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How changing aircraft altitude could cut flight's climate impact in half – CNN

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(CNN) — Greener fuels, electric engines and more efficient aircraft are all being touted as ways to reduce the environmental harm of flying, but a new study suggests one simple move could help existing flights drastically cut their impact.

By changing the flying altitude by just couple of thousand feet on fewer than 2% of all scheduled flights, a study by a team of scientists at Imperial College London concludes that aviation’s damage to the climate could be reduced by as much as 59%.

It’s all about eradicating airplane contrails — those white streaks you see criss-crossing the skies after an airplane has passed overhead.

Contrails, says NASA, are “a type of ice cloud formed by aircraft as water vapor condenses around small dust particles, which provide the vapor with sufficient energy to freeze.”

These cloud-like formations can have a cooling effect, acting to reflect sunlight that would otherwise heat the Earth. Contrails can also block outgoing heat from escaping the earth — essentially acting like a blanket, trapping heat.

In November 2019, a study by a group of MIT scientists concluded contrails account for 14% of climate and air quality damages per unit aviation fuel burn.

The big difference between C02 emissions produced by an aircraft and contrails, however, is that contrails don’t last very long, a maximum of about 18 hours.

“So if we were to stop producing contrails, the effect of contrails would go away the next day,” says Marc Stettler, who worked on the new study. “It’s a way that the aviation industry can really quickly address its impact on climate change.”

Flying an airplane higher or lower could help get rid of contrails because they only form in thinner areas of atmosphere, with high humidity — so it’s theoretically possible to avoid them and reap the eco-benefits.

“What we show is that you can make these minor modifications to the altitude of a flight, and avoid that flight from forming a contrail,” Stettler tells CNN Travel.

Tackling the issue

Reducing airplane contrails could help with aviation’s impact on climate change.

FABRICE COFFRINI/AFP via Getty Images

Stettler and his colleagues experimented with computer simulations to come to their conclusion: using data available on aircraft flying in Japanese airspace, the scientists tested what would happen if aircraft flew higher or lower than their current flight paths.

Diverging from the flight path does lead to an increase in fuel consumption, but the researchers say it’s less than a 0.1% rise — and the subsequent depletion in contrails offsets the extra C02 released.

Andrew Heymsfield, senior scientist at the National Center for Atmospheric Research, tells CNN Travel that the findings make sense, but questions how they could be employed in everyday aviation scenarios.

“The question is, how would they find out what those altitudes are [that] would be less amenable to the development of contrail?” says Heymsfield.

The airplane would have to use instruments that remotely sense humidity, he suggests.

“Those would have to be developed and deployed on an aircraft, so that a 3D depiction of those altitudes could be developed from aircraft which collect those data and then transmit it down to the ground,” says Heymsfield.

“Otherwise, I don’t know how aircraft air controllers would know where to allow the aircraft to fly.”

As Heymsfield points out, aircraft cannot fly anywhere, they have to stick to a specific path.

While the change, if adopted, would have lead to some reduction in emissions, it’s unlikely to assuage climate campaigners who want the aviation sector to drastically reduce its carbon footprint. Air travel currently contributes to between 2-3% of all global CO2 emissions and this would remain an issue even if airplanes were flying at different altitudes.

Stettler says his team are in discussion with aviation authorities about how their research might work practically.

“We are in the process of having discussions with air traffic management service providers, who are responsible for planning with airlines flight trajectories,” says Stettler.

“It’s very, very early days, but we’re we’re wanting to understand how that process works and how such a strategy can be implemented. We think it’s something that the aviation industry needs to take seriously.”

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SpaceX re-useable rocket misses landing ship – CTV News

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WASHINGTON, UNITED STATES —
SpaceX successfully launched its latest cluster of high-speed internet satellites into orbit Monday but was unable to land its rocket booster on an autonomous ship, missing a key milestone.

