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STS 41-C

        The following April, 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-mile-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., 12-sided cylinder, 14 feet in diameter and 30 feet 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. 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 have postponed the retrieval effort.

        On the third day of the mission, Challenger's orbit was raised to
about 300 miles, and it maneuvered to within 200 feet 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 when van Hoften attempted to
grasp it with the RMS arm, and the effort was called off.

        During the night, the Solar Max POCC, at Goddard Space Flight
Center, Greenbelt, Md., 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, Nelson and van Hoften tried to capture it again.  This
time they succeeded on the first try.  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 unique 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.

        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 and traveled 2.87 million miles.
Challenger was returned to KSC on April 18.