En route Mars
The Mars Climate Orbiter was the second flight of the Mars Surveyor Program. The probe was to enter a 160 km x 38600 km polar orbit around Mars on September 23,1999, and use aerobraking to reach a 373 km x 437 km x 92.9 degree sun-synchronous mapping orbit by November 23 1999. While the Mars Orbit Insertion burn began as planned on September 23, 1999 at 08:50 GMT, no signal was received after the spacecraft went behind the planet. Subsequent investigation showed that the spacecraft had plunged deep into the Martian atmosphere, with its closest approach to Mars being 57 km. It was concluded that the spacecraft burnt up in the atmosphere. It was later found that cutbacks in tracking, combined with incorrect values in a look-up table imbedded deep in the spacecraft software (use of pounds force instead of newtons) were to blame. This failure led to a shake-up of NASA's 'faster, better, cheaper' approach to unmanned spaceflight.