International satellite launched to measure sea level rise – Spaceflight Now


A Falcon 9 rocket takes off from Vandenberg Air Force Base with a Sentinel-6 Michael Freelach oceanographic satellite. Sincerely: SpaceX

Riding on a SpaceX Falcon 9 rocket from the Central Coast of California, a European-built satellite with unusual size of a home launched into orbit on Saturday carried a sophisticated radar altimeter to measure rising sea levels on our home planet .

The Sentinel-6 Michael Freelich observation satellite took off at approximately 140 mi (225) from Space Launch Complex 4-East at Vandenberg Air Force Base on Saturday from 9:17:08 pm PST (12:17:08 pm EST; 1717: 08 GMT). Lifted away; Kilometers) northwest of Los Angeles.

Flying south-southeast, the 229-foot-long (70-m) Falcon 9 rocket sent the satellite into orbit on the first mission of SpaceX from the West Coast launch site from June 2019.

Less than two-and-a-half minutes into the flight, the Falcon 9’s first-stage boosters disassembled and fired cold gas thrusters to fly around first and the tail flew. The Falcon 9 boosters directed towards the boost-back burn and entry burn Vandenberg by a subset of the rocket’s Merlin engines.

The supersonic return maneuver ended at the landing barn by the rocket’s center engine. Four landing legs stuck just before touchdown as the 15-story booster woke up about eight-and-a-half minutes after Bulsey’s landing at SpaceX’s rocket recovery facility at the Vandenberg Airforce Base.

The successful landing marks the third time SpaceX has returned a Falcon 9 booster at the onshore landing site in Vandenberg and the 66th recovery of a Falcon booster overall.

The rocket’s upper stage continued to fire its single Merlin to reach a parking orbit around the Earth, then 6 minutes after dispatch sent the Sentinel-6 Michael Freelich satellite to circulate its orbit before detaching Ruled the engine for about 10 seconds.

Live video of the Falcon 9’s upper stage shows a 2,628-pound (1,192 kg) spacecraft flying rocket-free in the Indian Ocean.

The Sentinel-6 Michael Frillich satellite was built by Airbus in Germany and is the size of a small pickup truck. Sentinel-6 Michael Freilich has carved a radar altimeter, a microwave radiometer and instruments to accurately locate the satellite in orbit. By working together, the equipment will track changes in sea level a few centimeters down.

The mission is a partnership between NASA, the European Space Agency, UMetsat and NOAA. The European Commission – the executive arm of the EU – and the French space agency CNES also supported the mission.

The Sentinel-6 Michael Freelich satellite is named for the former head of NASA’s Earth Science Division, who died of cancer earlier this year.

“Congratulations to all who made today’s launch of the Sentinel-6 Michael Freelich satellite possible!” NASA Administrator Jim Bridenstein tweeted. “A Tribute to an Incredible Trailblazer in Earth Science.”

Ground teams at the European Space Operations Center in Germany received signals from the new oceanographic satellite about one-and-a-half hours after liftoff, while the spacecraft departed at a ground station in Alaska. The controllers confirmed that the satellite enhanced its power-generating solar panels, and the spacecraft appeared to be in good shape at first glance’s health assessment.

Preliminary data showed that the Falcon 9 rocket placed the satellite in orbit very close to the target altitude of 830 miles (1,336 kilometers). The launcher aimed to inject the spacecraft at the equator, which was tilted about 66 degrees at the equator, the same orbital plane where a predecessor oceanographic satellite called Jason 3 flies.

Rising sea levels are a consequence of climate change. Data from previous satellites show that according to mission scientists the rate of rise in sea level is accelerating.

Sentinel-6 Michael Freilich is next in a series of oceanographic missions tracking sea level rise, beginning in 1992 with the US-French Topex / Posidon mission. Jason 1, Jason 2 and Jason 3 satellites Topex / Pozidon, and a similar satellite called Sentinel-6B called Sentinel-6 Michael Frillich are planned to be launched in 2025 to further the data record of sea level rise.

The Topex / Poseidon and Jason satellites have increased global sea levels by about 3.5 inches (9 cm) over the past 30 years, said Remco Shararu, the Sentinel-6 project scientist at Eumetsat.

According to Thomas Zurbuchen, head of NASA’s Science Mission Directorate, the two Sentinel-6 missions cost around $ 1 billion, and were split evenly between the US and European partner agencies.

“This satellite is so good that we made it twice,” said Jose Willis, a project scientist at NASA’s Jet Propulsion Laboratory, sentinel-6 project scientist.

