Astronomers See Progress in Talks With LEOs, Yet Future Is Uncertain

"We just have to hope ... discussions [with LEO operators] work," said Samantha Lawler, an associate astronomy professor at University of Regina in Saskatchewan.

The astronomy community has repeatedly voiced concerns about the proliferation of LEO constellations interfering with their observations. Given the rapidly changing state of orbiting satellites, "it's hard to take a look at what is currently up there and make any kind of straightforward forecast for what it will look like in one, five, 10 years from now," said Meredith Rawls, a researcher with the University of Washington's Rubin Observatory.

SpaceX's Starlink has “done a lot of great work” on making its satellites darker, particularly with coatings, said Lawler. Rawls added that SpaceX has been especially responsive and shown that it's genuinely interested in working with astronomers. She complimented the company for working on materials on satellite exteriors to reduce reflectivity, as well as considering their arrangement of solar panels and their orbits so they don't reflect as much in a certain direction.

However, the second-generation Starlinks are larger than the first, essentially canceling out the decreased reflectivity, Lawler said. With third-generation Starlinks expected to be far bigger, "how do you make that darker?" Rawls noted that AST SpaceMobile has only a handful of satellites in LEO, but they are particularly large, and more are coming.

Amazon's Kuiper “has been very good” at talking with astronomers even before its first launch, Lawler said. She added that it remains to be seen what kind of conditions its satellites result in when deployed in significant numbers, compared with the roughly 100 in orbit now.

Kuiper emailed us that it recently signed a coordination agreement with the National Science Foundation on "protocols and processes to ensure our satellite constellation can deliver on its mission to bring fast, reliable internet to customers and communities around the world, while also minimizing interference with astronomical observations."

University of British Columbia astronomer Aaron Boley told us that while there have been efforts by multiple companies to reduce the brightness of their satellites by diminishing reflectivity, the challenge is ensuring that others buy in to that work. "There's no way to see who is on board and who is not ... until they go up," Boley said.

He added that NSF coordination agreements, as required by the FCC, are helping tackle interference with radioastronomy. Yet there are problems with unintended RF emissions that aren't evenly distributed across frequencies, he said, noting that those affect different radioastronomy observatories differently.

Rawls told us that even when not transmitting, satellites have caused interference at very low frequencies with radioastronomy observations "just by virtue of having a computer in orbit."

NEPA

Astronomy interests mentioned satellite interference last week as they voiced opposition to the FCC's proposed changes to its enforcement of National Environmental Policy rules. The proceeding also saw criticism from some states, tribes and historic preservation interests (see 2509190053).

The American Astronomical Society said in docket 25-217 comments that ground- and space-based telescopes are already seeing contamination of their astronomical data by satellites, “representing a serious threat to their efficient operation and compromising decades of U.S. investment.”

Royal Astronomical Society President Robert Massey said interference from satellites affects “every radio and optical astronomical observatory on the surface of the Earth, no matter where they are located.”

Beyond raising concerns regarding non-geostationary orbit communications mega constellations, DarkSky International said proposals for satellites designed to reflect light onto the ground for illumination purposes are also troublesome. One operator, Reflect Orbital, has an application pending before the FCC for such a reflective NGSO (see 2508010001). DarkSky argued against any categorical exemption for reflective satellites, including communications satellites that happen to be reflective.

Astronomers also told us there are significant worries about the impact on astronomy from forthcoming Chinese mega constellations. "I don't think anybody has very high hopes of having any good discussions with the Chinese builders," said Lawler. Boley agreed these are "huge concerns."

Ultimately, satellites’ effect on research astronomy could end up mitigated by software and other fixes, but at the cost of astronomers' access to taxpayer-funded telescope time, Lawler said. There's frustration over the fact that the onus is on astronomers to monitor satellite companies' performance, she said. "We're already losing our telescope time because the satellite streaks are eating into our data, and now we all have to spend extra time doing measurements for these companies," she said. "I want to spend my funding for a student working on this project on getting scientific results, not counting satellites streaks."