| Acronym | Meaning |
| DPP | Data Processing Software System |
| EMU | Extravehicular Mobility Unit |
| FPS | Flight Per Second |
| TE | Time Earliest/Expected |
| SSC | L Shuttle System Commonality List |
| IOA | Input/Output Or Assembly |
| IDU | Interface Demonstration Unit |
| BFS | Backup Flight System |
| R | Ratio |
| ESRO | European Space Research Organization |