- 12.11.98: Launch (18:45:51 UT)
- 09.23.99: Last Contact (09:01 UT)
- Status: Spacecraft Lost
- PMIRR pressure modulated infrared radiometer
- MARCI Mars color imaging system (two cameras)
- UHF communications system
After the lander's three-month mission, MCO would have performed a two-year independent mission to monitor atmospheric dust and water vapor and take daily pictures of the planet's surface to construct an evolutionary map of climatic changes. Scientists hoped that such information would aid in reconstructing Mars' climatic history and provide evidence of buried water reserves.
Mars Climate Orbiter was lost on arrival September 23, 1999. Engineers concluded that the spacecraft entered the planet's atmosphere too low and probably burned up.
An investigation indicated that the failure resulted from a navigational error due to commands from Earth being sent in English units without being converted into the metric standard. The error caused the orbiter to miss its intended 140- to 150-kilometer altitude orbit and instead fall into the Martian atmosphere at approximately 57 kilometers altitude and burn up.