The U.S. space agency is preparing to end the mission of Mars rover Spirit, a geology robot that had six productive years on the red planet before getting stuck in sand. Sprit has not communicated with controllers on Earth for more than a year despite daily contact attempts by the National Aeronautics and Space Administration (NASA). The cause of Spirit's silence may never be known, but it is possible the bitter cold Martian winter damaged its electronics, preventing the six-wheel rover from awakening. The space agency for months has tried every idea to contact Spirit, but with no success. Project manager John Callas of NASA's Jet Propulsion Laboratory said the last commands will be sent up Wednesday. While orbiting spacecraft will continue to listen through the end of the month, it is highly unlikely that Spirit will respond. Callas said Spirit will be remembered for revealing Mars to millions of people. "Mars is no longer this mysterious, distant place," he said. "Mars is as familiar to us as any hometown, and it's because of Spirit." The solar-powered Spirit and its twin, Opportunity, parachuted to opposite ends of the Martian southern hemisphere in early 2004 for what was supposed to be the three-month mission. The rovers-the size of a golf cart-were popular with the public, which followed their moves as they rolled across the Martian plains and stopped to drill into rocks. Their greatest achievement was uncovering geologic evidence that Mars, now dry and dusty, was far warmer and wetter billions of years ago, with conditions that suggest the ancient environment could have been favorable for microbial life.
