Mars Surveyor

Mars Surveyor may refer to various NASA Mars probes:

Mars Surveyor '98 program

The Mars Surveyor '98 program comprised two spacecraft launched separately, the Mars Climate Orbiter (formerly the Mars Surveyor '98 Orbiter) and the Mars Polar Lander (formerly the Mars Surveyor '98 Lander); on board the Mars Polar Lander spacecraft were two surface-penetrator probes (Deep Space 2). The two missions were to study the Martian weather, climate, water and carbon dioxide (CO₂) budget, to understand the reservoirs, behavior, and atmospheric role of volatiles and to search for evidence of long-term and episodic climate changes.

Both spacecraft were launched during the 1998 Mars orbit insertion launch window. Both were lost, including the penetrator probes.

Loss of the orbiter

The orbiter was lost due to a miscalculation in trajectory caused by an unintended and undetected mismatch between metric and English units of measurement. The use of metric units as well as the data formats to employ were specified in a navigation software interface specification (SIS) published by JPL in 1996. Despite this, the flight operations team at Lockheed Martin provided impulse data in English units of pound-force seconds rather than newton seconds. These values were incorrect by a factor of 4.45 (1 lbf = 4.45 N). This caused erroneous course corrections that caused the orbiter to descend too low in Mars's atmosphere. The vehicle either burned up or bounced off into space.

Mars Surveyor 2001

The Mars Surveyor 2001 project was a multi-part Mars exploration mission intended as a follow-up to Mars Surveyor 1998. After the two probes of the 1998 project, Mars Climate Orbiter and Mars Polar Lander, were both lost, NASA's "better, faster, cheaper" exploration philosophy was re-evaluated, with a particular eye on the two 2001 project probes. As a result, the Mars Surveyor 2001 Lander was canceled in May 2000, but the decision was made to go ahead with its orbiter counterpart. Later, the body of the lander component was adapted into the Mars Phoenix Lander which landed successfully on Mars in 2008.

The Mars Surveyor 2001 Orbiter, renamed 2001 Mars Odyssey, was launched April 7, 2001 reached Mars on October 24, 2001. After aerobraking from October 2001 until January 2002, Mars Odyssey began mapping the planet on February 19, 2002.

By December 15, 2010 the orbiter broke the record for longest serving spacecraft at Mars, with 3,340 days of operation, claiming the title from NASA's Mars Global Surveyor, which had arrived sooner than Odyssey but failed in 2006. Some other active orbital missions during this period include Mars Express (since 2003) and Mars Reconnaissance Orbiter (since 2006), in addition there were a few landers and flybys.