NASA study warns of increasing danger to space telescopes from satellite proliferation

A recent study led by NASA warns that the surge of satellites in low-Earth orbit could compromise as much as 96% of images captured by certain space telescopes and observatories.

The concern is urgent because the growth in proposed satellite constellations is happening extremely fast, explained Dr. Alejandro Serrano Borlaff, a research scientist at NASA Ames Research Center and co-author of the study. We need to assess the impact on telescopes and explore possible mitigation strategies before these satellites are launched.

Satellites reflect sunlight, infrared, radio waves, and Earthshine. The study highlights that sunlight reflections can create bright streaks, known as satellite trails, which obscure astronomical images. Some of these streaks were seen even in Hubble Space Telescope images of colliding galaxies, although they are not visible to the naked eye.

Researchers discovered that these trails interfere with observations not only on Earth but also for telescopes in space. Nearly one-third of Hubble's exposures are predicted to be affected by satellite streaks.

To evaluate the potential scale of disruption, scientists simulated 18 months of observations assuming a crowded low-Earth orbit with 560,000 satellitesa scenario that could occur within the next decade. Their results showed that satellite streaks could impact between 40% and over 96% of images taken by major observatories.

The number of satellites in low-Earth orbit has jumped from around 2,000 in 2019 to 15,000 in 2025. As more satellites are launched, the available space for telescopes and astronomical research becomes increasingly limited, Borlaff noted.

The study examined four telescopes and found that three could experience up to 96% of their images affected by satellite streaks. This includes NASA's SPHEREx, launched in March, as well as Chinas Xuntian telescope and ESAs ARRAKHIS mission, both still on the ground.

These findings underline a growing conflict between the expansion of satellite networks and the ability of space telescopes to study distant galaxies, planets, and other key astronomical targets. We need to find ways to coexist with this increasing satellite presence, Borlaff said.

While it is possible to digitally remove satellite trails from images, Borlaff emphasized that any data beneath those pixels is permanently lost. As low-Earth orbit becomes more congested, the cumulative loss of information could be irreversible.

Alternative strategies, such as reorienting telescopes to avoid satellites, carry significant limitations, as they may prevent capturing certain targets or put stress on the instruments. Relocating satellites higher or telescopes farther into space is another option, but it is costly and exposes instruments to harsher conditions.

Author: Olivia Parker