The low Earth orbit is becoming increasingly crowded with satellites, which are gradually erasing the universe from our view. There are currently over 14,000 such objects in orbit, and this number is rising rapidly. This poses a significant challenge for astronomers.
The so-called light pollution caused by satellites is already interfering with the acquisition of a substantial number of images captured by ground-based observatories, and with plans to launch thousands of new satellites into low Earth orbit (LEO), the issue is only set to worsen.
“The night sky is one of humanity’s oldest windows to the universe,” says astrophysicist Astha Chaturvedi from the University of Surrey. “But it’s becoming increasingly difficult to see the true nature of things.”
Chaturvedi and a team of researchers from the United Kingdom believe they may have found a solution: Vantablack 310, a specialized formulation of one of the darkest materials ever created, designed for use on spacecraft. The findings of the study have been published in the journal Monthly Notices of the Royal Astronomical Society.
In laboratory tests, coating satellites with Vantablack 310 demonstrated that only 2 percent of incoming light was reflected.
“Our results indicate that relatively simple material choices can significantly influence how satellites affect astronomical observations, without requiring major changes to mission designs,” says Chaturvedi.
The researchers used physical models to evaluate the performance of the black coating across various orbital positions—for instance, a reflective satellite reflects light more effectively over snow than over an open ocean.
In the most reflective region, a satellite coated with Vantablack 310 scored between 6.7 and 7.0 on the AB magnitude scale (where lower values indicate greater brightness).
Across many simulated orbits, the results notably exceeded this benchmark, reaching values between 7.1 and 7.8.
The worst score of 6.7 falls just below the brightness threshold of 7 magnitude for satellites and orbital objects, as recommended by the International Astronomical Union.
This is also a significant improvement over the score of 3.7 recorded by the researchers for an untreated SpaceX satellite.
It is worth noting that SpaceX has also tested satellite brightness reduction techniques known as DarkSat and VisorSat. Vantablack 310 showed results comparable to or even better than these methods.
“Under identical geometric and spatial assumptions, the coated surface exhibits peak brightness levels that are lower than those of uncoated Starlink chassis, and are comparable to or lower than those of the DarkSat and VisorSat variants,” the researchers write.
Additionally, the team used an electron microscope to examine how the ultra-black coating affected the treated satellite.
They discovered that it formed “coral-like structures with cavity-like indentations,” indicating physical properties that trap light.
Vantablack 310 is a relatively new version of the original material, engineered for easier application and greater durability, though, as the researchers note, these aspects have yet to be tested in space.
“We emphasize that this study only considers optical characteristics,” the researchers write. “To examine the spacecraft’s thermal performance, environmental resistance, and system integration, specialized thermovacuum testing and on-orbit verification are required, so these issues fall outside the scope of this work.”
Further experiments are already in preparation, with Vantablack 310 set to be used in an upcoming CubeSat mission called Jovian-1. This will allow researchers to conduct real-world brightness measurements from Earth while the satellite is in orbit.
If we increasingly rely on these low-orbit satellites for communication systems (and possibly even for artificial intelligence data centers), this should not come at the expense of our ability to obtain a full view of the night sky.
These preliminary tests suggest that Vantablack 310 could help—though a different solution will still be needed to address the problem of space debris.
“Space is becoming more crowded, posing challenges not only for astronomers but also for anyone who values the pristine night sky,” says astrophysicist Noelia Noel from the University of Surrey. “What is encouraging about this study is that it moves us beyond merely identifying the problem and brings us closer to developing practical, evidence-based solutions.”
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