Nuclear Environmental Effects on Space: Guidance and Control Systems

The guidance and control system that is considered for analysis is a programmed inertial guidance unit with an astro-tracker for space coordinate corrections. For most missions the effects of space radiations on systems will be trivial; however, Van Allen radiation and solar flares can increase the dark current on the astro-tracker sensing element. Reactor radiation from the main propulsion system will cause degradation of: electrical wiring in servo valves, semiconductor electronics in the computer system, seals in the hot gas actuators, and solid or liquid propellent gas generators. Combinations of judicious material selection, design modifications, relocation of systems, and shielding will alleviate problems associated with the guidance and control systems operating in a nuclear environment.