| Acronym | Meaning |
| ATM | Apollo Telescope Mount (on Skylab) |
| EGRET | Energetic Gamma Ray Experiment Telescope |
| IGM | InterGalactic Medium |
| RTLS | Return To Launch Site |
| GSFC | Goddard Space Flight Center |
| CLAES | Cryogenic Limb Array Etalon Spectrometer |
| TOPS | Toward Other Planetary Systems |
| MMU | Manned Maneuvering Unit |
| RA | Right Ascension |
| SNR | Signal To Noise Ratio / SuperNova Remnant |