Phenomenal advances in MicroElectroMechanical Systems (MEMS) performance has made this technology attractive for the development of micro- and nano-spacecraft. However, much work remains to be done. The space environment is harsh: extreme heat and cold, thermal cycling, radiation effects, and corrosive environments put conventional device designs at risk. Reliably, packaging and flight qualification methodologies need to be developed for MEMS to produce robust devices for a successful future in space micromissions. These issues are discussed in this paper, along with examples of micromissions, MEMS devices in development for space applications, and the ultimate in device integration: a system-on-a-chip.