STS -51- D (English Space Transportation System) is a mission name for the U.S. Space Shuttle Discovery ( OV -103 ) from NASA. The launch took place on 12 April 1985. It was the fourth flight of the space shuttle Discovery and the 16th flight of the Space Shuttle.
- Karol Bobko ( second space flight), Commander
- Donald Williams ( first space flight), Pilot
- Rhea Seddon ( first space flight ), Mission Specialist
- Jeffrey Hoffman ( first space flight), Mission Specialist
- David Griggs ( first space flight), Mission Specialist
- Charles Walker ( second space flight), Payload Specialist
- Jake Garn ( first space flight), Payload Specialist
Charles Walker was again as an industrial astronaut of the U.S. air and aerospace company McDonnell Douglas in use, with Jake Garn was the first politician in space.
The launch was originally scheduled for 19 March 1985. After the mission STS -51 -E had been painted, the payload of 51 -D and 51- E was reassembled. Here in the Orbiter Processing Facility, an accident in which the cargo door of the Discovery was damaged occurred. Therefore, the amount recognized for the March 28 mission beginning on 12 April had to be postponed. On launch day itself the countdown was halted for 55 minutes because a ship had entered the locked for the splashdown of the solid rocket sea area.
STS -51- D suspended the satellite TELESAT -9 and LEASAT -3. In the latter case, however, the automatic startup of the antenna and the engine did not work. The mission was short-term extended by two days to fix the defect by the astronauts, but did not succeed. The satellite was then captured on the mission STS -51 -I again and repaired. In addition, various experiments were carried, including those which had been developed by American students.
On landing at the Kennedy Space Center in Florida, a damage to the braking system of the shuttle and blowouts occurred. Until the installation of a nose wheel control, therefore all subsequent landings were planned at Edwards Air Force Base.