The private company founded by billionaire Elon Musk has revolutionized spaceflight in recent years by developing rockets capable of delivering their payload in space then flying back to Earth and landing upright on a target zone, ready to be-reused.

It has successfully landed its booster 49 times previously and Monday’s mission would have been the 50th.

“We had an on-time liftoff this morning, a good stage separation, first stage made its way back to Earth,” manufacturing engineer Jessica Anderson said during a live feed of the mission, which launched from Cape Canaveral, Florida at 10:05am (1505 GMT).

“Unfortunately, we did not land the first stage on our drone ship, but it did make a soft landing on the water right next to the drone ship, so it does look like it might be in one piece,” she added.

The mission delivered the fifth load of 60 satellites of SpaceX’s broadband Starlink constellation, part of its plans to control a huge share of the future internet space market.

There are now around 300 Starlink satellites in orbit and that number could one day grow to thousands.

Several rivals have the same ambition, including London-based startup OneWeb and giant US retailer Amazon, whose Project Kuiper is far less advanced.

These have sparked concern among astronomers that they could obscure our view of the night sky, both visually and through radio interference.

Re-using rockets drastically lowers the cost of missions, and the Falcon 9 used in Monday’s launch was being flown for the fourth time.

It was not immediately clear why it missed its target. The rocket did not appear in the frame in live footage broadcast from the drone ship, but a plume of smoke or vapor was seen a short distance away.

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New Invention Generates Electricity “Out of Thin Air” – Offers Clean Energy 24/7 – SciTechDaily

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(Click image for full view.) Graphic image of a thin film of protein nanowires generating electricity from atmospheric humidity. UMass Amherst researchers say the device can literally make electricity out of thin air. Credit: UMass Amherst/Yao and Lovley labs

Renewable device could help mitigate climate change, power medical devices.

Scientists at the University of Massachusetts Amherst have developed a device that uses a natural protein to create electricity from moisture in the air, a new technology they say could have significant implications for the future of renewable energy, climate change and in the future of medicine.

As reported today in Nature, the laboratories of electrical engineer Jun Yao and microbiologist Derek Lovley at UMass Amherst have created a device they call an “Air-gen,” or air-powered generator, with electrically conductive protein nanowires produced by the microbe Geobacter. The Air-gen connects electrodes to the protein nanowires in such a way that electrical current is generated from the water vapor naturally present in the atmosphere.

“We are literally making electricity out of thin air,” says Yao. “The Air-gen generates clean energy 24/7.” Lovely, who has advanced sustainable biology-based electronic materials over three decades, adds, “It’s the most amazing and exciting application of protein nanowires yet.”

“We are literally making electricity out of thin air. The Air-gen generates clean energy 24/7.” — Jun Yao

The new technology developed in Yao’s lab is non-polluting, renewable and low-cost. It can generate power even in areas with extremely low humidity such as the Sahara Desert. It has significant advantages over other forms of renewable energy including solar and wind, Lovley says, because unlike these other renewable energy sources, the Air-gen does not require sunlight or wind, and “it even works indoors.”

The Air-gen device requires only a thin film of protein nanowires less than 10 microns thick, the researchers explain. The bottom of the film rests on an electrode, while a smaller electrode that covers only part of the nanowire film sits on top. The film adsorbs water vapor from the atmosphere. A combination of the electrical conductivity and surface chemistry of the protein nanowires, coupled with the fine pores between the nanowires within the film, establishes the conditions that generate an electrical current between the two electrodes.

The researchers say that the current generation of Air-gen devices are able to power small electronics, and they expect to bring the invention to commercial scale soon. Next steps they plan include developing a small Air-gen “patch” that can power electronic wearables such as health and fitness monitors and smart watches, which would eliminate the requirement for traditional batteries. They also hope to develop Air-gens to apply to cell phones to eliminate periodic charging.

