind only a small quantity of silicate rock and a large amount of metal. These materials combined to form a rare kind of world. If this theory is correct, the largest example would be an asteroid called 16 Psyche—named after the Greek goddess of the soul, Psyche, and because it was the 16th member of the asteroid belt to be discovered (in 1852).

This artist\u2019s rendering shows a highly cratered celestial object that is not quite spherical. This artist’s rendering suggests the kind of surface the asteroid 16 Psyche might have.Peter Rubin/JPL-Caltech/Arizona State University/NASA

16 Psyche is about as wide as Massachusetts and has metal-like density. This makes it large and dense enough to account for a full 1 percent of the total mass of the asteroid belt. Metal miners of the future may one day stake claims on it.

Psyche is also the name of a NASA mission to visit that asteroid. Led by Lindy Elkins-Tanton of Arizona State University and managed by NASA’s Jet Propulsion Laboratory, the Psyche mission will test astronomers’ theories about planetary-core formation and composition while it explores a world with a landscape unlike any that space probes have visited so far.

This photo shows a woman apparently giving a presentation. Lindy Elkins-Tanton of Arizona State University leads the Psyche mission’s scientific team.Bill Ingalls/NASA

The Psyche mission is scheduled to launch in August 2022, with the spacecraft reaching its destination more than three years later. What will it find there? Astronomers think we might see enormous surface faults from the contraction of freezing metal, glittering cliffs of green crystalline mantle minerals, frozen flows of sulfur lava, and vast fields of metal shards scattered over the surface from millennia of high-speed impacts. There will no doubt be plenty of surprises, too.

The long journey this space probe must make to reach its destination will be especially demanding. 16 Psyche resides in the outer part of the main asteroid belt, well beyond the orbit of Mars. The probe will begin circling the asteroid in January of 2026 and will study it for nearly two years.

Counterintuitively, arranging for a probe to orbit a small body like an asteroid is harder than orbiting a planet. Big planets have deep gravity wells, which allow spacecraft to enter orbit with a single low-altitude rocket burn. Small bodies have little gravity and provide essentially no gravitational leverage, so the spacecraft’s propulsion system must do all the work.

Astronomers think we might see enormous surface faults, glittering cliffs of green crystalline mantle minerals, frozen flows of sulfur lava, and vast fields of metal shards.

Not long ago, NASA managed this maneuver successfully with its Dawn mission, which sent a probe to orbit the asteroids Vesta and Ceres. The Dawn spacecraft used solar-electric propulsion. Its three highly efficient engines converted electricity from solar arrays into thrust by ionizing a propellant gas and accelerating it though a high-voltage electric field.

When our team at the Jet Propulsion Laboratory was designing the Psyche probe, we planned to do something similar. The main problem was figuring out how to do it without exceeding the mission’s budget. JPL engineers solved this problem by using what was for the most part existing technology, manufactured by Maxar, a company based in Westminster, Colo. It is one of the world’s largest providers of commercial geosynchronous communication satellites, produced at a division located in Palo Alto, Calif.

The Psyche spacecraft is built on the “chassis” used for those satellites, which includes high-power solar arrays, electric-propulsion thrusters, and associated power and thermal control elements. In many ways, the Psyche spacecraft resembles a standard Maxar communications satellite. But it also hosts JPL’s avionics, flight software, and the many fault-protection systems required for autonomous deep-space operation.

 This photograph shows technicians outfitted in clean-room garb working on a large blocky spacecraft that is suspended from a gantry by cables. Technicians at NASA’s Jet Propulsion Laboratory work on the Psyche spacecraft.Maxar

Making this concept work was difficult from the get-go. First, NASA management was rightfully wary of such cost-cutting measures, because the “ faster, better, cheaper” model of missions mounted in the 1990s produced some spectacular failures. Second, using Earth-orbiting systems on the Dawn mission resulted in large cost overruns during the development phase. Finally, many people involved believed (erroneously) that the environment of deep space is very special and that the Psyche spacecraft would thus have to be very different from a communications satellite intended only to orbit Earth.

