anti - assi
- apparent mass analysis
- apparent noon
- apparent rotation
- apparent specific impulse
- apparent speed
- apparent vertical
- applicable
- applicant
- application of power
- application of servicing equipment
- application satellite
- application technology satellite range and range rate
- applied materials and physics division
- applied moment
- applied research
- applied research branch
- applied space science
- applied torque vector
- appression
- approach
- approach angle
- approach azimuth
- approach azimuth antenna offset
- approach beacon
- approach computer
- approach control
- approach control office
- approach corridor
- approach elevation
- approach facility
- approach flow
- approach intercept point
- approach light contact height
- approach light system
- approach lighting
- approach lighting system
- approach procedure track
- approach progress display
- approach ramp building
- approach reference datum
