Mission Type: Lander
Launch Vehicle: Delta 7425-9.5 (no. D265)
Launch Site: Cape Canaveral, United States
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 583 kg at launch
1) MVACS Mars volatile and climate surveyor instrument package; a) SSI stereo surface imager, b) RA robotic arm, c) MET meteorology package, d) TEGA thermal and evolved gas analyzer, e) RAC robotic arm camera
2) MARDI Mars descent imager
3) LIDAR light detection and ranging instrument
Spacecraft Dimensions: 1.06 m tall and approximately 3.6 m wide
Spacecraft Power: Solar panels and rechargeable batteries
Maximum Power: 200 W
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, http://nssdc.gsfc.nasa.gov/
The Mars Polar Lander (MPL) was one of NASA's Mars Surveyor missions that called for a series of small, low-cost spacecraft for sustained exploration of Mars. MPL's primary goal was to deploy a lander and two penetrators (known as Deep Space 2) on the surface of Mars to extend our knowledge on the planet's past and present water resources. The objective was to explore the never-before-studied carbon dioxide icecap about 1,000 kilometers from the south pole.
The mission called for recording local meteorological conditions, analyzing samples of polar deposits, and taking multispectral images of local areas. MPL was to have performed its mission simultaneously with that of the Mars Climate Orbiter, which would have acted as a communications relay during its surface operations.
MPL itself comprised a bus section (for power, propulsion, and communications during the outbound voyage) and a 290-kilogram lander that stood 1.06 meters tall on the ground. The lander was equipped with a 2-meter-long remote arm to dig into the terrain and investigate the properties of Martian soil (using the thermal and evolved gas analyzer).
MPL was supposed to arrive at Mars on 3 December 1999. After atmospheric entry, about 10 minutes prior to landing, the spacecraft was to jettison its cruise stage and solar panels and then release the two 3.572-kilogram (each) Deep Space 2 microprobes. Unlike Mars Pathfinder, MPL was scheduled to make a completely controlled landing using retro-rockets all the way to the surface. Landing was scheduled for 21:03 UT on 3 December 1999, with two-way communications planned to begin 20 minutes later.
The two Deep Space 2 microprobes (renamed Amundsen and Scott on 15 November 1999), meanwhile, would impact the ground at a speed of 200 meters per second at about 50 to 85 seconds prior to the lander's touchdown about 100 kilometers away. Each penetrator was designed to obtain a small sample of subsurface soil using an electric drill for analysis. The microprobes' mission was expected to last about 36 hours, while the lander mission would continue until 1 March 2000.
Contact with MPL was lost at 20:00 UT on 3 December, about 6 minutes prior to atmospheric entry. With no communications for over two weeks, on 16 December 1999, NASA used the Mars Global Surveyor orbiting Mars to look for signs of the lander on the Martian surface, but the search proved fruitless. On 17 January 2000, NASA finally terminated all attempts to establish contact with the lost lander.
An independent investigation into the failure, whose results were released publicly on 28 March 2000, indicated that the most probable cause of the failure was the generation of spurious signals when the lander's legs deployed during the descent. These signals falsely indicated that the spacecraft had touched down on Mars when in fact it was still descending. The main engines prematurely shut down, and the lander fell to the Martian landscape.