Vantablack Goes to Space: Ultra-Black Coating Could Dim Satellites and Save the Night Sky
Featured image: The Vera C. Rubin Observatory in Chile, whose survey could have up to 40% of its images degraded by satellite streaks. Credit: Rubin Observatory/NOIRLab/NSF/AURA/H.
The number of active satellites in low Earth orbit is approaching 20,000, with proposals for as many as 1.7 million spacecraft in the coming years. Each one reflects sunlight, producing bright streaks across astronomical images and adding an artificial glow to the night sky that threatens to wash out the faint light of distant galaxies.
A new study published in the Monthly Notices of the Royal Astronomical Society offers one of the most practical solutions yet: coat the satellites with an ultra-black paint that reflects only 2 percent of incoming light and can be sprayed on by engineers in their own facilities.
The coating, Vantablack 310, is produced by Surrey NanoSystems, a spinoff from the University of Surrey. Unlike the original Vantablack, which used delicate carbon nanotube forests grown in clean rooms, Vantablack 310 is a sprayable carbon-black-based paint that is durable enough to survive handling, launch vibrations, and at least three years in orbit.
“Satellite constellations offer enormous benefits, but their growing brightness presents a challenge for ground-based astronomy,” said James Whitfield, applications scientist at Surrey NanoSystems, in a press statement. “Vantablack 310 combines ultra-black performance across a wide range of viewing angles with the durability needed for low-Earth orbit.”
Why satellite brightness matters
The problem is not just the visible streaks that trail across telescope images. Satellite constellations also increase the overall diffuse brightness of the night sky, making it harder to detect faint astronomical objects. The Vera C. Rubin Observatory in Chile, whose 10-year Legacy Survey of Space and Time will catalog everything from near-Earth asteroids to transient supernovae, is especially vulnerable. Astronomers estimate that satellite constellations could degrade up to 40 percent of Rubin’s images.
Starlink satellites currently range from magnitude 3 to 5, visible to the naked eye under dark skies. The International Astronomical Union has recommended brightness limits for satellites that would make them largely invisible without optical aid. Vantablack 310, the researchers calculate, brings satellites close to that target.
The study led by Astha Chaturvedi, a postgraduate researcher at the University of Surrey, tested Vantablack 310 under varying illumination angles in the laboratory, simulating how a coated satellite would appear as it moves across the sky. The coating maintains its optical performance across all angles of incidence, avoiding the bright glints and flares that plague polished satellite surfaces. Light that is not absorbed is scattered diffusely, eliminating the mirror-like reflections that produce the most visible brightening.
From carbon nanotubes to sprayable paint
The original Vantablack, unveiled in 2014, absorbed 99.96 percent of incoming light. It was the blackest material ever created, but it was also fragile. The carbon nanotube structures collapsed if touched and required controlled chemical vapor deposition in specialized facilities. It was unsuitable for mass satellite production.
Vantablack 310 trades a small amount of absorption performance for dramatically improved practicality. At roughly 2 percent reflectance, it is still far darker than conventional space paints, which typically reflect about 5 percent of incoming light. But unlike the original, it can be applied by satellite manufacturers themselves using conventional spray equipment.
The 310 series also addresses the thermal management problem that plagued SpaceX’s early attempts to darken Starlink satellites. SpaceX’s DarkSat coating caused overheating because the paint absorbed sunlight without effectively radiating heat. Vantablack 310’s proprietary binders increase both absorptivity and emissivity, bringing the coated surface closer to thermal equilibrium at approximately 5 degrees Celsius at 1 astronomical unit.
In durability tests simulating three years in orbit, Vantablack 310 showed negligible degradation. Competitor space paints, the researchers reported, “completely eroded” under the same simulated conditions.
Jovian-1: the orbital test
The next step is an actual flight demonstration. The Jovian-1 CubeSat, a student-led mission by the Universities of Surrey, Portsmouth, and Southampton, will carry a section of its solar panel coated with Vantablack 310. The satellite will rotate while ground-based telescopes measure its brightness from multiple angles.
Chaturvedi plans to present the team’s findings at the 2026 United Nations Workshop on Dark and Quiet Skies in Vienna, where policy recommendations for satellite brightness regulations are being developed. The study was co-authored by researchers from Surrey NanoSystems and the University of Surrey’s Advanced Technology Institute.
“The night sky is one of humanity’s oldest windows into the Universe, but it is becoming increasingly difficult to see things,” Chaturvedi said. “Our results show that relatively simple material choices could make a meaningful difference to how satellites affect astronomical observations without requiring major changes to mission design.”
Dr. Noelia Noël, senior lecturer in astrophysics at the University of Surrey, put the urgency of the problem in perspective: “Over the past five years, humankind has launched more satellites into space than it has done over the previous 60 years.”
Whether satellite operators will voluntarily adopt the coating remains an open question. Vantablack 310 adds cost and mass to satellite production, and the largest operators have shown limited enthusiasm for mitigation measures beyond what regulators require. But the study provides something the debate has lacked so far: a tested, commercially available, and space-qualified coating that could meaningfully reduce the worst effects of satellite light pollution without redesigning the satellites themselves.