Related by context. Frequent words. (Click for all words.) 41 zero gravity 40 cosmonauts 37 weightlessness 36 outer space 35 cosmonaut 35 International Space Station 34 spacesuit 34 motion sickness 33 Astronaut 33 Space Station 33 microgravity 33 astronaut 32 spaceflight 32 Nasa 32 astronauts 32 interplanetary 31 spaceship 31 spacesuits 30 Shenzhou 30 NASA 30 spacecraft 29 JAXA 29 Russian cosmonaut 29 orbital 29 orbiting laboratory 29 Lopez Alegria 29 Space 29 Malenchenko 28 suborbital 28 robotic 28 Russian cosmonauts 28 ISS 28 spacewalking 28 Astronauts 28 NASA astronaut 28 spaceships 28 Spacecraft 27 space 27 shuttle Atlantis 27 Space Agency 27 Padalka 27 orbit 27 manned spacecraft 27 weightless 26 earthbound 26 hypersonic 26 shuttle 26 robot 26 orbiting 25 Soyuz 25 teleportation 25 suborbital space 25 space shuttle 25 shuttle Discovery 25 Soyuz capsule 25 oxygen deprivation 25 orbiter 24 interstellar 24 space shuttle Endeavour 24 Soyuz spacecraft 24 Hawking 24 simulated 24 Space Shuttle 24 Virgin Galactic 24 Wakata 24 Earth orbit 23 orbital outpost 23 Mission Control 23 Space Shuttle Discovery 23 spacewalking astronauts 23 spacewalker 23 Russian Soyuz spacecraft 23 space shuttle Discovery 22 Space Shuttle Endeavour 22 Shuttle Discovery 22 Scaled Composites 22 Fincke 22 simulator 22 disorientation 22 spacewalk 22 Cape Canaveral Fla. 22 capsule 22 airlock 22 simulate 21 Mars rover 21 spacewalks 21 Mars Rover 21 Atlantis 21 liftoff 21 Orbiter 21 orbiting lab 21 Russian Soyuz 21 Red Planet 21 airship 21 Mars 20 Mike Fincke 20 jetpack 20 Eileen Collins 20 Melvill 20 lunar surface 19 blastoff