“The record of global sea level rise actually goes back to the early 90s,” said Willis. “What’s interesting about this is that you can see that the rate of growth is actually increasing. In the 90s, sea levels were rising about 2 millimeters per year. In the 2000s, it was more like 3 millimeters per year, and now it is closer to 4 or 5 millimeters per year. So we are seeing the rate of sea level rise before our eyes, and it is these types of satellites that allow us to do so. “

Artist concept of Sentinel-6 Michael Freelich satellite. Credit: ESA / ATG Medialab

Sentinel-6 mission scientist Craig Donlon at ESA said that rising sea water levels “threaten big cities, including New York, London, Amsterdam, Tokyo, and more. It is estimated that every 1 in sea level About 2 to 3 million people are exposed to the millimeter increase. ”

The Sentinel-6 Michael Freelich is the eighth satellite to launch for the European Copernicus planetarium, part of a fleet that orbits the Earth’s land surface, oceans, ice sheets, and radar, optical, microwave, ultimetry and spectral devices With the atmosphere. The European Commission administers the Copernicus program, with the ESA providing technical expertise and coordinating sentinel satellites.

A primary goal of Copernicus satellites is to collect data on the changing climate of the Earth. The fleet is the most capable satellite program focused on Earth observation. Sentinel satellites’ data is distributed free of charge worldwide.

“We see evidence of this dramatic shift in many different measurements and events around the world, but they all point in the same direction – the Earth is warming up,” Donald said at a pre-launch news conference. “And the biggest indicator of imbalance of this earth system is the rise in sea level. This is because it integrates the total effects of global warming. It is dominated by melting of ice sheets, thermal expansion of sea water and changes in terrestrial water storage. “

The Sentinel-6 Michael Freelich spacecraft carries a European dual-frequency Poseidon 4 radar altimeter that transmits signals more than 800 miles below the surface of the satellite. A receiver measures the time it takes for the signal to bounce from the ocean and return to the satellite.

A microwave radiometer provided by NASA measures atmospheric properties that can present a negative effect on the travel time of a radar altimeter signal, allowing scientists to correct for disturbances and obtain more accurate measurements of sea level .

The Sentinel-6 Michael Freilich also carries devices to help determine its precise location using GPS navigation signals, Doppler measurements, and laser tracking.

This chart raises the sea level observed by satellites since the early 1990s. Sincerely: NASA

The satellite will estimate the wave height and wind speed given the roughness of the ocean surface. It will cover 95 percent of the world’s oceans every 10 days.

The unusual house-like shape of the spacecraft is also an important factor in its performance. Donalden said engineers had designed it for simplicity, and because of its lack in building solar array wings and other structures “for a very stable satellite design, which was actually critical to a satellite altimeter mission is.”

Sentinel-6 Michael Freelich will take his measurements with higher resolution than earlier satellites, given the rise in sea level. This means that the new satellite will be able to better see how the sea level is affecting the sea shore.

After the completion of the three-day activation deadline, UMetset will conduct regular operations for Sentinel-6 Michael Frillich’s five-and-a-half-year mission.

The ground teams will run the Sentinel-6 Michael Freelich approximately 140 miles or 230 kilometers behind the Jason 3 satellite, which was launched in 2016 – a year worth cross-calibration to ensure the new spacecraft. Provides the same reliable data as its predecessor.

The Sentinel-6B Sentinel-6 will replace Michael Freilich after its launch in 2025, raising the record for sea level rise to at least 2030.

SpaceX recently planned reuse of the first phase to fly with the Sentinel-6 Michael Freilich mission on the next launch of NASA’s spacecraft from Vandenberg in July, with NASA launch director Tim Dunn’s recent launch of SpaceFlight Now Said in the interview.

On that flight, a Falcon 9 rocket would launch NASA’s Double Asteroid Redirection Test, or DART, mission from Vandenberg. This will mark the first time a NASA science mission has launched on an already running Falcon 9 booster.

The DART is scheduled for the opening of a window in July 2021, which allows the probe to reach its asteroid target in late 2022. The DART will intentionally orbit a small moon, which can be used by scientists to move the asteroid to test the hypothesis technique of the asteroid Didymos collision course with Earth.

Dunn said that NASA’s Launch Services Program, which manages procurement and preparations for NASA’s science missions, has approved a rocket reuse plan for the DART mission, the Sentinel-6 Michael Freelike mission The latter flight is pending subsequent inspection and refurbishment on the booster.

NASA has already approved the launch of SpaceX’s Dragon Space Station cargo ships on the Falcon 9 booster, and earlier this year the agency reused the next SpaceX crew flight in March 2021 The crew on the rockets agreed to launch the Dragon astronaut mission.

A warning for the future of the booster is its potential use as a backup for the SpaceX Crew-2 mission in March. Cathy Lieders, head of NASA’s manned spacecraft directorate, said last week that the Falcon 9 first stage from the Sentinel-6 Michael Freelich mission could be a backup for the Crew-2 launch if problems with the primary rocket assigned to the astronaut mission She comes.

NASA and SpaceX have agreed to use the same boosters for the Crew-2 launch that is sending the Crew-1 mission to the International Space Station on 15 November. The stage landed on a SpaceX drone ship in the Atlantic Ocean and returned to Cape Canaveral. It apparently slipped across the vessel’s deck in high winds or rough seas after being thin on Thursday.

The booster appeared to be otherwise in good condition, and SpaceX unloaded the rocket from the drone ship for transport to a hangar in Cape Canaveral for inspection and refurbishment.

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Follow Stephen Clarke on Twitter: @ StephenClark1.

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