WASHINGTON — A SpaceX Falcon 9 efficiently launched Nov. 21 the newest in a sequence of satellites developed by the USA and Europe to trace rising sea ranges.
The Falcon 9 lifted off from Area Launch Advanced (SLC) Four East at Vandenberg Air Drive Base in California at 12:17 p.m. Japanese. Its payload, the Sentinel-6 Michael Freilich satellite tv for pc, separated from the rocket’s higher stage practically an hour later, after a short second burn of the higher stage. The rocket’s first stage landed on a pad again at SLC-Four.
Sentinel-6 Michael Freilich is the primary of two satellites collectively developed by a gaggle of businesses in the USA and Europe, together with NASA, NOAA, the European Area Company, Eumetsat and the European Fee, to offer exact measurements of rising sea ranges.
The spacecraft will guarantee a continuity of measurements courting again practically three many years, beginning with the TOPEX/Poseidon satellite tv for pc launched in 1992 and adopted by the three Jason spacecraft launched in 2001, 2008 and 2016. These earlier spacecraft had been joint tasks of NASA, NOAA, Eumetsat and the French area company CNES, whereas Sentinel-6 Michael Freilich is taken into account a part of the Copernicus program of Earth statement satellites by ESA and the EU.
“It’s the primary time that ESA and NASA have actually collaborated in such an built-in means on an Earth statement satellite tv for pc,” mentioned Pierrik Vuilleumier, Sentinel-6 undertaking supervisor at ESA, throughout a Nov. 20 pre-launch briefing. NASA and ESA are every spending about half a billion dollars on the overall program, which features a second Sentinel-6 satellite tv for pc that may launch in the midst of the last decade.
The spacecraft itself, weighing 1,192 kilograms at launch, was constructed by Airbus Defence and Area in Germany. It has a particular look with two body-mounted photo voltaic panels that seem like the roof of a home. That design is meant to maximise the facility they will present with out requiring the usage of deployable arrays and motors than can induce vibrations within the spacecraft.
The spacecraft’s principal instrument is a radar altimeter offered by ESA, which bounces radio pulses off the ocean to measure sea stage in addition to wave peak and ocean pace. It’s supported by a microwave radiometer developed at NASA’s Jet Propulsion Laboratory, which measures water vapor within the ambiance to offering timing corrections for the radar altimeter.
Additionally on Sentinel-6 Michael Freilich is a worldwide navigation satellite tv for pc system radio occultation (GNSS-RO) instrument to offer measurements of the atmospheric temperature and moisture by measuring alerts from GPS and different navigation satellites. That instrument is just like these on the six COSMIC-2 satellites launched in June 2019. Along with measuring atmospheric circumstances, information from the GNSS-RO instrument will probably be used with that from three different sensors to exactly measure the spacecraft’s orbit, at an altitude of 1,336 kilometers and an inclination of 66 levels.
Sentinel-6 Michael Freilich will function in the identical orbit as Jason-Three, with the 2 satellites about 30 seconds aside. That can help within the commissioning of the brand new spacecraft, a course of that may take a few 12 months, mentioned Remko Scharroo, undertaking scientist for the mission at Eumetsat. “They’ll principally see the identical ocean circumstances, and that, in fact, makes evaluating the measurements significantly better,” he mentioned at a pre-launch briefing.
Whereas the spacecraft options improved decision and precision in comparison with its predecessors, scientists emphasised the significance of constant a sequence of measurements of sea stage peak courting again practically three many years. Sentinel-6 Michael Freilich “will proceed our file of sea floor peak observations nicely into the following decade,” mentioned Karen St. Germain, director of NASA’s Earth science division.
“It’s a essential statement for various causes, however its energy is absolutely unleashed after we mix our altimetry observations of the ocean floor peak measurements with the observations we get from the opposite satellites within the NASA fleet and the worldwide fleet,” she continued. “We will see not solely that the ocean stage is rising however we will additionally inform how a lot of that change is coming from melting ice sheets and glaciers, and the way a lot of that change is coming from thermal growth of the oceans themselves.”
That satellite tv for pc information has proven that sea ranges aren’t solely rising, but in addition that the speed of improve is accelerating. Sea ranges had been rising on the price of about two millimeters per 12 months within the 1990s, mentioned Josh Willis, undertaking scientist for the mission at JPL, however at the moment are growing at 4 to 5 millimeters per 12 months. “We’re watching the speed of sea-level rise improve proper earlier than our very eyes, and it’s satellites like this that enable us to do it,” he mentioned.
“We can’t ignore that our planet is altering,” mentioned Pierre Delsaux, deputy director basic for area for the European Fee, at a briefing in regards to the mission in October. “The local weather is altering. No one can deny it. From that perspective, we have to perceive why the local weather is altering, what are the components, and we have to monitor the state of affairs.”
NASA and ESA named the spacecraft after Michael Freilich, a former director of NASA’s Earth science division, throughout a ceremony early this 12 months. Freilich, who retired from NASA in 2019 after main NASA’s Earth science packages for greater than a decade, died of most cancers in August.
“This partnership may be very a lot aligned with what Mike Freilich’s ardour has been,” mentioned Thomas Zurbuchen, NASA affiliate administrator for science, on the pre-launch briefing, noting Freilich’s analysis in ocean sciences earlier than taking the NASA place. “I need to let you know how honored I really feel, and the way it nonetheless strikes me as we speak, that the identify of Michael Freilich is, in actual fact, on this spacecraft.”
“It’s an additional special occasion after we will see this satellite tv for pc launch, the satellite tv for pc that he labored so laborious to place in place,” mentioned St. Germain.