In a major milestone, the six-wheel Curiosity Mars rover took its first baby steps today, rolling about 15 feet forward, performing a slow 120-degree pirouette, and then backing up 8 feet to prove the $2.5 billion science lab is, in fact, mobile -- and ready to rove.
The short test drive began at 7:17 a.m. PT and took about 16 minutes to complete. The actual drive time was about a third of that, but the rover was programmed to stop and take multiple pictures of its tracks in the dusty, pebble-strewn soil of Gale Crater.
The move came one sol, or martian day, after the rover's four corner wheels passed an initial steering check, wiggling back and forth as commanded.
"I'm pleased to report that Curiosity today had her first successful drive on Mars," lead rover planner Matt Heverly told reporters. "This drive checkout, coupled with yestersol's checkout of the steering actuators on sol 15, means we have a fully functioning mobility system on our rover."
In a black-and-white panoramic image taken by the rover's navigation cameras, Curiosity's tire tracks could be seen in the martian soil, along with scour marks where the vehicle's sky crane descent rockets blasted away topsoil.
"In this image you can see our touchdown point, you can see the tracks driving away from that location as well as the scour marks to the right and the left of the rover's initial position," Heverly said. "It confirms our expectations the soil is firm, great for mobility, we're not seeing too much sinkage and we should have smooth sailing ahead of us."
Project Manager Pete Theisinger said the short drive was of crucial importance to the mission.
"It couldn't be more important," he said. "We built a rover, so unless the rover roves, we really haven't accomplished anything. So yes, (it's) tremendous, and the fact that we completely exercised it and everything's on track is a big moment, period."
The science team voted to name Curiosity's landing site "Bradbury Landing" after the late science fiction writer Ray Bradbury, whose lyrical stories about Mars provided inspiration to countless scientists and engineers.
"Today would have been Ray Bradbury's 92nd birthday," said Michael Meyer, director of Mars science at NASA Headquarters. "His books have truly inspired us. 'The Martian Chronicles' have inspired our curiosity and opened our minds to the possibility of life on Mars.
"In his honor, we declare the place that Curiosity touched down to be forever known as 'Bradbury Landing.'... It harkens back to a time when ships landed on the shores of other new worlds to explore. And this place might, in fact, with its water reference, be even more apropos."
Curiosity was lowered by its innovative sky crane landing system to a pinpoint touchdown in Gale Crater on August 6. Since then, engineers have been activating, checking out, and testing its major subsystems and science instruments, and 8 of its 10 high-tech instruments have passed initial checks. The only anomaly so far is a broken wind sensor, one of two mounted on the rover's main camera mast.
Engineers must still test Curiosity's sample-acquisition system -- a soil scoop and power drill -- and the complex equipment needed to move rock and soil samples to laboratory analyzers in the body of the rover.
But so far, so good, and after additional equipment checks are carried out, along with close-up inspections of the rocks revealed by the sky crane landing thrusters, scientists plan to begin a 1,300-foot drive to a nearby target area known as Glenelg, where three different rock types are visible in orbital photographs.
"On the way to Glenelg, we'd like to stop as soon as we encounter scoopable fine material to get going testing out the sample handling system and getting samples into SAM and CheMin," said Joy Crisp, the deputy project scientist.
The Sample Analysis at Mars experiment -- SAM -- will study atmospheric gases and soil samples to look for signs of carbon compounds using two ovens, a pair of spectrometers, and a gas chromatograph. The Chemistry and Mineralogy experiment -- CheMin -- uses X-ray diffraction to identify minerals in soil samples. Both are crucial to Curiosity's mission to search for evidence of past or present habitability.
"The first material would be scoopable fines, and we'd be trying to clean out the scoop and sample-handling system by doing that several times, just tossing it out on the ground and then taking a sample to put in SAM and CheMin," Crisp said.
"When we finally get to Glenelg, we want to study the outcrop there and take a look at the context between the three different terrain types and maybe there is where we would decide to do our first drilling into rock. And after Glenelg, we head for Mount Sharp. That will be a much longer drive with probably a few brief stops along the way. That's going to take several months before we get to that point."
Climbing the lower slopes of Mount Sharp, a three-mile-tall mound of layered rocks about 5 miles from Bradbury Landing, is the primary goal of Curiosity's mission. Scientists believe hundreds of thousands to tens of millions of years of martian history are preserved in the ancient rock beds the rover will cross during its anticipated ascent.
"It is fantastic how well everything's working," Meyer said. "We have high hopes this is really going to prove out this region and tell us whether or not it was ever potentially habitable."
But Theisinger quickly pointed out that testing was not yet complete.
"I wouldn't be doing my job if I didn't exercise a little bit of caution here," he said. "We are 16 days into a 2-year mission, OK? We haven't put the (robot) arm on the ground yet. We haven't exercised the sample-gathering capability, which is a key, key, key element of this rover science mission. So as good as it's gone, as wonderful as it is, we've only checked off about two of the level one requirement boxes -- launch on time, land on Mars, OK?
"We've got a long way to go before this mission reaches its full potential. But the fact that we haven't had any early problems is, in fact, fantastic."