Launch of Mars Climate Orbiter

The Mars Climate Orbiter was a NASA spacecraft intended to study the Martian atmosphere and weather and to act as a communications relay for the Mars Polar Lander. It was lost when it reached Mars, because it entered the atmosphere at a much lower altitude than planned and was destroyed or crashed. The investigation found that one team had supplied navigation data in imperial units, pound-force seconds, while another team's software expected the metric unit, newton seconds, so that small errors in trajectory corrections built up during the journey. The failure became a well-known example of the importance of unit conventions and verification in engineering, and led to changes in how NASA managed its missions.

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