Europe approves EPS Sterna polar microsatellite network

by Robert Schreiber
Berlin, Germany (SPX) Jan 12, 2026

The EUMETSAT Council has formally endorsed the EUMETSAT Polar System Sterna (EPS Sterna), clearing the way for a new constellation of polar orbiting microsatellites that will deliver frequent microwave measurements of atmospheric temperature, humidity and cloud properties. The decision confirms EPS Sterna as a mandatory programme for EUMETSAT and authorises full scale activities targeting the launch of the first satellites in 2029.

EPS Sterna data are projected to generate at least 30 billion euros in economic value for Europe over the lifetime of the programme, with a benefit cost ratio estimated at up to 51 to 1. According to EUMETSAT, this value will flow from more accurate forecasts produced by national meteorological and hydrological services and the better informed decisions that follow in areas such as emergency management, transport and energy.

The programme secured near unanimous backing, with 29 of EUMETSATs 30 member states supporting the initiative after a consultation process that began in 2022. This backing confirms that member states see EPS Sterna as a critical component of Europe's future meteorological satellite infrastructure and a key contribution to global observing systems.

"Recent years have brought record heatwaves, devastating storms, floods and wildfires across Europe," said Phil Evans, Director General of EUMETSAT. "The strong backing from EUMETSAT's member states shows the critical role EPS Sterna will play in enabling national meteorological and hydrological services to forecast such events which will have tremendous benefits for the lives and livelihoods of European citizens. Getting here has taken outstanding dedication from member states and the teams involved and we now look forward to delivering this critical programme together with our partners."

The first six EPS Sterna satellites are planned for launch in 2029, with additional satellites to be introduced over time to sustain operations until 2042. Each spacecraft will carry an identical advanced microwave sounder, and by flying in different orbital planes the constellation will deliver near global coverage in less than five hours, with most data available within about one hour of observation.

This observing pattern represents a substantial increase in temporal coverage compared to current polar satellite systems, which typically revisit the same area only twice per day. The higher refresh rate will provide more frequent observations over sensitive regions such as the Mediterranean, where rapid changes in atmospheric conditions can drive high impact storms. It will also address critical data gaps over the Arctic, the fastest warming region on Earth and a key source and amplifier of weather systems that affect Europe.

EPS Sterna builds on technology demonstrated by the European Space Agency's Arctic Weather Satellite (AWS), which has been collecting data since August 2024. Data from AWS are already being assimilated into forecasting systems run by national meteorological and hydrological services in EUMETSAT member states and are confirming the expected benefits of microwave sounding in high latitudes.

The constellation's microwave sounders can measure atmospheric conditions through cloud, rain and snow, capturing information that instruments operating only in visible and infrared wavelengths cannot access. This capability is particularly important for monitoring developing storms, precipitation structures and temperature gradients within weather systems.

Impact studies indicate that EPS Sterna observations will reduce forecast error across EUMETSAT member states by up to 6 percent and by as much as 9 percent in the Arctic region. These improvements are expected to translate into more accurate predictions of storm tracks, the timing and intensity of precipitation, and extremes of temperature, providing more lead time and confidence for forecasters and civil protection authorities.

Over the full duration of the programme, a total of 20 satellites will be launched to maintain the constellation and ensure continuity of data. The first generation of six microsatellites will establish the initial configuration, and subsequent units will replace aging satellites to sustain performance up to 2042.

Under the programme arrangements, EUMETSAT will procure the satellites through ESA, leveraging industrial development managed by the agency. EUMETSAT will in turn develop and operate the ground segment, procure launch services, commission and fly the constellation, and distribute the resulting data products through established channels.

Data dissemination will use platforms such as EUMETCast and EUMETView, which already serve operational satellite products to users across EUMETSAT member states and beyond. By integrating EPS Sterna data into these channels, meteorological services and other authorised users will be able to incorporate the new observations rapidly into their forecasting and analysis chains.

With Council approval now secured, EUMETSAT and its partners will move into the full implementation phase, including detailed satellite procurement, ground system development and launch preparation. The agency positions EPS Sterna as a major step forward in the global observing system, strengthening Europe's ability to monitor a changing atmosphere and to anticipate high impact weather in a warming climate.