Mars Polar Lander
Uncrewed NASA lander lost during descent to Mars.
The Mars Polar Lander, also called the Mars Surveyor '98 Lander, was an uncrewed NASA spacecraft weighing 290 kilograms. Launched on January 3, 1999, its mission was to examine the soil and climate of Planum Australe, an area near Mars’s south pole, as part of the broader Mars Surveyor '98 mission. Communication with the lander was expected to resume after its descent phase concluded on December 3, 1999, but it never did. Investigators later concluded that the engine likely shut down too early, causing the craft to hit the Martian surface at high speed. The mission’s total cost was US$165 million: US$110 million for spacecraft development, US$45 million for launch, and US$10 million for mission operations.
The lander was designed to gather ground-level climate data alongside an orbiter. NASA believed a large amount of frozen water might lie beneath a thin dust layer at the south pole, and this potential water content was the key factor in selecting the landing site. As part of the "Send Your Name to Mars" program, a CD-ROM carrying the names of one million children worldwide was placed aboard to spark interest in space exploration. The mission’s primary goals included landing on the layered terrain of the south polar region, searching for evidence of ancient climates and recent climate shifts, documenting current weather and seasonal changes at high latitudes—especially water vapor exchange between the atmosphere and ground—looking for near-surface ground ice, analyzing soil for chemically and physically bound carbon dioxide and water, and studying the landing site’s surface forms, geology, topography, and weather.
The lander carried two small, identical impactor probes called Deep Space 2 A and B. These were meant to strike the surface at high speed near 73°S 210°W, penetrating up to a meter into the soil to study subsurface composition. However, after entering the Martian atmosphere, all attempts to contact them failed. The New Millennium Program funded Deep Space 2, with development costs of US$28 million.
The spacecraft, with legs and solar arrays fully deployed, measured 3.6 meters wide and 1.06 meters tall. Its base featured an aluminum honeycomb deck, composite graphite-epoxy edge sheets, and three aluminum legs. During landing, the legs were to unfold from a stowed position using compression springs, absorbing impact with crushable aluminum honeyc
- Launch date
- January 3, 1999
- Loss of communication
- December 3, 1999
- Mass
- 290 kilograms
- Total cost
- US$165 million
- Mission
- Mars Surveyor '98
- Landing target
- Planum Australe, near Martian south pole
Lore & Background
The Mars Polar Lander was developed as part of the Mars Surveyor '98 mission, with a lander sought to gather climate data from the ground in conjunction with an orbiter. NASA suspected that a large quantity of frozen water may exist under a thin layer of dust at the south pole, and this potential water content was the strongest determining factor for choosing the landing location. A CD-ROM containing the names of one million children from around the world was placed on board as part of the 'Send Your Name to Mars' program. The spacecraft carried two small, identical impactor probes known as Deep Space 2 A and B, intended to penetrate the Martian soil and study subsurface composition, but attempts to contact them after atmospheric entry also failed.
Reader's Guide
The Mars Polar Lander represented a significant effort to study the Martian south polar region, particularly the potential for frozen water and climate history. Its failure highlighted the challenges of planetary landing and led to a post-mortem analysis that identified premature engine shutdown as the likely cause. The mission's total cost was US$165 million, with spacecraft development at US$110 million, launch at US$45 million, and mission operations at US$10 million. The loss of the Mars Climate Orbiter on September 23, 1999, forced the lander to rely on alternative communication methods, including a direct-to-Earth link and relay via Mars Global Surveyor. The Deep Space 2 probes, funded by the New Millennium Program at a development cost of US$28 million, also failed. The mission's objectives—searching for evidence of ancient climates, studying water vapor exchange, and analyzing soil—remained unfulfilled, but the data and engineering lessons informed subsequent Mars exploration efforts.
Did You Know?
- The Mars Polar Lander carried a CD-ROM containing the names of one million children from around the world.
- The lander carried two small impactor probes called Deep Space 2 A and B, which also failed to communicate after entering the Martian atmosphere.
- The total cost of the Mars Polar Lander was US$165 million, with spacecraft development costing US$110 million.
- The lander was originally intended to communicate through the Mars Climate Orbiter, which was lost on September 23, 1999.
Frequently Asked Questions
What is the Mars Polar Lander?
The Mars Polar Lander, also referred to as the Mars Surveyor '98 Lander, was an uncrewed 290-kilogram NASA spacecraft designed to study conditions near Mars's south pole. It launched on January 3, 1999, as part of the broader Mars Surveyor '98 program.
What was Mars Polar Lander's mission?
Its core objective was to analyze soil composition and atmospheric data at Planum Australe, a flat region close to the Martian southern polar area. The lander was meant to operate on the surface after a successful descent.
What happened to Mars Polar Lander?
Ground teams expected to regain signal once the descent phase wrapped up on December 3, 1999, but no contact was ever re-established. The spacecraft was officially declared lost that same day.
Why did Mars Polar Lander crash?
Investigation teams concluded that the descent engine most likely shut off well before it should have. As a result, the craft struck the Martian surface at a far higher speed than it was designed to tolerate.
How much did Mars Polar Lander cost?
NASA spent roughly US$165 million on the entire mission, from development through the loss of the spacecraft on Mars.
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