NASA has made its Mars rovers even smarter with computer upgrades beamed through space that give the robots greater power to act on their own on the red planet.

The multi-megabyte software upgrades installed four new capabilities into the Mars Exploration Rovers Spirit and Opportunity. Opportunity and Spirit have both lasted far longer than expected, giving NASA to field-test new capabilities on Mars useful to both the current missions and those of future rovers.

[Video: All Eyes on Mars]

The "auto-place" capability enables the rovers to calculate the best targets on which to place their instruments. Before, researchers would have to wait for images from the rovers, command them to perhaps move a bit to line up just right, and then plan a course for the arm to follow to bring the instruments down.

"Auto-place tries to eliminate all that work," Jet Propulsion Laboratory software engineer Khaled Ali told "We just checked out the autonomous mode on that and we should see some real benefits from that soon."

The "visual target tracking" capability enables the rovers to lock onto and keep recognizing a target as they move towards it, even if its appearance changes in size or angle as the rovers get closer or run up a slope.

Ideally, the visual target tracking capability will combine with the auto-place feature for an ability dubbed "go and touch," which will allow engineers on Earth to pick a target, for the rover will drive up to and then place instruments on," Ali said.

The new onboard science capability, often simply dubbed "watch," helps the rovers recognize dust devils and clouds, so they can take pictures for scientists and not waste time taking endless snapshots researchers don't want, freeing up rover communication time for additional scientific investigations. "Dust devil season is starting up on Mars, so the onboard science capability should become very useful in the near future," Ali said.

The final new capability, dubbed D*, helps the rovers plan maneuvers away from or around obstacles. "You could drop them in a middle of a maze, and they would find their way out," Ali said. "Still, ever since Spirit was severely hobbled, with one wheel not working anymore, it hasn't really had the chance to use it, and the area Opportunity is in doesn't present it with as many obstacles, so I'm not sure we'll really ever get to make full use of D* with these rovers."

While the upgrades were installed in September, NASA is still gradually checking each out to make sure each is safe for us. "I'm guessing it will take another couple of months," Ali said.

The Mars Exploration Rovers both landed on Mars a little more than three Earth years now Opportunity has been on Mars for 1,087 Martian days, or sols, which is 997 more than it was supposed to last, and has just logged more than 10 kilometers (6.2 miles) of travel. Spirit has lasted 1,107 sols, or 1,017 "past warranty," and has logged about 6.9 kilometers (4.3 miles).