HydroGNSS mission will now comprise two identical satellites to halve the time it takes to revisit the same place on Earth’s surface and re-measure various climate variables such soil moisture. Having two satellites in orbit will significantly improve the science that this exciting new Scout mission will yield.

With the development of the first HydroGNSS satellite already underway, this second satellite will now be built in parallel so that they can be launched together. Liftoff is planned for 2024.

Orbiting Earth 180 degrees apart, the two identical satellites will use a technique called Global Navigation Satellite System (GNSS) reflectometry to measure important climate variables such as soil moisture, freeze–thaw state over permafrost, inundation and biomass – all of which are linked to Earth’s water cycle. The satellites will also measure wind speed over the ocean and sea-ice extent as secondary products.