2022 has been an exceptional year for NASA, between the launch of the Artemis lunar mission, spectacular images from the James Webb Space Telescope, and the DART probe’s asteroid impact. But the year is not over yet. NASA and its partners are launching a mission on Thursday to see almost all of the water covering the Earth’s surface.
The Surface Water and Ocean Topography (SWOT) satellite is due to launch aboard a SpaceX Falcon 9 rocket on Thursday. The rocket will be launched from Spaceport 4-East at Vandenberg Space Force Base, California.
Once in orbit, SWOT will measure the depth of ocean water as well as the mass of fresh water over 90% of the Earth’s surface. Its innovative technology will improve the spatial resolution of scientific water height measurements.
Understanding the Water Cycle and Flood Prevention
“This is important because with global warming, the oceans are rising,” Karen Saint-Germain, director of NASA’s Earth Sciences Division, told reporters on Wednesday. “Our shores are changing, and we are seeing large fluctuations in inland waters – lakes, reservoirs and rivers. »
SWOT, she continued, will bring “revolutionary progress” to our understanding of the water cycle - how water moves from the oceans to land through the atmosphere and then back to the ocean.
“The SWOT data will inform communities around the world, from water managers and agricultural producers on land to coastal communities that are facing increased flood risk,” she added.
Four agencies involved
The SWOT mission is a joint effort between NASA and the National Center for Space Studies (CNES), the French space agency. The space agencies have also received assistance from the Canadian Space Agency (CSA) and the UK Space Agency.
NASA’s Jet Propulsion Laboratory (JPL) built the main component of the mission’s science payload: the Ka-band radar interferometer (KaRIn). Using radar interferometry, KaRIn will measure the level of the ocean and surface waters in a 120 km wide band with a deviation of about 20 km in nadir. The Canadian Space Agency has provided a high power assembly component for KaRIn.
The payload also includes a Jason class altimeter that will collect data between the KaRIn ranges. It will send and receive signals that move up and down in a straight line. The round trip time of each pulse will be used to determine the height of the sea surface.
Nadir altimeter and DORIS antenna for CNES
Then there is the DORIS antenna (Doppler orbitography and radio positioning integrated by satellite). This instrument, built by CNES, will pick up signals from 50 to 60 ground-based radio beacons evenly distributed across the Earth to provide good coverage. CNES also built the Nadir altimeter.
The payload also includes a microwave water vapor radiometer, an X-band antenna, an array of mirrors called a laser reflector, and a GPS receiver.
In June 2021, the Jet Propulsion Laboratory sent a payload to France, where an international team integrated the instruments into a satellite bus.
“Consider wearing glasses,” warns Karen St. Germain. “We will have a clear picture of these inland waters. We will go from a few thousand lakes and reservoirs to millions. This will have a huge positive impact on those who depend on knowledge of water levels to manage water for everything from agriculture to human consumption. »
Source: .com