The Robot is mounted on tracks. Yet in close-ups when it moves with a normal walking action and it is possible to see the actors legs move in the lower parts of the suit.
Doctor Smith seems to have a lot of possessions on board the Jupiter 2, considering he was a saboteur who never intended to go into space.
What ever happened to Penny Robinson's alien pet "Debbie the Bloop"?
The series never explores the emotionally- and mentally-challenging situation the Robinsons and Major West would have faced having to live and interact with Dr. Smith, their murderer had his sabotage operation succeeded.