| Acronym | Meaning |
| PDS | Power Distribution System (Subsystem) |
| SA | Support Area |
| PIL | Procurement Instrument Identification |
| DDDU | Digital Decoder Driver Unit |
| CIR | Cargo Integration Review |
| SSR | Staff SuPport Room |
| ETSS | External Tank Separation Subsystem |
| CCU | Crew Communications Unit |
| PDR | Preliminary Data Requirements |
| NHA | NNHA Next Higher Assembly |