Passage 3 Future Uncertain for Stuck Mars Rover
	“精神”与“机遇”,同生不同命 《今日美国》
	
	[00:01]Spirit has always been the unluckier of NASA's twin Mars rovers.
	[00:08]Just weeks after landing in a Martian crater in 2004,
	[00:15]it wasn't fuctioning well and transmitted gibberish to Earth.
	[00:22]Engineers eventually nursed it back to health.
	[00:26]As if the near-death experience wasn't enough,
	[00:31]Spirit was upstaged early on by its twin Opportunity,
	[00:37]which landed in a geologic gold mine and was the first to determine
	[00:42]that the frigid, dusty planet possessed a wetter past.
	[00:49]Bad luck has fallen again on Spirit.
	[00:53]As the workhorse rover marks its sixth year on the red planet on Sunday,
	[01:01]it finds itself stuck in a sand trap, perhaps forever.
	[01:07]The six-wheel robot geologist has been in jams before,
	[01:13]but this is the worst plight yet.
	[01:17]With Martian winter arriving in several months,
	[01:22]Spirit may not have enough power to keep going
	[01:27]unless scientists can point the solar-powered rover toward the sun.
	[01:34]The latest misfortune occurred in April when Spirit,
	[01:39]driving backward because of a lame wheel,
	[01:44]broke through the crusty ground like a person falling through a frozen pond
	[01:50]and got stuck in fluffy sand.
	[01:54]NASA was dealt a major setback recently
	[01:59]when another wheel appeared to have stopped moving,
	[02:03]leaving Spirit with only four working wheels to plot its great escape.
	[02:11]It's been a particularly rough year for Spirit.
	[02:17]Besides getting stuck in a sand rut,
	[02:20]it suffered periodic bouts of memory loss
	[02:25]and other sufferings including sudden computer reboots.
	[02:30]Though the forecast of getting Spirit out looks bleak,
	[02:36]scientists are not ready to give up yet.
	[02:41]But if they exhaust all escape options,
	[02:44]they will switch to Plan B and try to lean the rover to the north
	[02:51]where it can get more sunshine to keep running
	[02:54]so that it can continue to do science in one spot.
	[02:59]Unlike a rover, which performs science experiments as it wanders,
	[03:06]a lander studies its surroundings while stationary.
	[03:11]Fortunately for researchers, what may turn out to be
	[03:15]Spirit's final resting spot looks like a scientific godsend.
	[03:21]The sand is rich in sulfate, a mineral that forms in the presence of water.
	[03:29]Originally designed as a three-month mission,
	[03:33]Spirit and Opportunity have operated past their warranty.
	[03:39]Spirit and Opportunity are also closing in on the record
	[03:44]for longest-running Mars surface mission currently held
	[03:49]by the Viking 1 lander, which operated on the planet for six years and 116 days.
	[03:59]Opportunity didn't have to work hard to impress scientists
	[04:05]because it jumped to an ancient lakebed flooded with minerals
	[04:10]that pointed to geologic evidence of past water.
	[04:15]Spirit, on the other hand, touched down in the rugged rock plains of
	[04:22]a crater on the opposite side of the planet
	[04:25]and had to trek toward the hills to make discoveries.
	[04:30]With Spirit immobile, it's still snapping pictures of
	[04:35]its surroundings and sending data back to Earth.
	[04:41]Spirit's next challenge will be surviving the upcoming Martian winter.
	[04:47]Meanwhile, Opportunity has been busy grinding into a dark-toned rock
	[04:54]that scientists think may be a stony meteorite.