Satellite boom is a 'growing threat' to space telescopes: NASA study
A new NASA-led study shows that the increasing number of satellites in low-Earth orbit could ruin up to 96% of images from some orbiting telescopes and space observatories.
“The urgency starts in the moment we’re seeing a very rapid increase in the number of satellite constellations, in particular, not the satellites that have been launched, but in the satellites that are being proposed,” Dr. Alejandro Serrano Borlaff, research scientist at NASA Ames Research Center and co-author of the study, told ABC News. “Before these satellites become operational, we need to figure out what would be the consequences for the telescopes and if there is any way that we can mitigate any problem.”
Satellites reflect sunlight, Earthshine, infrared and radio waves. The study found that some of that reflected sunlight can create bright streaks that can obscure cosmic images, including one Hubble Space Telescope image of interacting galaxies. Researchers refer to those streaks as satellite trails, which aren’t visible to the naked eye.
Scientists at the NASA Ames Research Center found that these trails affect not only observatories here on Earth but also those in space. The study found that nearly one-third of Hubble’s exposures will show contamination by satellite trails.
To understand the scale of the problem, researchers simulated approximately 18 months of telescope observations under the assumption that low-Earth orbit would be crowded by 560,000 satellites, a situation that could arise in the coming decade. Under those conditions, they found that satellite streaks would interfere with 40% to more than 96% of images taken by major observatories.
Data shows the number of satellites in low-Earth orbit has increased from roughly 2,000 in 2019 to 15,000 in 2025.
“As we launch more satellites to space, the room for telescopes, and astronomy in general, gets narrower and narrower,” Borlaff said.
Researchers found that three of the four telescopes studied could see as many as 96% of their images disrupted by satellite streaks. That includes NASA’s SPHEREx, which launched in March, as well as China’s upcoming Xuntian observatory and ESA’s ARRAKHIS mission, both still on the ground.
NASA’s latest finding highlights a growing tension between expanding satellite networks and the ability of space telescopes to study distant galaxies, planets, and other key astronomical targets.
“We need to figure out a way to coexist,” Borlaff said.
One common misconception is that scientists can just “fix” the satellite trails. “Sure, you can do that,” Borlaff stressed, but anytime you change an image, in this case to remove a satellite trail, “the information under those pixels is forever lost.” In a more congested low-Earth orbit, that lost information adds up and some of it can never be recovered.
Other proposed workarounds come with serious trade-offs. Pointing telescopes vertically can avoid some of the traffic, but researchers can’t always do that without missing their targets or straining the instruments. Additionally, redesigning the entire space ecosystem by shifting satellites higher or telescopes farther out is expensive and risky, exposing observatories to harsher radiation.
