| Abbreviation | Definition |
|---|---|
| OS | Orbital Servicing |
| OS | Orbiter Specification |
| OS | Outer Space |
| OSA | Operational Support Area |
| OSC | Office of Space Communications |
| OSC | Operations Support Center |
| OSC | Orbital Sciences Corporation |
| OSC | OSCillator |
| OSCAR | Outer Space Collector of Astronomical Radiation |
| OSCRS | Orbital Spacecraft Consumables Resupply System |
| OSDH | Orbiter System Definition Handbook |
| OSE | Operating Support Equipment |
| OSE | Operations Simulations Engineer |
| OSE | Orbital Support Equipment |
| OSE | Orbiter Support Equipment |
| OSF | Ordnance Storage Facility |
| OSFD | Office of Space Flight Development |
| OSHA | Occupational Safety and Health Act |
| OSLM | Operations Shop/Lab Manager |
| OSM | Orbital Service Module |