NASA’s Metric Mistake: The $125 Million Error

In 1999, the Mars Climate Orbiter burned up in the Martian atmosphere. It was a catastrophic failure for NASA, but the cause was shockingly simple: a unit conversion error.

Lockheed vs. NASA

The spacecraft was built by Lockheed Martin, who designed the thruster software to output force in Pound-Seconds (Imperial units). However, NASA's navigation team assumed the data was in Newton-Seconds (Metric units).

The Result

1 Pound of force is equal to about 4.45 Newtons. Because the computer thought the "1" it received was a Newton (smaller) when it was actually a Pound (larger), the thrusters fired with 4.45 times more power than expected over time. This pushed the orbiter too low into the atmosphere, causing it to disintegrate. It serves as the ultimate cautionary tale for unit conversion!