Related by context. Frequent words. (Click for all words.) 73 weightlessness 68 microgravity 67 weightless 54 spacesuit 53 astronaut 50 outer space 50 International Space Station 50 cosmonauts 49 astronauts 49 spaceship 49 spacecraft 48 orbital 48 Astronauts 48 spacesuits 47 suborbital 46 spaceflight 46 Space Station 45 motion sickness 45 cosmonaut 44 interplanetary 44 robotic arm 43 lunar surface 43 orbit 43 NASA 43 hypersonic 43 NASA astronaut 42 space shuttle 42 Astronaut 42 flight simulator 42 simulated 41 Nasa 41 SpaceShipOne 41 Earth orbit 41 Space Shuttle Discovery 41 Soyuz 41 Wakata 41 spaceships 41 orbiting 40 cosmos 40 Russian cosmonauts 40 JAXA 40 orbiter 40 orbiting lab 40 spacewalk 40 lunar landing 40 Soyuz capsule 40 Mars 40 Hayabusa 40 shuttle 40 robotic 39 Hawking 39 Virgin Galactic 39 Mike Fincke 39 Huygens 39 Martian surface 39 midair 39 Space Agency 39 Mars rover 39 shuttle astronauts 39 earthbound 39 Padalka 39 simulator 39 robot 38 airship 38 Mission Control 38 SpaceShipTwo 38 Fincke 38 thruster 38 simulate 38 spacewalking astronauts 38 spacewalks 38 spacewalking 38 Spaceport 38 capsule 38 Chamitoff 37 Eileen Collins 37 Atlantis 37 X #B 37 Space 37 simulating 37 shuttle Discovery 37 Spacecraft 37 spherical 37 Saturn moon 37 Russian Soyuz 37 bungee 37 airlock 37 interstellar 37 space shuttle Discovery 36 lander 36 payload bay 36 Cape Canaveral Fla. 36 X #A 36 Space Shuttle 36 Soyuz TMA 36 Soyuz spacecraft 36 Red Planet 36 spacewalker 36 space 36 thrusters 36 Discovery astronauts