In 1994, two Canadian TV satellites, Anik E1 and E2, experienced catastrophic failures within just hours of each other. These satellites were operating in a geostationary orbit when a significant solar storm struck, resulting in electrostatic discharges that incapacitated their control electronics. This incident underscores the broader phenomenon of spacecraft environment discharge, which highlights the detrimental effects of electric charge buildup on satellites.
Recent research has unveiled a direct correlation between a spacecraft’s electric discharge and peaks in the flux of electrons in space. Scientists have identified hundreds of incidents that can trigger these surges, potentially leading to long-lasting damage to satellites. A dedicated team from Los Alamos National Laboratory embarked on a mission to investigate this phenomenon further by placing two sensors onboard the U.S. Department of Defense’s Space Test Program Satellite 6 (STP-Sat6).
Over the course of more than a year, the researchers collected extensive data that revealed a staggering 272 incidents of high-rate electrical discharge on the satellite. Each of these incidents occurred between 24 to 45 minutes after periods of peak electron activity in space. The findings, published in the journal Advances in Space Research, hold the promise of improving our ability to forecast spacecraft discharge and mitigate the adverse effects of the surrounding space environment on satellites.
The space environment is a complex landscape filled with charged particles that primarily originate from the Sun, manifesting as solar wind—a continuous stream of protons and electrons—and solar flares, which are massive bursts of electromagnetic radiation. Additionally, Earth’s orbit is inundated with charged particles emanating from the planet’s ionosphere and magnetosphere. As spacecraft traverse this charged environment, they are incessantly bombarded by these particles, which can gradually degrade their performance or, in some instances, cause sudden disruptions.
Spacecraft environment discharge is a critical concern for satellite operators, as it results from the accumulation and abrupt release of electrical charges on a satellite. When different components of the spacecraft achieve varying voltages, it can lead to sparks, electromagnetic interference, and transient currents. Consequently, satellites may encounter temporary glitches or suffer permanent damage due to these discharges.
The groundbreaking study conducted by the Los Alamos researchers is the first to definitively confirm that the buildup of electrical charges on a spacecraft is directly proportional to the number of electrons present in its surrounding environment. The sensors employed in the study were adept at measuring both the radio frequency of the electrical charges and the activity levels of electrons. This dual measurement capability enabled the researchers to analyze the rate of electrical charges and compare it to the electron activity in the surrounding environment.
In the majority of observations, peaks in electron activity were recorded between 45 to 24 minutes before an electrical discharge occurred on the spacecraft. This finding indicates that high-flux electrons surge first, leading to the charging of electrical currents on the spacecraft, which subsequently results in a series of discharges both within and around the spacecraft.
These new insights into spacecraft environment discharge not only deepen our understanding of the complex interactions between satellites and their charged surroundings but also pave the way for future developments aimed at enhancing satellite resilience. By forecasting spacecraft discharge and mitigating its impacts, we can ensure the continued functionality and longevity of satellites operating in the challenging environment of space.
