1991-051A
DSI's next satellites for DARPA were a cluster of seven Microsats for UHF communications store-forward relay. The 21 kg satellites were 0.48m in diameter and 0.19m high, and form the DSI (later Orbital-McLean) Picostar platform.
The NASA NB-52 carrier aircraft took off from Edwards on 1991 Jul 17 and dropped the Pegasus rocket over the Point Arguello Warning Area (PAWA) for launch up the Western Test Range. The three-stage solid Pegasus launch vehicle had a hydrazine HAPS fourth stage added which was intended to place the satellites in a 720 x 720 km x 82 deg orbit. However stage 1 did not separate properly from stage 2 and the vehicle was nearly lost when it made a partial loop. The guidance recovered and Pegasus/HAPS limped into orbit, but only achieved a 400 km altitude. The satellite reentered in Jan 1992. Some tests were done with the satellites using amateur radio networks and they appear to have survived until reentry.
| Microsat 1 | |||
| Date | Time | Event | Orbit |
|---|---|---|---|
| 1991 Jul 17 | 1625 | NB-52 008 takeoff from Edwards AFB | RW04/22 |
| 1733:53 | Launch of Pegasus over Point Arguello Warning Area | ||
| 1735:43 | Stage 1 sep, Stage 2 TIG | ||
| 1736:57 | Stage 2 cutoff | ||
| 1737:37 | Stage 2 sep | ||
| 1737:50 | Stage 3 TIG | ||
| 1738:58 | Stage 3 cutoff | ||
| 1739s | HAPS ignition | ||
| 1800s | HAPS burn 2 due | ||
| 1810s | Microsat dispersal due | ||
| 1830? | HAPS test burn 3 due | ||
| 1991 Jul 18 | 92.73 358 x 358 x 82.02 | ||
| 1991 Aug 2 | 92.68 360 x 451 x 82.0 | ||
| 1992 Jan 23 | Reentered | ||
