Britain has taken a major leap in space-based climate research with the launch of HydroGNSS, a pair of small satellites built to observe how water moves around the planet. The mission, which headed into orbit on 28th November aboard a SpaceX rocket, is the first of the European Space Agency’s new low-cost ‘Scout’ programme, and the UK is leading it.
Manufactured by Surrey Satellite Technology Ltd (SSTL) and supported by £26 million from the UK Space Agency, the satellites mark a significant moment for the nation’s expanding role in environmental monitoring from space.
Tracking Water Across A Warming World
HydroGNSS is designed to deliver rapid, global measurements that help scientists understand soil moisture, flooding, frozen ground, and vegetation cover. That information feeds directly into weather forecasting, climate modelling, agricultural planning and disaster response; areas where small improvements can make a major difference for communities and ecosystems.
Space Minister Liz Lloyd said the UK-built mission will “play an invaluable role up in space, helping tackle some of the most pressing environmental challenges we face on Earth.”
How The Technology Works
Instead of relying on large instruments or active radar, HydroGNSS uses a technique known as GNSS reflectometry. It listens for navigation signals, such as those from GPS or Galileo satellites, after they reflect off the Earth’s surface. Because these signals can pass through cloud and forest canopies, the method allows near-continuous monitoring under conditions that normally block conventional sensors. It also keeps costs down, which is one of the aims of ESA’s Scout missions.
Industry Milestone For SSTL
For SSTL, the launch represents another landmark. The HydroGNSS pair are the company’s 75th and 76th spacecraft, flying during its 40th anniversary year. Managing Director Andrew Cawthorne called it “a proud moment” as the satellites have already begun returning their first signals from space.
Supporting Flood Forecasting And Environmental Resilience
One of the biggest beneficiaries of the new data will be emergency and environmental agencies. Paul Clements of the Environment Agency said the UK must use advanced technology to protect people as climate change drives more severe weather. He added that the mission will “significantly strengthen our flood forecasting and warning capabilities.”
Part Of A Global Earth-Observation Network
HydroGNSS strengthens international efforts to monitor soil moisture and other hydrological variables, joining missions such as ESA’s SMOS and Biomass, and NASA’s SMAP. ESA says the satellite duo demonstrates how agile, low-cost missions can complement larger flagship programmes.
Simonetta Cheli, ESA’s Director of Earth Observation Programmes, said HydroGNSS marks an important step in the evolution of the agency’s rapid-development Scout missions.
Growing UK Influence In Space
The launch arrives at a time of rapid expansion for the UK space sector, which contributes £18.6 billion annually to the economy and supports more than 55,000 jobs. It also follows the UK’s £1.7 billion investment commitment to ESA programmes, boosting long-term collaboration with European partners.
HydroGNSS adds fresh momentum to Britain’s efforts to lead in small satellite innovation and to deliver science that helps the world adapt to a changing climate.
Published by Kerry Harrison
Kerry’s been writing professionally for over 14 years, after graduating with a First Class Honours Degree in Multimedia Journalism from Canterbury Christ Church University. She joined Orbital Today in 2022. She covers everything from UK launch updates to how the wider space ecosystem is evolving. She enjoys digging into the detail and explaining complex topics in a way that feels straightforward. Before writing about space, Kerry spent years working with cybersecurity companies. She’s written a lot about threat intelligence, data protection, and how cyber and space are increasingly overlapping, whether that’s satellite security or national defence. With a strong background in tech writing, she’s used to making tricky, technical subjects more approachable. That mix of innovation, complexity, and real-world impact is what keeps her interested in the space sector.