The rocket shown during the lift off is a different model then the one used later on in space.
At 36min you can see guards who were running after a suspect stop too soon. Because of this they remained on screen during the shoot.
While repairing the rocket in space there was no gravity, but on the moon gravity seems to be the same as on Earth when two men are fighting.
At the end of the episode just before our two heroes are transported to another time they lose their suits in space. Amazingly, they were still able to breathe normally.
The writers had a rather optimistic view of the future - just ten years ahead, the time travelers find a rocket that's bound for Mars! And, on the mission commander's initiative it can divert to the moon where there is a supply base!