NASA hasn't been able to contact the Mars Global Surveyor spacecraft since November 2nd. The probe was launched about ten years ago.
Nasa will use the Rover Opportunity on the surface of the Red Planet to try to speak to the 10-year-old spacecraft in the next couple of days.
However, mission officials concede they are not expecting success.
"While we have not exhausted everything that we could do, we believe the prospect of recovery of MGS is not looking very good at all," said Fuk Li, Mars exploration programme manager at Nasa's Jet Propulsion Laboratory (JPL) in Pasadena, California.
"However, MGS has been a good friend; it's had an illustrious career, the data it has collected has taught us a lot about Mars and it will continue to teach us a lot about Mars.