If Red Planet Turned Green, We Might Miss It

(Dec. 3) - If a little green man on Mars waved at us, would NASA notice?

Probably not, at least not at the moment. Three of the four U.S. spacecraft monitoring the Red Planet are on the fritz -- one of them perhaps never to recover.

The wheeled robot Spirit, which has motored around Mars since 2004, is stuck in a sand trench. Mars Odyssey, a satellite that has been circling the planet since 2001, put itself in "safe mode" over Thanksgiving weekend. And Mars Reconnaissance Orbiter, another satellite studying Mars from space, has been on the blink since August.

"It's the Mars gremlins at work," joked Brown University planetary scientist John Mustard, who has used data from the Mars spacecraft to study the history of water there.
NASA spokesman Dwayne Brown called the incidents "coincidence, also bad luck,"

The only fully functioning Mars spacecraft is Spirit's twin rover, Opportunity.

The lack of eyes on Mars means that if a comet or asteroid slammed into the planet, as happened to Jupiter in July, NASA would have no nearby satellites to view the crash scene. The only pictures would be snapped by Mars Express, a European-run satellite.

The breakdowns also mean that scientists are already missing out on valuable data on Martian weather, atmospheric changes and polar ice caps, which shrink and grow with the seasons.

"It's a big gap, and it's unfortunate," said Philip Christensen of Arizona State University, referring to the shutdown of Mars Reconnaissance Orbiter. "It's painful to lose months' worth of data."

Engineers began sending improved software to the orbiter, which has been suffering from glitches in its computer system, this week. It should be back to work in the coming weeks.
Mars Odyssey suffered a routine failure in its memory system. Engineers know how to fix it, so it should be up and running again by the end of the week, NASA said.

In the meantime, Odyssey hasn't been able to collect data or serve as a communications hub between Earth and the Mars rovers. That forces engineers on the ground to rely on a system for sending messages to the rovers that's 10 times slower.

One rover, Opportunity, is motoring along happily. But the other, Spirit, bogged down in a pit of slippery sand in the spring. Engineers aren't sure they'll be able to maneuver it to freedom. If they can't, the robot won't be able to wheel around the "wildly" interesting hills that surround it, which would be "a shame," Christensen said.

The spate of breakdowns at Mars is partly coincidence, but it's also partly because NASA's spacecraft are showing their age, scientists say.

Disentombing Spirit is made more difficult by its broken wheel, probably from wear-and-tear after nearly six years of chugging across the rugged Martian surface. The rover is, in human terms, "a centenarian, well into 150-year category," Mustard said.

Mars Reconnaissance Orbiter is only 4 years old, but that's a long time to spend in the harsh conditions of outer space. Its age may be one reason it's having more frequent problems.

A decade ago, one Mars spacecraft more or less would not have mattered so much. But NASA is not sending probes to Mars every few years as it once did, so the aging robots and satellites aren't being quickly replaced. The next spacecraft bound for Mars isn't scheduled to launch until late 2011.

"These spacecraft are getting old," Christensen said. "We need to send some new ones."