The film is set in 2020 and begins as the Ares spacecraft enters orbit around Mars. Andre Vishniac commands an international crew of seven astronauts. They try to land, but the small landing craft crashes as a result of an altimeter error. Vishniac is immediately killed, and five other crew members are stranded inside the toppled landing craft, unable to return to the waiting Ares mothercraft. With no spare landing craft, Lowell, the pilot of the Ares, returns to Earth with it.
The space armada from Mars, known as the Imperial Atomic Space Navy (Battle Group Seven), fights an interstellar war against their long-time enemy, the Arcturans. The armada is forced into battle by Enforcer Droids, tasked to keep the Martian soldiers in line, despite objections by some that it won't work. Meanwhile, an incompetent crew of a small Martian spaceship, from the Civilian Asteroid Patrol, intercept a distress signal from the fleet, followed by a Halloween rebroadcast of Orson Welles' 1938 The War of the Worlds radio dramatization.
Martian invader, Mota (Gregory Gaye), attempts to conquer the Earth as Mars is worried about its use of new atomic technology. They consider that it would be much safer, and beneficial for both Earth and Mars, if the Martians were in charge. Mota, having been shot down by an experimental ray gun, blackmails American scientist, and former Nazi, Dr. Bryant (James Craven) into assisting him and hires some criminals to be his henchmen.
The rocketship MR-1 (for "Mars Rocket 1"), returns to Earth after the first manned flight to Mars. At first thought to have been lost in space, the rocket reappears but mission control cannot raise the crew by radio. The ground crew land the rocket successfully by remote control. Two survivors are found aboard: Dr. Iris Ryan (Naura Hayden) and Col. Tom O'Bannion (Gerald Mohr), the latter's arm covered by a strange alien growth. The mission report is recounted by Dr. Ryan as she attempts to find a cure for Col. O'Bannion's arm.
In the year 2046, a research facility on Mars is suddenly attacked by an unknown assailant. Following a distress call sent by Dr. Todd Carmack, a group of marines, led by Asher "Sarge" Mahonin, is sent on a search-and-rescue mission. One of the Marines, John "Reaper" Grimm, accompanies his sister, Dr. Samantha Grimm, to one of the labs within the devastated sector to retrieve data; here he learns that the dig site where their parents were accidentally killed was re-opened and bones of an ancient group of genetically enhanced race were discovered.
The first mission to Mars led by physicist Dr. Lane (John Litel), includes Professor Jackson (Richard Gaines), engineer Jim Barker (Arthur Franz) and his assistant Carol Stadwick (Virginia Huston). Journalist Steve Abbott (Cameron Mitchell) is also on board to cover the expedition. A final interview with the scientific team makes Steve realize that there are grave risks to the mission.
Une expédition scientifique américaine composé de 4 scientifiques (3 hommes et une femme) ainsi que d'un journaliste après avoir atterri sur Mars en catastrophe en endommageant leur fusée, découvre que la planète rouge est habitée par une civilisation souterraine extrêmement évolué mais agonisante. Les Martiens sont divisés sur la conduite à tenir vis-à-vis des Terriens, la majorité du conseil dirigeant décide de les aider à réparer leur vaisseau, puis lorsque celui-ci sera prêt de s'en emparer et de s'en servir de modèle pour construite une flotte permettant aux martiens d'envahir la terre. Cependant les Terriens se font des sympathisants parmi les Martiens. Un plan nait qui permettra aux terriens de regagner la Terre en compagnie du chef de l'opposition et de la fille de son bras droit.
The film opens on Mars, showing the last moments of a Mars rover's mission. As the rover prepares to sample a Martian rock, the rover loses power and becomes inoperable. The scene pans up from the dead rover to show a huge, undiscovered Martian city just beyond the rock the rover was about to sample. A spaceship is seen quickly rocketing from the city and accelerating into space.
