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NFES 2009-805
July 2009

NASA's metric confusion caused Mars Orbiter loss

September 30, 1999

(CNN) - NASA lost a $125 million Mars orbiter because one engineering team used metric units while another used English units for a key spacecraft operation, according to a review finding released Thursday.

For that reason, information failed to transfer between the Mars Climate Orbiter spacecraft team at Lockheed Martin in Colorado and the mission navigation team in California. Lockheed Martin built the spacecraft.

"People sometimes make errors," said Edward Weiler, NASA's Associate Administrator for Space Science in a written statement.

"The problem here was not the error, it was the failure of NASA's systems engineering, and the checks and balances in our processes, to detect the error. That's why we lost the spacecraft."

The findings of an internal peer review panel at NASA's Jet Propulsion Laboratory (JPL) showed that the failed information transfer scrambled commands for maneuvering the spacecraft to place it in orbit around Mars. JPL oversaw the Climate Orbiter mission.

"Our inability to recognize and correct this simple error has had major implications," said JPL Director Edward Stone. Source: