NASA has approved up to 18 more months of operations for Spirit and Opportunity, the twin Mars rovers that have already surprised engineers and scientists by continuing active exploration for more than 14 months. “The rovers have proven their value with major discoveries about ancient watery environments on Mars that might have harbored life,” said Dr. Ghassem Asrar, deputy associate administrator for NASA’s Science Mission Directorate. “We are extending their mission through September 2006 to take advantage of having such capable resources still healthy and in an excellent position to continue their adventures.”