| Abbreviation | Definition |
|---|---|
| HAL | High-order Assembly Language |
| HAL/S | High-order Assembly Language/Shuttle |
| HALCAM | Helix Alpha Longitudinal Corrective Automated Mission |
| HALD | High-Altitude Long-Duration |
| HALEX | HAlogen Lamp EXperiment |
| HALO | High Altitude Logistics Orbital |
| HALO | High-Altitude Long Operation |
| HALOE | HALogen Occultation Experiment |
| HALW | Highly-Active Liquid Waste |
| HAM | Height Adjustment Maneuver |
| HAMP | High-Altitude Mission Planner |
| HAO | High-Altitude Observatory |
| HAP | Hardware Allocation Panel |
| HAP | Heuristic Astronomy Project |
| HAP | High-Altitude Platform |
| HAPI | High-Altitude Plasma Instrument |
| HAPS | High-Altitude Platform System |
| HARP | High-Altitude Research Program |
| HARP | Hyperbolic Analyzer Retarding Potential |
| HAS | Holddown Alignment Support |