| Abbreviation | Definition |
|---|---|
| PCS | Pressure Control System |
| PCS | Primary Coolant System |
| PCS | Procedure Completion Sheet |
| PCT | Percent |
| PCTC | Payload Crew Training Complex |
| PCTE | Portable Commercial Test Equipment |
| PCTO | Payload Cost Tradeoff Optimization |
| PCTR | Pad Connection Terminal Room |
| PCU | Payload Checkout Unit |
| PCU | Power Control Unit |
| PCU | Pressure Control Unit |
| PCU | Process Control Unit |
| PCV | Precheck Verification |
| PCV | Pre-Check Verification |
| PCV | Purge Control Valve |
| PCVB | Pyro Continuity Verification Box |
| PCVL | Pilot Controlled Visual Landing |
| PD | Pitch Down |
| PD | Preliminary Design |
| PD | Procurement Document |