UK-built HydroGNSS satellites arrive in California for launch

The HydroGNSS mission, built by Surrey Satellite Technology Ltd (SSTL) and funded by the UK Space Agency, has arrived in California and is preparing for launch.

• Mission arrival and launch preparations: HydroGNSS-1 and HydroGNSS-2 have landed in California and are ready for pre-launch processing; launch is expected later this year on a Falcon 9. The mission comprises two microsatellites (each carrying a GNSS reflectometry instrument) to fly in 500–600 km orbits, 180 degrees apart; the project received €30 million of funding from the UK Space Agency via ESA’s FutureEO programme.
• Mission scope and background details: HydroGNSS will observe four essential hydrological climate variables (soil moisture, inundation/wetlands, freeze/thaw state, above-ground biomass) and secondary products (wind speed over the ocean, sea-ice extent); it uses GNSS reflectometry (signals from Galileo, GPS) to derive these measurements, aims to fill data gaps after ESA’s SMOS and NASA’s SMAP missions end, and is the first of three ESA Scout missions complementing Earth Explorer research missions.