| Acronym | Meaning |
| OPIS | Orbiter Prime Item Specification |
| M | Mach |
| PSS | Payload Support System |
| NP | Neptunium |
| LPOT | Low-pressure Oxidizer Turbopump |
| SIO | Systems Integration Office |
| CAR | Certification Approval Request |
| VA | Vibro-Acoustic Test |
| COM-M | Common Mode |
| SWAD | Subdivision Of Work Authorization Document |