Related by context. Frequent words. (Click for all words.) 53 spaceflight 51 microgravity 50 Koichi Wakata 49 muscle atrophy 48 Piers Sellers 47 International Space Station 47 Nicole Stott 47 ESA astronaut 46 zero gravity 46 astronauts 46 Gravity Probe B 46 lunar missions 46 orbiting laboratory 46 Bob Thirsk 45 spaceflights 45 Greg Chamitoff 45 weightlessness 45 Hubble servicing 45 NASA Astronaut 45 Eyharts 44 Wakata 44 cosmonauts 44 Caldwell Dyson 44 NASA Space Shuttle 44 cosmic radiation 44 shuttle Atlantis 44 astronaut Peggy Whitson 44 Dan Tani 43 Lonchakov 43 Orion spacecraft 43 human spaceflight 43 Yurchikhin 43 Leroy Chiao 43 orbiting complex 43 astronaut 43 Krikalev 43 spacecraft 43 physiological 43 spacewalks 43 CALIPSO 43 NASA astronaut 43 NASA 43 orbital 42 peripheral neuropathies 42 Shuttle astronauts 42 taikonauts 42 Space Station 42 Robonaut 2 42 AEHF 42 space shuttle 42 GOCE 42 Iridium NEXT 42 Astronauts 42 Eric Boe 42 director Holly Ridings 42 Kaleri 41 Atlantis astronauts 41 Space Shuttle Endeavour 41 LASP 41 Heidemarie Stefanyshyn Piper 41 Flight Engineer 41 spacesuits 41 Oleg Skripochka 41 Space Shuttle Atlantis 41 oxygen uptake 41 Flight Readiness 41 Oleg Kononenko 41 Space Shuttle Program 41 spacewalking 41 Space Shuttle 41 Daniel Tani 41 orbiting outpost 41 orbiting 41 Shenzhou VI 41 orbit insertion 41 Shuttle Endeavour 40 spacesuit 40 Readdy 40 JAXA 40 Mike Suffredini NASA 40 Mikhail Kornienko 40 commander Peggy Whitson 40 orbital outpost 40 John Grunsfeld 40 shuttle Discovery 40 orbiting telescope 40 Astronauts aboard 40 decompression sickness 40 ISS 40 lunar outpost 40 Astronaut 40 metabolic 40 Lyndin 40 based Midcourse Defense 40 Lee Archambault 40 spacewalk 40 AA commenter 40 Roskosmos 40 Baikonur Kazakhstan 40 Mission Specialists 40 orbiters