On May 20, NASA’s Mars Exploration Rover Opportunity set a new endurance record for operating on the surface of Mars, surpassing the record of six years and 116 days set by NASA’s Viking 1 lander almost 30 years ago.
Opportunity landed in Mars’ northern hemisphere on Mars on January 25, 2004 for a mission that was originally planned to last 90 sols (Martian days; approximately 92 and a half Earth days) and cover less than a kilometre. Not only has Opportunity far outlived its ‘design lifetime’ it has already travelled more than 20 km across the Martian surface and still has about another 12 km to go to reach its long term destination, Endeavour Crater.
Opportunity’s twin rover, Spirit, actually landed on Mars three weeks before Opportunity: but due to the low amount of sunlight reaching its solar panels in Mars’ southern hemisphere winter, Spirit has been out of communication since March 22, and it is uncertain if the rover will survive the winter. If Spirit does resume communication when spring arrives, then it will actually become the holder of the Martian surface longevity record.
The previous record holder, Viking 1, landed on Mars on July 20, 1976. It was part of the Viking program, which consisted of two orbiters, each of which carried a stationary lander. Viking 2 arrived on the Martian surface on September 4, 1976 (Australian time). Viking 1 operated until November 13, 1982, more than two years longer than Viking 2 or either of the Viking orbiters.
The overall record for longest working lifetime of any spacecraft at Mars currently belongs to NASA’s Mars Global Surveyor, which arrived in orbit around Mars in 1997 and operated for more than 9 years. However, MGS’s record will soon be broken by another NASA orbiter, Mars Odyssey, which has been in orbit since 2001.