The people of Earth are startled by a news release announcing the first mission to Mars, which will be manned by Dr. Lane, physicist and leader of the project; Jim Barker, a brilliant engineer; his assistant Carol Stadwick; Professor Jackson, an outstanding scholar and Steve, a newspaper columnist, who will cover the expedition. As the last preparations are made for the launch, Steve hurries to interview the crew about why they would risk their lives to reach Mars. Jackson keeps his answers brief, explaining he is on his way to a television interview. After Steve asserts that their story is not for commercial gain, Jackson defends himself, saying he must leave the profits to his ailing wife and two grandchildren, in case he should not return. Suddenly Steve realizes that he too has agreed to make a trip with a very small chance of returning to Earth. Once in space, the crew members soon adjust to their new surroundings, but after forty-eight hours, the moon's gravitational pull necessitates a change in course, and they become anxious when they loose contact with Earth. Jackson believes he will never see his family again and Carol pines for Jim's attention and longs for a family of her own. Steve takes advantage of Carol's frustration by flirting with her. Lane tries to bolster morale by reminding them that their trip is essential to humanity's understanding of the universe. Soon after, they are suddenly hit by a meteor storm that ruins their landing gear. The crew must then decide to crash-land or turn back. Jackson urges them to continue, arguing that the primary reason for their flight was to collect data, which they can still send to Earth via self-propelled space cylinders with homing devices. After some debate, they agree that their survival is secondary and decide to crash-land. Once on the surface of the planet, they discover five human-like aliens who speak English. Ikron, the president of the planet's council, explains that they have learned the language from studying Earth's radio broadcasts, though their own efforts to contact Earth have only been reported as "faint signals coming from Mars." The Martians then escort the crew to their underground city, which is filled with flying ships and towering buildings with life-support systems fueled by a mineral called corium. The crew meets with the council, including past president Tillamar, now advisor to the council. Later, Terris, a young female Martian, shows them to their room and offers them automated meals, made from hydroponically grown food. Within hours they return to the council to ask for help in repairing their ship. In private, the devious Ikron reminds the council that they have almost exhausted their supply of corium and suggests that they help the crew repair the ship then abduct them before takeoff and build duplicate ships to evacuate their own people to Earth. Although Tillamar argues that the plan will necessitate battles with Earth, the council votes in Ikron's favor. The Martians assign a crew of workmen overseen by Alita, one of their leading scientists, while also sending Terris to spy on their progress. One night, after an explosion inside the ship, Jim explains to Terris that the takeoff will be postponed, when in actuality, he faked the explosion. Later, when they are alone, Alita tells Jim she knows his work comes first, but Jim takes her into his arms and kisses her. Meanwhile, Steve visits Carol's room and tells her she is wasting time on Jim. Soon after, Jim announces to the crew that the takeoff is scheduled for tomorrow and Tillamar and Alita, whom he has asked to be his wife, will join them. Jim explains that Tillamar plans to transmit a series of radio broadcasts from Earth in hopes of convincing the Martians to overthrow Ikron. The next day, the crew boards the ship and Terris reports the suspicious behavior to Ikron. Onboard, Carol asks Steve to collaborate with her on some stories upon their return, intimating that it might lead to a romantic collaboration for life. Before they are able to join the others, Alita and Tillimar are abducted by Ikron's men and taken to the council. When Jim finds out about their capture, he rushes from the ship to save them. Entering the council room just as Ikron orders the ship to be seized, Jim punches the guards who are holding Tillamar and Alita, and the three run towards the ship. Martian guards try to prevent them from climbing the loading stairs, but the three make it onboard safely and take off into space, heading for home.
