Related by context. Frequent words. (Click for all words.) 56 Yuri Gagarin 54 spaceflight 53 manned spaceflight 52 Sputnik 52 manned spacecraft 51 spacecraft 51 Gagarin 50 Perminov 50 Soyuz capsule 49 lunar landing 49 space shuttle 49 orbit 47 cosmonaut 47 astronauts 47 human spaceflight 46 Soyuz 46 lunar probe 45 International Space Station 45 manned missions 45 Baikonur Cosmodrome 45 Space Agency 45 lunar orbit 45 shuttle missions 45 astronauts aboard 45 shuttle Discovery 44 Soyuz spacecraft 44 shuttle Atlantis 44 shuttle fleet 44 orbiting 44 Roscosmos 44 Yurchikhin 44 Vostok 44 orbiters 44 space shuttles 43 spacesuits 43 spacewalk 43 spacesuit 43 lunar exploration 43 cosmonauts 43 Shenzhou 43 NASA 43 spaceship 43 Shuttle Discovery 43 blastoff 42 lunar module 42 Korolyov 42 Bulava 42 Chang'e 42 Russian Soyuz capsule 42 Jules Verne 42 Gerstenmaier 42 orbiter 42 Apollo astronauts 42 Tokarev 41 thrusters 41 Baikonur 41 JAXA 41 Endeavour astronauts 41 spacewalks 41 Russian Soyuz spacecraft 41 Russian cosmonaut 41 Padalka 41 sub orbital 41 Alexander Losyukov 41 X #A 41 Foale 40 shuttle 40 orbited 40 spacemen 40 orbiting lab 40 Skylab 40 NASA Administrator 40 Space Shuttle Atlantis 40 liftoff 40 Russian cosmonauts 40 Discovery astronauts 40 spacewalking 40 aboard Endeavour 40 Nasa 39 microgravity 39 shuttle Endeavour 39 Space Shuttle Discovery 39 Space Station 39 undocking 39 suborbital 39 undocked 39 CryoSat 39 Baikonur cosmodrome 39 lunar lander 39 NASA Space Shuttle 39 Hayabusa 39 Space Shuttle 39 Earth orbit 39 Alan Shepard 39 space shuttle Discovery 39 orbiting laboratory 39 lunar 39 Laika 39 Chandrayaan 39 unmanned spacecraft 39 PSLV