WASHINGTON — Two senators have asked the U.S. Government Accountability Office to review the Federal Communications Commission’s decision to exempt satellite constellations like SpaceX’s Starlink from an environmental review, given those satellites’ effect on the night sky.

In an April 2 letter to Comptroller General Gene Dodaro, Sens. Tammy Duckworth (D-Ill.) and Brian Schatz (D-Hawaii) asked the GAO to examine the FCC’s decision, made decades ago, to not subject satellite systems seeking FCC licenses from environmental assessments.

“Although we are enthusiastic about the increased broadband access these satellite constellations might enable, astronomers are concerned that launching thousands of bright satellites into space, as the FCC has approved doing, will interfere with their scientific research,” Duckworth and Schatz state in their letter, obtained by SpaceNews.

The senators cite in their letter a 1986 decision by the FCC that satellite systems were covered by a “categorical exemption” to the National Environmental Policy Act (NEPA), which requires an environmental impact statement (EIS) or environmental analysis (EA) for major actions conducted or overseen by the federal government. The exemption means that satellite systems seeking FCC licenses are not required to undergo an analysis, which can be expensive and time-consuming.

“While a broad categorical exclusion may have been warranted 34 years ago, more than three decades later, scientists are expressing concern that certain FCC activities, such as approving a private business to launch approximately 12,000 satellites into orbit, warrant an EA or EIS at a minimum,” the senators wrote.

Astronomers started warning about the potential impacts of SpaceX’s Starlink satellite system last year, after the initial group of 60 satellites appeared much brighter than expected in the night sky. That’s led to discussions between the astronomy community and SpaceX about ways to decrease the reflectivity of the satellites, including an experimental “DarkSat” launched in January that appeared to somewhat reduce its brightness.

SpaceX is not mentioned by name in the letter, but the company is planning an initial constellation of up to 12,000 satellites. SpaceX is continuing to launch unmodified Starlink satellites as it continues to experiment with ways to reduce their brightness. A seventh set of 60 Starlink satellites is scheduled for launch April 16.

The senators asked GAO in the letter to review the FCC’s categorical exemption of satellite systems from NEPA and recommend whether Congress should consider revoking it. It also asks the GAO to examine how the FCC applies NEPA and compare it to NASA’s implementation of the law.

The letter is not the first to question the FCC’s exemption of satellite systems from NEPA. In January, a paper by a Vanderbilt University law student attracted attention by arguing that the categorical exemption was inappropriate and that the FCC could be sued in federal court to overturn it.

While that paper garnered attention, astronomical organizations haven’t seriously considered going to court. “In all my discussions with the leadership of the AAS, there’s never been any interest in going down this path,” said Joel Parriott, director of public policy at the American Astronomical Society (AAS), during a March 31 meeting of the National Academies’ Committee on Astronomy and Astrophysics. “I’m not spending any time or energy worrying about it.”

He and other astronomers, during a committee discussion about the effects of Starlink and other satellite constellations on astronomy, emphasized they preferred working with companies to try and mitigate the effects of the satellites on observations. “The key here is partnership, not confrontation,” Parriott said.

At the committee meeting, astronomers said their discussions with SpaceX have been effective so far. “People have asked if SpaceX actually sincere about wanting to help astronomy,” said Jeffrey Hall, director of Lowell Observatory, recalling a meeting with SpaceX officials at the January meeting of the AAS in Honolulu. “I came away from AAS feeling they absolutely were.”

One issue, they acknowledged, is that there are no regulations regarding the brightness of satellites and their effects on astronomy at visible and infrared wavelengths. By comparison, in radio astronomy, the FCC licenses satellite systems and requires them to mitigate effects on astronomical research.

Parriott said the AAS has been doing congressional outreach on the issue, including meetings with staffers. “There’s been some specific member interest in the issue,” he noted. The AAS has also met with several other agencies and the National Space Council.

One potential vehicle for policy changes, he noted, is a future reauthorization bill for the National Science Foundation, which funds some ground-based astronomical observatories and associated research. “I don’t think we’re there yet,” he said, regarding including anything on the issue in that bill.