Radiation effects in solid-state microelectronics can be split into two general categories: cumulative effects and single-event effects (SEEs). Cumulative effects produce gradual changes in the operational parameters of the devices, whereas SEEs cause abrupt changes or transient behavior in circuits. The space radiation environment provides a multitude of trapped, solar, and cosmic ray charged particles that cause such effects, interfere with space-system operation, and, in some cases, threaten the survival of such space systems. This article will describe these effects and how their impact may be mitigated in silicon-based microcircuits.