EO·Atlas
HydroGNSS (ESA Scout)
Two-microsat ESA Scout constellation launched November 2025; GNSS-R instruments receive GPS and Galileo reflections to measure soil moisture, freeze-thaw state over permafrost, wetland inundation, and above-ground biomass at 500-600 km SSO.
HydroGNSS is an ESA Scout mission consisting of two microsatellites launched on 28 November 2025 into a sun-synchronous orbit at 550 km altitude and 98-degree inclination. As of mid-2026 the mission is in the commissioning phase, with science data release expected in July 2026.[1][2]
Each spacecraft carries an SGR-ReSI-Z GNSS reflectometry receiver designed to measure reflected GPS and Galileo signals and to derive soil moisture, freeze-thaw state of permafrost, wetland inundation extent, and above-ground biomass. The SGR-ReSI-Z is a new generation of the SGR-ReSI instrument flown on TechDemoSat-1, which demonstrated spaceborne GNSS-R ocean wind retrieval in 2014, and builds on techniques validated on the CYGNSS constellation.[3]
The two-satellite configuration provides repeat coverage to support seasonal monitoring of permafrost dynamics and flood inundation in high-latitude and wetland regions.[3][1]
Supply chain position
- [1]ESA HydroGNSS launched to scout for wateroperator press-2026-06-11
- [2]HydroGNSS satellites proving in-orbit capabilities, SSTL 2026operator press-2026-06-11
- [3]HydroGNSS/Scout-2 mission overview, eoPortalagency doc-2026-06-11
- [4]HydroGNSS data now available to researchers worldwide, SSTLoperator press2026-08-032026-10-19
How to cite this page
Plain text
HydroGNSS (ESA Scout). EO-Atlas, SpectraWorks B.V. https://eo-atlas.org/missions/hydrognss (CC BY 4.0)
BibTeX
@misc{eoatlas:missions:hydrognss,
title = {HydroGNSS (ESA Scout)},
author = {{EO-Atlas}},
publisher = {SpectraWorks B.V.},
note = {CC BY 4.0},
url = {https://eo-atlas.org/missions/hydrognss}
}