ICESat-II, ELaNa-XVIII: ELFIN, IT-SPINS, CHEFsat - Delta II 7420-10C - Vandenberg SLC-2W -15.09.2018

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Старый пишет:
Атлас-Аджена это не Атлас-Центавр.  

Летало и немало

Старый пишет:
Я бы не был столь смел чтобы обозвать Мерлины двигателями НЕ открытой схемы.  

Раптор, конечно Оговорился же

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Старый пишет:
Мерлины это и есть второе пришествие открытой схемы. В которых США и увидели перспективу.

А я вот "щитаю", что наоборот. США повернулись в сторону замкнутой схемы. И Китай туда же.

[Старый]

Александр Хороших пишет:

Старый пишет:
Мерлины это и есть второе пришествие открытой схемы. В которых США и увидели перспективу.

А я вот "щитаю", что наоборот. США повернулись в сторону замкнутой схемы. И Китай туда же.  

Это где и когда ж США повернулись в сторону замкнутой схемы? Когда отдались Маску или раньше?

[Старый]

Александр Хороших пишет:
И Китай туда же.

С Китаем та же история что и с США - за еду прикупил у хохлов наш движок.

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Старый пишет:
Это где и когда ж США повернулись в сторону замкнутой схемы? Когда отдались Маску или раньше?  

Не так давно Все перспективные РН проектируют с замкнутыми двигунами

Старый пишет:
С Китаем та же история что и с США - за еду прикупил у хохлов наш движок.

Дык! А к кому восходит история того двигуна? Ну это ладно, неважно. И Китай туда же. 

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Jonathan McDowell‏Подлинная учетная запись @planet4589 58 мин. назад

First two TLE sets for ICESAT-2 have a different inclination and probably refer to the post-SECO-3 Delta second stage, not to ICESAT. Later TLE sets have the correct 92.0 deg inclination

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https://spaceflightnow.com/2018/09/15/early-morning-launch-closes-book-on-delta-2-legacy/

Early morning launch closes book on Delta 2 legacy spanning nearly 30 years
September 15, 2018 | Stephen Clark


A United Launch Alliance Delta 2 rocket lifted off at 6:02 a.m. PDT (9:02 a.m. EDT; 1302 GMT) Saturday fr om Vandenberg Air Force Base, California. Credit: Alex Polimeni/Spaceflight Now

A United Launch Alliance Delta 2 rocket fired away from a California military base and disappeared into an overcast cloud deck Saturday on its final flight, carrying a NASA research satellite into orbit and closing the book on a nearly 30-year legacy of launches.

The 128-foot-tall (39-meter) rocket lit its kerosene-fueled Aerojet Rocketdyne RS-27A main engine at 6:02 a.m. PDT (9:02 a.m. EDT; 1302 GMT), then ignited four Northrop Grumman-built strap-on solid rocket boosters a few seconds later to propel the Delta 2 off its launch pedestal at Vandenberg Air Force Base, California.

Riding roughly 650,000 pounds of thrust, the Delta 2 rocket — emblazoned in its iconic bluish-green paint scheme — disappeared into low clouds, but long-range infrared tracking cameras followed the launcher's progress as it pitched to the south from Vandenberg, a military-run spaceport on California's Central Coast northwest of Los Angeles.

The four solid rocket boosters burned out and jettisoned to fall into the Pacific Ocean less than 90 seconds after liftoff, and the first stage's RS-27A main engine — tracing its design heritage to NASA's Saturn 1 and 1B rocket programs of the 1960s — shut down for the final time at T+plus 4 minutes, 24 seconds.

After releasing the first stage, the Delta 2's second stage Aerojet Rocketdyne AJ10-118K engine fired for the first of four burns on Saturday's mission, then shut down at around the 11-minue point of the flight. The Delta 2 coasted over Antarctica, then headed north over the Indian Ocean before reigniting the upper stage engine for less than 7 seconds to circularize its orbit.

