Unobstructed views of space are increasingly at risk as SpaceX builds out its Starlink megaconstellation in low Earth orbit. And with the company’s plans to deploy bigger, and potentially brighter, satellites, the problem could get even worse, according to astronomers.
During a panel discussion at the 240th Meeting of the American Astronomical Society (AAS), a group of astronomers discussed the brightness magnitude of SpaceX’s Starlink constellation, expressing concerns over the company’s next generation of Starlink satellites, as reported in Space News.
SpaceX has been working with the Federation of Astronomical Societies in an attempt to mitigate the effects of its Starlink satellites on telescopes’ views of the stars and galaxies. Elon Musk’s private space company is seeking to launch an unprecedented 42,000 satellites to low Earth orbit, where they will provide broadband internet across distant parts of the world. So far, SpaceX has more than 2,400 Starlink satellites already in orbit and the company is launching an additional 53 satellites on Friday.
The orbiting satellites add a lot of noise to images captured by ground-based observatories, which they do by reflecting sunlight. The satellites mess with scientific data, appearing as bright streaks in astronomical images. The company had agreed to keep the magnitude of its satellites to a maximum of seven to alleviate the issue.
That said, Musk recently detailed the design of the company’s next generation of Starlink satellites, describing them as larger, and more powerful. Current Starlinks weigh about 573 pounds (260 kilograms), but the future versions will be far larger at 2,755 pounds (1,250 kilograms). In fact, the satellites will be so big that only SpaceX’s upcoming Starship rocket will be able to deliver them to space. The larger size is causing astronomers to reignite their concerns over the artificial constellation.
“Bottom line is that they are bigger. This in turn would mean that — everything else being equal — they will be brighter than SL1 [the first generation of Starlink satellites],” Olivier Hainaut, an astronomer at the European Southern Observatory, told Gizmodo in an email.
Hainaut estimates that Starlink 2.0 satellites will be about a full magnitude brighter than their predecessors. “With all the mitigation efforts by Starlink, they had managed to get SL1 close to the magnitude 7 limit most of the time,” Hainaut said. “One magnitude brighter would mean that more of the [second generation] satellites would be problematic, which of course is not nice.”
Some astronomers do recognise that SpaceX has made an effort to prevent its megaconstellation from interfering with precious observations of the universe. When they first launched, the Starlink satellites were visible to the unaided eye and they saturated the lenses of telescopes pointed in their direction. However, the International Astronomical Union established the Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference, and SpaceX has been in talks with the union, in addition to other astronomers at various institutions. As a result, the company has changed the orientation of the satellites, the orientation of the solar panels, and installed visors to reduce the brightness of the satellites.
“I hope Starlink keeps the communication lines open, and that they have not forgotten about their commitment towards the astronomical community,” Hainaut said.