LOS ANGELES — Spirit has always been the unluckier of NASA's twin Mars rovers.
Just weeks after landing in a Martian crater in 2004, it went haywire and transmitted gibberish to Earth. Engineers eventually nursed it back to health.
As if the near-death experience wasn't enough, Spirit was upstaged early by its twin Opportunity, which landed three weeks after Spirit in a geologic gold mine and was the first to determine that the frigid, dusty planet possessed a wetter past.
Bad luck has fallen again on Spirit. As it marked its sixth year on the red planet Sunday, it finds itself stuck in a sand trap, perhaps forever. With Martian winter arriving in several months, Spirit may not have enough power to keep going unless scientists can point the solar-powered rover toward the sun.
It's been a particularly rough year for Spirit, the six-wheel robot geologist is down to four wheels. It has also suffered sporadic bouts of amnesia and other woes including sudden computer reboots.
Though the prognosis looks bleak, scientists are not ready to give up. After all, the 2004 landing was originally designed as a three-month mission. But if they exhaust all escape options, they will switch to Plan B and try to tilt the rover to the north where it can get more sunshine to keep running so that it can continue to do science in one spot.
"If we can't get the rover unstuck, it will become a Mars lander," project manager John Callas of NASA's Jet Propulsion Laboratory said.