Launch from Cape Canaveral (KSC); landing on Edwards AFB.

This flight was the fourth mission dedicated to Department of Defense. The crew deployed the military satellites KH-12 and Ferret into orbit. Observation and photo experiments for visibility of small structures on Earth surface was done. During the flight, the crew shut down a thruster in the reaction control system (RCS) because of indications of a leak. Also, an RCS heater malfunctioned.

Postflight analysis of STS-28 discovered unusual heating of the thermal protection system (TPS) during re-entry, caused by an early transition to turbulent plasma flow around the vehicle. A detailed report identified protruding gap filler as the likely cause.