Mars Polar Lander

The Mars Polar Lander was a spacecraft of the U.S. space agency NASA with the purpose of exploring the planet Mars, which, probably, crashed in December 1999 during the landing process. He should land near the Martian south pole in the Planum Australe and there perform extensive studies on the composition of the polar ice caps.

Instruments

The Mars Descent Imager ( MARDI ) should take about ten pictures of the Martian surface during the descent of the lander.

After landing should, in addition to numerous other experiments, current weather data (temperature, pressure, humidity, wind speed and direction ) are recorded. For soil sampling, a robotic arm was provided. The samples should be analyzed automatically in bord own laboratory and the content of water, carbon dioxide and water-containing minerals can be determined. In addition, the isotopic composition of oxygen and carbon of the soil samples and the Mars air should be measured. In addition to the robot arm, a camera was mounted.

A second camera, which was installed on a 1.5 m long, rotating mast should provide 3D ​​panoramic images. With the LIDAR (Light Detection And Ranging ) wanted to measure the dust content of the Martian atmosphere. The Mars Polar Lander was the first Mars probe is a microphone on board. Thus, it would have been possible to record sounds in the immediate vicinity of the lander, as they are for example caused by the wind.

The life of the lander was designed for about three months. When after onset of Martian winter, the temperature would have fallen to about -125 ° C - too cold for electronics. The low sun would strongly affects the energy supply of the cells of the lander. The probability that the probe would "wake up" again in the Martian spring, had been classified as only slightly.

Mission

The 576 kg mass spacecraft was launched on 3 January 1999 with a Delta 7425 rocket. The intended landing site was located about 800 km from the South Pole away, in 76 ° south latitude, about 4000 m above mean sea level (equivalent to 6.1 mbar pressure level ). Also referred to as the " Polar Layered Deposits" - - From what is perceived as several kilometers thick layered deposition of dust and ice they wanted to close on the younger climatic history of Mars. At the landing site temperatures from -60 ° C to -5 ° C were expected (Mars summer).

During the Mars Polar Lander was still on the way, the Mars Climate Orbiter ended with the total loss. A commission of inquiry was immediately commissioned as soon as possible to determine whether the cause of the total loss of the orbiter could also affect the lander and should rapidly develop recommendations on how the lander could be prevented from failing on the same problem.

On 3 December 1999, the probe began with the descent. About two minutes before entering the atmosphere, the two carried penetrator probes Amundsen and Scott were separated from the landing module. You should s (700 km / h) 60 cm deep burrow just under 190 m / unbraked in the Martian soil to investigate where soil samples. With the two probes you wanted to check if this type of cost-saving landing can be successful.

Neither the Mars Polar Lander still the two microprobes could be contacted after their landing. On 17 January 2000, the communication experiments were terminated.

Loss

The cause of the crash, it is assumed that the braking thrusters were turned off too early. A jolt to the landing sensor during unfolding and locking the landing legs transfer, which was located at the end of a leg and was supposed to report contact with the ground - probably was - still high above the surface. This then led to a premature shutdown of the braking engines and ultimately crash the Landers.

The entire Mars program at NASA, which was at that time under great financial constraints, has been carefully reviewed and restructured after the failed missions Mars Polar Lander and Mars Climate Orbiter. The Mars probe Mars Odyssey 2001 then a new good start has been daring.

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