NASA's ICESat 2 satellite, kicking off a $1 billion mission using lasers to measure global ice sheet changes from space, deployed from the rocket's upper stage around 53 minutes after liftoff. A live video view beamed down from the Delta 2 showed the 3,340-pound (1,515-kilogram) NASA research craft flying away from the rocket against the inky black backdrop of space.

ULA programmed the rocket to release ICESat 2 in an orbit nearly 300 miles, or about 474 kilometers, above Earth. Delta 2 flight commentator Patrick Moore confirmed the rocket achieved an orbit very close to pre-flight predictions.

ICESat 2, built by Northrop Grumman Innovation Systems, unfurled its solar panel shortly after separating from the Delta 2, commencing a 60-day commissioning schedule before starting regular scientific observations of land and sea ice in November.

Спойлер

The Delta 2 rocket climbs away from Space Launch Complex 2-West at Vandenberg Air Foce Base, California. Credit: NASA/Bill Ingalls

Another burn by the Delta 2's AJ10 second stage engine slightly adjusted its orbit to set up for the separation of four CubeSats developed by university students. The CubeSats launched on Saturday's mission were:

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• ELFIN, or the Electron Losses and Fields Investigation, a space weather mission developed at UCLA using three scientific instruments in a 3U+ CubeSat form factor.
• ELFIN-STAR, also from UCLA,, an identical 3U+ CubeSat that will allow scientists to more precisely measure the radiation environment in low Earth orbit.
• DAVE, or the Damping and Vibrations Experiment,, a 1U CubeSat developed at Cal Poly with a payload to evaluate a mechanical damping technology in microgravity.
• SurfSat, a 2U CubeSat developed at the University of Central Florida to measure static charging on spacecraft surfaces in orbit.
  

Meanwhile, the Delta 2 upper stage fired once more for a braking burn to drop out of orbit and re-enter Earth's atmosphere over the Pacific Ocean, wh ere the rocket was expected to break apart and burn up. The deorbit burn was intended to ensure the mission does not add more space junk to orbital traffic lanes, and the re-entry marked the formal conclusion of the final Delta 2 flight.

"I'm a little bit sad," said Tim Dunn, NASA's launch director for the ICESat 2 mission. "I'm thrilled with mission success, and that we were able to close the chapter on Delta with a huge success of an incredibly important science payload.

"ICESat 2 is going to do cutting edge scientific data-gathering, the precision measurements it's going to do from space are just going to be incredible," said Dunn, a 22-year veteran of the Delta 2 rocket program at Boeing and NASA. "So to be able to say that we launched this very important science mission on the final flight of the industry workhorse is just a huge accomplishment for the entire team. I have a lot of personal feelings about the Delta 2, but I'm really just a very small part of the entire Delta 2 team."

While ULA's Delta 4 rocket will remain in service for several more years, the Delta 2 rocket was the last U.S. launcher flying that could trace its basic design to the dawn of the Space Age.


The Delta 2 rocket launched Saturday featured four strap-on solid rocket boosters. Credit: United Launch Alliance

...

Here are some statistics on Saturday's launch:

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• 381st Delta rocket launch since 1960
• 724th launch of a Thor-based rocket
• 237th Delta launch with NASA involvement
• 155th Delta 2 rocket mission since 1989
• 14th Delta 2 to fly in the 7420 configuration
• 241st flight of an RS-27 engine
• 277th flight of an AJ10 engine
• 1,000th-1,003rd GEM-40 solid rocket motors launched on Delta 2s
• 54th Delta 2 mission overseen by NASA
• 45th Delta 2 rocket launch from Vandenberg Air Force Base
  

"The Delta 2 vehicle has touched the life of probably every single person in America in the technoloy that it's enabled over its 30 years," Messer said. "It's been a very, very prominent part of space history."

Other Delta 2s dispatched NASA's first three Mars rovers — Sojourner, Spirit and Opportunity — toward the red planet, along with the MESSENGER mission to orbit Mercury, the Dawn mission to the asteroid belt, the Spitzer Space Telescope, the planet-hunting Kepler observatory, weather satellites, and dozens of commercial and military communications spacecraft.