We and our many NASA colleagues addressed each of these issues by teaming with engineers at Maxar. We kept costs under control by using hardware from the company’s standard product line and by minimizing changes to it. We could do that because the thermal environment in geosynchronous orbit isn’t in fact so different from what the Psyche probe will encounter.

Soon after launch, the Psyche spacecraft will experience the same relatively high solar flux that communications satellites are built for. It will also have to handle the cold of deep space, of course, but Maxar’s satellites must endure similar conditions when they fly through Earth’s shadow, which they do once a day during certain times of the year.

Because they serve as high-power telecommunications relays, Maxar’s satellites must dissipate the many kilowatts of waste heat generated by their microwave power amplifiers. They do this by radiating that heat into space. Radiating lots of heat away would be a major problem for our space probe, though, because in the vicinity of 16 Psyche the flux of light and heat from the sun is one-tenth of that at Earth. So if nothing were done to prevent it, a spacecraft designed for orbiting Earth would soon become too cold to function this far out in the asteroid belt.

Maxar addressed this challenge by installing multilayer thermal blanketing all over the spacecraft, which will help to retain heat. The company also added custom louvers on top of the thermal radiators. These resemble Venetian blinds, closing automatically to trap heat inside when the spacecraft gets too cold. But plenty of other engineering challenges remained, especially with respect to propulsion.

To reduce the mass of propellant needed to reach the asteroid, the Psyche spacecraft will use solar-electric thrusters that accelerate ions to very high velocities—more than six times as high as what can be attained with chemical rockets. In particular, it will use a type of ion thruster known as a Hall thruster.

The photograph on the left shows a luminous ring with a diffuse glow around it. The photograph on the right shows the source of this light, a black cylindrical device bolted to the side of the spacecraft. A Hall thruster, four of which will propel the Psyche spacecraft, produces an eerie blue glow during testing [left]. The unit consists of a ring-shaped anode, which has a diameter similar to that of a dinner plate, and a narrow, cylindrical cathode mounted to one side [right].JPL-Caltech/NASA

Soviet engineers pioneered the use of Hall thrusters in space during the 1970s. And we use four Russian-made Hall thrusters on the Psyche spacecraft for the simple reason that Maxar uses that number to maintain the orbits of their communications satellites.

Hall thrusters employ a clever strategy to accelerate positively charged ions [see sidebar, “How a Hall Thruster Works”]. This is different from what is done in the ion thrusters on the Dawn spacecraft, which used high-voltage grids. Hall thrusters, in contrast, use a combination of electric and magnetic fields to accelerate the ions. While Hall thrusters have a long history of use on satellites, this is the first time they will go on an interplanetary mission.

How a Hall Thruster Works

A Hall thruster uses an electron discharge to create a plasma—a quasi-neutral collection of positive ions and electrons—not unlike what goes on in a fluorescent lamp.

The thruster includes a hollow cathode (negative electrode), placed outside the thruster body, and an anode (positive electrode) positioned inside a ring-shaped discharge chamber. If these electrodes were all there was, the power applied to the thruster would just go into making a current of electrons flowing from cathode to anode, emitting some blue glow along the way. Instead, a Hall thruster applies a radially directed magnetic field across its discharge channel.

The electrons emitted by the cathode are very light and fast. So this magnetic field impedes the flow of electrons to the anode, forcing them instead to go in circular orbits around the center line of the thruster. The positive xenon ions that are generated inside the discharge chamber accelerate toward the cloud of circling electrons, but these ions are too massive to be affected by the weak magnetic field. So they shoot straight out in a beam, sweeping up electrons along the way. The ejection of that material at high speed creates thrust. It’s not much thrust—equal to about the weight of a few quarters—but applied steadily for months on end, it’s enough to get the spacecraft zooming.

We kept costs under control by using hardware from Maxar's standard product line and by minimizing changes to it.

You might think that thrusting around Earth isn’t any different from doing so in deep space. There are, in fact, some big differences. Remember, the power to run the thrusters comes from solar panels, and that power must be used as it is generated—there is no great big battery to store it. So the power available to run the thrusters will diminish markedly as the spacecraft moves away from the sun.

