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Mars Climate Orbiter
Mars Climate Orbiter Mission to Mars

Mission Type: Orbiter
Launch Vehicle: Delta 7427-9.5 (no. D264)
Launch Site: Cape Canaveral, United States, launch complex 17A
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 629 kg
Spacecraft Instruments:
1) PMIRR pressure modulated infrared radiometer
2) MARCI Mars color imaging system (two cameras)
3) UHF communications system
Spacecraft Dimensions: 2.1 m high, 1.6 m wide, and 2 m deep
Spacecraft Power: Three solar panels and rechargable batteries
Maximum Power: 1000 W (500 W at Mars)
Antenna Diameter: 1.3 m
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi

National Space Science Data Center,

Mars Climate Orbiter was the second probe in NASA's Mars Surveyor program, which also included Mars Global Surveyor (launched in November 1996) and Mars Polar Lander (launched in January 1999).

Mars Climate Orbiter was designed to arrive at roughly the same time as Mars Polar Lander and conduct simultaneous investigations of Mars's atmosphere, climate and surface. Mars Climate Orbiter was also designed to serve as a communications relay for the latter.

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.

The spacecraft was scheduled to arrive in Mars orbit on 23 September 1999 and attain its operational near-circular sun-synchronous orbit at 421 km by 1 December 1999. After the end of its main mapping mission on 15 January 2001, Mars Climate Orbiter would have acted as a communications relay for future NASA missions to Mars.

After launch, the spacecraft performed four midcourse corrections on 21 December 1998, 4 March, 25 July, and 15 September 1999. At 09:01 UT (received time) on 23 September 1999, the orbiter began its Mars orbit insertion burn as planned. The spacecraft was scheduled to reestablish contact after passing behind Mars, but no further signals were received from the spacecraft.

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-km altitude orbit and instead fall into the Martian atmosphere at approximately 57 km altitude and burn up.

Key Dates
11 Dec 1998:  Launch (18:45:51 UT)
23 Sep 1999:  Last Contact (09:01 UT)
Status: Unsuccessful
Fast Facts
Mars Climate Orbiter Facts Mars Climate Orbiter launched (right) 11 December 1998.

Mars Climate Orbiter was designed to arrive at roughly the same time as Mars Polar Lander and conduct simultaneous investigations of Mars's atmosphere, climate and surface.

This mission was unsuccesful due to navigation error caused by the failure to translate English units to metric.
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Last Updated: 10 Dec 2010