The 12 celebrities land on "Mars."

Just as they were settling into life on the red planet, the remaining celebrities must figure out how to replenish their water supply.

The 10 remaining contestants brave the elements of the Martian desert when a fire breaks out.

The contestants are sent on a mission which tests their perseverance; two are eliminated.

Four new crew members land on Mars, but their supply craft goes off course and crashes.

The celebs must work together to plug holes in the walls of the hab caused by meteors.

A virus takes over the artificial intelligence system and two celebronauts are stuck outside.

The nine remaining celebronauts need to repair solar panels damaged by a series of solar flares.

The remaining celebronauts discover they are not alone on Mars.

The seven remaining celebronauts must find the hab's missing house pet, Raddog.

The hab detects a weak distress signal that the crew must investigate immediately.

The crewmates must assemble a satellite tower and broadcast a personalized message to Earth.