HydroGNSS, a UK‑led Earth observation mission, entered orbit on 28 November aboard SpaceX’s Falcon 9 from Vandenberg as the European Space Agency’s first Scout mission. ESA reported liftoff at 19:44 CET on the Transporter‑15 rideshare and confirmed first signals at 22:45 CET; prime contractor Surrey Satellite Technology Ltd (SSTL) later reported successful acquisition of signal.
Designed and built by SSTL in Guildford, HydroGNSS has £26 million in support from the UK Space Agency. The government’s launch notice adds that these spacecraft are SSTL’s 75th and 76th, marking a production milestone for the firm.
HydroGNSS uses Global Navigation Satellite System reflectometry, comparing direct GPS and Galileo signals with those reflected from Earth’s surface to estimate soil moisture, wetlands and inundation, freeze–thaw states and above‑ground biomass. Operating at L‑band enables observations through cloud and dense canopy where optical sensors often fail.
UK Space Agency materials set out clear end‑users: national forecasters, flood risk teams and agricultural planners. The Environment Agency says the enhanced soil‑moisture and inundation inputs should strengthen flood forecasting and warning operations during high‑impact events.
Commissioning is under way. The World Meteorological Organization’s OSCAR register lists both satellites as launched on 28 November into a sun‑synchronous orbit near 550 km, with operations not yet started. Data access will be provided via hydrognss.org: standard products are typically released around 30 days after measurement, with an option for near‑real‑time delivery within 48 hours for approved users under ESA terms.
As the first mission in ESA’s FutureEO Scout line, HydroGNSS demonstrates a rapid, lower‑cost approach intended to complement larger Earth Explorer missions. ESA documentation describes two small satellites in polar orbit at about 550 km, each carrying a GNSS‑R instrument focused on essential hydrological variables.
The launch comes ahead of an organisational change in the UK. The UK Space Agency is due to combine with the Department for Science, Innovation and Technology’s Space Directorate on 1 April 2026 to form a single civil space unit. The UKSA Corporate Plan says the change is intended to streamline strategy, policy and delivery while reducing duplication.
Budget decisions taken this week provide further context. On 27 November, the government announced a £1.7 billion package for ESA programmes at the Ministerial Council in Bremen, taking planned UK support to £2.8 billion over 2025/26–2034/35. ESA’s summary highlights allocations for launcher capability, space‑weather vigilance and exploration.
Member states also agreed an ESA budget of about €22.1 billion for 2026–2028, roughly 30% higher than the prior period. Reporting by Reuters and the Financial Times notes increases for space transportation and Earth observation and the creation of a European Resilience from Space programme.
For departments and agencies, the immediate task is practical: prepare to assimilate new soil‑moisture and inundation products, plan for differences in data latency between standard and fast streams, and align procurement to forthcoming UKSA–DSIT accountability changes. HydroGNSS is designed to complement ESA’s SMOS and Biomass missions and NASA’s SMAP, helping sustain key inputs for forecasting as legacy sensors age.