The Mars Climate Orbiter

Selected by Jocelyn Bell Burnell

The Mars Climate Orbiter was a robotic space probe launched by NASA on December 11th 1998 to study the climate, atmosphere and surface changes on Mars. On September 23rd 1999, NASA issued a press release stating that the Mars Climate Orbiter was believed to be lost. A day later they abandoned their search and it was logged as a failed mission. After a week of investigations, NASA finally revealed what happened to the 125 million dollar spacecraft. They announced in a statement that, “people sometimes make errors.”

The error was that one team used imperial units while the other used metric. The software being used calculated the force the thrusters needed to exert in pounds, then a separate piece of software took in the data assuming it was in metric units or newtons—a factor of four and a half difference! Their planned approach of the planet, at an altitude of about 150 kilometres, was therefore off and it hit Mars’ atmosphere at an altitude of about 60 kilometres. As a result, the Mars Climate Orbiter likely disintegrated due to atmospheric pressure.

The world looked on, amazed that the NASA engineers didn’t catch the mistake. Even at the highest level errors happen and can go unnoticed, proving that attention to detail is always paramount.

About Jocelyn Bell Burnell

Jocelyn Bell Burnell was born in Belfast in 1943, at a time when science was not a subject commonly studied by girls. In 1965, Jocelyn earned a B.Sc. degree in physics from the University of Glasgow. Later that same year she began work on her Ph.D. at Cambridge University. It was while she was a graduate student at Cambridge, working under the direction of Antony Hewish, that Jocelyn discovered pulsars. This was one of the most significant astronomical developments of the twentieth century but in 1974, when her supervisor Antony Hewish was awarded the Nobel Prize, Jocelyn was not included in the award. Awarded her Ph.D. in radio astronomy from Cambridge University in 1968, Jocelyn has studied the sky in almost every region of the electromagnetic spectrum and has received many honours and awards for her contributions to science. She was the first female president of the Institute of Physics of the UK and Ireland, became Pro-Chancellor of Trinity College Dublin in 2013 and is a visiting Professor of Astrophysics at Oxford University.