2022 has been an exceptional year for NASA, between the launch of the Artemis lunar mission, the spectacular images from the James Webb space telescope, or the strike of an asteroid with the DART probe. But the year is not over yet. NASA and its partners are launching a mission on Thursday to see almost all the water that covers the Earth’s surface.
The Surface Water and Ocean Topography (SWOT) satellite is set to launch aboard a SpaceX Falcon 9 rocket on Thursday. The rocket will launch from Space Launch Complex 4-East at Space Force Base Vandenberg, California.
Once in orbit, SWOT will measure the depth of water in the ocean, as well as masses of fresh water, over more than 90% of the Earth’s surface. Its innovative technology will increase the spatial resolution of scientific measurements of the height of the water.
Understanding the water cycle and preventing floods
“It’s important because with global warming, the oceans are rising,” Karen St. Germain, director of NASA’s Earth Sciences Division, told reporters on Wednesday. “Our coasts are changing, and we are seeing great fluctuations in inland water bodies – lakes, reservoirs and rivers. »
SWOT, she continued, will bring a “revolutionary advance” in our understanding of the water cycle – how water moves from the oceans to land through the atmosphere and then back to the ocean.
“The data from SWOT will inform communities around the world, from water managers and agricultural producers inland to coastal communities who face an increased risk of flooding” , she added.
Four agencies involved
The SWOT mission is a joint effort between NASA and the Center National d’Etudes Spatiales (CNES) – the French space agency. Space agencies have also received help 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 ocean and surface water levels over a 120 km wide band, with a deviation of about 20 km at nadir. The Canadian Space Agency provided a high power assembly component for KaRIn.
The payload also includes the Jason-class altimeter, which will collect data in the gap between KaRIn bands. It will send and receive signals that move in a straight line up and down. The round trip travel time of each pulse will be used to determine the sea surface height.
Nadir altimeter and DORIS antenna for CNES
Then there is the DORIS antenna (Doppler Orbitography and Radiopositioning Integrated by Satellite). This instrument, built by CNES, will pick up signals from 50 to 60 radio beacons on the ground, evenly distributed on Earth to ensure good coverage. CNES also built the Nadir altimeter.
The payload also includes a microwave radiometer to measure water vapor between, an X-band antenna, an array of mirrors called a laser reflector assembly, and a GPS receiver.
In June 2021, the Jet Propulsion Laboratory shipped the payload to France, where an international team integrated the instruments into the satellite bus.
“Consider putting on glasses,” warns Karen St. Germain. “We will have a clear picture of these inland water bodies. We will go from a few thousand lakes and reservoirs to millions. This will have a huge positive impact for those who depend on knowledge of water levels to manage water for everything from agriculture to human consumption. »
Source: ZDNet.com