| Abbreviation | Definition |
|---|---|
| SEOS | Synchronous Earth Observation Satellite |
| SEP | Separation |
| SEP | Source Evaluation Panel |
| SEP | Support Electronics Package |
| SEP | Support Equipment Package |
| SEPAC | Space Experiment with Particle Accelerators |
| SEPAP | Shuttle Electrical Power Analysis Program |
| SEPAR | Shuttle Electrical Power Analysis Report |
| SEPB | Space Exploration Puzzle Book |
| SEPS | Solar Electric Propulsion System |
| SEQ | Safety, Environment, and Quality |
| SER | Serial |
| SER | Space Emergency Rescue |
| SERB | Shuttle Engineering Review Board |
| SERB | Systems Engineering Review Board |
| SERS | Shuttle Equipment Record System |
| SERV | Service |
| SERV | Single Stage Earth Orbital Reusable Vehicle |
| SERVO | Servomechanism |
| SES | Shuttle Engineering Simulation |