From the Associated PressTwo Indiana University geologists have helped develop devices that will be on board the next Mars rover. The Curiosity rover is part of NASA's Mars Science Lab which launches Saturday and is expected to arrive on Mars in August 2012. The rover has 10 science instruments and a robotic arm that can drill into rocks, scoop up soil and deliver samples to analytical instruments. Its mission is to help determine whether life ever existed on the red planet. IU researchers David Bish and Juergen Schieber helped develop two of the instruments. Bish helped create a device that will use X-rays to test minerals for signs of past water or life. Schieber worked on a high-definition color camera on the turret at the end of the rover's robotic arm.