| Abbreviation | Definition |
|---|---|
| SEICO | Support Equipment Installation and Checkout |
| SEII | Servoactuator Error Indication Interrupt |
| SEL | Select, Selector |
| SELDADS | Environment Laboratory Data Acquisition and Display System |
| SELSIS | Space Environment Laboratory Solar Imaging System |
| SEM | Sample Exchange Mechanism |
| SEM | Scanning Electron Microscope |
| SEM | Scanning electron microscopy |
| SEM | Seller's Engineering Memorandum |
| SEM | Space Environment Monitoring |
| SEM | Spacecraft Equipment Module |
| SEM | System Engineering Management |
| SEMA | Support Equipment Move Authorization |
| SEMS | Space Environment Monitor System |
| SEN | Sensor |
| SEND | Shared Equipment Need Date |
| SENS | SENSitivity |
| SEO | Special Engineering Order |
| SEO | State Engineer's Office |
| SEO | Subtransfer Earth Orbit |