The little robot that could is poised to make a life or death descent into the depths of one of the largest craters on Mars. The U.S. space agency said today that the rover Opportunity is scheduled to begin exploring the Red Planet's massive Victoria Crater by inching its way down a treacherous rocky slope. The chance to explore the interior of a crater of this size, the scientists at NASA have judged, outweighs the potential risks of damage to the long-lived robotic vehicle.
"While we take seriously the uncertainty about whether Opportunity will climb back out, the potential value of investigations that appear possible inside the crater convinced me to authorize the team to move forward into Victoria Crater," said Alan Stern, the NASA associate administrator of the Science Mission Directorate. "It is a calculated risk worth taking, particularly because this mission has far exceeded its original goals."
The Opportunity team, based in Pasadena, Calif., at the Jet Propulsion Laboratory (JPL), expect to gather valuable exo-geological information on the composition of the Martian surface by examining data relayed from the meandering rover. The insides of large craters such as Victoria are composed of strata, or layers, of the planet's earlier surfaces, perhaps including materials that may have once been exposed to water.
Opportunity already has been exploring layered rocks in cliffs around Victoria Crater for the past nine months. Now, the robotic craft is positioned to follow the route judged most favorable by its controllers back on Earth to make its way down into the giant pit --at a point named Duck Bay -- to see what it can discover.
"Duck Bay looks like the best candidate for entry," said John Callas, the JPL rover project manager. "It has slopes of 15 to 20 degrees and exposed bedrock for safe driving."
Opportunity has already proved that it can handle daunting assignments. It previously made a six-month inspection of the interior of a much smaller crater, called Endurance, in 2004. Moreover, the vehicle has operated more than 12 times longer than its originally intended 90 days, according to NASA.
"These rovers are well past their design lifetimes," Callas noted. "If Opportunity were to lose the use of a wheel inside Victoria Crater, it would make it very difficult, perhaps impossible, to climb back out."
"We don't want this to be a one-way trip," said Steve Squyres, the principal investigator for the rovers' science instruments, from Cornell University, in Ithaca, N.Y. "We still have some excellent science targets out on the plains that we would like to visit after Victoria. But if Opportunity becomes trapped there, it will be worth the knowledge gained."
Somehow, you have to believe that this little planetary explorer is going to surprise everyone -- again.