Curiosity wiggles wheels ahead of first drive on Mars

Curiosity rover has wiggled its four corner wheels to prepare for its first drive on Mars, NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California announced.

JPL said the six-wheeled rover wiggled its four corner wheels side to side for the first time on Mars Tuesday as a test of the steering actuators on those wheels. This was critical preparation for Curiosity's first drive on Mars, reported Xinhua.

"We wanted to test the steering, because otherwise we would be driving in whatever direction we landed in," Curiosity Mission Manager Michael Watkins of JPL explained during a teleconference Tuesday.

Watkins said the commands will be sent up Tuesday night for a drive of just a few metres, incorporating a turn to the right and a backing-up manoeuvre. That initial movement should occur "in the middle of the night our time" and last about half-hour, he said.

The six-wheeled rover has a versatile steering system, with two front and two rear wheels that can be independently twisted so much that the car-sized, one-tonne vehicle pirouettes in place.

The two middle wheels can push as well, but they are not built for turning. Each wheel measures 20 inches in diameter, which is about the size of an automotive tyre, according to JPL.

Successful driving is the key to Curiosity's two-year, $2.5 billion mission, because its ultimate goal is to reach the flanks of a 3-mile-high mountain within the crater, known as Aeolis Mons or Mount Sharp, which is about 20 km away, Watkins said.

Once the rover is fully into its drive mode, it's expected to trek up to the length of a football field in a day.

Curiosity's first destination is an intersection of three geological formations about a quarter-mile from the landing site, known as Glenelg, according to JPL.

The rover is due to spend the next couple of months checking out that area, and then it will turn its wheels toward Mount Sharp. That's where scientists expect to read the geological history of Mars over the course of billions of years, as recorded in the layers of rock going up the mountainside.

Those readings could show how habitable the planet might have been at different epochs, JPL said.