Agricultural Research Service 
Air Rescue Service 
Automatic Restraint System 
Automatic Route Selection 
Adaptive Receptive System 
American Rocket Society 
Army Regulations 
Assignment Requests 
Access Routers 
Action Request System 
acute radiation syndrome 
Advanced Reconnaissance Satellite 
Advanced Record System 
Advanced Recovery System 
Air Reserve Station 
Air Revitalization System 
Alternate Route Selection 
American Radium Society 
amplified response spectrum 
Atmosphere Revitalization System 
Accruals Reporting System 
Active Repeater Satellite 
advance record system 
Advanced Reconnaissance System 
Aerial Reconnaissance and Surveillance 
aerial refueling store 
Agriculture Research Service 
Air Refueling Squadron 
Air Rescue Science 
Air Rescue Squadron