Space Technology 5 Launch and Operations

The three spacecraft that made up the Space Technology 5 (ST5) mission were successfully launched and deployed from their Pegasus launch vehicle on March 22, 2006. Final contact with the spacecraft occurred on June 30, 2006, with all Level 1 requirements met. By the end of the mission, all ST5 technologies had been validated, all on-board attitude control system (ACS) modes had been successfully demonstrated, and the desired constellation configurations had been achieved to demonstrate the ability of small spacecraft to take quality science measurements, However, during those 100 days (ST5 was planned to be a 90-day mission), there were a number of anomalies that made achieving the mission goals very challenging. This paper will discuss: the chronology of the ST5 launch and early operations, work performed to diagnose and work-around a sun sensor anomaly, spacecraft tests devised to demonstrate correct operation of all onboard ACS modes, the maneuver plan performed to achieve the desired constellation, investigations performed by members of the ST5 GN&C and Science teams of an anomalous spin down condition, and the end-of-life orbit and passivating operations performed on the three spacecraft.