STS 41-C encyclopedia topics

Crew

Number in parentheses indicates number of spaceflights by each individual prior to and including this mission.

Robert L. Crippen (3) - Commander
Francis R. Scobee (1) - Pilot
George D. Nelson (1) - Mission Specialist
James D. A. van Hoften (1) - Mission Specialist
Terry J. Hart (1) - Mission Specialist

Mission parameters

Mass:

Orbiter liftoff: 115,361 kg
Orbiter landing: 89,344 kg
Payload: 17,357 kg

Perigee: 222 km
Apogee: 468 km
Inclination: 28.5°
Period: 91.4 min

Space walks

Nelson and van Hoften - EVA 1
EVA 1 Start: April 8, 1984 - 14:18 UTC
EVA 1 End: April 8, - 16:56
Duration: 2 hours, 38 minutes

Nelson and van Hoften - EVA 2
EVA 2 Start: April 11, 1984 - 08:58 UTC
EVA 2 End: April 11, 1984 - 15:42 UTC
Duration: 6 hours, 44 minutes

Mission highlights

In April 1984, Challenger was once again flying in space, this time on the STS 41-C mission. Liftoff took place at 8:58 a.m. EDT, on April 6, 1984. It marked the first direct ascent trajectory for the Shuttle which reached its 288 nautical miles (533 km) high orbit using the Orbiter Maneuvering System engines only once -- to circularize its orbit.

The flight had two primary objectives. The first was to deploy the huge Long Duration Exposure Facility (LDEF), a passive, retrievable, 21,300 lb (9,660 kg), 12-sided cylinder, 14 feet (4.3 m) in diameter and 30 feet (9 m) long carrying 57 experiments. The second objective was to capture, repair and redeploy the malfunctioning Solar Maximum Mission satellite -- "Solar Max" -- launched in 1980.

The five-man crew included Robert L. Crippen, commander, on his third Shuttle flight; pilot Francis R. Scobee; and mission specialists, James D. A. van Hoften, Terry J. Hart and George D. Nelson.

On the second day of the flight, the LDEF was grappled by the RMS arm and successfully released into orbit. Its 57 experiments, mounted in 86 removable trays were contributed by 200 researchers from eight countries. Retrieval of the passive LDEF had been scheduled during 1985, but schedule delays and the Challenger accident postponed the return until January 12, 1990 when Columbia retrieved LDEF on mission STS-32.

On the third day of the mission, Challenger's orbit was raised to about 300 nautical miles (556 km), and it maneuvered to within 200 feet (60 m) of Solar Max. Astronauts Nelson and van Hoften, wearing space suits, entered the payload bay. Nelson, using the MMU, flew out to the satellite and attempted to grasp it with a special capture tool called the Trunnion Pin Acquisition Device (TPAD). Three attempts to clamp the TPAD onto the satellite failed. It began tumbling on multiple axes when Nelson attempted to grab Solar Max by hand, by a solar array, and the effort was called off.

During the night, the Solar Max POCC, at Goddard Space Flight Center, Greenbelt, Maryland, was able to establish control over the satellite by sending commands ordering the magnetic torque bars to stabilize the tumbling action. This was successful and the Solar Max went into a slow, regular spin.

The next day, Crippen maneuvered Challenger back to Solar Max and Hart was able to grapple Solar Max with the RMS. They placed Solar Max on a special cradle in the payload bay using the RMS. They then began the repair operation, replacing the satellite's attitude control mechanism and the main electronics system of the coronagraph instrument. The ultimately successful repair effort took two separate space walks. Solar Max was deployed back into orbit the next day, thus concluding one of the most unusual rescue and repair missions in the history of the space program.

After a 30 day checkout by the Goddard POCC, Solar Max resumed full operation.

Other STS 41-C mission activities included a student experiment located; in a middeck locker to determine how honeybees make honeycomb cells in a microgravity environment. They did so successfully, just as on Earth.

Highlights of the mission, including the LDEF deployment and the Solar Max repair were filmed using an IMAX movie camera, and the results appeared in the IMAX movie The Dream is Alive.

The 6-day, 23-hour, 40-minute, 7-second mission ended on April 13, at 5:38 a.m. PST, with Challenger landing on Runway 17, at Edwards AFB. It had completed 108 orbits. Challenger was returned to KSC on April 18.