Exploration Space flight Exploration of outer space 15 Astronautics 13 History 12 Interplanetary voyages 11 Science and civilization 11 more ... Space ships 11 Scott, Montgomery (Fictitious character) 7 Sulu, Hikaru (Fictitious character) 7 Vol spatial 7 Human-alien encounters 6 Manned space flight 6 Astronautique 5 McCoy, Leonard (Fictitious character) 5 Astronautics and state 3 Enemies 3 Histoire 3 Kirk, James T. (Fictitious character) 3 Space flights 3 Space sciences 3 Spock (Fictitious character) 3 Aeronautics and state 2 Enterprise (Imaginary space vehicle) 2 Forecasting 2 Interstellar travel 2 Juvenile literature 2 Lunar exploration 2 NASA PROGRAMS 2 Outer space 2 less ...