 When Rodney goes back to check on the nukes for the first time, he  mentions that there are two "TK421" bombs and a "1138". TK421 was  the stormtrooper number Han Solo used in _Star Wars (1977)_ (qv),  and 1138 is a reference to _THX 1138 (1971)_ (qv), an early  George Lucas (qv) film.