Related by context. Frequent words. (Click for all words.) 33 Aldrin 31 Noguchi 30 Bolden 28 JPL 27 Zhai 26 Satcher 26 Chiao 25 Roco 25 Squyres 25 microgravity 24 Planetary Society 22 lunar surface 22 NASA 22 astronaut 21 Mars 21 weightlessness 21 Astronaut 21 lunar exploration 21 Hubble 21 Pontes 20 Melroy 20 Space Shuttle 20 Reisman 20 outer space 19 Nasa 19 Gerstenmaier 19 Grunsfeld 19 Wakata 19 Tani 18 lunar landing 18 Buzz Aldrin 18 human spaceflight 18 spacecraft 18 orbiter 17 astronauts 17 zero gravity 17 SPACE.com 17 spacewalker 17 Gagarin 17 Bowersox 17 moon 17 Fincke 17 NASA astronaut 17 Mars Rover 16 spacewalkers 16 space shuttle 16 Tondo 16 Dittemore 16 Discovery 15 spaceflight 15 shuttle missions 15 Parazynski 15 Sharipov 15 Constellation 15 Hayabusa 15 Armstrong 15 Alan Shepard 15 ISS 15 spacesuit 15 Space Station 15 Garriott 14 orbit 14 Mission Control 13 lunar orbit 13 Padalka 13 International Space Station 13 manned missions 13 Endeavour astronauts 13 Mike Fincke 13 Neil Armstrong 13 Baikonur 13 Shenzhou 12 Baikonur Cosmodrome 12 Soyuz 12 Space Shuttle Discovery 12 crewmates 12 Astronauts 12 NASA Administrator 12 space shuttles 12 manned spaceflight 12 Endeavour 12 manned spacecraft 12 Apollo 11 Massimino 11 Eileen Collins 11 Soyuz capsule 11 cosmonaut 10 Discovery astronauts 10 Atlantis 10 Heras 10 space 10 Soyuz TMA 9 Lopez Alegria 9 Yuri Gagarin 9 HTV 8 cosmonauts 7 moonwalk 7 Merckx 6 Solar Impulse 5 Russian cosmonauts 4 Mark Polansky