Call for Tenders – SateLIGHT ASTRA Project – Satellite Light – Assessment, Standardization, and Technical Response for Astronomers

The growing number of satellites, particularly those belonging to large constellations in low-Earth orbit, is increasingly disrupting astronomical observations. Dark skies are essential to preserving the continuity of ground-based astronomical observation activities. Sunlight reflected by these satellites creates visual interference—such as streaks across the night sky—that distort data, especially during long-exposure observations, and degrade the quality of astronomers’ data. These disturbances pose a threat not only to the astronomical community but also to humanity as a whole, which benefits from astronomy through scientific discoveries, education, international cooperation, and broader philosophical reflection.

Nevertheless, satellites in low Earth orbit offer valuable applications. They help bridge the digital divide (in line with the United Nations Sustainable Development Goals) and advance scientific research by providing data that would otherwise be inaccessible. Striking a balance between the needs of astronomy and satellite deployment requires a concerted effort to assess the issue, propose mitigation strategies, and develop harmonized methodologies. A major gap that has been identified is the lack of a standardized method for calculating the apparent magnitude of satellites.

This project will be based on collaboration between astronomers, satellite operators, and manufacturers.

The following objectives have been identified for this activity:

• Define a methodology for assessing the visual magnitude of satellites,
• Define standards and requirements aimed at reducing satellite reflectivity and mitigating the visual impact of space operations,
• Provides technological (including materials and coatings), operational, and coordination solutions and guidelines to minimize the impact on astronomy.

Following the European Commission’s approval of a proposal from CEN, prepared by AFNOR/BNAE, funding is available to establish a team of paid experts for this project.
CEN has delegated the recruitment of these experts to AFNOR/BNAE.

Please apply for this project by following the detailed instructions and requirements outlined in the call for proposals, before May 11, 2026.