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Everything about the Starlink Satellite Internet project. Part 11. Starlink and Astronomers

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Starlink and Astronomers



Starting with the first "train of Elon Musk" - a chain of 60 satellites that were very clearly visible against the background of the starry sky due to the "sunbeam", SpaceX began to friction with astronomers, sometimes reaching a very high degree.





Video: Satrlink satellites captured over the Netherlands



First of all, the reason why Starlink satellites are visible is shown in this picture:





The sun's rays are reflected from the surface of the flat phased antennas. Although everything happens in a relatively short period of time after sunset, this has not greatly reassured astronomers.



In the past year since the first launch of 60 Starlink satellites, SpaceX has made a titanic effort to address this issue. She first applied a special coating for flat phased array antennas, codenamed DarkSat:





And then they came up with a special visor that protects the antennas from the sun's rays (VisorSat):





And so it looks like SpaceX engineers were able to solve this problem. On August 6, 2020, the following entry appeared on the website of observers of objects in space:

ā€œThe Starlink satellite 'Visorsat' (spacetrack # 45713) was not seen on 2020 August 6 at 01:21:00 UTC. A star of magnitude 6.7 was clearly observed in the field of view so the limiting magnitude was around 7. The observation was made with 15 x 50 binoculars under slightly hazy skies The satellite altitude was 482 km and its range was 502 km. regular Starlink satellite at that distance would be approximately magnitude 4.4. So, confirmation of this preliminary result would imply that Visorsat is, at most, only about 10% as bright as a regular Starlink satellite ".


For SpaceX, this will greatly facilitate the task of public acceptance and consensus on the Starlink project in the scientific community.



However, there is another problem for Starlink - it raises concerns for radio astronomers. In October 2020, SKA (Square Kilometer Array) published an analysis of the impact of Starlink and other constellations on the array. It was found that they would interfere with one of the radio channels that SKA plans to use, making it difficult to find organic molecules in space, as well as water molecules used as a key marker in cosmology.



The Square Kilometer Array (SKA) is an international project in South Africa, where 197 antennas aimed at space will be located in a PA-sized radio silence zone, where even a mobile phone will be banned to prevent radio interference. However, these precautions will not save this astronomical radio telescope project, which is due for completion in the late 2020s, as tens of thousands of Starlink communications satellites are emitting radio signals straight from the skies. ā€œThe sky will be full of it all,ā€ says SKA CEO Phil Diamond.



SpaceX promises to solve this problem. But radio astronomers are also looking for regulation opportunities through the UN. The United Nations Office for Outer Space Affairs (UNOOSA), already discussed the analysis prepared by SKA at a workshop in early October 2020, and is considering ways to prevent the night sky from being polluted by light and radio signals from satellites not only for astronomy, but also for wildlife. Astronomers also hope that intervene and the International Telecommunication Union (ITU), Radioastron Michael Garrett, director of the Center for Astrophysics Jodrell Bank in the United Kingdom, says: "In my opinion, the only government intervention can stop this development" .





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