The radiation environment for earth-orbiting astronomical satellites

The near-earth radiation environment consists primarily of geomagnetically trapped and solar flare energetic electrons and protons, together with a component of galactic cosmic rays. These charged particles give rise to a variety of physical effects which can compromise the operation of the sensitive detectors and electronics currently used to make detailed astronomical observations from space. Data from astrophysical instruments flown on the Cos-B satellite and the Soviet space station, Mir, are used to illustrate how the terrestrial radiation environment can interfere with the study of distant celestial objects. Standard numerical radiation environment models are used to interpret the data, and limitations and improvements to the models are discussed.