LOS ANGELES (Reuters) - NASA has officially called it quits for the Mars landing craft Phoenix, two years after the stationary probe touched down on the frigid northern polar surface of the Red Planet, the space agency said on Monday.
Phoenix, a solar-powered spacecraft roughly the size of a minivan, landed on Mars on May 25, 2008, and operated for five months, collecting and analyzing soil samples for signs of chemical compositions that would be conducive for life.
But the probe went dormant after the sun dipped below the polar horizon, plunging the landing site into super-cold, round-the-clock darkness for the fall and winter months of the Martian calendar. It takes just under two Earth years for Mars to complete a single orbit around the sun.
NASA scientists at the Jet Propulsion Laboratory in Pasadena, California, near Los Angeles, did not expect Phoenix to survive the polar Martian winter intact. The failure of NASA's Mars Odyssey orbiter to make radio contact with the probe after recently flying over its landing site 61 times confirmed that Phoenix was incapable of being revived.
Moreover, a new image transmitted by a second NASA satellite, the Mars Reconnaissance Orbiter, showed signs of severe ice damage to the lander's solar panels.
Phoenix was the sixth spacecraft to successfully land on Mars since robot exploration of the planet's surface began in the 1970s with the Viking program.
Two NASA probes remain operational on Mars' surface -- the rovers Spirit and Opportunity, which arrived in early 2004 and have out-lasted their design lifetimes by several years, though Spirit has been stuck in a sand dune since last year.
One of the most startling findings of Phoenix was the discovery in the Martian soil of perchlorate, an oxidizing chemical on Earth that nourishes some microbes but is potentially toxic to others.
(Reporting by Steve Gorman; Editing by Eric Beech)