| Abbreviation | Definition |
|---|---|
| MMS | Modular Multiband Scanner |
| MMS | Multimission Modular Spacecraft |
| MMSE | Multiuse Mission Support Equipment |
| MMS-F | Matra Marconi Space-Tolouse, France |
| MM-SS | Minute:Second |
| MMT | Mass Memory Test |
| MMTBDS | Mobile Multi-Temperature Beverage Delivery System (NASA Coffee Mug) |
| MMU | Manned Maneuvering Unit |
| MNA | Main Bus A |
| MNB | Main Bus B |
| MNC | Main Bus C |
| MO | Major Objective |
| MO | Manned Orbiter |
| MO | Manual Orientation |
| MO | Manufacturing Order |
| MO | Mars Observer |
| MO | Master Oscillator |
| MO | Mid-deck Overhead |
| MO | Mission Operations |
| Mo | Molybdenum |