Lucy and Vivian dress in their former Navy Waves military uniforms to go to a NASA lecture. They unwittingly volunteer to take a special psychological test as part of a "women in space" experiment.
They must successfully spend 24 hours together, in which they stay in a sealed simulated space capsule. The two live in the cramped conditions and Vivian is claustrophobic. Lucy must now prevent Vivian from pulling the "chicken switch".
The publicity goes to Lucy's head, so Viv and Harry scheme to bring her down to earth and teach her a lesson. Viv convinces the redhead that she's been chosen to be the first woman astronaut and must leave immediately for Cape Canaveral.
Special Notes: Nancy Kulp appears in this episode and is best known for her role as Jane Hathaway in "The Beverly Hillbillies" (1962-71). For trivia fans, it is Lucille Ball who has claustrophobia in real life, not Vivian Vance (as revealed in the "isolation" scene).