| Acronym | Meaning |
![](file.png) | OAS | Orbiter Aeroflight Simulator |
![](file.png) | OAS | Orbiter Atmospheric Simulator |
![](file.png) | OAS | Orbiter Avionics System |
![](file.png) | OASCB | Orbiter Avionics Software Control Board |
![](file.png) | OASIS | Oceanic And Atmospheric Scientific Information System |
![](file.png) | OASPL | Overall Sound Pressure Level |
![](file.png) | OAST | Office Of Aeronautics And Space Technology |
![](file.png) | OAT | Operational Acceptance Test |
![](file.png) | OAT | Overall Test |
![](file.png) | OB | Onboard |
![](file.png) | OB | Operational Base |
![](file.png) | OB | Outboard |
![](file.png) | OBC | Onboard Computer |
![](file.png) | OBCO | Onboard Checkout (Instrumentation) |
![](file.png) | OBCS | Onboard Checkout Subsystem |
![](file.png) | OBS | Observe |
![](file.png) | OBS | Operational Bioinstrumentation System |
![](file.png) | OBS | Operational Bioinstrumentation System |
![](file.png) | OBS | Operational Biomed Sensors |
![](file.png) | OBS | Operational Biomedical System |
![](file.png) | OBV | Oxidizer Bleed Valve |
![](file.png) | OC | On Center |
![](file.png) | OC | On-Condition |
![](file.png) | OC | Open Circuit |
![](file.png) | OC | Orbital Check |
![](file.png) | OC | Overcurrent |
![](file.png) | OC | Quality Control |
![](file.png) | OCALC | Oklahoma City Air Logistics Center |
![](file.png) | OCC | Office Of Contract Compliance |
![](file.png) | OCC | Operations Control Center |
![](file.png) | OCD | Operational Capability Development |
![](file.png) | OCDR | Orbiter Critical Design Review |
![](file.png) | OCDU | Optics Coupling Data Unit (G&N) |
![](file.png) | OCE | Ocean Color Experiment |
![](file.png) | OCF | Onboard Computational Facility |
![](file.png) | OCF | Orbiter Computational Facilities |
![](file.png) | OCH | Orbiter Common Hardware |
![](file.png) | OCM | Organic Content Monitor |
![](file.png) | OCN | Order Control Number |
![](file.png) | OCO | OMS Cutoff |
![](file.png) | OCO | Open-Close-Open |
![](file.png) | OCP | Output Control Pulse |
![](file.png) | OCR | Optical Character Recognition |
![](file.png) | OCRM | Orbiter Crash And Rescue Manuals |
![](file.png) | OCS | Onboard Checkout System |
![](file.png) | OCT | Octal |
![](file.png) | OD | Operational Downlink/Downlist |
![](file.png) | OD | Operations Directive |
![](file.png) | OD | Outside Diameter |
![](file.png) | OD | Oxygen Drain |