| Abbreviation | Definition |
|---|---|
| CL | Control Logic |
| CLA | Couple Loads Analysis |
| CLASS | CLASSification |
| CLC | Change Letter Control |
| CLC | Critical Load Cycle |
| CLCS | Checkout and Launch Control System |
| CLDST | Closed Loop Dynamic Stability Test |
| CLG | CeiLinG |
| CLIN | Contact Line Item Number |
| CLIP | Combined Laser Instrumentation Package |
| CLM | Care Logic Module |
| CLMC | Central Logistics Management Center |
| CLN | Change Leaders Network |
| CLNR | Cleaner |
| CLOC | Canadian Logistics Operation Center |
| CLRB | Cost Limit Review Board |
| CLS | Capsule Launch System |
| CLS | Closed Loop Stimulation |
| CLS | Contingency Landing Site |
| CLSO | Contingency Landing Support Officer |