By Bayo Adeseni
A UK-built climate-monitoring satellite, HydroGNSS, has successfully entered orbit after launching on November 28, 2025, aboard a SpaceX rocket.
HydroGNSS is the first mission under the European Space Agency’s (ESA) Scout programme and was designed and built by Surrey Satellite Technology Ltd (SSTL) in Guildford, UK. The project received £26 million in funding from the UK Space Agency, highlighting Britain’s growing role in space-based climate research.
UK Government and Space Officials Praise Mission
Space Minister Liz Lloyd hailed HydroGNSS as a landmark achievement in British space innovation. She stated, “This UK-built satellite will play an invaluable role in tackling some of the most pressing environmental challenges we face on Earth. Groundbreaking missions like HydroGNSS show that Britain is at the forefront of space technology with real-world impact for people and the planet.”
HydroGNSS Mission and Capabilities
Now operational in orbit, HydroGNSS will monitor water movement across the planet, measuring soil moisture, surface flooding, frozen ground, and vegetation coverage. These measurements will support weather forecasting, flood prediction, agricultural planning, and long-term climate research.
The satellite uses GNSS Reflectometry, a technique that captures signals from navigation satellites after they bounce off Earth’s surface. This allows HydroGNSS to gather data through clouds, vegetation, and other conditions that can obstruct traditional sensors, providing a cost-effective and reliable way to monitor environmental changes.
SSTL Managing Director Andrew Cawthorne said, “It’s a proud moment to see HydroGNSS satellites successfully launched and sending back their first signals. This mission exemplifies how the UK, working with ESA and the UK Space Agency, delivers world-class climate science from space. HydroGNSS also marks SSTL’s 75th and 76th satellites, launched during our 40th anniversary year, showcasing the UK’s space industry leadership in Europe.”
Supporting Climate Science and Disaster Response
HydroGNSS will supply frequent global measurements to improve climate models and deepen understanding of the water cycle. Its data will help analyze climate impacts on ecosystems, guide agricultural decision-making, and enhance disaster response in areas affected by drought, flooding, and extreme weather.
Paul Clements, Director of Operations at the UK Environment Agency, emphasized the mission’s public benefits: “With climate change driving more frequent and severe environmental incidents, HydroGNSS provides cutting-edge data that strengthens flood forecasting and warning systems, helping protect lives, property, and infrastructure.”
Collaboration and Global Impact
HydroGNSS complements international Earth observation missions, including ESA’s SMOS and Biomass satellites, as well as NASA’s SMAP satellite, contributing to a broader global effort to monitor environmental change.
ESA’s Director of Earth Observation Programmes, Simonetta Cheli, highlighted the mission as a milestone for Scout missions, emphasizing their rapid, low-cost, and innovative approach. HydroGNSS demonstrates how small satellites can deliver high-value scientific data efficiently, complementing larger Earth Explorer missions while advancing understanding of the planet’s water systems.
