Operation of commercial R3000 processors in the Low Earth Orbit (LEO) space environment

Spacecraft processors must operate with minimal degradation of performance in the Low Earth Orbit (LEO) radiation environment, which includes the effects of total accumulated ionizing dose and Single Event Phenomena (SEP) caused by protons and cosmic rays. Commercially available microprocessors can offer a number of advantages relative to radiation-hardened devices, including lower cost, reduced development and procurement time, extensive software support, higher density and performance. However, commercially available systems are not normally designed to tolerate effects induced by the LEO environment. Lawrence Livermore National Laboratory (LLNL) and others have extensively tested the MIPS R3000 Reduced Instruction Set Computer (RISC) microprocessor family for operation in LEO environments. We have characterized total dose and SEP effects for altitudes and inclinations of interest to systems operating in LEO, and we postulate techniques for detection and alleviation of SEP effects based on experimental results.. Authors: Kaschmitter, J. L. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]; Shaeffer, D. L. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]; Colella, N. J. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]; McKnett, C. L. [JAYCOR, Inc., Santa Monica, CA (United States)]; Coakley, P. G. [JAYCOR, Inc., Santa Monica, CA (United States)]. DOE Contract: W-7405-ENG-48. Subjects: 42 ENGINEERING; 426000; 440200; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; COMPONENTS, ELECTRON DEVICES AND CIRCUITS; COSMIC RADIATION; DESIGN; MICROPROCESSORS; PHYSICAL RADIATION EFFECTS; RADIATION DOSES; RADIATION EFFECTS ON INSTRUMENT COMPONENTS, INSTRUMENTS, OR ELECTRONIC SYSTEMS; SATELLITES