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, and water and carbon dioxide budget, to understand the reservoirs, behavior, and atmospheric role of volatiles and to search for evidence of long-term and episodic climate changes. Mars Climate Orbiter during tests The Mars Climate Orbiter (formerly the Mars Surveyor 98 Orbiter) was one of two spacecraft in the Mars Surveyor 98 program, the other being the Mars Polar Lander (formerly the Mars Surveyor 98 Lander). ... Conceptual drawing of the Mars Polar Lander on the surface of Mars. ... The Deep Space 2 mission, which launched in January 1999 as part of NASAs New Millennium Program, consisted of two highly advanced miniature probes to Mars. ...

Both spacecraft were launched during the 1998 Mars orbit insertion launch window. Both spacecraft were lost, including the penetrator probes. Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... Orbit insertion is a maneuver performed by an inter-planetary spacecraft designed to allow the spacecraft to be captured into orbit around a planet or other body such as a moon. ... Launch window is a term used in aerospace to describe a time period in which a particular rocket must be launched. ...

The orbiter was lost due to a miscalculation in trajectory. The miscalculation was 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). The mix-up caused erroneous course corrections that resulting in the orbiter descending too low in Mars atmosphere. The vehicle either burned up or bounced off into space. Look up si, Si, SI in Wiktionary, the free dictionary. ... The Imperial units are an irregularly standardized system of units that have been used in the United Kingdom and its former colonies, including the Commonwealth countries. ... Lockheed/BAE/Northrop F-35 Lockheed Trident missile C-130 Hercules; in production since the 1950s, now as the C-130J Lockheed Martin (NYSE: LMT) is an aerospace manufacturer formed in 1995 by the merger of Lockheed Corporation with Martin Marietta. ... The pound-force is a non-SI unit of force or weight (properly abbreviated lbf or lbf). The pound-force is equal to a mass of one pound multiplied by the standard acceleration due to gravity on Earth (which is defined as exactly 9. ...

The most likely cause of the Lander’s failure, investigators decided, was that a spurious sensor signal associated with the craft’s legs falsely indicated that the craft had touched down when in fact it was some 40 meters above the surface. When the landing legs unfolded they made a bouncing motion that accidentally set of the landing sensors, thus caused the descent engines to shut down prematurely and the Lander to free-fall out of the Martian sky. Another possible reasons for failure was inadequate preheating of catalysis beds for the pulsing rocket thrusters. Hydrazine fuel decomposes on the beds to make hot gases that throttle out the rocket nozzles; cold catalysis beds caused misfiring and instability in crash review tests. Hydrazine is the chemical compound with formula N2H4. ...

The Mars Surveyor 1998 program spacecraft development cost US$193.1 million. Launch costs were estimated at US$91.7 million and mission operations at US$42.8 million. The Mars Climate Orbiter was part of NASA's 10-year Mars Surveyor Program, which feature launches every 26 months when the Earth and Mars are favorably aligned.