Radiation Environment and Its Influence on Spacecraft Design

Janet L. Barth
Component Technology and Radiation Effects Branch, NASA/GSFC

The energy range of particles that affects electronics on spacecraft, aircraft avionics, and even electronics here in the ground is not the energy range importa nt in meeting science research goals. Thus modelers for engineering applications are often stuck in the middle ground between plasma and high-energy astrophysics. Also, while imaging is an exciting technique for global understanding of processes in sun-earth systems, it does not provide data for the quantitative models that engineers and device physicists need to design reliable space systems. Radiation environment models used in engineering calculations are based on space data collected in the 1960's and 1970s, and very few new, high quality data sets exist that can be used for engineering models. In the past, large design margins were applied to environment specifications to account for the lack of accuracy in the environment models. The demise of the radiation-hardened component market, coupled with the push to design smaller, lighter spacecraft with more capability, has made the use of large design margins impractical. This has posed problems in designing electronics for spacecraft in all regions of space, even for low earth orbits.

In this talk, I will describe the radiation effects on electronic systems, the environments that cause them, and point out where the environment and interaction models are lacking. We will discuss management of radiation problems, including how that management has changed in recent times. Finally, we will explore what to expect in the future, including the role of "Space Weather" predictions in the management of healthy spacecraft.