| Abbreviation | Definition |
|---|---|
| ACBM | Active Common Berthing Mechanism |
| ACC | Aft Cargo Carrier |
| ACCA | Automatic Cloud Cover Assessment |
| ACCMS | Advanced Checkout, Control, and Maintenance System |
| ACCS | Advanced Checkout and Control System |
| ACE | Advanced Composition Explorer |
| ACE | Apollo Checkout Equipment |
| ACES | Acoustic Containerless Experiment System |
| ACF | Auto-Correlation Function |
| ACFS | Advanced Concepts Flight Simulator |
| ACIO | Agency Chief Information Officer |
| ACIP | Assembly Configuration and Integration Panel |
| ACLUF | American Civil Liberties Union Foundation |
| ACO | Assembly and Checkout Officer |
| ACP | Automated Change Processing |
| ACR | Active Cavity Radiometer |
| ACR | Apollo Cosmetic Reconstruction |
| ACR | Astronaut Crew Rescue |
| ACR | Attitude Controlled Re-entry |
| ACRBC | Acceptance, Checkout, Retest, and Backout Criteria |