STS 51-C

Flight Crew

MATTINGLY, Thomas Kenneth, 48, USN, commander, 3rd mission Previous missions: Apollo 16 (1972); STS-4 (1982)

SHRIVER, Loren James, 40 USAF, pilot ONIZUKA, Ellison Shoji, 38, USAF, mission specialist 1 BUCHLI, James Frederick, 39, USMC, mission specialist 2 PAYTON, Gary Eugene, 36, USAF, payload specialist

Flight Log

This mission was originally to have been designated STS-10 and to have flown in January 1984. When it finally got to the launch pad as STS 51-C (originally designated STS-20), it was assigned to orbiter Discovery, rather than Challenger, which was suffering a rather disturbing tile problem. The assignment of Discovery to the mission caused a disruption to the 1985 Shuttle schedules. Although a classified military mission, press leaks resulted in most people knowing full well what the STS 51-C crew would be doing: deploying a geostationary electronic monitoring satellite on an IUS upper stage. It was also unique in that it carried the first military specialist passenger, Gary Payton, from a cadre of US Air Force Manned Space Flight Engineers, most of whom it was anticipated at the time would fly on later military Shuttle missions.

The launch of STS 51-C was delayed by one day by the coldest weather in memory at the KSC and was quite spectacular a day later at 14: 50 hrs. The countdown had not been announced until T — 9 minutes under new rules for military launches, although observers could tell it was in progress a lot earlier by seeing wisps of liquid oxygen coming off the ET. Discovery entered a 28.4° inclination orbit with a maximum altitude of 341 km (212 miles). Trouble with the IUS on the STS-6 mission had been the main reason for this mission’s delay, and after the Acquacade ELINT (electronic

signals intelligence satellite) had been deployed, the IUS misbehaved again, its first stage thrust shortfall being made up by thruster firings.

Discovery also carried a blood flow experiment but little else was officially reported about the mission, which ended after the shortest five-crew flight of just T + 3 days 1 hour 23 minutes 13 seconds on runway 15 at the KSC.

Milestones

103rd manned space flight

46th US manned space flight

15th Shuttle mission

3rd flight of Discovery

1st US classified manned military mission

1st flight of a Military Spaceflight Engineer (MSE – Payton)