Guildford-built HydroGNSS, the first mission in ESA’s Scout programme, is moving from test bay to pad. Surrey Satellite Technology Ltd (SSTL) says both 65kg spacecraft are integrated at Vandenberg and awaiting a November lift-off on a SpaceX Falcon 9 rideshare. The UK Space Agency updated its case study today confirming the November 2025 window with SpaceX.

What the pair will measure is straightforward and commercially useful. Using GNSS reflectometry - listening to GPS and Galileo signals reflected off land, ocean and ice - HydroGNSS will track soil moisture, permafrost freeze–thaw, inundation, above‑ground biomass, ocean wind speed and sea‑ice extent. The measurements contribute to the Essential Climate Variables framework, which lists 55 indicators, around 60% observable from orbit.

For investors and suppliers, the delivery model is the story. ESA’s Scout framework targets roughly three years from kick‑off to launch and caps mission budgets at about €35m, with industry contracted to provide the science data as a service. That discipline suits the UK’s small‑sat strengths and keeps order books moving for primes and SMEs alike.

Launch economics also matter. Sharing a Falcon 9 from California trims cost and schedule risk versus buying a dedicated rocket. Industry schedules point to a mid‑November Transporter rideshare from Vandenberg, and SSTL confirms its on‑site integration campaign is complete.

On the demand side, the UK Space Agency highlights uses in climate and weather modelling, agricultural planning and flood preparedness. In practice that means more timely inputs for crop analytics, re/insurance flood risk models and energy network maintenance - areas where frequent soil‑moisture and inundation updates can tighten decision cycles.

The hardware is small by design - two washing‑machine‑sized satellites - but the ambition is to scale. HydroGNSS is framed as a pathfinder for an affordable constellation able to capture faster‑moving phenomena such as daily soil‑moisture swings and permafrost freeze–thaw cycles, plugging gaps left by traditional sensors.

Funding and leadership remain squarely UK‑centred. The mission is backed by £26m from the UK Space Agency alongside ESA support. SSTL leads design, build and operations in Guildford, with partners spanning Italy’s Sapienza, Tor Vergata and IFAC‑CNR, Finland’s FMI, Spain’s ICE/IEEC, plus the National Oceanography Centre and the University of Nottingham.

HydroGNSS also speaks to the industrial context. SSTL sits within Airbus’s space portfolio, and Europe’s big three - Airbus, Thales and Leonardo - are working towards a joint satellite venture expected to be announced around now, subject to approvals. Consolidation could standardise procurement and benefit UK suppliers already in these pipelines, though integration tends to bring change.

A second Scout mission, CubeMAP, extends the UK role from the water cycle to upper‑atmosphere chemistry. Three 12‑litre CubeSats, led industrially by GomSpace, will carry thermal‑infrared spectrometers plus a visible–near‑IR imager to study tropical upper troposphere and stratosphere composition - including aerosols, water vapour, carbon dioxide, methane and nitrous oxide - with the UK leading the science and payload via RAL and partners.

What to watch next: lift‑off from Vandenberg later in November, commissioning, and first datasets for early adopters. The agency lists a planned three‑year operational life, extendable to five or six. If performance and demand track well, expect proposals for a larger HydroGNSS‑style constellation and new downstream services built on GNSS‑R.