Space Shuttle Atlantis

5 - 18 October 1989 - STS-34 - 39B - Edwards AFB - 4 days, 23 hours, 39 minutes, 20 seconds - 1,800,000 miles (2,900,000 km) - Deployed the Galileo probe bound for Jupiter.
6 - 28 February 1990 - STS-36 - 39A - Edwards AFB - 4 days, 10 hours, 18 minutes, 22 seconds - 1,837,962 miles (2,957,913 km) - Mission dedicated to Department of Defense. STS-36 deployed a single satellite believed to have been a Misty reconnaissance satellite.
7 - 15 November 1990 - STS-38 - 39A - KSC - 4 days, 21 hours, 54 minutes, 31 seconds - 2,045,056 miles (3,291,199 km) - Mission dedicated to Department of Defense. Deployed USA-67 believed to have been a secret Magnum ELINT (ELectronic INTtelligence) gathering satellite.
8 - 5 April 1991 - STS-37 - 39B - Edwards AFB - 5 days, 23 hours, 32 minutes, 44 seconds - 2,487,075 miles (4,002,559 km) - Deployed Compton Gamma Ray Observatory (GRO), the second of the Great Observatories program.