Following the Shuttle Disaster, contracts were awarded for MLV I & II (Delta & Atlas) to carry into orbit DSCS would use the Atlas/Centaur to reach a transfer orbit, but still required a kick motor to reach its' final orbit. The Integrated Apogee Boost Subsystem was designed for this purpose Provides Velocity to Change Orbit From Geotransfer to Geosynchronous Two Bi-Prop Liquid Apogee Engines (LAE) at 110 Lb Thrust Each Spin Stabilized at 20 rpm Uses DSCS Processor, TT&C, and Batteries.