The Impact of Satellite Constellations on Radio Astronomy

As the number of satellites in Earth’s orbit continues to increase, there is a growing concern about the pollution of wavelength bands designated for radio astronomy. Recent research conducted by engineer Federico Di Vruno from the SKA Observatory and the International Astronomical Union has shed light on the issue. Di Vruno explains, “This study represents the latest effort to better understand satellite constellations’ impact on radio astronomy. Previous workshops on Dark and Quiet Skies theorized about this radiation, our observations confirm it is measurable.” The interference caused by these satellites can potentially hinder our ability to conduct astronomical studies.

SpaceX, a prominent player in the space industry, has already deployed around 4,365 small internet satellites in Earth’s orbit. Despite efforts to address concerns about visible light pollution by designing dimmer satellites, the impact on radio astronomy remains a challenge. Additionally, other companies like OneWeb and Amazon have their own satellite constellations, further contributing to the growing number of satellites in space. With plans for launching thousands more, the interference caused by these satellites poses a significant concern for the scientific community.

While satellites primarily use radio frequencies between 10.7 and 12.7 gigahertz for communication downlink, there is a possibility that they may emit unintended radio waves outside this band. To further investigate this issue, Di Vruno and his colleagues employed the LOw Frequency ARray (LOFAR) in Europe. LOFAR is a network consisting of approximately 20,000 radio antennas distributed across 52 locations, known for its high sensitivity. By observing 68 Starlink satellites using LOFAR, the researchers successfully detected electromagnetic leakage from 47 of them. This leakage occurred within the frequency range of 110 to 188 MHz, which encompasses a protected band allocated to radio astronomy.

The emission of radio waves by the satellites appears to be unintentional and originates from their electronics. Currently, these emissions do not violate any regulations as there are no strict restrictions on electrical devices to control electromagnetic interference in space. However, as the number of satellites emitting unintentional radio signals increases, the impact on radio astronomy is expected to intensify. To address this problem, the researchers have reached out to SpaceX, which is actively working on methods to reduce or eliminate this unintentional leakage.

Future Solutions and Regulations

While the impact of satellite constellations on radio astronomy is a concern, it is crucial to recognize that we are still in the early stages of satellite constellation technology. The discovery of this satellite radio leakage problem is timely, as it allows for future designs to be adjusted to mitigate the issue. Additionally, regulators can work towards establishing rules to fill the unexpected gap in regulations. Astronomer Michael Kramer from the Max Planck Institute for Radio Astronomy emphasizes the need for support from the satellite industry and regulators, stating, “The present study highlights an example of the various channels of how technology development may have unforeseen side effects on astronomy. With SpaceX setting an example, we are now hoping for the broad support from the whole satellite industry and regulators.”

The pollution of wavelength bands designated for radio astronomy caused by the growing number of satellites is a significant concern. The unintentional emission of radio waves by satellites, particularly from the electronics on SpaceX’s Starlink satellites, poses a threat to our ability to conduct astronomical studies. However, efforts are underway to address this issue, both through the cooperation of satellite companies like SpaceX and through the establishment of regulations. With continued collaboration and careful adjustments to future satellite designs, it is possible to minimize the impact of satellite constellations on radio astronomy and ensure the preservation of our ability to explore and understand the universe.