| Acronym | Meaning |
| SEDS | Students For The Exploration And Development Of Space |
| TOPEX | Ocean Topography Experiment |
| MPC | Minor Planets Circular |
| GUGK | Glavnoye Upravileniye Geodesii I Kartografii |
| LRB | Liquid Rocket Booster |
| SMS | Shuttle Mission Simulator |
| S | Spiral (for Galaxies) |
| ORFEUS | Orbiting And Retrievable Far And Extreme Ultraviolet Spectrometer |
| VLA | Very Large Array |
| TDT | Terrestrial Dynamic Time |