| Abbreviation | Definition |
|---|---|
| AGSS | Attitude Ground Support System |
| AHU | Air Handling Unit |
| AI | Associate Investigator |
| AIM | Aeronomy of Ice in the Mesosphere |
| AIM | Automated Informed Maintenance |
| AIMS | Automated Informed Maintenance System |
| AIO | Analog Input/Output |
| AIRS | Atmospheric Infrared Sounder |
| AIS | Action Item Sheet |
| AIS | Air Injection System |
| AIS | Airlock Illumination Subassembly |
| AIS | Analog-In Single-ended |
| AIS | Automated Information Security |
| AIS | Automated Inspection System |
| AIST | Agency of Industrial Science and Technology |
| AIT | AerITalia |
| AIT | Assembly, Integration and Test |
| AIT | Astronauts In Trouble |
| AIT | Atomic International Time |
| AIU | Abort Interface Unit |