Centaur (rocket Stage) - Mishaps

Mishaps

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Although Centaur has a long and successful history in planetary exploration, it has had its share of problems, especially early on:

• May 8, 1962: Centaur weather shield separated early; stage exploded. Footage of this was used in the film Koyaanisqatsi.
• June 30, 1964: RL-10 hydraulic actuator pump shaft broke, preventing one of the two RL-10 engines from vectoring. This led to no roll control, and uncovering of LOX inlet.
• December 11, 1964: Restart attempt failed, due to problem with ullage rockets.
• April 7, 1966: Centaur did not restart after coast — ullage motors ran out of fuel.
• August 10, 1968: Centaur restart failed.
• May 9, 1971; Centaur guidance failed, destroying itself and the Mariner 8 spacecraft bound for Mars orbit.
• Feb 11, 1974: Titan-Centaur; boost pump failed.
• June 9, 1984: Centaur LOX tank failed; no restart.
• April 18, 1991: Centaur failed due to icing of hydrogen pump impeller blades (not understood at the time)
• August 22, 1992: Centaur failed to restart (icing problem again)
• April 30, 1999: Launch of the USA-143 (Milstar-3) communications satellite failed when a Centaur programming error resulted in incorrect burn times, placing the satellite in a useless orbit.
• June 15, 2007: the engine in the Centaur upper stage of an Atlas V shut down early, leaving its payload — a pair of National Reconnaissance Office ocean surveillance satellites — in a lower than intended orbit. The failure was called "A major disappointment", though later statements claim the spacecraft will still be able to complete their mission. The cause was traced to a stuck-open valve that depleted some of the hydrogen fuel, resulting in the second burn terminating four seconds early. The problem was fixed and the next flight was nominal.