Space warfare 212 Astronautics, Military 36 Life on other planets 36 Space weapons 28 Human-alien encounters 26 Interplanetary voyages 26 Good and evil 17 more ... Robots 15 Extraterrestrial beings 14 Guerre spatiale 14 Military policy 14 Imaginary wars and battles 12 Strategic Defense Initiative 11 Ballistic missile defenses 10 Space colonies 10 Space flight 9 Star Wars fiction 9 History 7 Science fiction, American 7 War 7 National security 6 Space ships 6 Espacio exterior 5 Exploration 5 Government policy 5 Initiative de défense stratégique 5 Armes spatiales 4 Arms control 4 Astronautique militaire 4 Child soldiers 4 less ...