| Acronym | Meaning |
| EHR | Earned Hour Ratio |
| RSS | Reactants Supply System |
| VALID | Validation |
| GPS | Global Positioning Satellite |
| GT | Gyro Torque |
| TSLD | Troubleshooting Logic Diagram |
| MPC | Manual Pointing Controller |
| SCN | Specification Change Notice |
| IMU | Inertial Measurement Unit |
| MCP | Measurements Control Procedure |