Impact of Megaconstellations on Space-Based Astronomy

A new study published in the journal Nature highlights significant risks posed by current and future megaconstellations to space-based astronomy. The research, conducted by three scientists at NASA Ames Research Center in California, emphasizes that satellite reflections from companies like Amazon, OneWeb, and SpaceX, as well as from government initiatives in China and the United States, threaten the integrity of astronomical images.

The paper notes that between 2018 and 2021, 4.3 percent of images captured by the Hubble Space Telescope already contained artificial satellite trails, and with proposed satellite counts increasing dramatically, this percentage is expected to rise.

SpaceX has launched approximately 3,000 Starlink satellites in 2025 alone, with plans for a total of around 30,000 satellites in low Earth orbit, while China aims to operate a fleet of 12,992 Guowang satellites.

The study warns that if all proposed satellite constellations are deployed, 96 percent of exposures from observatories like NASA's SPHEREx, ESA's ARRAKIHS, and China's forthcoming Xuntian will show at least one Sun-illuminated satellite trail.

Although SpaceX has implemented measures to mitigate its satellites' brightness and has engaged with the astronomy community to find solutions, researchers argue that these efforts may not sufficiently reduce the impact on space-based telescopes.

The paper further discusses complications arising from satellite end-of-life operations, which could lead to uncontrolled tumbling and increased light reflection affecting observations. The importance of detailed de-orbit plans and enforcement policies for satellite constellations is underscored as critical to minimizing their interference with astronomical research.