The film begins 25 years after the revolution. Alec (Robert Patrick) has become a sullen, retiring man burdened over losing his wife and daughter, while Jake is now a lieutenant in the Colonists. Jake is informed that the remains of the EDF Dreadnought Hydra—destroyed in orbit by Alec at the end of the revolution—is falling to Mars and must be searched for valuable technology. When searching the Hydra, with the help of Tess, an Earth technology expert, he discovers a group of Marauders dressed similar to the ones he remembers kidnapping Lyra, carrying away a device from the ship. Jake attacks one to discover it is a soldier who he believes to be Lyra.
A large ship drifts into New York Harbor, seemingly abandoned. The ship is discovered to be carrying large containers of coffee, hidden inside of which are a series of football-sized green eggs. The crew sent in to explore the ghost ship find the mutilated remains of the former crew gathered in one place, and they soon discover the reason why: when disturbed, the green eggs explode, spraying a viscous liquid over everything. The liquid is toxic to living creatures, and causes the body to immediately explode.
Nyah, a female alien commander from Mars, dressed in shiny black vinyl, heads for London in her flying saucer. She is part of the advanced alien team that is looking for Earth men to replace the dying male population on her world. Because of damage to her saucer, caused by entering Earth's atmosphere and then colliding with an aircraft, she is forced to land her damaged flying saucer in the remote Scottish moors, near a local village. She is armed with a raygun that can paralyze or kill, and she also has a tall, menacing robot named Chani.
An American astronomer obtains images of Mars suggesting large-scale environmental changes are occurring at a pace that can only be accomplished by intelligent beings with advanced technology. At the same time a colleague claims to have been contacting Mars by radio, using technology stolen from the Nazis after World War II. He communicates first through an exchange of mathematical concepts, like the value of pi, and then through answers to specific questions about Martian life. The transmissions claim that Mars is a utopia fueled by nuclear power, which has led to great technological advancement and the elimination of scarcity, but that there is no fear of nuclear war.
Destination Earth begins with the emperor Ogg (reminiscent of Stalin) sending a bumbling subordinate Martian on a mission to Earth to find a better power source for his royal limousine. The Martian sets off and lands in the United States. He ventures into a nearby city and becomes awestruck when he sees average citizens with "powerful and reliable automobiles" that make their daily lives easier. The Martian then enters a library and researches the "secrets" the remarkable power source. The Martian triumphantly returns to Mars with stolen library books on the oil industry. After reading from them the population of Mars deserts Ogg and sets up their own oil companies. The short ends with the slogan "destination unlimited" written across the screen.
Four men and a woman blast into outer space from the White Sands Proving Ground aboard the RX-M (Rocketship Expedition-Moon) on humanity's first expedition to Luna. Halfway to their destination, the RX-M's engines shut down; the problem is resolved by recalculating the fuel mixture ratios and then moving around some of the propellent tanks and their connecting hoses. When the engines are reignited, the RX-M rapidly careens out of control, accidentally setting the spaceship on a runaway course heading beyond the Moon and into deep space. During this burst of rapid acceleration, the crew, one by one, becomes unconscious due to a drop in oxygen pressure. The engines are shut off just in time. At some later time, perhaps many days, they slowly come around. The revived crew soon discovers the RX-M has traveled some 50,000,000 miles while they were unconscious. Against all odds, this surprising sequence of events has put them on a direct course heading toward Mars. They also notice the RX-M's speed is still increasing, this time due to gravitational attraction: the Red Planet is drawing them in. They quickly calculate they are only 50,000 miles away. This forces Dr. Karl Eckstrom (John Emery) to "pause and observe respectfully while something infinitely greater assumes control.
NASA successfully lands a robotic surveyor on Mars. The rover begins to explore, but after just a few minutes it is completely destroyed by what appears to be a high energy surge. At that exact same instant back at mission control, Dr. Dave Fielding (Kent Taylor), in charge of the project, suddenly feels oddly disconnected and not himself; he shakes it off and then goes to face the crowd of expectant reporters. Right after he leaves, his exact body double is sitting at his desk.