July 24, 2013
Curiosity Rover Covers 110 Yards In One Day: Longest Drive To Date
Brett Smith for redOrbit.com - Your Universe Online
In its continuing mission to survey Mars, NASA's Mars Curiosity rover drove its farthest distance ever on Sunday, the space agency said.
NASA engineers took advantage of the rover's previous high vantage point to take Curiosity out for a spin at the start of its 340th Martian day, or sol. The Curiosity team said they will begin using the rover's automatic navigation, or "autonav," program to trace a path across the landscape and drive more often in the coming weeks.
The Sunday drive of 110 yards was the longest since July 21, when the rover scooted 54 yards across the alien terrain. Using Curiosity's stereo imaging from the Navigation Camera (Navcam) and telephoto images from its Mast Camera (Mastcam), the drivers broke down the 110-yard drive into three segments - making turns at the end of the first and second sections.
"What enabled us to drive so far on Sol 340 was starting at a high point and also having Mastcam images giving us the size of rocks so we could be sure they were not hazards," said team member Paolo Bellutta of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. "We could see for quite a distance, but there was an area straight ahead that was not clearly visible, so we had to find a path around that area."
On February 28, NASA had to switch Curiosity from its A-side computer to its backup B-side because of a flash-memory issue. Testing during the spring indicated that the Navcam connected to the B-side computer is more sensitive to temperature than the A-side Navcam. A subsequent software update now allows the rover to use visual odometry through a range of temperatures to see how far it has traveled. Without the update, Curiosity's onboard analysis could calculate different distances to the same point, depending on temperature.
"For now, we're using visual odometry mostly for slip-checking," said Jennifer Harris Trosper, deputy project manager for Curiosity at JPL. "We are validating the capability to begin using autonav at different temperatures."
Autonav will allow the team to drive the rover beyond a route that has been confirmed safe from previous images. To make those 'blind' drives, the rover would be instructed to use its autonomous capability to seek a safe path beyond a predetermined distance. The autonav system is expected to aid the rover on its current course toward the lower levels of Mount Sharp.
Earlier this month, Curiosity passed a significant milestone by driving a total distance of over 1 kilometer. "When I saw that the drive had gone well and passed the kilometer mark, I was really pleased and proud," said rover driver Frank Hartman from JPL. "Hopefully, this is just the first of many kilometers to come."
The drive marked the halfway point of Curiosity's prime mission of its first year on Mars. In a statement, NASA said the rover already accomplished one main objective - finding indications for an ancient wet environment that could have supported life.