extr - fear
- extra crew member
- extra-atmospheric source
- extra-cockpit visual simulation
- extra-foveal vision
- extracabin sensory field
- extracellular fluid space
- extrajection
- extraneous sensory event
- extraocular muscle
- extraphysical
- extrapsychic
- extrapsychic factor
- extrapunitiveness
- extrasensory
- extratcnsiveness
- extraterrestrial biology
- extraterrestrial environment
- extraterrestrial flight
- extraterrestrial life
- extraterrestrial life form
- extraterrestrial life search
- extraterrestrial matter
- extraterrestrial resource
- extraterrestrial space
- extravehicular
- extravehicular (space) suit
- extravehicular activity
- extravehicular activity time
- extravehicular astronaut
- extravehicular excursion
- extravehicular flight
- extravehicular gloves
- extravehicular maneuver
- extravehicular mobility
- extravehicular mobility unit
- extravehicular operation
- extravehicular propulsion apparatus
- extravehicular protective system
- extravehicular scaphander
- extravehicular simulator
