STS -93 (English Space Transportation System) is the designation for a flight mission of the U.S. Space Shuttle Columbia ( OV -102) from NASA. The launch took place on 23 July 1999. It was the 95th Space Shuttle mission and the 26th flight of the Space Shuttle Columbia.

When launched, it came with a dissolved oxygen nozzle to a hydrogen leak in one of the engines, so that the engine shuts down automatically early. Thus the intended orbit height has not been fully achieved. The mission could still be carried out successfully.


  • Eileen Collins ( third space flight), Commander
  • Jeffrey Ashby ( first space flight), Pilot
  • Steven Hawley ( fifth space flight), Mission Specialist
  • Catherine Coleman ( second space flight ), Mission Specialist
  • Michel Tognini ( second space flight), Mission Specialist ( CNES / France)

( During this flight, the Space Shuttle was first commanded by a woman)

Mission Description

With the Columbia, the X-ray telescope Chandra was placed in a low Earth orbit. Just a few hours after the start it was catapulted after a short system check of the cargo bay. The two-stage Inertial Upper Stage brought the satellite later on an elliptical orbit 1200-72000 km altitude.

Aboard the Space Shuttle experiments were then carried out in the areas of biology, astronomy, atmospheric science and space technology. So thruster firings were used for calibrating the sensors of the satellite launched in 1996 MSX ( Midcourse Space Experiment). He flew the space shuttle in about 600 miles away. The influence of engine exhaust gases to the surrounding ionosphere has been studied in the experiment SIMPLEX. It should be the source of high-frequency radar echoes caused by the orbiter, are being targeted. The data are needed to determine turbulence in the ionosphere can. On the middle deck of the Columbia there was a coupled to a UV telescope CCD camera ( Southwest Ultraviolet Imaging System). With its images of celestial bodies can be made in our solar system in rapid succession. Observation objects were the planets Mercury, Venus and Jupiter and the moon and a comet. From the Middle deck also images of the earth were made with an electronic camera ( Earth KAM).

Was further investigated the influence of microgravity on the production of gelatinous mixtures. This should be demonstrated that precursors of Compositkeramiken in weightlessness get a more uniform structure. Technological research included the testing of shape memory metals for folding of individual solar cells panels (Lightweight Flexible Solar Array Hinge ) and testing the performance of accelerometers, gyro systems and sensors for takeoff, landing and during the stay in weightlessness (Micro - Electrical Mechanical Systems).

For biological studies, it went to a confirmation of the models for the tissue and function loss of muscle, bone and skin cells by the stress factors weightlessness and increased radiation ( Cell Culture Module). At the cellular level, cell skeleton, metabolism, membrane integrity and protease activity were examined. In addition, pharmaceutical preparations were tested, which should slow the loss of tissue. In the experiment Space Tissue Loss cell cultures were monitored with a microscope system to record their immediate responses to changes in the environment can. On the other was explored whether plants are suitable to display by direct physiological responses changes in the environment ( Plant Growth Investigations in Microgravity ). Also on board were the experiments Commercial Generic Bioprocessing Apparatus and Biological Research In Canister a.

During the mission was taken to school classes several times over the SAREX experiment amateur radio contact. The bicycle training was not only physical training but also the study of the vibrations caused thereby and ways to dampen this. At the start of Columbia, several problems were encountered. Apparently came from an engine of hydrogen. The overheating of the engine could have led to its automatic shutdown. Then the space shuttle would not have reached orbit. Also during the starting phase, a short circuit occurred. On the night landing in Florida both defects had no effect.