That’s an issue because electric thrusters are usually designed to run best at their maximum power level. It turns out to be pretty easy to throttle them a little, maybe to about half their maximum output. For example, the Hall thrusters Maxar uses on its communications satellites can run at as much as 4.5 kilowatts when the satellite’s orbit needs to be raised. For more routine station keeping, these thrusters run at 3 kW. We needed these thrusters to run at less than 1 kW when the spacecraft neared its destination.

The problem is that efficiency decreases when you do this kind of throttling. In that sense, a Hall thruster is like the engine in your car. But the situation is worse than in a car: The electrical discharge inside a thruster can become unstable if the power is decreased too much. The throttled thruster can even quit firing altogether—like a flameout in a jet engine.

But with some clever engineering, we were able to make modifications to how we run Maxar’s thruster so that it could operate stably at power levels as low as 900 W. We then tested our reengineered thruster in facilities at NASA’s Glenn Research Center and at JPL to prove to ourselves that it would indeed operate reliably for the full six-year Psyche mission.

This CAD drawing shows the major components of the Deep Space Optical Communications system: a cylindrical optical transceiver assembly, a photon-counting camera attached to one side of that assembly, a \u201cfloating\u201d electronics package attached to the base of the unit, and three of the four isolation struts attaching the system to the spacecraft. The Psyche mission will test equipment for sending and receiving data optically. This Deep Space Optical Communications (DSOC) system must be pointed with great precision and kept isolated from vibration.JPL-Caltech/Arizona State University/NASA

The Psyche probe will venture more than three times as far from the sun as Earth ever does. Generating the 2 kW of power needed to operate the spacecraft and fire its thrusters when it reaches its destination requires an array of solar cells large enough to generate more than 20 kW near Earth. That’s a lot of power as these things go.

Fortunately for NASA, the cost of solar power has dropped dramatically over the past decade. Today, the commercial satellites that beam television and Internet signals across the globe generate these power levels routinely. Their solar-power systems are effective, reliable, and relatively inexpensive. But they are designed to work while circling Earth, not at the outer edges of the asteroid belt.

When the Psyche mission was conceived in 2013, Maxar had successfully flown more than 20 spacecraft with power levels greater than 20 kW. But the company had never built an interplanetary probe. JPL, on the other hand, had years of experience operating equipment in deep space, but it had never built a power system of the size required for the Psyche mission. So JPL and Maxar combined forces.

The challenge here was more complicated than just dealing with the fact that sunlight at 16 Psyche is so dim. The solar cells on the Psyche spacecraft would also have to operate at temperatures much lower than normal. That’s a serious issue because the voltage from such cells rises as they get colder.

When orbiting Earth, Maxar’s solar arrays generate 100 volts. If these same arrays were used near 16 Psyche, they would produce problematically high voltages. While we could have added electronics to reduce the voltage coming out of the array, the new circuitry would be costly to design, build, and test for space. Worse, it would have reduced the efficiency of power generation when the spacecraft is far from the sun, where producing adequate amounts of power will be tough in any case.

Fortunately, Maxar already had a solution. When one of their communications satellites passes into Earth’s shadow, it’s powered by a bank of lithium-ion batteries about the size of what’s found in electric cars. That’s big enough to keep the satellite running while it is in darkness behind Earth, which is never for much longer than an hour. But the voltage from such batteries varies over time—perhaps from as low as 40 V on some satellites when the battery is deeply discharged all the way up to 100 V. To handle that variability, Maxar’s satellites include “discharge converters,” which boost voltage to provide power at a constant 100 V. These converters were flight proven and highly efficient—ideal to repurpose for Psyche.

The key was to rewire the solar array, lowering the voltage it produced in the vicinity of Earth to about 60 V. As the spacecraft moves away from the sun, the voltage will gradually rise as the arrays get colder until it reaches about 100 V at 16 Psyche. Maxar’s discharge converters, normally attached to batteries, are connected to the solar array instead and used to provide the spacecraft with power at a constant 100 V over the entire mission.

