Capricorn One (1978)
"Classic conspiracy tale about the first manned mission to Mars. All appears to be going well until the astronauts are pulled off the ship just before launch by shadowy government types and whisked off to a film studio in the desert. It transpires that the space vehicle has a major defect which NASA just daren't admit. At the studio, over a course of months, the astronauts are forced to act out the journey and the landing to trick the world into believing they have made the trip. Meanwhile, a Journalist (played by Gould) is getting suspicious and every clue he uncovers seems to result in an attempt on his life! The astronauts are just about to splashdown when a further twist to the tale occurs, leaving them with no choice but to try and escape..." -imdb.com
Wasn't a five star, but a three and one-half will work. I watched it to the end. A little uplifting to the script should have been done before filming. Not so bad.