Mysterious Space Signal Traced to Long-Dead NASA Satellite

Newsweek

24-06-2025

Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources.
Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content.
A brief but extremely powerful radio signal thought to have coming from deep space has now been traced to a dead NASA satellite in Earth orbit.
Relay 2 was one of a pair of experimental communications satellites, the first launched in 1962 and the second in 1964.
The signal from the decommissioned satellite was picked up in June last year—and it lasted less than 30 nanoseconds.
Despite the fleeting nature of the burst, the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope. managed to trace it back to its origin.
Radio signals from space are not an uncommon occurrence; in fact, telescopes pick up signals all the time coming from pulsars, black holes, massive galaxies, stars and various other cosmic phenomena.
But far from being from a distant cosmic source, researchers determined that the fast radio burst (FRB) actually came from the 60's satellite in Earth orbit.
Relay 2 satellite pictured by NASA.
Relay 2 satellite pictured by NASA.
NASA
Relay 2 operated for just over a year and a half, at which point the only facility equipped to communicate with it—the Mojave Desert Ground Station—was retasked to a different satellite program.
The transponders onboard Relay 2 stopped responding to radio signals in June 1967, after which point the satellite went silent—until last June.
According to the researchers, Relay 2 did not miraculously come back online to send a signal to Earth. Instead, they believe that either an electrostatic discharge (ESD) or a plasma discharge following a micrometeoroid impact could have set off the burst.
"Our observation opens new possibilities for the remote sensing of ESD, which poses a serious threat to spacecraft, and reveals a new source of false events for observations of astrophysical transients", the researchers say.
With limited fuel capacity and subject to wear and tear caused by outer space, satellites don't last forever. But what happens to them after they stop working?
The National Environmental Satellite, Data, and Information Service, says that satellites orbiting closer to Earth are typically de‑orbited to burn up in Earth's atmosphere within 25 years, as per the "25‑year rule."
However, this is only allowed when operators can show that the probability of injury or property damage is less than 1 in 10,000. When this is not the case, a controlled de-orbit directs the satellite into a remote ocean area, known as the "Spacecraft Cemetery".
Satellites that lack sufficient fuel for re‑entry are sent into a graveyard orbit, where their instruments and subsystems are shut down, the remaining fuel is depleted and they are left to orbit indefinitely.
Do you have a science story to share with Newsweek? Do you have a question about space? Let us know via [e-mail].
James, C. W., Deller, A. T., Dial, T., Glowacki, M., Tingay, S. J., Bannister, K. W., Bera, A., Bhat, N. D. R., Ekers, R. D., Gupta, V., Jaini, A., Morgan, J., Jahns-Schindler, J. N., Shannon, R. M., Sukhov, M., Tuthill, J., & Wang, Z. (2025). A nanosecond-duration radio pulse originating from the defunct Relay 2 satellite. https://doi.org/10.3847/2041-8213/ade3d3