| Abbreviation | Definition |
|---|---|
| R | Recovery |
| R | Redundant |
| R | Regulate |
| R | Rehydratable |
| R | Reliability |
| R | Replace |
| R | Resistance |
| R | Right |
| R | Roentgen |
| R | Roll |
| R | Rugged |
| R | Yaw Rankine Rate |
| R&CC | Recorder and Communication Control |
| R&DO | Research and Development Operations (MSFC) |
| R&M | Reliability and Maintainability |
| R&OA | Reliability and Quality Assurance |
| R&P | Reserve and Process |
| R&PM | Research and Program Management |
| R&R | Remove and Replace |
| R&R | Rendezvous and Recovery |