Upcoming Satellite Launch May Distort Hubble Space Telescope Images

Should space companies proceed with plans to deploy hundreds of thousands of satellites, up to a third of the images captured by the Hubble Space Telescope may be compromised.

In the last five years alone, over 75% of the approximate 14,000 satellites now orbiting Earth have been launched, many as part of megaconstellations, notably Elon Musk’s Starlink. Proposals indicate that we could see the deployment of as many as 500,000 satellites by the end of the 2030s, according to submissions to the US Federal Communications Commission (FCC).

Astronomers have long raised concerns regarding the potential impact of these satellites on ground-based telescopes. However, research by Alejandro Borlaf and his team at NASA’s Ames Research Center indicates that space telescopes are at risk as well.

“A telescope in space benefits from an unblemished environment; there’s no atmosphere or city lights,” Borlaf explains. “For the first time, we’re facing the issue of a man-made object contaminating our observations. This discovery was startling.”

By analyzing filings from the FCC and the International Telecommunication Union, Borlaf’s team estimated the anticipated number of satellites and their orbits over the next decade. They simulated the effect of these satellites blocking observations from four space observatories, including Hubble and China’s Shuntian telescope, as well as the Arrakis dark matter telescope set to launch in 2030, and the already launched SPHEREx galaxy telescope.

The researchers found that if 560,000 satellites are launched as projected, Hubble photos may capture an average of two satellite orbits, while Xuntian images could have approximately 90 satellite orbits due to a broader field of view and orbital altitude.

They validated their simulations by demonstrating that with the existing number of satellites, 4% of Hubble’s images would be influenced by the trajectories of these satellites, consistent with analyses of actual images.

These predictions could materialize if satellite launches proceed as planned. According to John Valentine from Dark Sky Consulting, a Tucson-based firm, it’s uncertain how many satellites will ultimately launch. “Many experts believe that over the next 15 years, the number of operational satellites could stabilize between 50,000 and 100,000.”

If the final number turns out to be only a fraction of the proposed figures, Valentine suggests, the impact on space telescopes would be notably reduced. “The number of trajectories per image would increase only slightly for ARRACHIS and Xuntian, while remaining relatively unchanged for SPHEREx and HST.”