| Abbreviation | Definition |
|---|---|
| MER | Mars Exploration Rover |
| MER | Meridian |
| MER | Mission Evaluation Room |
| MERB | Materials and Engineering Review Board |
| MERL | Materials Engineering Research Laboratory |
| MERL | Materials Equipment Requirement List |
| MERLIN | Multi Element Radio Linked Interferometer Network |
| MERSAT | Meteorology and Earth Observation Satellite |
| MERU | Milliearth Rate Unit |
| MERU | Milli-Earth Rate Unit |
| MES | Main Engine Start |
| MES | Mated Elements Simulator |
| MES | Mated Events Simulator |
| MES | Mission Events Sequence |
| MESA | Marshall Engineers and Scientists Association |
| MESA | Miniature Electrostatic Accelerometer |
| MESA | Miniature Electro-Static Accelerometer |
| MESA | Modular Equipment Stowage Assembly |
| MESA | MSFC (Marshall Space Flight Center) Engineering Support Area |
| MESA | MSFC Engineering Support Area |