As SpaceX’s connectivity constellation continues its deployment with already more than 3,000 units in orbit, this agreement with the US National Science Foundation (NSF) is a new milestone for astronomical observation. Will it be enough? It’s already more than with other operators…
Another association sues SpaceX for light pollution of the sky.
Find common ground
With more than 3,000 active satellites today and authorization to deploy an additional 7,500 obtained in 2022, SpaceX will continue to set up its megaconstellation of Starlink internet connectivity satellites. This did not prevent, from the first take-offs in 2019, professional and amateur astronomers from noting the damage to sky observation and warning about the situation to come with several thousand units.
There had already been some efforts on the part of SpaceX, but several researchers welcomed this new agreement unveiled on January 10 between the Californian firm and the NSF, manager and responsible for large American telescopes. In fact, in the absence of strict regulations on the matter, the aim was to limit the impact of the constellation on the observations of professionals, and in particular of the large laboratories.
Big constellation, small steps
The agreement is based on three measures and a common desire to continue constructive exchanges to limit the future impact of the constellation as much as possible. The first part, already more or less in place, is SpaceX’s commitment to ensure that its satellites do not have a magnitude lower than 7 when positioned in the constellation (a satellite becomes visible to the eye naked in a clear sky from about 6). This won’t protect the measurements of large telescopes, but at least assures the American and world public some preservation of the night sky.
Then, SpaceX will ensure by geolocation that its satellites do not transmit when they pass directly over observatories (in particular radio) to limit disturbances. In addition, the Starlink satellites will be removed from the ephemeris catalog used by observatories for their observations of the universe by laser pointing. Indeed, SpaceX has conducted a study, and it seems that the pointers of these large telescopes (which are known to be able to disturb some onboard sensors) do not cause any particular discomfort within the constellation.
Argue or attack?
Of course, these efforts are not everything. The impact of megaconstellations, of which SpaceX is ultimately only one of the pioneers (with OneWeb, whose 600 satellites in orbit are less visible, but disturb more in terms of signals), continues to grow and is still poorly documented. The situation is changing fast, and ground tools and in-flight strategies are changing too. However, the problem is present, the projections are pessimistic and the disturbances should increase in the years to come. Nor will all the players have the responsiveness and clarity of exchange that SpaceX was able to conduct with the NSF. In addition, discussions are already heating up around other players such as Amazon with Kuiper or AST Spacemobile with the gigantic antennas of its BlueWalker satellites.
For its part, in a movement to obtain a legal framework in an accelerated manner, the IDA (International Dark-Sky Association) has taken SpaceX to court in order to obtain case law for its environmental impact. The association argues that light pollution deprives amateur and professional astronomers of their right to enjoy the sky.
Source : SpaceNews
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