on c - orga
- orbiting primate spacecraft
- orbiting radio astronomical observatory
- orbiting radio beacon ionospheric satellite
- orbiting recombination ramjet
- orbiting repeater
- orbiting satellite
- orbiting solar observatory
- orbiting space laboratory
- orbiting telescope
- orbiting vehicle
- orbiting velocity meter
- orbiting weapon
- order board
- order book
- order for attack
- order for defense
- order in battery
- order of battle
- ordered
- orderly
- ordinary atmospheric conditions
- ordnance air physics laboratory
- ordnance assembly building
- ordnance depot
- ordnance factory
- ordnance field depot
- ordnance guided missile maintenance company
- ordnance guided missile management orientation courses
- ordnance guided missile operations officer courses
- ordnance magazine
- ordnance piece mark
- ordnance plant
- ordnance repair shop
- ordnance special weapons depot
- ordnance supply
- ordnance unit
- ordnance vehicle
