Raumfahrt - Astronomers and SpaceX coming together to make Starlink megaconstellation less disruptive to science



Astronomers are praising SpaceX's response to months of outcry over the visibility of the company's Starlink internet satellites from scientists dismayed by interference with observations.

The SpaceX response includes a new strategy for reducing the amount of light Starlink satellites reflect down to Earth. But Starlink is only the first of the so-called megaconstellations that companies plan to develop. These programs aspire to encompass thousands, sometimes even tens of thousands, of satellites in orbit around Earth. SpaceX is the first company to have a fleet of hundreds in orbit, and that vanguard alerted optical astronomers they had a new problem to tackle: a huge increase in satellites reflecting streaks of light at scientific observatories.

"We all knew [the satellites] were coming, but we never imagined they were going to be so bright," James Lowenthal, an astronomer at Smith College in Massachusetts, said during a plenary talk at the 236th meeting of the American Astronomical Society (AAS), held virtually on June 2.

"For one thing, we didn't know how big the satellites were; that was not public information," Lowenthal, a member of a working group formed by AAS to address the issue, continued. "And we didn't know what elevation they were going to be at. The combination has made them much, much brighter than we anticipated — that was the big surprise."

The problem has been particularly noticeable soon after each Starlink launch, before the satellites reach their final orbital altitude of about 340 miles (550 kilometers), since they can be seen by the unaided eye during this time. But operational satellites continue to interfere with sensitive observatories.

And despite the outcry of astronomers, these satellites aren't going anywhere anytime soon. Lowenthal said independent estimates value the Starlink program at about $10 billion, on the financial scale of NASA's massive James Webb Space Telescope.

SpaceX to test 'sunshades' on Starlink satellites to reduce visibility
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