NASA rover "Opportunity" was laid to rest on Tuesday night as attempts to make contact with the long-lived, space explorer wrapped up. Eight months ago, a ferocious, fast-moving Martian dust storm is thought to have covered the solar panels on the rover and cutoff the vital supply of sunlight needed to power the device. NASA says the rover was designed to operate for only 3 months, but the rugged, over-engineered, robotic geologist kept sending data that led to amazing discoveries about Mars for nearly 15 years. It outlived its twin golf cart-sized rover named "Spirit" by 8 years. Since 2004, the rover has traveled a record 28 miles on the surface of the red planet and discovered "evidence that ancient Mars had water flowing on its surface and might have been capable of sustaining microbial life." Opportunity was exploring Mars' Perseverance Valley, fittingly, when the fiercest dust storm in decades hit and contact was lost. The storm was so intense that it darkened the sky for months, preventing sunlight from reaching the rover's solar panels. When the sky finally cleared, Opportunity remained silent, its internal clock possibly so scrambled that it no longer knew when to sleep or wake up to receive commands. Flight controllers sent more than 1,000 recovery commands, all in vain. NASA Administrator Jim Bridenstine said the overriding goal is to search for evidence of past or even present microbial life at Mars and find suitable locations to send astronauts, perhaps in the 2030s. "While it is sad that we move from one mission to the next, it's really all part of one big objective," he said.