Over a hundred astronomers are calling on the U.S. Federal Communications Commission (FCC) to halt all Starlink and mega-constellation launches with concerns over the environmental and scientific impacts of deploying vast satellite networks.
In an open letter to the FCC the astronomers argued that until the risks associated with large-scale satellite deployment are thoroughly assessed, the launch of such mega-constellations should not proceed. Currently, these large networks are excluded from environmental reviews by the FCC.
“Artificial satellites, even those invisible to the naked eye, can obstruct astronomical observations that help detect asteroids and understand our place in the universe,” said Robert McMillan, an astronomer at the University of Arizona and one of the signatories, in an interview with Space.com.
He added that the long-term environmental impact of launching “tens of thousands of satellites” remains uncertain.
As of now, there are over 9,000 active satellites in Earth’s orbit, with more than half belonging to SpaceX’s Starlink program, which launched its first satellites in 2019. Harvard astronomer Jonathan McDowell estimates that around 6,500 of these satellites are operational, reflecting an explosive increase in space activity. Historically, only about 19,500 satellites have ever been launched, meaning Starlink alone accounts for a significant portion of all operational satellites today.
These mega-constellations have complicated observations of the night sky, with their brightness affecting astronomers’ ability to gather data from deep-space telescopes. Furthermore, evidence is emerging that radiation from satellite electronics is interfering with radio telescopes, disrupting our capacity to explore the cosmos through radio signals.
Concerns extend beyond astronomical interference; the environmental impact of these expendable satellites is also a growing worry. Low Earth orbit has become increasingly congested with “space junk” over the years, and mega-constellations have exacerbated this issue. Many satellites are designed to re-enter and burn up in Earth’s atmosphere after a few years of operation, but this process could release pollutants. There are also safety concerns, as some spacecraft components that were supposed to disintegrate during re-entry have instead crashed down to Earth. The Federal Aviation Administration (FAA) has warned that falling satellite debris could even pose a danger to human life.
“The space industry has moved faster than the public or regulators were able to keep up,” explained Lucas Gutterman, the letter’s lead organizer and director at the nonprofit Public Interest Research Group.
“The speed and scale of the new space race should be a kitchen-table issue, not an esoteric discussion among a small group of industry insiders.”