An official website of the United States government

U.S. Statement – Agenda Item 17 – Dark and Quiet Skies – 60th Session of STSC of COPUOS
As Prepared for U.S. Representative Ashley VanderLey, Vienna, Austria, February 10, 2023

Image of Earth

U.S. Statement as Prepared for U.S. Representative Ashley VanderLey
Agenda Item 17 – Dark and Quiet Skies
Vienna, Austria, February 10, 2023


Thank you, Chair. The United States appreciates this important topic being included again on the agenda for this year’s Subcommittee. There are now close to one million people receiving broadband internet services from satellites in low- Earth orbit, and we recognize the growing opportunities this new technology enables, including for scientific research and development, weather monitoring and emergency preparedness, and disaster response. At the same time, construction is nearing completion for the National Science Foundation’s Vera C. Rubin Observatory, and we recognize the challenges these constellations pose to astronomical observatories worldwide, such as the International Gemini Observatory, for which the United States is a proud partner with Canada, Chile, Brazil, Argentina and the Republic of Korea. Close collaboration between satellite owner-operators and the astronomical community is important to mitigate impacts that could hinder scientific discoveries in the coming decade.


The National Science Foundation’s NOIRLab is a co-host of the International Astronomical Union’s new Center on the Protection of Dark and Quiet Skies, or IAU CPS, along with the Square Kilometre Array Observatory. The approach taken by the Industry and Technology Hub of the IAU CPS to work on a set of best practice guidance is an important development, and the United States encourages the voluntary implementation of the guidance in satellite design and development. We also encourage implementation of the IAU CPS recommendations on the many steps astronomical observatories can take to mitigate these challenges including software development and tools for image processing, more robust receivers and enhanced detector technologies. The United States is proud of the fact that U.S. companies are working with the National Science Foundation and its astronomical observatories to negotiate coordination agreements with commitments to not only align with guidance developed through processes facilitated by, and reflected in the Recommendations of, the International Telecommunication Union Radio communication sector, but also commitments to do more. One company has already signed such an agreement with NSF, and the United States is encouraged by the prospect that others may soon take similar steps. These U.S. companies are deciding to continue to work towards following current best practice guidance, including working to reduce optical brightness to 7th visual magnitude or fainter, and providing orbital information publicly that astronomers can use for scheduling observations around satellite locations for telescopes with narrow fields of view. We invite you to a technical presentation this afternoon. Additionally, some U.S. companies are committing to coordinate dynamically with impacted United States radio astronomy facilities, to avoid main beam illumination. As with optical mitigations, these are steps that have been undertaken proactively and cooperatively. The NSF’s National Radio Astronomy Observatory has undertaken a series of field tests and has more planned in the coming year to verify that radio astronomy observations are not impacted.


The United States appreciates the work by Chile, Spain, Slovakia, Bulgaria, the International Astronomical Union, the European Organization for Astronomical Research in the Southern Observatory, and the Square Kilometre Array Observatory in preparing another Working Paper on the Protection of Dark and Quiet Skies. The United States strongly supports the intention and spirit of this Working Paper, including the recognition of the boundaries between responsibilities of the Subcommittee and the International Telecommunication Union Radiocommunication sector.


The United States supports the proposal to create an Expert Group and we would encourage this group to focus on promoting awareness, synthesizing and reporting back to the Subcommittee, and enabling communication and cooperation between Committee Members and stakeholders, all while leveraging the excellent work and organizational structure already being implemented by the IAU CPS. The United States also supports the proposal of a three-year Agenda Item and Expert Group on “General Exchange of views on Dark and Quiet Skies” to allow for a productive exchange among all stakeholders beginning at the 61st session of the Subcommittee in 2024.


In conclusion, the United States is proud of the leadership from both astronomers and members of the commercial sector, working collaboratively, to identify and address challenges and to lead technical solutions. We look forward to continuing engagement on this issue.


Thank you, Chair.


US Statement as Prepared for Ashley VanderLey – Feb 2023 COPUOS STSC Agenda Item 17 – Dark and Quiet Skies (PDF)