Prowler is reportedly a secret geostationary satellite, which was deployed by Space Shuttle Atlantis (STS 38).
Prowler was secretly deployed and received no USA designation as usual for secret military satellites. The satellite was identified by amateur satellite observers based on publicized orbital data.
Reportedly the satellite was based on the commercial Hughes HS-376 bus and served probably in an satellite inspection or ELINT mission. Prowler maneuvered near the orbital positions of several russian communications satellites. Therefore some kind of RF interception or satellite inspection equipment seems likely.
The satellite featured apparently a stealth feature like the LES 8 satellite, which made it harder to observe. After the end of the mission, Prowler showed an increase in brightness, which might hint to a mirror plane no longer oriented to the earth side of the satellite.
|Type / Application:||ELINT or Inspection ?|
|Power:||Solar cells (body mounted and drop-skirt), batteries|
|Prowler 1||1990-097D ?||15.11.1990||CC LC-39A||Shuttle [PAM-D ?]||with Atlantis F7 (STS 38), SDS-2 2|