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.