When the Liberator is landing inside Spaceworld, night time shots of an a commercial Earth airport runway are shown. There is even one shot of a plane landing on the runway. Later when the Liberator takes off a movie taken from inside a plane landing at night is shown in reverse.
Just after Blake, Jenna, and Avon leave the control room, at 31:10, a cat that found its way onto the sound stage could be heard meowing.