Related by context. Frequent words. (Click for all words.) 44 space shuttle 39 Challenger 36 Space Shuttle Challenger 36 shuttle Challenger 35 Space Shuttle Columbia 35 teacher Christa McAuliffe 35 Rick Husband 33 shuttle 33 Space Shuttle 32 Kalpana Chawla 32 NASA 32 space shuttles 31 Christa McAuliffe backup 30 Shuttle 29 Challenger exploded 29 Christa McAuliffe 29 Astronaut 29 Chuck Yeager 28 June Scobee Rodgers 27 Sputnik satellite 27 Flight 27 NASA Space Shuttle 27 spacecraft 27 Hindenburg 27 Launius 26 Tibbets 26 STS 26 Discovery 26 orbiter 25 shuttle fleet 25 Space Shuttle Program 25 spaceship 25 McCool 25 Apollo 24 Endeavour 24 spacecrafts 24 McAuliffe 24 Sturckow 23 booster rockets 23 Launch Vehicle 23 heat shield 22 Readdy 22 Sputnik 22 rocketship 22 Concorde 21 foam 21 Hubble servicing 20 Soyuz 20 CEV 20 Leinbach 20 Canadair 19 lunar missions 19 Gehman 19 XCOR 19 Rocket 19 Columbia Accident Investigation 19 Rocketplane 18 Polansky 18 Endeavor 18 CAIB 17 Atlantis 17 Voyager 16 Launch Pad 16 Bresland 16 Bombardier Challenger 15 Scott Kalitta 15 Fendt 15 QF 15 Falcon 15 Cessna 15 Total Reads 14 Dave Villwock 13 Intrepid 13 Zina Garrison 12 Dent 11 Jet 11 Taurus 10 GSLV 10 Brengle 10 Runabout 9 powerboat 8 Victory 7 ATP Challenger 6 Kei Nishikori 6 Horizon 6 Challenger Gray 5 inboard 5 Kafelnikov 5 Hewitt 4 TSB 3 Astra 2 Challenger Gray & 2 Vijay Amritraj 1 Radisich 0 Allaster 0 Challengers 0 AC# [001] -1 Generation X -1 Velocity -2 Kantarian -4 Spectrem