Ten months after a spectacular landing in Gale Crater, NASA's Curiosity Mars rover is wrapping up a second drilling campaign, mission managers said Wednesday, and the science team is gearing up to begin the long trek to Mount Sharp, a towering mound of layered rock 5 miles away that is expected to shed new light on the red planet's history and habitability.
But getting there will not be quick, with scientists saying they expect to stop and change course as required to study enticing targets of opportunity along the way.
To date, the rover has traveled about 2,400 feet -- less than half a mile -- across the floor of Gale Crater from the point where it touched down last August.
To reach the lower slopes of Mount Sharp, Curiosity will have to traverse more than 10 times that distance, a trip that could take another 10 months to a year or longer to complete.
The journey is expected to begin in a few weeks, after the science team completes a final series of observations to better characterize the region known as Glenelg, where three different types of terrain come together.
At the same time, scientists are studying high-resolution photographs from NASA's Odyssey and Mars Reconnaissance Orbiter to identify potential paths from the rover's current location to Mount Sharp, on the lookout for scientifically interesting areas along the way.
Engineers also are factoring in the locations of discarded hardware used by Curiosity's "sky crane" landing system to determine if it might be feasible for the rover to take a closer look at some of the components as it slowly rolls toward Mount Sharp.
"We'll be planning the general path in the next few weeks," said Jim Erickson, the Curiosity project manager at the Jet Propulsion Laboratory in Pasadena, Calif. "And then we'll start our trek to the base of Mount Sharp.
"Along the way, we will likely stop at some of the locations we eventually identify. ... We are on a mission of exploration. If we come across scientifically interesting areas, we are going to stop and examine them before continuing the journey."
Asked how long the trip might take, Erickson hedged his bets, saying that depended on how often Curiosity is directed to stop for close-up observations of rocks and soil along the way.
"It's very difficult to say exactly how long it's going to take," he said. "I would hazard a guess of somewhere between 10 months and a year might be something like a fast pace. If there's really scientifically interesting things that we find, we'll stay until we've completed them."
Despite the slow pace of the mission to date, Joy Crisp, the deputy project scientist, said the science team will not hesitate to stop.
"But there's nothing that we see from orbit that's like some super-compelling clue to life or something like that," she said. "What we have is a real desire to get to Mount Sharp, because there we see variations in the mineralogy, from the base of Mount Sharp going up in higher levels in the mountain, where we should see a record of a change in the environment."
She said the science team has been extremely pleased with the initial results of the mission. But even the science team is ready for a change of scenery.
"We've spent so much time in the Glenelg region, I think most people are getting a little antsy and actually do want to drive," she said. "It's like being on a vacation and you've spent a lot of time in a little area and you've really done a lot there. You want a change of pace."