The "fuel cells" for the water distillation unit are actually metal encased vacuum tubes of the type used in early car radios.
Judy, Penny, and Will are seen playing 'Interstellar Monopoly', which has a circular board. This episode aired long before Parker Brothers was acquired by Hasbro (in 1991), spawning a panoply of 'Monopoly' variants. One of the spaces being argued over is 'The Big Dipper'.