Delta 7425-9.5 | Mars Polar Lander
Status: Success | Launched: Jan 03, 1999 20:21 UTC
Launch Provider & Rocket
- Provider: United States Air Force (Government)
- Rocket: Delta II 7425-9.5 — Delta family
Mission
The Mars Polar Lander, also known as the Mars Surveyor '98 Lander, was a 290-kilogram robotic spacecraft lander launched by NASA on January 3, 1999 to study the soil and climate of Planum Australe, a region near the south pole on Mars. It formed part of the Mars Surveyor '98 mission. On December 3, 1999, however, after the descent phase was expected to be complete, the lander failed to reestablish communication with Earth. A post-mortem analysis determined the most likely cause of the mishap was premature termination of the engine firing prior to the lander touching the surface, causing it to strike the planet at a high velocity.
- Type: Robotic Exploration
- Orbit: Heliocentric N/A (Helio-N/A)
Launch Site
- Pad: Space Launch Complex 17B
- Location: Cape Canaveral SFS, FL, USA
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Launch data sourced automatically from the Launch Library 2 API. Last refreshed: 2026-08-22T21:02:10.804714+00:00.