This approach incurs some energy losses, but those are greatest when the spacecraft is close to Earth and power is abundantly available. The system will operate at its highest efficiency when the spacecraft nears 16 Psyche, where generating power will be a lot harder. It uses flight-proven hardware and is far more economical than sophisticated systems designed to eke out peak power from a solar array throughout a deep-space mission.

One day the technology being tested may enable you to watch astronauts tromping around the Red Planet in high-definition video.

In addition to the set of scientific instruments that will be used to study the asteroid, the Psyche spacecraft will also be carrying what NASA calls a “technology demonstration” payload. Like so many things at NASA, it goes by an acronym: DSOC, which stands for Deep Space Optical Communications.

DSOC is a laser-based communications system intended to outdo current radio technology by as much as a hundredfold. DSOC will demonstrate its capability by transmitting data at up to 2 megabits per second from beyond the orbit of Mars. One day similar technology may enable you to watch astronauts tromping around the Red Planet in high-definition video.

The DSOC instrument has a “ground segment” and a “flight segment,” each of which includes both a laser transmitter and a receiver. The transmitter for the ground segment, a 7-kW laser, will be installed at JPL’s Optical Communications Telescope Laboratory, located about 60 kilometers northeast of Los Angeles. A sensitive receiver, one capable of counting individual photons, will be attached to the 5.1-meter-wide Hale Telescope at Caltech’s Palomar Observatory, located a similar distance northeast of San Diego.

This photo shows a dish antenna that is covered by fabric being tested inside a chamber that is lined with material shaped to absorb electromagnetic radiation The Psyche spacecraft’s high-gain radio antenna, shown here being tested at the Maxar's facilities in Palo Alto, Calif., will provide the data communications throughout the mission.Maxar

DSOC’s flight segment, the part on the spacecraft, contains the same type of equipment, but much scaled down: a laser with an average power of 4 watts and a 22-centimeter telescope. The flight segment sounds simple, like something you could cobble together yourself at home. In fact, it’s anything but.

For one, it needs some rather elaborate gear to point it in the right direction. The Psyche spacecraft itself is able to keep DSOC pointed toward Earth to within a couple of milliradians—about a tenth of a degree. Using built-in actuators, DSOC then searches for the laser beacon sent from the ground. After detecting it, the actuators stabilize the pointing of DSOC’s own laser back at Earth with an accuracy measured in microradians.

The flight segment is able to point so steadily in the same direction because it’s housed in a special enclosure that provides thermal and mechanical isolation from the rest of the spacecraft. DSOC also uses a long sun shield to eliminate stray light on its laser receiver, with a deployable aperture cover to ensure that the unit remains clean.

During DSOC operations in space, the spacecraft cannot use its thrusters or gimbal its solar arrays, which would introduce problematic movements. Instead, it will keep its attitude fixed solidly in one direction and will use its star-tracking system to determine what that direction is. The constraints on what the spacecraft can do at these times is not an impediment, though, because DSOC will be used only for tests during the first year of the mission, while traveling to just past the orbit of Mars. When the spacecraft reaches 16 Psyche, it will transmit data back to Earth over a microwave radio link.

Having emerged from nearly a decade of planning, and having traveled for more than three years, the Psyche spacecraft will finally reach its target in early 2026. There will no doubt be plenty of tension in the air when controllers at JPL maneuver the spacecraft into orbit, waiting the many minutes it will take signals to be returned to find out whether all went well in this distant corner of the asteroid belt.

If all goes according to plan, for the following two years this communications-satellite-turned-space-probe will provide scientists with a close-up look at this odd metallic world, having already demonstrated an advanced optical system for high-data-rate communications. These achievements will have been a long time coming for us—but we expect that what is learned will be well worth the many years we’ve put into trying to ensure that this mission is a success.


Match ID: 29 Score: 5.00 source: spectrum.ieee.org age: 225 days
qualifiers: 5.00 travel(|ing)

Filter efficiency 96.068 (30 matches/763 results)

ABOUT THE PROJECT

RSS Rabbit links users to publicly available RSS entries.
Vet every link before clicking! The creators accept no responsibility for the contents of these entries.

Relevant

Fresh

Convenient

Agile

CONTACT

We're not prepared to take user feedback yet. Check back soon!

rssRabbit quadric