| Acronym | Meaning |
 | MSEC | Millisecond |
| MSF | Maintenance Source File |
| MSF | Manned Space Flight |
| MSFC | George C. Marshall SPace Flight Center |
| MSFC | Marshall Space Flight Center |
| MSFN | Manned Space Flight Network |
| MSFP | Manned Space Flight Program |
| MSG | Mechanical Subsystem Group |
| MSG | Message |
| MSG | Mission SupportGroup |
| MSI | Maintenance Significant Items |
| MSI | Medium Scale Integration |
| MSIA | Multispectral Image Analyzer |
| MSID | Measurement Stimulation Identification |
| MSK | Manual Select KeYboard |
| MSL | Mean Sea Level |
| MSL | Mechanical System(s) Laboratory |
| MSL | Missile |
| MSLD | Mass Spectrometer Leak Detector |
| MSM | Manned SupportModule |
| MSN | Mission |
| MSO | Model For Spare(s) OPtimization |
| MSOB | Manned Spacecraft Operations Building (O&C Preferred) |
| MSOCC | Multisatellite Operations Control Center |
| MSOIN | Minor Subcontractor Or IDWA Notification |
| MSR | Module Support Rack |
| MSS | Maintenance Status System |
| MSS | Manufacturers Standardization Society |
| MSS | Mechanical Support Systems |
| MSS | Mission Status Summary |
| MSS | Mission Specialist Station |
| MSS | Mobile Service Structure |
| MSS | Multispectral Scanner System |
| MST | Measurement Status Table |
| MST | Mobile Service Tower |
| MST | Module Service Tool |
| MST | Mountain Standard Time |
| MSTR | Master |
| MSU | Mass Storage Unit |
| MSU | Measuring Stimuli Units |
| MSV | Monitored Sine Vibration (Test) |
| MSVP | Master Shuttle Verification Plan |
| MSW | Microswitch |
| MT | Magnetic Tape |
| MT | Master Timer |
| MT | Master Tool |
| MT | Maximum Torque |
| MT | Mean Time |
| MT | Mechanical Technician |
| MT | Mission Time |
Browse by Letter:
