A satellite orbiting Mars may have found debris from one of the worst accidents in NASA's planetary program. In a new analysis of 5-year-old images, researchers believe they see a discarded parachute and an imprint from the rocket engines of Mars Polar Lander, which crashed in December 1999. Planned high-resolution photos of the site should help mission scientists refine their theory of why the lander failed.
The $165 million Mars Polar Lander crashed near the Martian south pole less than 3 months after a sister mission, Mars Climate Orbiter, burned up while entering the planet's atmosphere at the wrong altitude. NASA investigators concluded that the descent rockets on Mars Polar Lander turned off too quickly, dooming the craft to a 40-meter freefall. An orbiting probe called Mars Global Surveyor searched for the crash site in 1999 and early 2000. The images contained a half-dozen candidate spots, but no one could firmly identify the debris.
New clues have come from the successful Mars rovers Spirit and Opportunity. When those rovers landed last year, they also used parachutes and rocket-engine blasts to slow their descents. Orbiter photos clearly show the ditched parachutes and patches where the rockets blew away dust, says planetary scientist Michael Malin of Malin Space Science Systems in San Diego, California, who built the orbiter's camera.
Using those hints, Malin re-examined his old images of the Mars Polar Lander crash region. A white spot of the right brightness and shape looks like the parachute, while a dark patch scoured into the planet's fine dust looks like the rocket blast zone nearly 500 meters away. A tiny fleck within that zone may even show the small lander itself. Malin reports his new analysis in the July issue of Sky & Telescope.
"Our confidence that this is the prime candidate [for the crash site] has increased quite a bit," says Richard Zurek of NASA's Jet Propulsion Laboratory in Pasadena, California, the lander's project scientist. If confirmed, the images would rule out an alternative scenario that the lander tumbled down a steep slope, Zurek says. Malin plans to take sharper photos later this year, using a new technique that adjusts for the satellite's fast motion in orbit. Those images should help scientists calculate when the lander's rocket engines cut off, and they may show whether the probe ever deployed its solar panels on the surface, Zurek says.