Scientists were preparing to send Curiosity on its first test drive over the billion-year-old rocks of Mars and said a busted wind sensor wouldn’t jeopardise its mission of determining whether life could exist there.

Engineers at Nasa’s Jet Propulsion Laboratory in Pasadena turned four of the rover’s six wheels in place this week in a successful “wheel wiggle” to test the steering for Wednesday’s trek, mission manager Mike Watkins said.

The rover will move forward about 3m, turn right, then back up and park slightly to the left of its old spot, Watkins said. “You will definitely see tracks,” he said.

The test drive is part of a health checkup the rover has been undergoing since arriving on Aug. 5. Eventually, the rover could roam hundreds of feet a day over the ancient crater where it landed.

Meanwhile, researchers discovered the damaged wind sensor while checking out instruments that Curiosity will use to check the Martian weather and soil.

The cause of the damage wasn’t known, but one possibility is that pebbles thrown up by Curiosity’s descent fell onto the sensor’s delicate, exposed circuit boards and broke some wires, said Ashwin Vasavada, deputy project scientist for Curiosity.

A second sensor is operating and should do the job, but Vasavada said scientists may “have to work a little harder” to determine wind speed and direction, which are important factors that can determine when the rover is allowed to move. “But we think we can work around that,” he added.

Scientists also continued to test and calibrate Curiosity’s 2,1m-long arm and its extensive toolkit — which includes a drill, a scoop, a spectrometer and a camera — in preparation for collecting its first soil samples and attempting to learn whether the Martian environment was favorable for microbial life. — Sapa-AP