Several exciting circuit opportunities are available as a result of recent advances in silicon-on-insulator (SOI) material. These include radiation-hardened memories for space applications, bipolar SOI, the combination of bipolar and CMOS on the same chip, and three-dimensional integration. With all these advances, the first significant application of SOI in operational systems appears most likely to be an SRAM using CMOS circuitry, designed for space applications. The requirements for a space-based memory are well matched to properties that can be provided by CMOS devices fabricated on SOI material. These requirements include hardness to gamma radiation (total-dose hardness) and resistance to upset from ionizing particles (SEU), in addition to the more usual requirements of high density, high speed, low power, and high reliability.