| Abbreviation | Definition |
|---|---|
| MSL | Mechanical Systems Laboratory |
| MSLD | Mass Spectrometer Leak Detector |
| MSM | Manned Support Module |
| MSME | Medical, Space, and Mission Electronics |
| MSO | Model for Spares Optimization |
| MSOB | Manned Spacecraft Operations Building |
| MSOB | Manned Spacecraft Operations Building (O&C preferred) |
| MSOCC | Multisatellite Operations Control Center |
| MSOIN | Minor Subcontractor or IDWA Notification |
| MSR | Mars Sample Return |
| MSR | Module Support Rack |
| MSR | Monthly Status Report |
| MSRT | Multistage Shuttle Run Test |
| MSS | Maintenance Status System |
| MSS | Manufacturers Standardization Society |
| MSS | Mechanical Support System |
| MSS | Message Switching System |
| MSS | Mission Specialist Station |
| MSS | Mission Status Summary |
| MSS | Mobile Service Structure |