| Abbreviation | Definition |
|---|---|
| HEI | High Energy Ignition |
| HEM | Hitchhike Experiment Module |
| HEMI | HEMIspherical antenna |
| HEMV | Helium Manual Valve |
| HEO | High Energy Orbit |
| HEOMD | Human Exploration and Operations Mission Directorate |
| HEPA | High Efficiency Particle Air |
| HEPA | High efficiency particulate air |
| HER | HIM (Hardware Interface Module) Equipment Rack |
| HERSCP | Hazardous Exposure Reduction and Safety Criteria Plan |
| HESS | High Energy Squib Simulator |
| HETM | Hybrid Engineering Test Model |
| HEX | Heat EXchanger |
| HEX | HEXadecimal |
| HF | Hard Failure |
| HF | Horizontal Flight |
| HF | Hot Firing |
| HF | Hydrogen Fill |
| HF | HyperFiltration |
| HFA | High Frequency Accelerometer |