NASA has announced it has ended attempts to regain contact with the Mars Exploration Rover Spirit.
The US space agency broadcast its last transmission this week to the mission, which last communicated in March last year.
NASA has explored the possibility that Spirit might reawaken as the solar energy available to it increased after a stressful Martian winter without much sunlight.
However without enough energy to run its survival heaters, it is likely that the Rover experienced colder internal temperatures last year than in any of its prior six years on Mars.
Many critical components and connections would have been susceptible to damage from the cold, NASA said.
"We're now transitioning assets to support the November launch of our next generation Mars rover, Curiosity," said Dave Lavery, NASA’s program executive for solar system exploration.
"However, while we no longer believe there is a realistic probability of hearing from Spirit, the Deep Space Network may occasionally listen for any faint signals when the schedule permits."
Communications assets that have been used by the Spirit mission in the past, including NASA's Deep Space Network of antennas on Earth and two NASA Mars orbiters that can relay communications, are now needed to prepare for NASA's Mars Science Laboratory (MSL) mission.
Spirit landed on Mars in January 2004 for a mission designed to last three months, but after accomplishing its prime-mission goals it worked on additional objectives.
Spirit's twin, Opportunity, continues active exploration of Mars.