Spacecraft charging is a physical phenomenon where spacecraft accumulate electrical charge while operating in space environments. This effect occurs due to interactions between the spacecraft and the surrounding plasma environment, solar radiation, and cosmic rays.
Spacecraft charging develops through several mechanisms:
The charging process varies significantly by orbit. Geosynchronous orbits experience severe charging during geomagnetic storms, while low Earth orbits face charging in polar regions and during night passages. [1]
Spacecraft charging poses several operational threats: [2]
Incidents caused by spacecraft charging include the 2010 Galaxy 15 communications satellite failure, which drifted uncontrolled for eight months after a charging event disrupted its command systems, and the complete loss of the ADEOS II satellite in 2003. [2]
Several spacecraft were launched to understand the causes and effects of charging. SCATHA (Spacecraft Charging AT High Altitudes) was launched by the United States Air Force in 1979, and "proved to be a boon to the space-science and satellite-engineering communities". The spacecraft experienced arcs, and measured "both the space environment and the charging of the whole satellite and several of its surfaces in response to it". Several satellites were developed by the Los Alamos National Laboratory; others include the Geostationary Operational Environmental Satellites (GOES). [4]
Several approaches were developed to minimize charging risks:
Modern spacecraft design increasingly relies on comprehensive modeling to prevent charging anomalies during mission operations.