From Vandenberg, Delta 2 rockets hauled the bulk of Iridium's first-generation fleet of voice and data relay satellites into low Earth orbit on 12 launches from 1997 through 2002. Those satellites are now being replaced by an upgraded Iridium fleet launching on SpaceX Falcon 9 rockets.

The Globalstar satellite network, also designed for mobile communications, was deployed by a series of Delta 2 rockets launched from Cape Canaveral.

Saturday's launch extended the Delta 2's record to 100 successful launches in a row, a streak dating back to Jan. 17, 1997, when the workhorse suffered one of the most memorable rocket failures of the last quarter-century. A Delta 2 exploded just 13 seconds after a launch from Cape Canaveral with a GPS satellite, raining debris back down on its launch pad, leaving a cratered parking lot and destroyed cars outside the pad bunker.

No one was injured in the accident, and the Delta 2 returned to flight less than four months later with an Iridium satellite launch from California.

"The Delta 2 will go down in history as one of the world's most successful launch vehicles, and we're proud to be part of that legacy," said Eileen Drake, CEO and president of Aerojet Rocketdyne, supplier of the Delta 2's first and second stage engines.

The RS-27A main engine, which generates 200,000 pounds of thrust at sea level, is a descendant of the H-1 engine used on the main stages of NASA's Saturn 1 and Saturn 1B rockets, the predecessors of the Saturn 5 moon rocket in the Apollo program. In addition to a main thrust chamber, the RS-27A has two vernier engines for roll control during flight.

The second stage's AJ-118K engine has its roots in the ballistic missile programs of the 1950s, and was later updated to power the Transtage, an upper stage that flew on Titan rockets, according to Aerojet Rocketdyne. It burns a combination of Aerozine 50, a fuel cocktail made by mixing hydrazine and unsymmetrical dimethyl-hydrazine, and nitrogen tetroxide oxidizer to provide 9,850 pounds of thrust at altitude.

Elizabeth Jones, Aerojet Rocketdyne's RS-27 and AJ10 program manager, said Friday that the Delta 2's engines went through several upgrades over the decades, adding thrust and performance as the rocket's size crew larger. Both types of engines will not fly again after Saturday's mission, but a similar engine to the AJ10 will continue launching with NASA's Orion crew capsule.

"We've been saying at some of our meetings, who's going be the first one to crack? Is anybody going to tear up? It's an emotional time, there's a long legacy to be proud of," Jones said.

"I'll miss the work, I'll miss the people," said Latanjia Robinson, Aerojet Rocketdyne's AJ10 chief engineer. "I'll miss traveling to the launch sites to support the various tasks prior to launch, and the launches themselves.

"But it'll be rewarding. I look forward to a successful mission," Robinson said in an interview before Saturday's launch.

The Delta 2 could fly with three, four or nine solid rocket motors built by Northrop Grumman Innovation Systems, formerly known as Orbital ATK. Over the history of the program, more than 1,000 of the solid motors have launched with Delta 2 rockets.

Other holdover practices from the early Space Age that continued with the Delta 2 included a manual command from the control center to start the RS-27A main engine. Delta 2 countdowns didn't use an auto sequencer like newer rockets.


The ICESat 2 satellite was encapsulated inside the Delta 2's clamshell-like payload fairing after it was mounted on top of the rocket. Credit: USAF 30th Space Wing/Alex Valdez

The Delta 2's payloads were encapsulated inside the rocket's nose cone on top of the launch pad's mobile gantry in a cramped clean room, whereas satellites riding newer U.S. launchers are closed up inside their fairings in more expansive offsite processing facilities, then transported to the pad.
...

ICESat 2 begins ice-surveying mission

Спойлер

ICESat 2 stands for Ice, Cloud and land Elevation Satellite 2, a follow-on to NASA's ICESat mission which measured global ice sheets from 2003 until 2009.

Featuring an improved laser instrument designed to provide more precise measurements than its predecessor, ICESat 2 will extend a data series which has shown ice is melting around the edges of Greenland and Antarctica, and is thinning in the oceans.

