AAC Clyde Space's technology onboard the European Space Agency's (ESA) Arctic Weather Satellite has received strong praise for its performance, marking an important milestone towards the future EPS-Sterna constellation. The satellite, launched in 2024, carries a cutting-edge microwave radiometer developed by AAC Clyde Space's subsidiary AAC Omnisys in Gothenburg, as well as the spacecraft's "brain" and "heart"-the SIRIUS avionics and STARBUCK power system - both flagship, high-volume products developed and produced at AAC Clyde Space's facility in Uppsala.
The Arctic Weather Satellite (AWS) is a prototype mission designed to demonstrate how high-quality atmospheric data can be delivered quickly and cost-effectively to improve short-term weather forecasting, particularly over the Arctic. ESA has now confirmed that AWS is performing on par with larger, traditional weather missions, a significant validation of the New Space approach and of AAC Clyde Space's advanced technology.
AWS forms the basis for the proposed EPS-Sterna programme, a constellation of Weather Satellites planned by EUMETSAT. The constellation would dramatically improve temporal coverage of microwave weather observations, benefitting both regional and global forecasts. A decision on the programme is expected in the second half of 2025.
ESA and leading European meteorological institutions have confirmed the performance of the AWS radiometer, including its novel 325 GHz sounding channel - a frequency never before used for operational weather forecasting. The data have already shown measurable benefits for short-term forecasting, especially in Arctic regions where the weather can change rapidly.
"We are proud to see our advanced technology helping shape the future of weather forecasting. This recognition from ESA reinforces our position at the forefront of space-based weather intelligence." says Luis Gomes, CEO of AAC Clyde Space.
In February 2025, AAC Clyde Space announced that it had received an order from OHB Sweden to procure key instrument components for the EPS-Sterna programme. These long lead-time components will be delivered by the end of 2025, with a total order value of EUR 1.0 million (approx. SEK 11.8 million). The procurement is part of a risk mitigation measure by EUMETSAT to ensure the timely deployment of the initial constellation.
The EPS-Sterna Programme is a new EUMETSAT mission that will develop a comprehensive system, including a constellation of small satellites, launcher services, and the ground segment necessary for 13 years of operations. The mission aims to complement microwave sounding observations from Metop-SG and NOAA JPSS polar-orbiting meteorological satellites, improve the accuracy of global Numerical Weather Prediction (NWP) models by increasing microwave sounding observations, and enhance Nowcasting applications at high latitudes through more frequent microwave observations. Additionally, it will contribute to climate monitoring by adding to the record of upper tropospheric humidity with increased spatiotemporal sampling.
EUMETSAT has outlined that the mission approval is assumed in mid-2025, with the start of all development activities, including the space segment, immediately after approval. The initial constellation of six satellites is expected to launch in early 2029, with a total of 20 satellites to ensure continuous operations until the mission's end in 2042.
The Space Segment of the EUMETSAT EPS-Sterna system will be developed in cooperation with ESA, which will act as a procurement agency for EUMETSAT. Similar to AWS, OHB Sweden will be the prime contractor for the space segment, platform provider, and system integrator, with AAC Clyde Space as the instrument prime.
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