When the head of NASA's manned Mars missions discovers that the capsule meant to carry the astronauts will suffer a catastrophic failure, he forces the three astronauts to participate in a hoax by broadcasting their 'Mission' from a studio built at a now abandoned air force base. Over the many months of the mission, the astronauts send broadcasts to Earth on their progress and all goes well until their space capsule burns up on re-entry. They soon realize that the only way for the hoax to be maintained is for them to die and they make a desperate attempt to escape their captors. Throughout this period, an investigative reporter gets wind of the fact that something is amiss with man's first mission to Mars and slowly puts together the pieces of the mystery.

One of the stunt helicopter pilots, Frank Tallman, claimed this film was the most dangerous film he'd ever flown for. He was killed in a crash soon after filming finished.

Robert Caulfield:
You wouldn't know sincerity if it ran over you.


Judy Drinkwater:
Not if you were driving it.

Plot holes: For much of the flight, and in particular during the launch when the astronauts have not yet been informed of the deception, we're told their voices from the spacecraft are simulated by recordings that were made during the practice simulations. This trick would stop working as soon as anything was said to them requiring a reply that had not occurred in the simulations, or as soon as they had any quiet time and would naturally be expected to chat about their present experience.