Astronauts Charles Brubaker (James Brolin), Peter Willis (Sam Waterston), and John Walker (OJ Simpson) are the crew for the first manned mission to Mars, Capricorn One. Except they're not. A poorly made life-support system that would have killed the astronauts three weeks into their trip means they'll have to fake it, as Congress can't afford another screw-up. The spacecraft is launched empty, and the crew are taken to a remote Air Force base, where they are forced to act out the Mars landing in a studio for the benefit of television cameras.
Elliot Whitter (Robert Walden), one of the technicians at mission control, notices something strange — that the television signals are being transmitted ahead of the telemetry — and tells his reporter friend Robert Caulfield (Elliott Gould). But Elliot is killed, and he's been made an Unperson. Then when Caulfield interviews Brubaker's wife Kay (Brenda Vaccaro), her reaction to something strange Brubaker said helps him realize there's some sort of Government Conspiracy at work.
Then, when the empty spacecraft burns up on re-entry due to a defective heat shield — or so NASA says — the astronauts realize they know too much and decide to make a run for it.
Tropes featured in this film:
- Aerial Canyon Chase: A chase over the Sierras, rather distinctly using numerous shots from behind the plane in a chasing camera.
- Always Know a Pilot: Caulfield hires cropduster Albain to search for astronaut Charles Brubaker. Albain immediately deduces that Caulfield is working a heist, and demands half the take as payment. Albain flies his biplane well enough to checkmate two helicopter gunships bent on eradicating all witnesses.
- Artistic License Geography: The plot hinges on the astronauts being about an hour's drive from Houston. When they're shown dying in the desert, they should be in South Texas, which is mostly grassland and swamps.
- Attending Your Own Funeral: The last surviving astronaut makes it to a memorial service for the crew, exposing the conspiracy.
- Big Bad: Dr. James Kelloway, the NASA official who's the main orchestrator of the Mars landing hoax and is determined to dispose of anything and anyone who poses a threat to exposing it.
- Black Comedy Pet Death: Invoked, in which one of the astronauts running through the desert to avoid getting killed by a Government Conspiracy improvises a joke to cheer himself up about a man who encounters a friend after a long time of not seeing and the friend telling the joke's protagonist that his pet cat died horribly. The joke's protagonist tells the friend that it would have been better to tell a tale about how the cat went up on the rooftop and died a comedic death... which is the very same tale the man then says when he speaks about the protagonist's mother committing suicide.
- Black Dude Dies First: A variation. Of the three astronauts on the run, it's the black dude who gets recaptured first (although the audience may rightly assume that they subsequently killed him — he was supposed to have died during "re-entry", after all).
- Black Helicopter: A matched set of Army Loaches (LOH-6 Cayuses). OK, they're actually olive drab, but still, they're used to highly ominous effect when the astronaut crew are trying to escape through the desert. You don't actually see much of the search other than the helicopters so they end up being an abstract representation of the conspiracy. They fly and maneuver in a way that makes them seem alive and predatorial (pointing and looking with their "noses") and at one point a delirious astronaut sees them as Circling Vultures.
- Black Site: The compound where the astronauts have been sequestered to.
- Circling Vultures: Subverted. One of the astronauts being hunted by government agents in the desert, delirious from heat and thirst, thinks he sees "birds" circling above him — and in the camera shot depicting his blurred vision, it does look like vultures circling. Turns out to be those Black Helicopters, though.
- Conspiracy Thriller: Though it's also partly a Deconstructive Parody / Stealth Parody of theories about the supposed Apollo Moon landing hoax.
- Cue the Billiard Shot: A rack is broken to open the scene where Intrepid Reporter Caulfield meets his contact in a bar. The contact starts explaining that the mission's telemetry is completely wrong, but when Caulfield gets distracted, his contact has vanished.
- Cutting Corners: Sometimes it doesn't pays to go for the lowest bidder on a space exploration mission, especially when they are so crooked that they give you back a faulty life-support system and re-entry heat shield.
- Deadpan Snarker: Willis.Oh, the marvels of American science. Here we are millions of miles from Earth, and we can still send out for pizza.
- Discussed Trope:Caulfield: Look, when a reporter tells his assignment editor that he thinks he may be on to something that could be really big, the assignment editor is supposed to say: "You've got forty-eight hours, kids, and you better come up with something good, or it's going to be your neck!" That's what he's supposed to say, I saw it in a movie.Loughlin: You're not crazy, I'm crazy. I'm crazy for listening, and I'm crazy for saying what I'm about to say. I'll give you twenty-four hours to come up with something. Not forty-eight. I saw the movie, too; it was twenty-four.