“This is just the beginning of new era of protein-based electronic devices” — Jun Yao

Yao says, “The ultimate goal is to make large-scale systems. For example, the technology might be incorporated into wall paint that could help power your home. Or, we may develop stand-alone air-powered generators that supply electricity off the grid. Once we get to an industrial scale for wire production, I fully expect that we can make large systems that will make a major contribution to sustainable energy production.”

Continuing to advance the practical biological capabilities of Geobacter, Lovley’s lab recently developed a new microbial strain to more rapidly and inexpensively mass produce protein nanowires. “We turned E. coli into a protein nanowire factory,” he says. “With this new scalable process, protein nanowire supply will no longer be a bottleneck to developing these applications.”

The Air-gen discovery reflects an unusual interdisciplinary collaboration, they say. Lovley discovered the Geobacter microbe in the mud of the Potomac River more than 30 years ago. His lab later discovered its ability to produce electrically conductive protein nanowires. Before coming to UMass Amherst, Yao had worked for years at Harvard University, where he engineered electronic devices with silicon nanowires. They joined forces to see if useful electronic devices could be made with the protein nanowires harvested from Geobacter.

Xiaomeng Liu, a Ph.D. student in Yao’s lab, was developing sensor devices when he noticed something unexpected. He recalls, “I saw that when the nanowires were contacted with electrodes in a specific way the devices generated a current. I found that that exposure to atmospheric humidity was essential and that protein nanowires adsorbed water, producing a voltage gradient across the device.”

In addition to the Air-gen, Yao’s laboratory has developed several other applications with the protein nanowires. “This is just the beginning of new era of protein-based electronic devices” said Yao.

Reference: “Power generation from ambient humidity using protein nanowires” by Xiaomeng Liu, Hongyan Gao, Joy E. Ward, Xiaorong Liu, Bing Yin, Tianda Fu, Jianhan Chen, Derek R. Lovley and Jun Yao, 17 February 2020, Nature.
DOI: 10.1038/s41586-020-2010-9

The research was supported in part from a seed fund through the Office of Technology Commercialization and Ventures at UMass Amherst and research development funds from the campus’s College of Natural Sciences.

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SpaceX delivers more Starlink satellites to orbit, booster misses drone ship landing – Spaceflight Now

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A Falcon 9 rocket lifted off at 10:05:55 a.m. EST (1505:55 GMT) Monday with 60 more SpaceX Starlink satellites. Credit: SpaceX

Sixty more satellites for SpaceX’s Starlink broadband network launched Monday on a Falcon 9 rocket from Cape Canaveral, bringing the total number of Starlink platforms deployed in orbit since last May to 300.

More Starlink missions are on tap in the coming months, with the next slated to fly aboard another Falcon 9 launcher as soon as early March.

Monday’s mission began with a burst of flame from SpaceX’s Falcon 9 booster, followed by the release of hold-down clamps to allow the 1.2-million-pound Falcon 9 to climb into a partly cloudy sky over Cape Canaveral’s Complex 40 launch pad.

The 229-foot-tall (70-meter) rocket lifted off at 10:05:55 a.m. EST (1505:55 GMT) powered by thrust from nine kerosene-fueled Merlin 1D engines.

The Falcon 9 quickly cleared lightning towers at pad 40 and steered toward the northeast, sending a window-shaking roar across the Florida spaceport.

Two-and-a-half minutes into the mission, the Falcon 9’s first stage booster shut down its engines and separated, allowing a single Merlin engine on the launcher’s second stage to fire into orbit.

Seconds later, the Falcon 9’s payload shroud jettisoned as the rocket soared into space, revealing the launcher’s more than 34,000-pound (15.6-metric ton) payload package, comprised of 60 flat-panel signal relay nodes for SpaceX’s Starlink network.

While the second stage accelerated into orbit, the first stage of the Falcon 9 descended back through the atmosphere and attempted landing on SpaceX’s football field-sized drone ship “Of Course I Still Love You” holding position nearly 400 miles (630 kilometers) northeast of Cape Canaveral.

