Related by context. Frequent words. (Click for all words.) 73 zero gravity 67 microgravity 65 weightless 50 spaceflight 49 astronaut 48 astronauts 47 cosmonauts 47 spacecraft 45 International Space Station 45 motion sickness 45 spacesuit 44 suborbital 44 spaceship 44 Virgin Galactic 44 outer space 44 Soyuz 43 lunar surface 43 cosmonaut 43 robotic arm 42 orbital 42 SpaceShipTwo 42 suborbital space 42 SpaceShipOne 42 orbiter 42 orbit 42 Space Station 42 spacesuits 41 Wakata 41 Soyuz capsule 41 NASA 41 spacewalker 41 Martian surface 41 Nasa 41 Space Shuttle Atlantis 41 Russian cosmonauts 41 X #A 41 Space Shuttle Discovery 40 orbiting lab 40 blastoff 40 Soyuz spacecraft 40 hypersonic 40 Earth orbit 40 JAXA 40 orbital outpost 40 space shuttle 40 LCROSS 40 NASA astronaut 40 airlock 40 disorientation 40 orbiting 39 flight simulator 39 Padalka 39 shuttle Discovery 39 capsule 39 shuttle 39 Space Agency 39 Gs 39 Eileen Collins 39 lunar orbit 38 liftoff 38 orbiting laboratory 38 lander 38 Shuttle Discovery 38 crewmates 38 Astronaut 38 thrusters 38 Cape Canaveral Fla. 38 Scaled Composites 37 Mike Fincke 37 Malenchenko 37 lunar landing 37 ISS 37 Apollo astronauts 37 Thomas Reiter 37 space shuttle Endeavour 37 Saturn moon 37 shuttle astronauts 37 spaceships 37 spacewalk 37 Soyuz TMA 37 Red Planet 37 Lopez Alegria 37 spacewalks 37 space shuttle Discovery 37 astronauts aboard 37 turbulence 37 shuttle Atlantis 37 curvature 37 airship 37 Russian Soyuz spacecraft 37 nausea 37 orbiting outpost 36 Orbiter 36 Russian Soyuz 36 spacewalkers 36 Astronauts 36 Phoenix Mars Lander 36 oxygen deprivation 36 earthbound 36 spacewalking 36 Shenzhou