STS-93 astronauts -- in front, Commander Eileen Collins
(left) and Mission Specialist Michel Tognini; in back,
Mission Specialist Steve Hawley (left), Pilot Jeff Ashby
(middle) and Mission Specialist Cady Coleman -- pose for
the traditional inflight crew portrait on Columbia's middeck.
here to see more STS-93 images in the Gallery.
Deploys Chandra X-Ray Observatory
Space Shuttle Columbia lifted off for its 26th flight -- mission
STS-93 -- on July 22, 1999, at 11:31 p.m. CDT (0431 GMT July
23, 1999). The purpose of the five-day mission was to deploy
the Chandra X-Ray Observatory.
when Columbia reached orbit, it was 11 kilometers (7 miles)
short of its target. This was due to premature main engine
cutoff an instant before the scheduled cutoff. This problem
was traced to a hydrogen leak in the No. 3 main engine nozzle.
The leak was caused when a liquid oxygen post pin came out
of the main injector during main engine ignition, striking
the hotwall of the nozzle and rupturing three liquid hydrogen
coolant tubes. Columbia eventually reached its proper altitude
and continued its mission.
Day 1, the shuttle crew successfully deployed Chandra. The
observatory was propelled into orbit by a two-stage Inertial
Upper Stage, or IUS. Following
the second IUS burn, Chandra's solar arrays were deployed
and the IUS separated from the observatory as planned.
the rest of the mission the crew activated secondary payloads
and experiments, including the Southwest Ultraviolet Imaging
System which was used to capture ultraviolet imagery of Earth,
the Moon, Mercury, Venus and Jupiter.
monitored several plant growth experiments and collected data
from a biological cell culture experiment. They used the exercise
treadmill and the Treadmill Vibration Information System to
measure vibrations and changes in microgravity levels caused
by on-orbit workouts. High-Definition Television equipment
was tested for future use on both the shuttle and the International
Space Station to conform to evolving broadcasting industry
standards for television products.