The mission

HydroGNSS is the first ESA Scout mission. The two-satellite mission uses a technique called Global Navigation Satellite System reflectometry to measure hydrological climate variables, including soil moisture, freeze–thaw state over permafrost, inundation and wetlands, and biomass.

Embracing the concept of New Space, Scout missions pave the way to innovative science in a quick and agile fashion, and complement ESA’s Earth Explorer research missions.


The launch

Date: 28 November 2025
Site: Vandenberg, California, US
Rocket: Falcon 9

HydroGNSS.png
1st Scout mission
2 identical satellites
550 km altitude
25 km resolution

Latest news

HydroGNSS launched to ‘scout’ for water
HydroGNSS
HydroGNSS satellite twins ready for launch
Scout HydroGNSS mission

Latest images

Surface water over South America from HydroGNSS

Latest videos



HydroGNSS videos

Video gallery

HydroGNSS mission kit

HydroGNSS mission kit cover

HydroGNSS documents and publications

Documents and publications

Related links

HydroGNSS
HydroGNSS at Surrey Satellite Technology facilities
Wetland – a fragile water-dependent ecosystem
HydroGNSS from below


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