Space ships Interplanetary voyages 14 Space flight 13 Exploration 10 Human-alien encounters 10 Science and civilization 7 Exploration of outer space 6 more ... Interstellar travel 5 Enemies 4 Robots 4 Friendship 3 Scott, Montgomery (Fictitious character) 3 Space colonies 3 Sulu, Hikaru (Fictitious character) 3 Astronauts 2 Astronaves 2 Closed caption video recordings 2 Enterprise (Imaginary space vehicle) 2 Introduced organisms 2 Manned space flight 2 Perseveration (Psychology) 2 Radio 2 Space warfare 2 Survival 2 Transmitters and transmission 2 Vuelo espacial tripulado 2 War 2 Women ship captains 2 Audio-visual materials 1 DVDs 1 less ...