But the rocket missed the drone ship and appeared to make a soft landing in the water nearby, according to streaming video from the offshore vessel. The missed landing marked the first time a first stage booster on a Falcon 9 rocket has missed a landing attempt on a SpaceX drone ship since 2016.

The rocket used on Monday’s mission was a veteran of three previous launches and landings. It’s not likely to be reused after landing in sea water.

Two other SpaceX vessels were positioned in the Atlantic Ocean to try to catch the two halves of the Falcon 9’s payload shroud. SpaceX did not announce the results of the fairing recovery attempt, but a company employee said engineers are still experimenting with catching the aerodynamic shroud using fast-moving ships fitted with giant nets. Previous catch attempts have been hit or miss.

Around the same time as the first stage reached the ocean, a SpaceX launch controller announced that the Falcon 9 upper stage had arrived in orbit and was poised to release the 60 Starlink satellites, the mission’s primary objective.

After firing thrusters to enter a controlled spin, the upper stage released retention rods holding the Starlink satellites to the rocket. That allowed the spacecraft — each weighing about a quarter-ton — to fly away from the Falcon 9 as the vehicles soared over the North Atlantic Ocean.

One change introduced Monday different from past Starlink missions was the release of the Starlink payloads into an elliptical transfer orbit, instead of a circular orbit.

SpaceX did not respond to questions from Spaceflight Now on the reason for the change in launch profile, but a host on the company’s webcast Monday said all future Starlink missions will use the new trajectory to inject the satellites into an elliptical orbit after a single upper stage burn.

“We are executing a direct inject of the Starlink satellites into an elliptical, or oval-shaped, orbit,” said Jessica Anderson, a manufacturing engineer at SpaceX. “In prior Starlink missions, we deployed the satellites into a 290-kilometer (180-mile) circular orbit, which required two burns of the Merlin vacuum engine on the second stage.

“Keep in mind the stack of 60 Starlink satellites combined is one of the heaviest payloads we fly, so putting them directly into this orbit requires more vehicle performance and makes recovery more challenging,” she said. “Going forward, and starting with today, we will deploy the satellites shortly after the first burn of the second stage, putting the Starlink satellites into an elliptical orbit.

A stack of 60 Starlink satellites. Credit: SpaceX

“Once checkouts are complete, the satellites will then use their on-board ion thrusters to move into their inteded orbits at an operational altitude of 550 kilometers (341 miles).”

According to preflight predictions, the Starlink craft on Monday were programmed for deployment in an elliptical, or egg-shaped, orbit ranging between 131 miles (212 kilometers) and 239 miles (386 kilometers) in altitude, with an inclination of 53 degrees to the equator.

As a result of the orbit change, the Falcon 9’s second stage remained in orbit after release the Starlink satellites Monday. It is expected to passively re-enter the atmosphere in the coming months, instead of performing a controlled de-orbit burn, as the stage did after previous Starlink launches.

Like SpaceX’s previous Starlink launches, the satellites deployed in a tight cluster. SpaceX ground teams will activate krypton ion thrusters and other systems on the satellites to maneuver them into a higher orbit, targeting an altitude of 341 miles for operational service broadcasting signals in Ku-band.

The first phase of SpaceX’s Starlink program, which aims to beam consumer broadband to customers around the world, will include 1,584 of the flat-panel satellites — including spares — in orbit 341 miles above Earth.

SpaceX has approval from the Federal Communications Commission to operate nearly 12,000 Starlink satellites in Ku-band, Ka-band and V-band frequencies, with groups of spacecraft flying at different altitudes with various orbital tilts, or inclinations.

Last year, SpaceX signaled to the International Telecommunication Union that it may seek authority to operate up to 30,000 additional broadband satellites in low Earth orbit, potentially bringing the total Starlink fleet to 42,000 platforms.

But SpaceX says the fleet’s growth will hinge on demand, and the company must launch roughly 20 more missions before completing the first phase of its Starlink network.

