The incredible Martian adventure of Nasa's Spirit rover is at an end.
Engineers have conceded they are unlikely ever to hear from the vehicle again and are ceasing attempts to make contact with it.
Spirit got stuck in soft sand in May 2009 and sent its last communication to Earth some 14 months ago.
The robot geologist's mission has been an astonishing success. Its rock studies have shed new light on the Red Planet's wetter and warmer past.
But the US space agency (Nasa) has accepted it has virtually no chance of receiving more data from the rover.
A transmission that will end on Wednesday will be the last in a series of attempts to re-establish communications.
Spirit's position in the sandtrap has meant its solar panels have not been ideally angled to ensure adequate energy is available to run its survival heaters, especially during Mars' harsh winters.
Dust on the panels is thought to have further compromised their efficiency. It is probable that extreme cold has damaged many critical components and connections on the robot.
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