An artist’s concept portrays a NASA Mars Exploration Rover on the surface of Mars. Two rovers were launched in 2003 and arrived at sites on Mars in January 2004.
Image credit: NASA/JPL/Cornell University

NASA’s Opportunity rover has now been on Mars for 15 years, but the milestone is a bittersweet one.

Opportunity touched down on the night of Jan. 24, 2004, a few weeks after its twin, Spirit, landed on a different patch of Red Planet ground. Both solar-powered rovers embarked on three-month missions to search for signs of past water activity — and both delivered in spades, finding plenty of such evidence and continuing to roam long after their warranties expired.

“Fifteen years on the surface of Mars is testament not only to a magnificent machine of exploration but the dedicated and talented team behind it that has allowed us to expand our discovery space of the Red Planet,” John Callas, project manager for Opportunity at NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement.

Spirit finally went silent in March 2010. After getting bogged down in thick sand, the rover lost the ability to orient itself to catch the winter sun and ended up freezing to death, NASA officials have said. Spirit finally went silent in March 2010. After getting bogged down in thick sand, the rover lost the ability to orient itself to catch the winter sun and ended up freezing to death, NASA officials have said.

Opportunity may have recently met a similar fate: It hasn’t made a peep since June 10, 2018.