Artist’s illustration of a Starlink satellite. Credit: SpaceX

SpaceX also needs to test the network and begin selling the Starlink service, and work continues on user terminals to link customers on the ground with the satellite network in space. The company has not announced a price or Internet speeds for its consumer-grade service.

The rapid-fire deployment of Starlink satellites — coupled with plans for other large satellite fleets — has astronomers worried that the proliferation of small spacecraft could impact observations by ground-based telescopes.

The Starlink satellites are brighter than predicted, sometimes reflecting sunlight and becoming as bright as the most luminous stars in the night sky. But the brightest sightings occur only soon after a launch, when the satellites are flying at lower altitudes and are clumped close together.

The satellites are harder to spot as they spread out in the weeks after a launch and begin raising their orbits to their 341-mile-high operating altitude. But scientists caution they will pose a threat to high-power telescopes, such as the U.S. government-funded Vera C. Rubin Observatory under construction in Chile.

The International Astronomical Union — a global body chartered in 1919 to “promote and safeguard the science of astronomy” — said last week that it “considers the consequences of satellite constellations worrisome.”

“They will have a negative impact on the progress of ground-based astronomy, radio, optical and infrared, and will require diverting human and financial resources from basic research to studying and implementing mitigating measures,” the IAU said in a press release.

“A great deal of attention is also being given to the protection of the uncontaminated view of the night sky from dark places, which should be considered a non-renounceable world human heritage,” the IAU said.

At the request of the IAU, scientists from the Vera Rubin Observatory, the University of Michigan, the Centro Astronómico Hispano-Alemán, the European Southern Observatory and the European Space Agency modeled the frequency, location and brightness of satellites in planned “mega-constellations” flying in low Earth orbit.

The IAU said the results of the simulations are preliminary. Some of the simulations assumed more than 25,000 broadband satellites could be deployed in low Earth orbit, in which case between 1,500 and a few thousand spacecraft could be above the horizon at any given time, depending on the observer’s latitude.

The “vast majority” of those satellites would not be visible to the naked eye, according to the IAU. The simulations showed that around 250 to 300 of the spacecraft above the horizon at any given time would have an elevation of more than 30 degrees, the region of the sky where astronomers perform most of their observations.

At astronomical dawn and dusk — when the sun is 18 degrees below the horizon — simulations suggest around 1,000 satellites could be illuminated by sunlight and above the horizon. Around 160 of the illuminated spacecraft could be higher than 30 degrees in the sky at one time, and those are the satellites that pose the greatest threat to astronomical research.

The numbers of illuminated satellites will decrease in the middle of the night, according to the IAU.

This 333-second exposure taken last year by the Dark Energy Camera on the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory shows 19 streaks attributed to Starlink satellites passing through the camera’s field-of-view shortly after their launch Nov. 11 from Cape Canaveral. Credit: NSF’s National Optical-Infrared Astronomy Research Laboratory/NSF/AURA/CTIO/DELVE

In response to astronomers’ concerns, SpaceX launched one satellite in early January with an experimental darker coating. The long-term effectiveness of the external treatment will not be known until the satellite reaches the Starlink fleet’s operational altitude.

Gwynne Shotwell, SpaceX’s president and chief operating officer, said in December the company was in dialog with astronomers about the issue.

“Astronomy is one of a few things that gets little kids excited about space,” Shotwell said. “There are a lot of adults that get excited, too, who either depend on it for their living or for entertainment. But we want to make sure we do the right thing, to make sure little kids can look through their telescopes. It’d be cool for them to see a Starlink. I think that’s cool. But they should be looking at Saturn and the moon.”

The other company on the cusp of launching hundreds, and perhaps thousands, of broadband satellites is London-based OneWeb.

OneWeb has launched 40 satellites to date, with plans to launch roughly 32 to 36 more every month to deploy an initial fleet of nearly 650 spacecraft. But like SpaceX, OneWeb has plans to grow from there.

