| Abbreviation | Definition |
|---|---|
| PROC | Processor |
| PROC | Procurement |
| PROG | Program |
| PROJ | Project |
| PROP | Propellant |
| PROP | Proportioning |
| PROP | Propulsion |
| PROP | Propulsion Engineer |
| PROPLT | Propellant |
| PROTO | Private Rocket To Orbit Tiny Objects |
| PROX | PROXimity |
| PRPS | Programming Requirements Process Specification |
| PRR | Parts Replacement Request |
| PRR | Preliminary Requirements Review |
| PRR | Program Requirements Review |
| PRR | Pulse Repetition Rate |
| PRS | Payload Retention Subsystem |
| PRS | Payload Rotation Stand |
| PRS | Personnel Rescue Service |
| PRS | Personnel Rescue System |