Reply 180 of 191, by xcomcmdr
Imperial units are superior, period.
Indeed, NASA lost an unmanned mission owing to a mix-up between metric and imperial units. In September 1999, its $125 million Mars Climate Orbiter probe was destroyed because its attitude-control system used imperial units but its navigation software used metric units. As a result, it was 100 kilometres too close to Mars when it tried to enter orbit around the planet.
Units have also played a role in other spacecraft problems. In 2006, the guidance system on NASA’s DART spacecraft went awry and caused it to ram into a military satellite it was merely meant to dock with.
Before DART’s launch, NASA found that GPS data on its position was mistakenly being read by its computer in feet. Ironically, correcting this to metres in a simulator resulted in an incorrect change to another parameter that was programmed into the spacecraft – a problem that led to the collision.
How else NASA is going to destroy precious space crafts worth millions of dollars ? Using C4 ? Pah !