Related by context. Frequent words. (Click for all words.) 67 spaceflight 56 astronauts 56 shuttle missions 55 astronaut 52 manned spaceflight 51 NASA 51 spacecraft 51 human spaceflight 50 manned missions 50 suborbital 50 manned spacecraft 49 spacewalks 49 space shuttle 49 Space Adventures 49 cosmonaut 48 Soyuz spacecraft 48 NASA astronaut 48 Yuri Gagarin 48 NASA Administrator 47 SpaceShipOne 47 SPACE.com 47 Virgin Galactic 47 cosmonauts 47 spacewalk 47 astronaut corps 47 orbiters 47 orbit 47 Soyuz 46 International Space Station 46 Nasa 46 space shuttles 46 Astronauts 45 SpaceX 45 Space Station 45 Earth orbit 45 spacewalking 45 shuttle Discovery 44 Russian Soyuz 44 spacewalkers 44 Soyuz capsule 44 orbiter 44 lunar landing 44 Russian Soyuz spacecraft 44 flybys 44 SpaceShipTwo 43 spaceship 43 shuttle Atlantis 43 expeditions 43 orbiting laboratory 43 microgravity 43 Padalka 43 payloads 43 zero gravity 43 Astronaut 43 flight 43 Russian cosmonaut 42 Russian cosmonauts 42 NASA Headquarters 42 spacesuit 42 shuttle astronauts 42 shuttle 42 JAXA 42 Lopez Alegria 42 Discovery astronauts 42 Buzz Aldrin 42 astronauts aboard 41 Shenzhou 41 lunar exploration 41 spacewalking astronauts 41 rovers 41 Space Shuttle 41 spacewalker 41 spacesuits 41 weightlessness 41 experiments 41 spaceships 41 Space Shuttle Discovery 40 Ansari X 40 Hayabusa 40 voyages 40 Eileen Collins 40 Space Agency 40 Gagarin 40 Burt Rutan 40 blastoff 40 Scaled Composites 40 Simonyi 40 missions 40 STS 40 Atlantis astronauts 39 Gerstenmaier 39 Chiao 39 Garriott 39 space shuttle Discovery 39 Chandrayaan 39 Rutan 39 orbital 39 X #A 39 liftoff 39 Wakata 38 flights