Reports are brought into Mission Control for the historic launch of the experimental moon probe, XMP-13. The Air Force liaison officer, Paul, warns them that the base is on a tight schedule to prepare for launch, but has allowed a few minutes for questions. Mary McCauley and her son Pete, the wife and son of mission commander Colonel Edward McCauley, are escorted in and introduced to the reporters. Finally, McCauley and his two crew members, communications officer Major Joe Hale and navigational officer Major Billy Williams, arrive to address the reporters. McCauley tells them that their trip around the Moon will take two days and reluctantly admits that they don't have the know-how to conduct a lunar landing... yet.
The one-hour countdown begins and McCauley kisses his wife goodbye and gives his eagle's wings to Pete to wear until his father goes back. McCauley, Hale, and Williams then board the XMP-13 and prepare for launch. They recite nursery rhymes over the radio and the liaison officer informs the press that the officers will continue to do so to confirm that they are suffering no ill effects from the massive g-forces resulting from liftoff.
The XMP-13 lifts off on schedule and the first stage booster ignites and then detaches, boosting the spaceship beyond Earth's gravity. The efforts of the three crew members become increasingly strained and Mary and Pete recite nursery rhymes with Colonel McCauley to help him and until they clear Earth's orbit.
The g-forces finally ease off but Mission Control confirms that the XMP-13 is seven degrees off of the planned trajectory. They need to activate the third-stage boosters to course correct, but the second stage booster has failed to detach. The Air Force technical officer informs the reports that as long as the second stage booster is still attached, the crew can't ignite the third stage. McCauley and his crew check for malfunctions and a circuit gives out, forcing McCauley to unstrap and float over in zero-g to put out the electrical fire.
The astronauts confirm that the second stage is still partially detached due to a jammed release bar caused by a circuit malfunction. McCauley realizes they have no choice but for him to don an EVA suit, leave the ship, and burn through the release bar. Hale briefs Mission Control while Williams helps McCauley suit up. Once McCauley is outside and attached to a lifeline, he confirms that only one release bar is jammed and uses an acetylene torch to burn through it. The release bar suddenly frees, hitting the torch so that it cuts through McCauley's lifeline. The impact knocks him off the ship and sends him rocketing through the void of space before Hale and Williams can do anything to help him.
Once Mission Control is notified of McCauley's dilemma, it coordinates with mini-tracks around the world to pinpoint McCauley's ever-shifting location. They realize that they only have a half-hour to find McCauley before his signal is too faint to track. Hale and Williams finish the circuitry repairs and Mission Control sends them coordinates for McCauley's last known position. They ignite the third-stage booster and proceed to the coordinates, and find McCauley drifting outward. Williams dons a suit and tosses a lifeline to McCauley and then pulls him into the airlock. Once the colonel is secure, the crew radios Mission Control for instructions.
XMP-13 successfully touches down and McCauley is reunited with his family. Later, he comes to Mission Control for a debriefing and meets with Paul. The liaison officer is pleased that they proved it was possible to repair a missile in mid-flight. McCauley agrees, but notes that more impressively, for 30 minute everyone on Earth came together to ensure that a human life was saved.