The launch of STS-83, the first Microgravity Science Laboratory (MSL-1) mission, was postponed for a day to replace some insulation around a water coolant line in Columbia's payload bay. Liftoff was further delayed 20 minutes due to anomalous oxygen readings in the orbiter's payload bay. STS-83 was cut short due to a problem with one of the three fuel cells that provide electricity and water to Columbia (flight rules required that all three must be operating). At 14:30 GMT on April 6 the crew were ordered to begin a Minimum Duration Flight (MDF). On April 8 the OMS engines ignited at 17:30 GMT for the deorbit burn, and Columbia landed on Runway 33 at Kennedy Space Center at 18:33 GMT.
With delays in International Space Station construction leaving ample room in the shuttle schedule, NASA made the unique decision to leave the equipment installed in Columbia and refly this mission with the same crew later in 1997 as STS-94.
The launch came at 1920:36 GMT on Apr 4. Solid rocket motors RSRM-59 separated two minutes after launch and the external tank ET-84 was jettisoned at 19:29 GMT, leaving Columbia in an elliptical transfer orbit with an apogee near 300 km. The OMS 2 orbit circularization burn came at 20:00 GMT. Columbia opened its payload bay doors by 21:09 GMT, beginning what was intended as a marathon Spacelab research mission.
Cargo Bay Payloads:
In-Cabin Payloads: SAREX, MSX
The mission this time went for its full two week duration as the crew conducted the full list of experiments. The deorbit burn was at 0944 GMT following payload bay door closing at around 0700 GMT. Columbia landed on KSC's Runway 33 at 1046:34 GMT on Jul 17.
Development Test Objectives / Detailed Supplementary Objectives / Risk Mitigation Experiments