| Abbreviation | Definition |
|---|---|
| EGRET | Energetic Gamma Ray Explorer Telescope |
| EGRS | EGResS |
| EGSE | Electrical Ground Support Equipment |
| EGT | Elapsed Ground Time |
| EGT | Estimated Ground Time |
| EGUN | Electron GUN (fast pulse) |
| EH/M | Extension Hose/Mouthpiece |
| EHC | Electrical Heating Control |
| EHOT | External Hydrogen/Oxygen Tank |
| EHP | Effective HorsePower |
| EHP | Electron-Hole Pair |
| EHP | Extended High Power |
| EHPC | Extended High Priority Command |
| EHR | Earned Hour Ratio |
| EHS | Enhanced HOSC (Huntsville Operations Support Center) System |
| EHS | Environmental Health Services |
| EHX | Experiment Dedicated Heat Exchanger |
| EI | Electromagnetic Interference (irregular form, usually EMI) |
| EI | Electronic Interface |
| EI | End Item |