| S | Second | - | Organizations |
| S | Second (Astronomical Tables) | - | Organizations |
| S | Side | - | Organizations |
| S | Sta R | - | Organizations |
| S | Stere | - | Organizations |
| S | CHGSupercharge | - | Organizations |
| S | PRES Star Present | - | Organizations |
| S | TRKStar Tracker | - | Organizations |
| S&A | Safe And Arm (Device) | - | Organizations |
| S&A | Science And Application | - | Organizations |
| S&AD | Science And Applications Directorate | - | Organizations |
| S&E | Science And Engineering (MSFC Directorate) | - | Organizations |
| S-BD | S-Band | - | Organizations |
| S-N | Stress Number | - | Organizations |
| S/0 | Shutoff | - | Organizations |
| S/0 | Switchover | - | Organizations |
| S/8 | Standby | - | Organizations |
| S/A | Safe And Arm | - | Organizations |
| S/A | Scheduled/Actual | - | Organizations |
| S/A | Site Activation | - | Organizations |
| S/A | Spacecraft Adapter | - | Organizations |
| S/A | Subassembly | - | Organizations |
| S/AC | Stabilization/Attitude Control | - | Organizations |
| S/C | Sensor/Controller | - | Organizations |
| S/C | Signal Conditioner | - | Organizations |
| S/C | Software Contractor | - | Organizations |
| S/C | Spacecraft | - | Organizations |
| S/C | Splitter/Combiner | - | Organizations |
| S/C | Stabilization And Control | - | Organizations |
| S/C | Stripchart (Recorder) | - | Organizations |
| S/C | Subcontractor | - | Organizations |
| S/EOS | Standard Earth Observation Satellite | - | Organizations |
| S/F | Safety Factor | - | Organizations |
| S/F | Single Flow | - | Organizations |
| S/G | Strain Gage | - | Organizations |
| S/L | Shop/Laboratory | - | Organizations |
| S/M | Scheduled Maintenance | - | Organizations |
| S/M | Service/Maintenance | - | Organizations |
| S/M | Structural/Mechanical | - | Organizations |
| S/M | Systems Management | - | Organizations |
| S/N | Serial Number | - | Organizations |
| S/N | Signal-to-Noise Ratio | - | Organizations |
| S/P | Serial To Parallel | - | Organizations |
| S/P | Signal Processor | - | Organizations |
| S/R | Send And Receive | - | Organizations |
| S/R | Shift Register | - | Organizations |
| S/R | Stimulus/Response | - | Organizations |
| S/S | Samples Per Second | - | Organizations |
| S/S | Single Sideband | - | Organizations |
| S/S | Space Shuttle | - | Organizations |
| S/S | Subsystem | - | Organizations |
| S/SYS | Subsystem | - | Organizations |
| S/U | Set Up | - | Organizations |
| S/V | Space Vehicle | - | Organizations |
| S/V | SuPply Valve | - | Organizations |
| S/W | Software | - | Organizations |
| S@MSCC | Shuttle Mission Simulator Computer Complex | - | Organizations |
| S@MSCC | SYstem | - | Organizations |
| SA | Safing Area | - | Organizations |
| SA | Shaft Angle | - | Organizations |
| SA | Single Access | - | Organizations |
| SA | Site Activation | - | Organizations |
| SA | Subaccount | - | Organizations |
| SA | Supplemental Agreement | - | Organizations |
| SA | Support Area | - | Organizations |
| SAA | Safety Assurance Analysis | - | Organizations |
| SAA | South Atlantic Anomaly | - | Organizations |
| SAAC | Schedule Allocation And Control | - | Organizations |
| SAALC | San Antonio Air Logistics Center | - | Organizations |
| SAAM | Special Air Force Airlift Mission | - | Organizations |
| SAAMA | San Antonio Air Material Area | - | Organizations |
| SAAS | Shuttle Aerosurface Actuator Simulation | - | Organizations |
| SAB | SACstrategic Air Command(USAF) | - | Organizations |
| SAB | Shuttle Avionics Breadboard | - | Organizations |
| SAB | Spacecraft Assembly Building | - | Organizations |
| SAB | Storage And Assembly Building | - | Organizations |
| SACS | SADshuttle AuthorizedDocument | - | Organizations |
| SACS | Software Avionics Command SuPport | - | Organizations |
| SACS | Spacecraft Attitude Display | - | Organizations |
| SACS | SuPport Action Center | - | Organizations |
| SACS | SYstems AllocationDocument | - | Organizations |
| SACS | Systems Software Avionics Command SuPport | - | Organizations |
| SADEC | SAEsociety Of Automotive Engineers | - | Organizations |
| SADEC | SAEFspacecraft Assembly And EncaPsulation Facility | - | Organizations |
| SADEC | SAES | - | Organizations |
| SADEC | SAFESan Andreas Fault Experiment | - | Organizations |
| SADEC | Spin Axis Declination | - | Organizations |
| SADEC | Stand-Alone Engine Simulator | - | Organizations |
| SAEF | Spacecraft Assembly And Encapsulation Facility (KSC) | - | Organizations |
| SAG | E SAILShuttle Avionics Integration Laboratory | - | Organizations |
| SAG | E Stratospheric Aerosol Gas Experiment | - | Organizations |
| SAIL | Shuttle Avionics Integration Laboratory (JSC) | - | Organizations |
| SAL | SALCSacramento Air Logistics Center | - | Organizations |
| SAL | Scientific Airlock | - | Organizations |
| SAL | Shuttle Avionics Laboratory | - | Organizations |
| SAM | SAMPShuttle Automated Mass Properties | - | Organizations |
| SAM | SAMSShuttle Attachment ManiPulator SYstem | - | Organizations |
| SAM | Shuttle Attachment ManiPulator | - | Organizations |
| SAM | SYstem Activation And Monitoring | - | Organizations |
| SAMSO | Space And Missile SYstems Organization (USAF) | - | Organizations |
