Will Robinson (Billy Mumy) is easy to remember from the many scenes in “Lost in Space” where the Robot shouts things like “Danger, Will Robinson!.”
The other Robinsons were his sisters Penny (Angela Cartwright) and Judy (Marta Kristin); his mother Maureen (June Lockhart); and his father John (Guy Williams).
Also aboard the Jupiter II were Dr. Zachary Smith (Jonathan Harris) and Major Don West (Mark Goddard).
Bob May played the Robot, with Dick Tufeld providing the voice.