TIMED Integrated Electronics Module (IEM)

he Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) program is the fi rst to use the Integrated Electronics Module (IEM) spacecraft architecture. The IEM is based on the idea of incorporating the electronics for several spacecraft subsystems into a single chassis using plug-in cards. In addition to the space and mass savings realized with this approach, the concept can be adapted to many space missions over an extended period, providing savings by building on prior confi gurations rather than “starting from scratch.” The command and data handling, Global Positioning System Navigation, and RF communications subsystems, along with associated power converters, are packaged in the TIMED IEM. This article describes the adaptation of the IEM concept for the TIMED mission, which has been operating fl awlessly since it was launched on 7 December 2001.