| Abbreviation | Definition |
|---|---|
| MLR | Monodisperse Latex Reactor |
| MLRS | Monodisperse Latex Reactor System |
| MLW | Maximum Landing Weight |
| MLX | Merritt Island, Florida, Spaceflight Tracking Data Network station, Second Antenna |
| MM | Main Memory |
| MM | Main Module |
| MM | Major Mode |
| MM | Mass Memory |
| MM | Math Model |
| mm | milliMeter |
| MM | Mission Manager |
| MM | Module Mirror |
| MMA | Mass Memory Assembly |
| MMACS | Maintenance Management And Control System |
| MMACS | Maintenance, Mechanical Arm, and Crew System Engineer |
| MMAG | Martin Marietta Astronautics Group |
| MMC | Martin Marietta Corporation |
| MMC | Mid Motor Controller |
| MMC | Mission Management Center |
| MMCA | Midbody Motor Control Assembly |