| Abbreviation | Definition |
|---|---|
| OSMP | Operational Support Maintenance Plan |
| OSO | Ocean Systems Operation |
| OSO | Orbiting Solar Observatory |
| OSO-1 | Orbiting Solar Observatory 1 |
| OSO-2 | Orbiting Solar Observatory 2 |
| OSO-3 | Orbiting Solar Observatory 3 |
| OSO-4 | Orbiting Solar Observatory 4 |
| OSO-5 | Orbiting Solar Observatory 5 |
| OSO-6 | Orbiting Solar Observatory 6 |
| OSO-7 | Orbiting Solar Observatory 7 |
| OSO-8 | Orbiting Solar Observatory 8 |
| OSOP | Orbiter Systems Operating Procedures |
| OSP | Operations Support Plan |
| OSP | Orbital Space Plane |
| OSR | Obital Ship Repair |
| OSR | Operations Support Room |
| OSS | OEX (Orbiter Experiments) Support System |
| OSS | Office of Space Science |
| OSS | Operational Support System |
| OSS | Optics Sub-System |