"What we learned from ICESat about the ice sheets of Greenland and Antarctica is that they are particularly losing ice around coastal areas, which means, one, that they were losing ice, and also two, it was probably tied to changes occuring in the ocean," said Tom Wagner, NASA's cryosphere program scientist.

That's important because ice conditions are linked to other factors that drive Earth's climate, such as currents and temperatures in the oceans. And rising sea levels could threaten cities along coastlines, according to scientists.

"In Antarctica and Greenland, we have about two-thirds of the Earth's fresh water," said Helen Fricker, a member of ICESat's science definition team at the Scripps Institution of Oceanography. "If all of that ice melted, we would raise global sea level on average by about 180 feet (54 feet), which is very significant."

Altimetry data collected by by the U.S.-French TOPEX/Poseidon and Jason series of satellites show the average global sea level rose by 77 millimeters (3 inches) from 1993 through 2017. Scientists will compare data from missions like ICESat 2 with gravity measurements from missions like GRACE-Follow On, which launched in May and is sensitive to the mass of the ice.

"ICESat 2 really is a revolutionary new tool for both land ice and sea ice research," said Tom Neumann, ICESat 2's deputy project scientist at NASA's Goddard Space Flight Center.

Read our earlier story for a detailed report on ICESat's science objectives.

NASA has used satellites to look at ice for decades, but tracking ice coverage is easier than measuring the height, and estimating the thickness, of floating sea ice and ice caps covering land masses.

Rather than relying on a single laser beam, as ICESat did, the new mission will fire six laser beams down to Earth and measure the time it takes for the light to bounce off the surface and back to a telescope on-board the spacecraft. The results will yield information on the height and slope of the ice.

The ICESat 2 satellite was built by Northrop Grumman Innovation Systems, and its single instrument — the Advanced Topographic Laser Altimeter System, or ATLAS — was developed at NASA's Goddard Space Flight Center.

"ATLAS essentially acts like a stop watch," said Donya Douglas-Bradshaw, ATLAS instrument manager at Goddard. "The ATLAS laser fires 10,000 pulses per second with a trillion photons in each shot. Each time the laser fires, it starts the stop watch. It takes about 3.3 milliseconds for the beam to exit the instrument, reach the surface and return back to the telescope."

Only about a dozen or so photons will make it back to ICESat 2's receiving telescope, with the rest of the light scattering in the atmosphere or back into space.

The laser package "has the ability to time tag a single photon to billionth of a second accuracy," Douglas-Bradshaw said in a briefing with reporters. "This precision allows the instrument to detect annual changes in ice elevation on the order of half of a centimeter (0.2 inches)."

The photon-counting method is new, and development the ATLAS laser proved to be a challenge, delaying ICESat 2's launch more than two years, and adding several hundred million dollars to the mission's cost.

Ground controllers plan to open a protective door covering the ATLAS instrument's sensitive optics around a week after launch, followed by the switch-on of the ATLAS laser about a week after that, according to Doug McLennan, ICESat project manager at Goddard.

After around 60 days of commissioning, officials expect to declare ICESat 2 ready for science observations.

ICESat is designed for a three-year mission, but it carries enough fuel to remain useful for more than 10 years, McLennan said.

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НОРАД частично идентифицировал 5 объектов запуска

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ULA‏Подлинная учетная запись @ulalaunch 17 сент.

Delta II launched its final mission on Saturday, but the memories live on. Use the #DeltaII hashtag to share your favorite memory about this rocket for your chance to win a prize pack. We'll randomly select winners Sept 18, Sept 20 and Sept 24.

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Vandenberg launches ULA Delta II
30th Space Wing Public Affairs
Sept. 15, 2018 | 0:45


(video 0:45)

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НОРАД идентифицировал главную ПН запуска

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Tory Bruno‏Подлинная учетная запись @torybruno 11 ч. назад

The Great Workhose, Delta II, ended her career with another Bullseye. #IceSat2

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Rocket Cam! Delta II ICESat-2

United Launch Alliance

Опубликовано: 20 сент. 2018 г.

