On September 23, 1999 at 09:00 the Mars Climate Orbiter’s main engine burners fired. The goal was to change the probe’s trajectory to orbit Mars. At 09:04, communications with the probe was lost. Upon further investigation NASA discovered that the Orbiter had come too close to the upper atmosphere of Mars and disintegrated on contact. The Mars Climate Orbiter was a $125 million project.

What caused this expensive catastrophe?

It was a few innocuous assumptions that lead to mismatched expectations and not-so good results, such as the destruction of the Climate Orbiter.

Lockheed Martin, the spacecraft team that helped develop…