A new peer-reviewed study published in Nature has issued one of the strongest warnings yet about the growing impact of satellite megaconstellations on the low Earth orbit (LEO) environment and the future of astronomical research. With companies such as SpaceX, Amazon, and OneWeb—and national governments including those of the United States and China—pushing ahead with plans for fleets of hundreds to tens of thousands of satellites, scientists say the consequences for space-based and ground-based observations could be profound.
Simulated exposure for Hubble (a), SPHEREx (b), Xuntian (c) and ARRAKIHS (d) space observatories, showing sectors affected by satellite trail contamination. The satellite trails represent the effects of the planned satellites using the orbital and physical parameters of the announced constellations to be operational by 2040. Background galaxies were modelled on the basis of previous studies. Graphic: Borlaff et al via Nature
The paper, released on Dec. 3 by researchers at NASA’s Ames Research Center in California, highlights escalating “strong concerns among the scientific community” regarding the pollution of astronomical images caused by sunlight reflecting off these satellites. The interference already affects images captured from observatories on Earth and is increasingly posing risks to space telescopes.
Among the missions scientists say are vulnerable to this growing interference are NASA’s upcoming SPHEREx mission, the European Space Agency’s ARRAKIHS observatory and China’s next-generation space telescope, Xuntian.
The study notes that satellite streaks are already visible in legacy observatories. “A recent study demonstrated that 4.3 percent of the images obtained by the Hubble Space Telescope between 2018 and 2021 already present artificial satellite trails,” the authors wrote. With satellite numbers expected to surge by two orders of magnitude, they warn that the fraction of compromised images “will increase very soon.”
The concern comes as SpaceX continues rapid expansion of its Starlink broadband constellation. In 2025 alone, the company launched its 3,000th Starlink satellite—pushing the fleet close to one-third of all Starlinks deployed since the program began in 2019. SpaceX ultimately aims to operate more than 30,000 satellites and plans to begin deploying its larger Starlink Version 3 spacecraft aboard Starship in 2026.
China is accelerating its own ambitions with the Guowang constellation and is seeking approval for a network of 12,992 satellites.
While the paper offers limited mitigation strategies—such as reducing astronomical imaging during dawn and dusk—it emphasizes that such steps are unlikely to shield observatories from substantial interference. Even space-based telescopes positioned above Earth’s atmosphere will face frequent contamination from Sun-illuminated satellites. The researchers forecast that, if all proposed constellations are completed, up to 96 percent of exposures from SPHEREx, ARRAKIHS, and Xuntian could contain at least one satellite trail.
SpaceX has frequently acknowledged the problem and outlined several approaches to reduce Starlink brightness, including collaboration with astronomers and technical changes to spacecraft design. “While SpaceX is the first large constellation manufacturer and operator to address satellite brightness, we won’t be the last,” the company noted in a 2020 update, pointing out the need for industry-wide standards as more constellations come online.
However, the new study argues that some mitigation techniques have unintended consequences. For example, SpaceX’s decision to orient deployed satellites perpendicularly to the ground to reduce visible reflections can actually increase the spacecraft’s reflective cross-section as seen by space-based telescopes. The orientation of solar panels—which face the Sun—can similarly direct more reflected light toward observatories pointing away from it.
Complicating matters further, satellites that become non-operational may lose attitude control, causing them to tumble unpredictably and reflect sunlight in ways that are far harder to correct in astronomical data. The authors stress that robust de-orbit plans and stringent regulatory enforcement will be essential as thousands of satellites near end-of-life.
Add comment
Comments