| Director | John Sturges |
|---|---|
| Budget | $8 million |
| Box office | $4.1 million |
Three U.S. astronauts Commander Jim Pruett, "Buzz" Lloyd, and Dr. Clayton "Stoney" Stone are the crew of an experimental space station on an extended-duration mission. About five months into a planned seven-month mission, the crew in general and Lloyd in particular begins exhibiting erratic and substandard performance, and NASA management elects to end the mission early. While oriented for retrofire, the main engine on the spacecraft, dubbed Ironman One, fails. Mission Control determines that Ironman does not have enough fuel remaining to initiate atmospheric entry, nor to redock with the station and wait for rescue. The crew is marooned in orbit.
NASA debates whether a rescue flight can reach the crew before their oxygen runs out. No backup launch vehicles are available at Kennedy Space Center and NASA Director of Manned Spaceflight Charles Keith opposes using an experimental U.S. Air Force lifting body, the X-RV, that would be launched on an Air Force Titan IIIC booster rocket; neither the spacecraft nor the booster is man-rated. Colonel Ted Dougherty, NASA's chief astronaut, opposes Keith, claiming most time-consuming preparation items can be dismissed. The President agrees with Dougherty and tells Keith that failing to try a rescue mission will kill public support for the crewed space program. Despite his initial opposition, Keith accepts the decision, and works furiously on the rescue mission. Dougherty appoints himself as pilot.
The astronauts' wives are brought to the control room and allowed to speak to their husbands, but this exacerbates Lloyd's already-agitated condition. As launch time approaches, a hurricane heading for Cape Canaveral causes the mission to be scrubbed. While Keith addresses the news media at the Cape, a USAF weather officer informs Keith the eye of the storm will pass over the Cape 90 minutes later during a subsequent launch window, permitting enough time to launch a rescue mission.
When the eye of the hurricane passes over the Cape, the X-RV is successfully launched. However, insufficient oxygen remains for all three astronauts to survive until Dougherty arrives. Pruett and his crew debate what to do. Stone argues that they can survive by taking sleeping pills to reduce oxygen consumption, but Pruett overrides him. An agitated Lloyd offers to leave, since he is "using up most of the oxygen anyway," but Pruett overrules him as well. He orders everyone into their spacesuits and exits the ship, ostensibly to attempt repairs.
After Pruett goes on his EVA, Lloyd realizes he is planning to sacrifice himself and attempts to follow. Stone restrains Lloyd, and they both watch Pruett from the hatch. A hiss of air occurs as a large gash in Pruett's space suit is torn on a metal protrusion from the service module's S-band antenna array. Helpless to stop the leak, Pruett drifts away from the ship as Lloyd and Stone look on. With Pruett gone, Stone takes command and sedates Lloyd.
A Soviet Voskhod spacecraft suddenly appears and its cosmonaut tries to make contact. Since his ship is too small to bring the astronauts aboard, the cosmonaut attempts to bring oxygen to the Apollo spacecraft. Stone and Lloyd, suffering oxygen deprivation, do not understand the cosmonaut's gestures or Keith's instructions from Houston. Lloyd drifts out of the hatch and away from the ship. Dougherty arrives in the X-RV and retrieves Lloyd using a maneuvering pack. The cosmonaut moves into the Apollo spacecraft and attaches an oxygen tank onto Stone's suit. Dougherty transfers the two surviving Ironman astronauts into the rescue ship. After separating, both the Soviet ship and the X-RV execute retrofire to return to Earth, and the final scene fades out with a view of the abandoned Ironman One adrift in orbit.