The commander of a spaceship orbiting 250 miles above Earth disappears through the airlock and is ejected into space. Although at first it appears to have been an accident, some of the crew come to suspect that it may have actually been a murder.
| Actor | Role |
|---|---|
 George MaharisDr. Dan Summit | Dr. Dan Summit |
 Cameron MitchellArnold Chester | Arnold Chester |
 Margaret O'BrienPam Rhodes | Pam Rhodes |
 Robert Walker Jr.Major Barry Wolfe | Major Barry Wolfe |
 Susan OliverCarla Burke | Carla Burke |
 Jeremy SlateCliff Rocky Rhodes | Cliff Rocky Rhodes |
 William BryantMajor Doc Henry | Major Doc Henry |
| LLynnette MetteyNot listed | Not listed |
 John CarterNot listed | Not listed |
 Jason WingreenNot listed | Not listed |
| AArch WhitingNot listed | Not listed |
 Don KnightDr. King | Dr. King |
 Sandy KenyonDr. Hart | Dr. Hart |