Rocket's eye view of NASA's Ice, Cloud and land Elevation Satellite (ICESat)-2 mission from ULA's Delta II rocket.

(3:22)

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NASA ICE‏Подлинная учетная запись @NASA_ICE 21 сент.

Week 1 update: #ICESat2 is looking great! Solar array deployed, all subsystems turned on, and we're busy checking everything out. Navigation works perfectly, guiding us along our planned orbit. ~1 week until it's time to open the door & turn on the laser!

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NASA ICE ‏Подлинная учетная запись @NASA_ICE 42 мин. назад

Our door is open!
The ATLAS instrument on #ICESat2 was designed with a door to protect the instrument as it settles into orbit – this morning the operations team successfully issued the commands to open the door and start letting the light in!

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NASA ICE‏Подлинная учетная запись @NASA_ICE 12 ч. назад

The #ICESat2 laser is on, and has fired its first photons! 10,000 pulses each second, hundreds of trillions of photons with each pulse- all to measure the height of 's surface.
#pewpewpew

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https://www.nasa.gov/feature/goddard/icesat-2-laser-fires-for-1st-time-measures-antarctic-height

Oct. 3, 2018

ICESat-2 Laser Fires for 1st Time, Measures Antarctic Height

The laser instrument that launched into orbit last month aboard NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) fired for the first time Sept. 30. With each of its 10,000 pulses per second, the instrument is sending 300 trillion green photons of light to the ground and measuring the travel time of the few that return: the method behind ICESat-2's mission to monitor Earth's changing ice. By the morning of Oct. 3, the satellite returned its first height measurements across the Antarctic ice sheet.

Спойлер

"We were all waiting with bated breath for the lasers to turn on and to see those first photons return," said Donya Douglas-Bradshaw, the project manager for ICESat-2's sole instrument, called the Advanced Topographic Laser Altimeter System, or ATLAS. "Seeing everything work together in concert is incredibly exciting. There are a lot of moving parts and this is the demonstration that it's all working together."

ICESat-2 launched on Sept. 15 to precisely measure heights and how they change over time. It does this by timing how long it takes individual photons to leave the satellite, reflect off the surface, and return to receiver telescope on the satellite. The ATLAS instrument can time photons with a precision of less than a billionth of a second, which allows the mission to detect small changes in the planet's ice sheets, glaciers and sea ice.


(video 2:48)
Pho, a plucky bright green photon of light, must travel from a NASA spacecraft down to Earth and back again to help complete a crucial science mission in this educational short film. The animation was created and produced by media art students from the Savannah College of Art in Design in Georgia, in collaboration with ICESat-2.
Credits: NASA/Goddard/Savannah College of Art and Design et al
Download this video in HD formats from NASA Goddard's Scientific Visualization Studio

Once ICESat-2 was in space, the ATLAS team waited to turn on the lasers for about two weeks to allow any Earthly contaminants or gases to dissipate.

"It's very critical when you fire the lasers that you don't have contaminants because you could damage the optics," Douglas-Bradshaw said. "Fourteen days is well beyond the time needed for that, but we wanted to be safe."

During those two weeks, the ICESat-2 operations team turned on and tested the various systems and subsystems of the spacecraft and instrument, and fired thrusters to start placing the satellite in its final polar orbit, approximately 310 miles (500 kilometers) above Earth.

Before the laser was even turned on, however, the team eagerly awaited another milestone, Douglas-Bradshaw said. The door that protected the telescope and detector elements during launch had to be opened. The team had two chances to release one of two spring-loaded pins to open the door. This was successfully accomplished on Sept. 29.

The following day, it was the laser's turn. The engineering team had been working with the operations team that controls the instrument on orbit, so the commands were ready to go — first turning on the laser itself, waiting for it to warm up, and then issuing commands to put it in fire mode.

The laser energy levels jumped up, and the device that starts ATLAS's sophisticated stopwatch was active — two different, independent indicators that the laser was firing away.

