In 1999, NASA lost a $125 million Mars spacecraft because of a metric-versus-imperial mix-up — the kind of conversion mistake most of us have made, only this one ended with a probe disappearing into the Martian atmosphere

When the Mars Climate Orbiter left Earth on December 11, 1998, it carried a clear and substantial set of objectives. The spacecraft was designed to spend a Martian year in orbit, mapping the planet’s weather patterns and seasonal shifts in water vapor and carbon dioxide ice —data scientists needed to better understand Mars’s climate history, [...] The post In 1999, NASA lost a $125 million Mars spacecraft because of a metric-versus-imperial mix-up — the kind of conversion mistake most of us have