- Faceless Goons: The relentless Army aviators. Even when they dismount to search on foot, they don't take off their helmets.
- Government Conspiracy: The plan to fake the "Capricorn One" mission from launch to landing, including having to kill those who know too much, because America can't afford to look foolish.
- He Knows Too Much: Whittier disappears when he notices that the video feed is coming ahead of the telemetry. The bad guys also make several attempts to murder Caulfield throughout the movie, since Whittier shared much of what he had discovered to him.
- I Have Your Wife: When the astronauts are first told about the setup, it's pointed out to them that their families are all on the same plane back from the launch and a "device" has been planted on the plane.
- Intrepid Reporter: Caulfield wants to be one of these (and gets his chance in the end). However, his history of trying to find hot scoops led to a long list of embarrassments which prevent his editor from taking him seriously.
- Moon-Landing Hoax: The inspiration behind the film. A faked Mars landing has to be filmed due to failures in the life support system.
- Next Sunday A.D.: The film was made in the late 1970s and is seemingly supposed to take place in the first half of the 1980s.
- Now What?: The movie ends straight as Caulfield and Brubaker attend the fake memorial service for the astronauts and the elaborate Government Conspiracy is exposed.
- Oh, Crap!: Near the end of the film, Caulfield manages to find the Black Site where the landing was filmed. After finding a necklace from Brubaker's wife buried in the fake Martian sand, he quickly breaks into a run to find him.
- Out-of-Character Alert: Brubaker makes possibly the subtlest one in film history by getting the previous year's family holiday mixed up. This is just enough to draw attention to it, and Caulfield spots that it has happened from the expression on Mrs. Brukbaker's face, but when he finds out what it is, he at first thinks nothing of it and then leaves. Later, he comes back and finds out the key point — on the previous year's holiday, they had visited a film set.
- Race Against the Clock: Caulfield is on the verge of being pulled away from the scoop of the century by his editor. Bargaining for time, he argues that "the assignment editor is supposed to say "you've got 48 hours, kids, and you'd better come up with something good or it's going to be your neck!" That's what he's supposed to say, I saw it in a movie." The editor then gives him 24 hours, "Not forty eight. I saw the movie too; it was twenty four."
- Soft Glass: Brubaker jumps through a window at the remote gas station to escape the Army aviators.
- Stealth Parody: Of Moon landing hoax theories — the film quietly showcases how incredibly unlikely it is that the truth of "astronauts never left the Earth" would remain secret even with the best (and most murderous) cover-up in the business.
- Survival Mantra: One of the escaping astronauts keeps reciting jokes to himself as he struggles through a harsh desert. When he gets to the punchline, he reaches the top of the mountain he was climbing...and finds the two helicopters there waiting for him.
- Took a Level in Jerkass: Dr. Kalloway is initially quite ashamed of having to pull off such a massive deceit to America to preserve the reputation of NASA, and it clearly pains him to inform the astronauts that they'll kill their families if they don't comply. But his remorse doesn't last long, as he goes about executing anyone who knows too much without a second thought or slightest bit of empathy.
- Unperson: The bad guys try to remove all traces of NASA technician Elliot Whittier. They move someone else into his apartment and she pulls out rent receipts to "prove" she has lived there for years. However, they are unable to change every phone book in Houston (which had a population of over a million and a half at the time) so the astute reporter finds Whittier still listed as living there.
- Unusual Euphemism: Willis' attempt to reassure himself as he's climbing up the side of a cliff and then runs into the choppers that had landed at the top and he's captured and maybe killed is a Black Comedy joke involving this, in which a man gets told with Brutal Honesty that his dog had died and so he asks the man who told him about the dog why not make up some story about the dog climbing up to the roof and then falling off, after which he asks how his mother is doing... and the one who told him about the dog's death starts talking about the man's mother "climbing up to the roof"...
- Vehicular Sabotage: The bad guys not only cut Caufield's brake lines, they disable his parking brake, jam his gearshift lever in Drive, and somehow yank his accelerator pedal all the way down to the floor.
- Vice President Who?: Instead of the President, the Vice President attends the historic launch. Doctor Kelloway notes this and regards it as a sleight by the White House, a symbolic vote of no confidence in Kelloway's leadership at NASA.