The Last Days On Mars

Sci-fi thriller starring Liev Schreiber. During the first manned space mission to Mars, one of the crew discovers what he believes is proof of bacterial life on the planet.

Unwilling to let anyone else take the credit for his find, he sets out against the wishes of his fellow crew members to attain a sample before their relief vessel arrives.

However, during what should be a routine excavation, the ground collapses and he falls into the resulting pit.

The crew succeed in recovering him, but when they get back to the ship there's something very different about him...