On the Threshold of Space: In the early stages of the space program, Capt. Jim Hollenbeck undergoes any experiment needed to ensure success in the new Air Force branch -- even though he's not required to be a subject in the tests. Always remaining a constant source of support, his wife, Pat, accepts his unwavering commitment to scientific progress. When Maj. Ward Thomas becomes the new head of the program, Hollenbeck must convince him of the necessity of taking the extra steps.