New study links satellite discharges to electron buildup in orbit

New study links satellite discharges to electron buildup in orbit
by Clarence Oxford
Los Alamos NM (SPX) Sep 03, 2025

For the first time, researchers have established a direct correlation between the frequency of spacecraft electrical discharges and the number of electrons in the surrounding space environment. The findings could inform future methods of protecting satellites from potentially damaging effects.

Spacecraft environment discharges (SEDs) are short-lived electrical breakdowns that can harm sensitive electronics and disrupt communications. They result when electrons accumulate on spacecraft surfaces, creating uneven charging. When the voltage reaches a critical threshold, the stored energy is suddenly released - similar to a static shock on Earth.

"We've long known that these SEDs exist," said Amitabh Nag, a scientist at Los Alamos National Laboratory and lead author of the study. "But we haven't understood the relationship between the electrons in the space environment and SEDs. To do that, we needed two sensors on a single spacecraft: one that looked at the number and activity of electrons, and another that looked at the radio frequency signal."

The Department of Defense's STP-Sat6 satellite in geostationary orbit carries both instruments, developed at Los Alamos. This unique configuration enabled researchers to analyze electron activity alongside radio frequency discharge data collected over more than a year.

The team identified more than 270 periods of high-rate discharges and several hundred episodes of elevated electron flux. In about 75 percent of cases, surges in electron activity preceded SED events by 24 to 45 minutes. This suggests low-energy electrons in the 7.9 to 12.2 keV range play a critical role in priming spacecraft surfaces for discharges.

"We observed that as electron activity increases, especially in that 7.9 to 12.2 keV range, the spacecraft starts to accumulate charge. This continues until a tipping point is reached and SEDs occur," Nag said. "That lead time opens the door for potential forecasting tools to mitigate risks."

According to the researchers, integrating real-time monitoring of low-energy electrons into future missions could provide operators with early warning of impending charging events, allowing preventive measures to safeguard spacecraft systems.

Research Report:Radio Frequency Transients Correlated with Electron Flux Measured On-Board the STP-Sat6.