Doomsday Machine is an American science fiction film directed by Herbert J. Leder, Harry Hope, and Lee Sholem. It was mostly filmed in 1967, but completed and released without the original cast or sets in 1972.
American spies infiltrate a Chinese base and learn that a Doomsday Device is set to go off within days, with no way to disarm it. In response, a manned mission to Venus on the spaceship Astra is pushed ahead of schedule, and half of the all-male crew is replaced by women, to the objection of the men. They do not realize this is so humanity can be repopulated until they have already launched, and moments before their home planet is blown apart. But tensions are high, and only increase with the revelation that the ship cannot outpace the resulting nuclear radiation of the exploding Earth without some sacrifices.
This film uses the following Tropes:
- Adam and Eve Plot: Invoked by the people behind the Astra launch, who ordered half the crew to be replaced with women after learning of Earth's imminent annihilation. Played straight at the very end, when only one male and one female human remains.
- Bolivian Army Ending: The film ends with the two remaining members of the Astra crew learning that they cannot stay on Venus, but something great will await them at the edge of the universe, before their new ship blasts off to parts unknown.
- Breaking the Glass Ceiling: The women, though belittled by the male crew, are still experts in their fields of study. One of them, from Russia, takes pride in being the only women in her otherwise all-male classes.
- Chaos Architecture: Exterior shots of the Astra seem to be cobbled together from several different sources, leading to the ship changing shape every 15 minutes or so. Early on, it's Stock Footage of a real Saturn V rocket, then it resembles a ring-shaped satellite, and then it swaps between a few different Retro Rocket designs.
- Cold Equation: Thoroughly zig-zagged. The oldest astronaut aboard the Astra notices the increase in space radiation and realizes that at their current velocity, they'll all be sterilized by the time they reach Venus. They can increase speed to reach Venus before that happens, but only if they jettison a bunch of equipment—and four of the seven crew members. He uses a computer to calculate who should live and who should die, but those equations ironically never get used. Before the results can be announced, one of the male crew succumbs to Space Madness, then gets himself and a female crew member killed. Then the captain elects to disregard the calculations because he doesn't want anyone else dying, so they're just going to increase velocity and hope for the best. But when it comes time to jettison part of the ship, it gets stuck—so Daniel and Georgiana go spacewalking to get it unstuck, knowing that they'll be left behind as the Astra accelerates, thus fulfilling the original equation anyway. Except in the final twist, the surviving crew aboard the Astra get Killed Offscreen, while Daniel and Georgiana survive by finding an abandoned (but still somehow functioning) spacecraft from a prior Soviet mission to Venus.
- Doomsday Device: The titular creation that ends up annihilating the world.
- Earth-Shattering Kaboom: The Astra crew gets to see their homeworld utterly destroyed using a viewscope. They even have to deviate from their planned course to avoid a collision with a flying chunk of what used to be Earth.
- Explosive Decompression: Averted; two of the crew are accidentally exposed to the vacuum of space when one tries assaulting the other, but while they do die, they do not explode in the process.
- For the Evulz: Exactly why the Chinese would want to destroy the world — themselves included — is never explained.
- Hive Mind: The remaining crew is eventually contacted by the collective consciousness of an alien race on Venus.
- Homeworld Evacuation: The Astra mission becomes an impromptu attempt at this once the doomsday machine is discovered. The crew doesn't finds out until they see the Earth-Shattering Kaboom.
- Killed Offscreen: Two of the crew find an abandoned Soviet spaceship after fixing damage to the Astra's hull and explore it. When they try to contact the Astra from inside it, though, they are contacted by Venusians who tell them the other ship no longer exists.
- "Shaggy Dog" Story: The original goal of reaching and colonizing Venus is a failure, because Venus is already inhabited by an alien race that forbids all humans from entering after what they did to their own planet.
- Space Madness: Affects one of the male crew after learning of Earth's destruction, who then attempts to sexually assault one of the females.
- Stay in the Kitchen: The mentality of the male astronauts.