| Abbreviation | Definition |
|---|---|
| SFTWR | SoFTWaRe |
| SFU | Standard Firing Unit |
| SFW | SoFtWare |
| SFWE(M) | Static Feed Water Electrolysis (Module) |
| SG | Signal Generator |
| SGC | Stabilized Ground Cloud |
| SGG | Superconducting Gravity Gradiometer |
| SGGM | Superconducting Gravity Gradiometer Mission |
| SGL | Space Ground Link |
| SGLS | Space Ground Link Station |
| SGLS | Space Ground Link System |
| SGMT | Simulated Greenwich Mean Time |
| SGOS | Shuttle Ground Operations Simulator |
| SGP | Single Ground Point |
| SGR | Soft Gamma Ray |
| SGS | Space Gateway Support |
| SGS | Steep Glide Slope |
| SGSC | Strain Gauge Signal Conditioner |
| SGSS | Solar Generator Subsystem |
| SH | Super Heat |