| O.B. |
Operation Blackboard |
| O.B.C. |
Other Backward Classes |
| O.I.L. |
Oil India Limited |
| O.M. |
Order of Merit |
| OA |
Object Address |
| OA |
Output Axis |
| OA |
Orbital Assembly |
| OA |
Operational Instrumentation MDM-Aft |
| OA |
Operational Aft |
| OA |
Office of Applications |
| OAA |
Orbiter Alternate Airfield |
| OAA |
Orbiter Access Arm |
| OACES |
Ocean-Atmosphere Carbon Exchange Study |
| OAE |
Ohio Award for Excellence |
| OAFD |
Orbiter Atmospheric Flight Test Office |
| OAFTO |
Ogden Air Logistics Center |
| OAG |
Official Airline Guide |
| OAL |
Oem Adaptation Layer |
| OALC |
Orbital Attitude and Maneuvering System |
| OALT |
Operational Acceptable Level of Traffic |
| OAM |
Order of Australia Medal |
| OAME |
Own Account Manufacturing Enterprise |
| OAMP |
Oklahoma Agriculture Mediation Program |
| OAMS |
Orbiter Ancillary |
| OANS |
Orbiting Astronomical Observatory |
| OAO |
Office of Advanced Research and Technology |
| OAO |
Orbiting Astronomical Observatory |
| OAO-3 |
Orbiter Avionics System |
| OAPECO |
Organisation of Arab Petroleum Exporting Countries |
| OARE |
Orbital Acceleration Research Experiment |
| OARG |
Osteoporosis And Arthritis Research Group |
| OART |
Orbiter Atmospheric Simulator |
| OAS |
Organisation of American States |
| OAS |
Orbiter Aeroflight Simulator |
| OAS |
Office Automation System |
| OAS |
Orbiter Avionics Software Control Board |
| OAS |
Operational Analysis And Simulation Of Integrated Systems |
| OAS |
Organization Of American States |
| OASCB |
Oceanic and Atmospheric Scientific Information System |
| OASIS |
Old Age Social and Income Security |
| OASPL |
Overall Sound Pressure Level |
| OAST |
Office of Aeronautics and Space Technology |
| OAT |
Operational Acceptance Test |
| OAT |
Outside Air Temperature |
| OATS |
Osteochondral Autograft Transfer System |
| OAU |
Organisation of African Unity |
| OAW |
Off-airway Weather Station |
| OB |
Operation Blackboard |
| OBA |
Oxygen Breathing Apparatus |
| OBC |
Other Backward Classes |