| Acronym | Meaning |
| P&M | Pulse Modulation |
| FMOFEV | First Manned Orbital Flight With EVA |
| HCL | Horizontal Centerline |
| TCSSS | Thermal Control Subsystem Segment |
| EFF | Efficiency |
| SOTS | Suborbital Tank Separation |
| IDU | Interface Demonstration Unit |
| TGSE | Telemetry Ground Support Equipment |
| INTF | Interface |
| PM | PMADPerformance Monitor Annunciation Driver |