| Abbreviation | Definition |
|---|---|
| RLCD | Redline Cutoff Device |
| RLEO | Request Liaison Engineering Order |
| RLF | Relief |
| RLG | Research Libraries Group |
| RLO | Rack Level Outgassing |
| RLSS | Regenerative Life Support System |
| RLT | Return Line Tether |
| RLV | Reusable Launch Vehicle |
| RM | Reconfiguration Module |
| RM | Redundancy Management |
| RM | Reference Mission |
| RM | Remote Manipulator |
| RM | Rendezvous Maneuver |
| RM | Rescue Module |
| RM | Right Mid |
| RM/MS&C | Redundancy Management/Moding, Sequencing, and Control |
| RMA | Remote Manipulator Arm |
| RMC | Redundancy Management Control |
| RMCD | Radiation Monitoring Container Dosimeter |
| RMF | RCS Module Forward |