GoKawiilSTS-51-F mission's first launch attempt aborted seconds before ignition
On July 12, 1985, the launch of the Space Shuttle STS-51-F was halted at T−3 seconds due to a coolant valve malfunction in engine number two, leading to an automatic abort. The shuttle successfully launched on its second attempt on July 29, 1985, after a delay caused by uplink issues, but experienced an in-flight engine sensor failure that resulted in a lower-than-planned orbit. This was the only RS-25 engine failure during the shuttle program's operational history.
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This incident highlights the importance of early technical checks and the effectiveness of onboard systems and crew response in preventing catastrophic failures. The successful second launch demonstrated the resilience of the shuttle's abort procedures and the importance of rapid decision-making in spaceflight safety. It also underscores the challenges of engine sensor reliability in maintaining mission integrity.
- First launch attempt was aborted due to coolant valve failure
- Second launch achieved orbit but with engine sensor failures
- Crew and systems effectively prevented a potential loss of vehicle and crew
Source: en.wikipedia.org, 2026-10-02
Published there as: “STS-51-F Abort-to-Orbit (1985)”
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