Nasa's Mars Odyssey orbiter is set to listen for possible radio transmissions from the Phoenix Mars lander, to check if it has survived the Martian winter.
The agency said that communication from the lander was "extremely unlikely".
Phoenix's last communication was on 2 November 2008, after it completed its study of an arctic Martian site.
Since then, this landing site has gone through autumn, winter and part of spring, and Phoenix was not designed to survive such temperature extremes. Its electronics are likely to have broken up as temperatures plummeted.
But, just in case, Odyssey will pass over the Phoenix landing site approximately 10 times each day during three consecutive days of listening, beginning on 18 January.
It will undertake two longer "listening campaigns" in February and March.
The solar-powered Phoenix landed in May 2008, in the middle of the Martian summer, when the Sun never set at its polar landing site.
During its ground operations, the robot dug up and tested the Martian soil to see whether it had ever been capable of supporting life.
Probably its biggest achievement was in becoming the first Mars mission to "touch water" in the form of the ice it found just below the topsoil.
BBC News has contributed to the report.
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