STS -51 (English Space Transportation System) was a name for a mission of the U.S. Space Shuttle Discovery NASA. The launch took place on 12 September 1993. It was the 57th Space Shuttle mission and the 17th flight of the Space Shuttle Discovery.


  • Frank Culbertson ( second space flight), Commander
  • William Readdy ( second space flight), Pilot
  • James Newman ( first space flight), Mission Specialist
  • Daniel Bursch ( first space flight), Mission Specialist
  • Carl Walz (1st space flight), Mission Specialist

Mission History

Attempts to start and start

Especially in this mission was the fact that the crew every time already was when the three start crashes aboard the Space Shuttle and these had then quit again.

  • The first launch attempt on July 17, 1993 had to be canceled due to a problem with a pyrotechnic controller in one of the solid rocket boosters.
  • The second launch attempt on 24 July had to be canceled due to a further defect of the right SRB.
  • The third launch attempt on August 12, was initially successful until ignition of the three main engines. Three seconds before lift-off the engines had to back off and the start will be aborted. The fuel flow meter an engine was defective. This so-called RSLS demolition (Redundant Set Launch Sequencer ) automatically runs when the computer monitor to determine a technical malfunction of the engines in the ignition.
  • The fourth launch attempt on 12 September was finally successful and the Discovery launched at 11:45 UTC on its 17th flight.

Mission overview

The main objective of the mission was exposing the Advanced Communications Technology Satellite ( ACTS) and the Orbiting Retrievable Far and Extreme Ultraviolet Spectrometers ( ORFEUS ), mounted on the Shuttle Pallet Satellite ( SPAS ). The latter was equipped with U.S. and German scientific experiments, including an ultraviolet spectrometer. In addition, it was an IMAX film camera, with the scenes for the movie were filmed Destiny in Space.

In the ACT satellites, it was an experimental communications satellite. After exposure on the first day of flying this activated its engines and thus raised to a geostationary orbit. This was preceded by a delay, there was a half hour before the scheduled launch communication problems between the Johnson Space Center and the Shuttle. This was fixed by changing the frequency of the S-band communication unit.

On September 16, Mission Specialists Newman and roll led by a seven-hour spacewalk. They tested different tools and supports and footrests that should use in December the astronauts during the servicing mission of the Hubble Space Telescope. As the crew was faster than expected, in addition further experiments could be performed. However, then a tool box did not close as intended, so that the EVA had to be extended by 45 minutes, reaching a total duration of seven hours and five minutes.

Inside the cabin also various biological tests and material research experiments were carried out. Among other things, was examined with a mounted on the lower deck of the Discovery ergometer the effect of gravity on human muscle cells. In preparation for future missions to space station as a test fuel cell has stopped and then restarted.

After six days, the free-flying ORFEUS palette, which had in the meantime removed up to about 65 km from the Discovery was captured with the help of the robot arm Canadarm and stowed in the payload bay. Then all the parts are not needed were stowed in the cabin and prepared the orbiter on the landing.

After 158 orbits around Earth, the Discovery landed as scheduled on September 22 at 07:56:11 UTC on the Shuttle Landing Facility at Kennedy Space Center in Florida. This was the first night landing of a space shuttle at this landing site.