Capricorn One—the first crewed mission to Mars—is on the launch pad. Just before liftoff, astronauts Charles Brubaker, Peter Willis, and John Walker are suddenly ordered out of the spacecraft by a
NASA official. Bewildered, they are flown in secret to an abandoned military base in the desert. The launch proceeds on schedule, with the public unaware the spacecraft is empty. At the base, NASA head Dr. James Kelloway informs the astronauts that a faulty life-support system would have killed them in-flight. He says they must help counterfeit the televised footage during the flight to and from Mars. Another failed space mission would result in NASA's funding being cut and private contractors losing billions in profits. Kelloway threatens their families to force their cooperation. The astronauts are held captive during the spaceflight and appear to be filmed after landing on Mars, although they are actually inside an elaborate
set at the base made to look like the surface of Mars. At the command center, only a few officials know about the conspiracy until an alert technician, Elliot Whitter, notices that ground control receives the crew's televised transmissions before the spacecraft
telemetry arrives. Whitter reports this to his supervisors, including Kelloway, but is told it is due to a faulty workstation. Whitter partially shares his concerns with a TV journalist friend, Robert Caulfield. Whitter suddenly vanishes, and when Caulfield goes to Whitter's apartment the next day, he discovers someone else living there and that all evidence of Whitter's recent life has been erased. As Caulfield leaves, he survives a car crash into a river after his car had been
tampered with. Upon returning to Earth, the empty spacecraft burns up during
atmospheric reentry due to a faulty
heat shield, which would have killed the astronauts had they been on board. The astronauts realize officials will need to kill them to keep the hoax a secret. They escape in a small jet which quickly runs out of fuel, forcing a crash-landing in the desert. They split up on foot to increase their chances of finding help and exposing the plot. Kelloway sends helicopters after them. Willis and Walker are found and killed, while Brubaker evades capture. Caulfield interviews Brubaker's "widow", Kay, after reviewing a televised conversation between the astronauts and their wives. Kay Brubaker had seemed confused when her husband mentioned their last family vacation. She explains that the family had actually gone to a different location, where a western movie was being filmed. Brubaker was intrigued by how special effects and technology made it seem real. Caulfield believes Brubaker would never make such a mistake and may have been sending his wife a message. Caulfield goes to the deserted western movie set and is shot at. As he investigates further, federal agents break into his home, arresting him for possessing cocaine that they planted there. His exasperated boss bails Caulfield out, then fires him. A reporter friend tells Caulfield about an abandoned military base located 300miles (about ) from Houston. The base is now deserted, but Caulfield finds a medallion belonging to Brubaker, confirming the astronauts were there. Caulfield hires a crop-dusting pilot named Albain to search the desert. They spot and follow two helicopters to a closed isolated gas station where Brubaker is hiding. They rescue him as he attempts to escape his pursuers. The helicopters chase their plane through a canyon but crash when Albain blinds them with
crop spray, allowing the plane to get away. Caulfield and Brubaker arrive halfway through a memorial service being held for the three astronauts, where they are seen by Kelloway, Kay Brubaker, all assembled service attendees, and the
television cameras that were present and covering the service for
live broadcast. ==Cast==