Mars Dust Spells Trouble for Rover

July 20, 2007 — Unless a massive dust storm on Mars abates soon, the rim of a crater that scientists hoped would open a new chapter in the search for past water on Mars may instead become the final resting place of the rover Opportunity.

NASA spent months driving the rover around the rim of the crater, known as Victoria, before deciding last month to risk driving down into the hole for close-up studies of its walls and surface features.

But shortly before Opportunity was to begin its descent, a dust storm delayed the journey. The storm so far has showed no signs of relenting. The planet's thin atmosphere is so filled with dust that 99 percent of the direct sunlight, needed to recharge the rover's batteries, is being blocked, leaving only a fraction of diffused light from which to draw power.

"We're rooting for our rovers to survive these storms, but they were never designed for conditions this intense," said NASA's associate administrator for science, Alan Stern.

Any further power cutbacks and Opportunity will be unable to keep itself warm, resulting in an electronic coma from which recovery would be unlikely, NASA said.

In a last-ditch effort to save the rover, flight directors suspended communications sessions with Opportunity, which is using more power to maintain its systems than it is currently able to generate. All science operations had previously been suspended.

Before the dust storm, the rover had been producing about 700 watts of electricity per day. On Wednesday, it plunged to a new low of 128 watts. By cutting radio contact with Earth to a few times a week, rover operators hope to reduce the rover's power draw to less than 130 watts per day.

Opportunity's robotic twin, Spirit, which is perched on the other side of the planet, is faring a bit better, but is also threatened by power shortages due to the dusty skies.

"We are taking more aggressive action with both rovers than we needed before," said rover project manager John Callas, at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The rovers, which were designed to last three months on Mars, have been operating for for more than 3.5 years. NASA warns the dust storms could leave one or both of the rovers unable to continue their studies.

A new Mars lander is scheduled for launch from Cape Canaveral Air Force Station in Florida in two weeks.

The Phoenix probe will not be able to move around like Spirit and Opportunity. Its mission is to dig down into the frozen soil near the planet's north pole and analyze samples to determine if conditions were once favorable for life to develop.