The satellites owned by OneWeb are smaller than the Starlink spacecraft, and they orbit higher, allowing the company to provide global coverage with fewer satellites than SpaceX. The higher altitude also means they will be dimmer to ground observers, the company says.

“We’re going to do the most we can to mitigate (astronomers’ concerns),” said Adrian Steckel, OneWeb’s CEO. “We’re not visible to the naked eye. We are visible to telescopes. It’s hard to get around some of those facts.”

Scientists have also questioned whether constellations of thousands of satellites broadcasting broadband data will interfere with radio astronomy, which uses giant antennas to listen to faint radio signals generated from distant stars and galaxies.

“With respect to radio frequency … we’ll try,” Steckel said earlier this month. “We’re going to do the most we can. I don’t know if there will be a solution that will make everybody happy. At least we’re in dialog, and we’re trying to get feedback on what can we do.”

The IAU said there is still uncertainty in the eventual impacts of huge flocks of satellites on astronomy.

“At the moment it is difficult to predict how many of the illuminated satellites will be visible to the naked eye, because of uncertainties in their actual reflectivity,” the IAU said, referencing the unknown outcome of SpaceX’s experiments with darker coatings.

The Vera Rubin Observatory is under construction in Chile. Credit: Vera Rubin Observatory

“The appearance of the pristine night sky, particularly when observed from dark sites, will nevertheless be altered, because the new satellites could be significantly brighter than existing orbiting man-made objects,” the IAU said. “The interference with the uncontaminated view of the night sky will be particularly important in the regions of the sky close to the horizon and less evident at high elevation.”

The IAU said astronomical impacts during the period of time when Starlink satellites are brightest — soon after a launch — depend on how long the spacecraft are flying at lower altitudes, and the frequency of launches.

“Apart from their naked-eye visibility, it is estimated that the trails of the constellation satellites will be bright enough to saturate modern detectors on large telescopes,” the IAU concluded. “Wide-field scientific astronomical observations will therefore be severely affected. For instance, in the case of modern fast wide-field surveys, like the ones to be carried out by the Rubin Observatory (formerly known as LSST), it is estimated that up to 30 percent of the 30-second images during twilight hours will be affected.”

Formerly known as the Large Synoptic Survey Telescope, the Vera Rubin Observatory will capture deep, wide-field images of the entire available sky, allowing astronomers to learn more about dark energy and dark matter, and detect potentially hazardous asteroids with orbits near Earth, among other objectives.

“Instruments with a smaller field of view would be less affected,” the IAU continued. “In theory, the effects of the new satellites could be mitigated by accurately predicting their orbits and interrupting observations, when necessary, during their passage. Data processing could then be used to further ‘clean’ the resulting images. However, the large number of trails could create significant and complicated overheads to the scheduling and operation of astronomical observations.”

The IAU’s statement last week focused on optical astronomy. Astronomers continue studying the possible interference that signals transmitted by broadband satellites in low Earth orbit will have on radio astronomy.<

The IAU said there are no internationally-agreed rules of guidelines on the brightness of satellites. The group said it will present its findings to the United Nations to bring the attention of world government representatives on the issue.

“The IAU stresses that technological progress is only made possible by parallel advances in scientific knowledge,” the group said. “Satellites would neither operate nor properly communicate without essential contributions from astronomy and physics. It is in everybody’s interest to preserve and support the progress of fundamental science such as astronomy, celestial mechanics, orbital dynamics and relativity.”

SpaceX’s next launch is scheduled for 1:45 a.m. EST (0545 GMT) March 2, again from pad 40 at Cape Canaveral, when a Falcon 9 rocket will loft a Dragon cargo capsule into orbit on a resupply mission to the International Space Station.

Another Starlink launch on a Falcon 9 rocket is also scheduled as soon as March 4 from nearby pad 39A at the Kennedy Space Center.

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Follow Stephen Clark on Twitter: @StephenClark1.

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