Simulations show that hundreds of thousands of planned satellite launches could severely impact images from space-based telescopes like Hubble. Researchers predict one in three Hubble photos might be ruined by satellite trails. The study highlights growing concerns over mega-constellations polluting pristine space observations.
Astronomers are warning that the rapid proliferation of satellites could compromise key space telescopes. More than three-quarters of the nearly 14,000 satellites currently orbiting Earth have launched in the past five years, including many from mega-constellations such as Starlink, operated by Elon Musk's company. According to US Federal Communications Commission filings, up to half a million more satellites are planned by the end of the 2030s.
Alejandro Borlaff at NASA Ames Research Center in California and his team analyzed these projections using FCC and International Telecommunication Union data. They simulated interference with observations from four space observatories: the Hubble Space Telescope, China's Xuntian telescope, the upcoming ARRAKHIS dark matter telescope set for 2030, and the SPHEREx galaxy telescope launched this year.
The results are stark. If 560,000 satellites launch as planned, Hubble images could average two satellite trails each, while Xuntian's larger field of view might see around 90 trails per photo. Current satellite numbers already affect 4 percent of Hubble images, a figure that aligns with real-world analysis.
"When you position a telescope in space, it’s usually a very pristine environment. You don’t have any atmosphere, or city lights," Borlaff said. "Now, for the first time, you have man-made objects that are somehow polluting the images – that was very striking."
However, John Barentine of Dark Sky Consulting in Tucson, Arizona, cautions that actual launches may fall short. "Many experts feel that the number of satellites that will actually orbit the Earth within about the next 15 years will reach a steady-state value of something more like 50,000 to 100,000," he noted. In that scenario, impacts would be milder, with trails only slightly higher than current levels for most telescopes.