SpaceX makes a deal with astronomers to reduce light pollution

An agreement between SpaceX and the National Science Foundation (NSF) includes several options to reduce the impacts of the new generation of Starlink satellites on the observations of astronomers. However, this agreement does not satisfy everyone.

The agreement was announced at the 241e meeting of theAmerican Astronomical Society (AAS), January 10. For years, the scientific community has been concerned about the disastrous damage of light pollutionlight pollution and interferenceinterference radio of the megaconstellation of SpaceXSpaceX on observations of the sky from professional observatories.

For years, the passage in the field of view of “trains” star linkstar link (several dozen communication satellites inhabiting a plane in low orbit) reduces the availability of the sky for scientists. The National Science Foundation (NSF) specified that the negotiation of the agreement was made ahead of the announcement of the federal communications court of the United States of a new license, authorizing the company toElon MuskElon Musk to put into orbit only a quarter of the 30,000 satellites requested.

SpaceX concessions

On the one hand, SpaceX is committed to reducing the brightness of the new Starlinks, so as to make their magnitudemagnitude beyond 7 (i.e. invisible toeyeeye naked). If the light pollution generated will be less strong, it will nevertheless be present. On the other hand, SpaceX agrees to no longer make transmissions when its satellites pass over a radio observatoryradio observatory major, to avoid interference with radio telescopesradio telescopes.

Finally, SpaceX agrees to withdraw its Starlinks from the databasedatabase CHL (Laser ClearingHouse). The latter is used by astronomersastronomers using adaptive optics to correct optical aberrations of their telescopetelescopewith the aid of laserlaser guidance. This laser can damage the optics of satellites, but not Starlink according to SpaceX. Thus, astronomers will have more WindowsWindows time during which they can observe.

64 m² is the surface area of ​​the deployable antenna of AST Space Mobile’s Bluewalker 3 demonstrator, a new luminous enemy of astronomers. © AST Space Mobile

If Starlink populates more than half of the active satellites in space, this agreement with the NSF in no way solves the light pollution from the others. SpaceX was willing to negotiate this deal, but other operators of future low-orbit megaconstellations are coming, some like AST Space Mobile are making people cringe. Moreover, if the NSF is happy with this agreement, the association IDA (International Dark Sky), defending the sky nocturnalnocturnal, maintained its complaint against SpaceX with the FCC. The fight goes on.


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