"We were all incredibly excited and happy, everyone was taking pictures of the screens showing data plots," Douglas-Bradshaw said. "Someone noted: 'Now we have a mission, now we have an instrument.'"


A visualization of ICESat-2 data, called a photon cloud, shows the first set of height measurements from the satellite, taken as it orbited over the Antarctic ice sheet. Each blue dot represents a photon detected by the ATLAS instrument. This photon cloud shows the elevation measured by photons in the middle of the ice sheet, following along 6.2 miles (10 kilometers) of the satellite's ground track, from left to right. The speckled dots are background photons from sunlight, but the thick blue line is actually a concentration of dots that represent laser photons that returned to the ICESat-2 satellite.
Credits: NASA's Goddard Space Flight Center

Three days later, the ICESat-2 team had the first segment of height data, taken as the satellite flew over Antarctica.

Computer programmers were up all night analyzing the latitude, longitude and elevation represented by each photon that returned to the ATLAS instrument — and by 6 a.m., Tom Neumann, ICESat-2 deputy project scientist, was texting screenshots of the height data to the rest of the team.

"It was awesome," Neumann said. "Having it in space, and not just simulating data on the ground, is amazing. This is real light that went from ATLAS to Earth and back again."

When scientists analyze the preliminary ICESat-2 data, they examine what is called a "photon cloud," or a plot of each photon that ATLAS detects. Many of the points on a photon cloud are from background photons — natural sunlight reflected off Earth in the exact same wavelength as the laser photons. But with the help of computer programs that analyze the data, scientists can extract the signal from the noise and identify height of the ground below.

The first photon cloud generated by ICESat-2 shows a stretch of elevation measurements from East Antarctica, passing close to the South Pole at a latitude of 88 degrees south, then continuing between Thwaites Glacier and Pine Island Glacier in West Antarctica.

https://www.youtube.com/watch?time_continue=2&v=bNsOBCd7cFs
(video 3:23)
Opto-Mechanical Engineer Tyler Evans explains how the photons that bounce back from Earth are received and filtered by the ATLAS telescope. ATLAS is the primary instrument on board the ICESat-2 spacecraft, which measures the height of Earth's features.
Credits: NASA's Goddard Space Flight Center
Download this video in HD formats from NASA Goddard's Scientific Visualization Studio

Next up for ICESat-2 is a suite of procedures to optimize the instrument, Neumann said, including tests to ensure the laser is pointing at the precisely correct angle and lasing at the precisely correct wavelength to allow as many photons as possible to hit the detector.

"It will take a couple of additional weeks," he said, "but about one month after launch we'll hopefully start getting back some excellent science-quality data."

ICESat-2 launched from Vandenberg Air Force Base on the final United Launch Alliance Delta II rocket. The spacecraft was built by Northrop Grumman, which also controls the observatory from their Mission Operations Center in Dulles, Virginia.

By Kate Ramsayer
NASA's Goddard Space Flight Center, Greenbelt, Md.

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Last Updated: Oct. 3, 2018
Editor: Rob Garner

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NASA ICE‏Подлинная учетная запись @NASA_ICE 21 ч. назад

Take a look at the first photon returns from #ICESat2's six beams as it orbits over Antarctica! The green lines are number of photons detected, while the X-axis shows how long it took the photons to get from ICESat-2 to the ground and back!


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NASA ICE‏Подлинная учетная запись @NASA_ICE 3 мин. назад

The #ICESat2 photons keep returning! A set of height measurements over a boreal forest in Siberia shows the laser light reflecting from both the leaves/branches of trees & the forest floor (courtesy of K.Harbeck). https://go.nasa.gov/2ybKUyt 

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NASA ICE‏Подлинная учетная запись @NASA_ICE 17 ч. назад

Check out how #ICESat2 sees sea ice! Here's a first look at photon returns over the North Atlantic and Arctic oceans near Svalbard, showing heights where open water (red arrows) breaks up chunks of floating ice (courtesy K. Harbeck)