Space Shuttle Atlantis
USA-67, launched aboard Space Shuttle Atlantis (OV-104) in November 1990 (STS-38 mission), was initially identified as a third Magnum satellite owing to the presence of two upper stages in orbit after its deployment, suggesting that an Inertial Upper Stage (IUS) had been used to deploy it. It was later determined that the second upper stage was from the stealthy Prowler spacecraft, and that USA-67 was a Satellite Data System (SDS-2) communications satellite.