HydroGNSS facts and figures

Launch
Both HydroGNSS satellites launched together on 28 November 2025

Rocket
Falcon 9 from Vandenberg, California, US

Orbit
Near-polar, Sun-synchronous low-Earth orbit. They orbit 180 degrees apart

Altitude
550 km

Revisit time
Two satellites cover >80% land in 15 days, assuming a resolution of 25 km

Life
>3 years

Satellite
Each satellite: 45 cm × 45 cm × 70 cm; 75 kg

Payload Delay
Doppler mapping receiver, a zenith antenna, a nadir antenna, low noise amplifiers

Revisit station
Svalbard ground station, Norway

Main applications
Measures important climate-related variables such as soil moisture, freeze–thaw state over permafrost, inundation and biomass

Mission
Developed by ESA

Funding
ESA’s FutureEO programme

Prime contractor
Surrey Satellite Technology Ltd (SSTL)

Data access
SSTL distributes the data to users