The new international satellite mission called Surface Water and Ocean Topography (SWOT) — slated for launch in late 2022 — will measure the height of Earth's surface water. The data the spacecraft will collect will help researchers understand and track the volume and location of water around the world. The satellite will assist with monitoring changes in floodplains and wetlands, measuring how much fresh water flows into and out of lakes and rivers and back to the ocean, and tracking regional shifts in sea level at scales never seen before. The satellite will also provide information on small-scale ocean currents that will support real-time marine operations affected by tides, currents, storm surge, sediment transport, and water quality issues.

The payload is taking shape in a clean room at NASA's Jet Propulsion Laboratory in Southern California before being shipped to France. There, technicians and engineers from the French space agency Centre National d'Etudes Spatial (CNES), their prime contractor Thales Alenia Space, and JPL will complete the build and prepare the satellite for shipment to its California launch site at Vandenberg Air Force Base. JPL project manager Parag Vaze (pronounced vah-zay) is central to ensuring the handoff to his CNES counterpart Thierry Lafon goes smoothly.

SWOT is being jointly developed by NASA and CNES, with contributions from the Canadian Space Agency (CSA) and United Kingdom Space Agency (UKSA). JPL, which is managed for NASA by Caltech in Pasadena, California, leads the U.S. component of the project. For the flight system, NASA is providing the Ka-band Radar Interferometer (KaRIn) instrument, a GPS science receiver, a laser retroreflector, and a two-beam microwave radiometer. CNES is providing the Doppler Orbitography and Radioposition Integrated by Satellite (DORIS) system, nadir altimeter, and the KaRIn RF subsystem (with support from the UKSA). CSA is providing the KaRIn high-power transmitter assembly. NASA is providing associated launch services.