NASA burned $327M over two words

Added: 2026-06-04

[00:00:00]a spacecraft burned up over Mars, and a $327 million mission burned with it. The reason, two teams of engineers never agreed on one thing, meters or pounds.

[00:00:12]On December 11th, 1998, NASA launched the Mars Climate Orbiter to study the planet 's climate.

[00:00:20]The cruise to Mars would take 286 days. The orbiter 's thruster software was written in imperial units, pound seconds.

[00:00:30]NASA 's ground software read that data back, expecting metric units, Newton seconds.

[00:00:37]For nine months, nobody noticed.

[00:00:40]One pound second is four and a half Newton seconds.

[00:00:45]Every course correction burn added a tiny push in the wrong direction.

[00:00:49]286 days later, the orbiter was 100 kilometers off from where the team believed it was.

[00:00:55]On September 23rd, 1999, at 9.01 in the morning UTC, the Mars Climate Orbiter fired its main engine to slip into orbit 226 kilometers above Mars.

[00:01:09]It was at 57.

[00:01:11]The minimum safe altitude was 85.

[00:01:15]The signal cut out 49 seconds early. In that moment, the team understood everything.

[00:01:21]The orbiter burned.

[00:01:24]Nine months of work became a cloud of dust over Mars.

[00:01:27]The cause, two words in one program that nobody ever checked.