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Description of Driving Event:

On February 22, 1996, the STS-75 Space Shuttle Columbia was launched at 53/20:18 GMT. The orbiter was inserted into a 296 km (160 nautical mile) orbit at an inclination of 28.5 degrees. The crew consisted of 7 members, including commander, pilot, 3 mission specialists, 1 payload commander, and 1 payload specialist. The TSS-1R payload was a reflight of TSS-1 in 1994, where deployer mechanism problems limited the tether deployment to slightly less than 300 m. The planned duration of the flight was 14 days. The payload bay configuration consisted of the Tethered Satellite System (TSS) experiments, two U.S. Microgravity Lab pallets (USMP-3), Orbiter Acceleration Research Experiment (OARE) pallet, and Extended Duration Orbiter (EDO) pallet.

Deployment of the satellite began at 56/20:46 GMT. On 57/01:29:26 GMT, at a tether length of 19.7 km, the satellite tether broke within the 12 m deployer boom, and the satellite separated from the orbiter. The rate of tether deployment was under control of the science computer. At the time of the tether separation, the deployment rate was being ramped down, per timeline, in preparation for halting at 20.7 km tether length. The tether deployment rate was approximately 1 m/s when it separated. There were no injuries and no damage to the orbiter or its subsystems due to the tether break.

The orbiter was located at 2 degrees N latitude and 100.4 degrees W longitude, and was at an altitude of 296 km (160 nautical miles) at the time of tether break. The TSS-1R experiments were in the passive mode, with no current flowing in the tether. The tether had an electric potential of -3500 VDC with respect to the orbiter ground, as planned, during this mode.

Telemetry from the orbiter and the satellite was operating prior to, during, and after the tether separation. Video imagery of the tether was available after the separation, but no video coverage exists showing the break itself. Video and still photography were taken during the mission of the failed end of the tether within the boom. The tether remaining in the boom was rewound on the reel during the mission.