The Mars rover Spirit will soon try to drive itself out of a sand trap where it has been stuck for the past six months.
NASA is set to outline plans to try to free Spirit, a risky process that could take months.
Details of the extraction attempt will be announced later Thursday.
For the past several months, engineers have been busy testing different escape routes on Earth using prototype rovers.
Spirit and its twin Opportunity landed on Mars in 2004 and have outlasted their primary three-month mission.