11-year-old Sofi Collis of Arizona stands beside the Mars Exploration Rover model during a visit to JPL. Sofi submitted the winning essay in a naming contest by suggesting the names Spirit and Opportunity. Image Credit: NASA/JPL
NASA has approved another 18 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 already completed 11 months of extensions on top of their successful three-month prime missions. "We now have to make long-term plans for the vehicles because they may be around for quite a while," said Jim Erickson, rover project manager at NASA's Jet Propulsion Laboratory.