BEIJING, July 18 (Xinhuanet) -- Mars rover Spirit has begun driving in reverse to overcome a balky front wheel.

    Engineers expect the probe to keep covering a lot of Martian ground despite the technical difficulty, reported Saturday's CRI online.

    The six-wheeled Spirit recently discovered a rock outcrop, a formation that offers the potential for layered rocks that could give geologists a view far back into Mars' geologic past.

    However, Spirit's right front wheel began to draw more and more electrical current, which is a sign of resistance in the mechanism.

    The mission scientists are working on ways to help Spirit move with only five wheels, so that the rover can continue its research and move closer to the outcrop.

    Spirit's twin, Opportunity landed right next to a similar outcrop in January and quickly found a wealth of evidence that the site in the Meridiani Planum region was once saturated with water.

(CRIENGLISH.com)

GROUP PHOTOS: Splendours of Mars