| Abbreviation | Definition |
|---|---|
| REM | Release Engine Mechanism |
| REM | Release Engine Module |
| REM | Release Escape Mechanism |
| REM | Release-Engage Mechanism |
| REM | Remove |
| REM | Rocket Engine Module |
| REM | Roentgen Equivalent Man |
| REND | Rendezvous |
| RENRAD | Rendezvous Radar |
| REPGROW | Effects of Spatial Environment on the Reproduction and Growth of Bacteria |
| REPL | Replace |
| REPR | Repressurization |
| REPRO | Reproduction |
| REPT | Relativistic Electron Proton Telescope |
| REQD | Required |
| REQMTS | Requirements (RQMTS preferred) |
| REREX | Remote Readout Experiment |
| RES | Reserve |
| RES | Reservoir |
| RESID | Residual |