In the 21st century, we rely more and more on earth-orbiting satellites to support communications technologies here on the ground. But scientists are now discovering a potential problem with satellite emissions that may warrant attention.
A recent article posted to the Sky&Telescope website provides an overview of recent research conducted by space experts at the Max-Planck Institute for Radio Astronomy in Germany and other institutions associated with the Square Kilometre Array Observatory. According to the article, researchers looked for radio signals from satellites in SpaceX’s Starlink fleet. Of the 68 satellites they observed, they detected radio emissions from 47 satellites in the 110-188 MHz frequency spectrum, well below the 10.7-12.7 GHz signals used for downlink communication signals from the satellites. The leaked signals detected by the researchers are stronger than those allowed under current regulatory limits, but current limits apply only to intentional emissions, with no stated limits applicable to unintentional emissions.
The obvious challenge for researchers, according to the article, is the additional time required to eliminate from their research data that may have been contaminated by the unintentional emissions. But the potentially larger issue is that weaker signals that hide under the underlying noise might lead to incorrect research assumptions and results.
Researchers say that the unintended emissions problem is not limited to Starlink satellites, but instead is a potential issue for each of thousands of the satellites that operate in earth orbits. This significantly raises the risk that the operation of ground-based radio telescopes will be impacted.
The solution, according to the researchers, is for scientists and industry to actively work together to develop effective mitigation strategies, while also campaigning for regulatory changes that address the root cause of the problem.