| SMES | Shuttle Mission Engineering Simulator | In English | |
| SMES | Shuttle Mission Evaluation Simulation | In English | |
| SMG | Space Flight Meteorology Group | In English | → Meteorology, climatology |
| SMIRR | Shuttle Multispectral Infrared Radiometer | In English | |
| SML | Spacecraft Markup Language | In English | → Programming languages |
| SMPTRB | Shuttle Main Propulsion Test Requirement Board | In English | → Organizations and associations |
| SMS | Synchronous Meteorological Satellite | In English | → Meteorology, climatology |
| SMS | Solar Maximum Satellite | In English | |
| SMS | Shuttle Mission Simulator | In English | |
| SMSCC | Shuttle Mission Simulator Computer Complex | In English | → Hardware |
| SMSG | Shuttle Maintenance Steering Group | In English | → Organizations and associations → Maintenance and logistics |
| SMTAS | Shuttle Modal Test and Analysis System | In English | |
| SMTF | Shuttle MIssion Trainer Facility | In English | |
| SMVP | Shuttle Master Verification Plan | In English | → Quality management |
| SMVRD | Shuttle Master Verification Requirements Document | In English | → Quality management |
| SN | Space Network | In English | → Astronomy |
| SNAP | Space Nuclear Auxiliary Power | In English | → Nuclear technology |
| SNIAS | Société Nationale Industrielle Aéronautique et Spatiale | In French | → Aeronautics, aircraft |
| SNPO | Space Nuclear Propulsion Office | In English | → Nuclear technology |
| SNS | Shuttle Network System | In English | |
| SNSO | Space Nuclear Systems Office | In English | → Nuclear technology |
| SO | Shuttle Operations | In English | |
| SO/SI | Space Operations and Scientific Investigation | In English | → Astronomy |
| SOAR | Shuttle Orbital Applications and Requirements | In English | |
| SOARS | Shuttle Operation Automated Reporting System | In English | → Knowledge management |
| SOC | Space Operations Center | In English | |
| SOC | Shuttle Operations Center | In English | |
| SOCAR | Shuttle Operational Capability Assessment Report | In English | → Quality management |
| SOCC | Shuttle Operations Computing Center | In English | → Computer science |
| SOCC | Satellite Operations Control Center | In English | |
| SOCH | Spacelab Orbiter Common Hardware | In English | → Hardware |
| SODB | Shuttle Operational Data Book | In English | |
| SODS | Shuttle Operational Data System | In English | → Data |
| SODS | Shuttle Operational Data Submittal | In English | → Data |
| SODS | Skylab Orbit-Deorbit System | In English | |
| SOF | Safety Of Flight | In English | → Aeronautics, aircraft |
| SOFT | Space Operations and Flight Technique | In English | → Aeronautics, aircraft |
| SOFT | Suborbit Flight Test | In English | → Aeronautics, aircraft |
| SOI | Space Object Identification | In English | |
| SOIS | Spacelab/Orbiter Interface Simulator | In English | → Human-computer interaction |
| SOM | Suborbital Mission | In English | |
| SOMS | Shuttle Orbiter Medical System | In English | → Medicine |
| SOP | Spacecraft Operations Plan | In English | |
| SOP | Spacelab Opportunity Payload | In English | |
| SOPC | Shuttle Operations and Planning Center | In English | |
| SOR | Stable Orbit Rendezvous | In English | |
| SOS | Synchronous-Orbit Satellite | In English | |
| SOSI | Space Operations Scientific Investigation | In English | |
| SOSMAN | Space Operations System Manifesting Program | In English | |
| SOSRM | Strap-On Solid Rocket Motor | In English | |
| SOT | Solar Optical Telescope | In English | → Astronomy |
| SOTS | Suborbital Tank Separation | In English | |
| SP | Solid Propellant | In English | |
| SPA | Space Processing Application | In English | |
| SPACE | Spacecraft Prelaunch Automatic Checkout Equipment | In English | |
| SPAD | Shuttle Payload Accommodation Document | In English | |
| SPADATS | Space Defense Acquisition and Tracking System | In English | → Military engineering |
| SPADCCS | Space Defense Command and Control System | In English | → Military engineering |
| SPADE | Space Acquisition Defense Experiment | In English | → Military engineering |
| SPADOC | Space Defense Operations Center | In English | → Military engineering |
| SPADS | Shuttle Problem Analysis Data System | In English | |
| SPAH | Spacelab Payload Accommodations Handbook | In English | |
| SPAN | Spacecraft Analysis | In English | |
| SPAR | Shuttle Pointed Autonomous Research | In English | |
| SPARS | Space Precision Attitude Reference System | In English | |
| SPART | Space Research And Technology | In English | → Astronomy |
| SPARTAN | Shuttle Pointed Autonomous Research Tool for Astronomy | In English | → Astronomy |
| SPAS | Space Pallet Satellite | In English | |
| SPAS | Shuttle Pallet Satellite | In English | |
| SPAS | Shuttle Pallet Applications System | In English | |
| SPAT | Satellite Performance Analysis Team | In English | |
| SPC | Shuttle Processing Contract(or) | In English | |
| SPF | Spacelab Processing Facility | In English | |
| SpFl | Spaceflight | In English | → Serial publications, periodicals |
| SPICE | Survey Probe Infrared Celestial Experiment | In English | → Astronomy |
| SPICE | Survey Program of Infrared Celestial Experiments | In English | → Astronomy |
| SPICE | Spacelab Payload Integration and Coordination in Europe | In English | |
| SPICE | Shuttle Payload Integration Cargo Evaluation | In English | |
| SPIDPO | Shuttle Payload Integration and Development Program Office | In English | |
| SPIF | Shuttle Payload Integration Facility | In English | |
| SPIF | Shuttle Processing Interface Facility | In English | |
| SPII | Shuttle Program Implementation Instruction | In English | |
| SPIMS | Shuttle Program Information Management System | In English | → Knowledge management |
| SPIRE | Spectral Infrared Rocket Experiment | In English | → Astronomy |
| SPIRIT | Spatial Infrared Telescope | In English | → Astronomy |
| SpMar | Space Markets | In English | → Serial publications, periodicals → Astronomy |
| SpMME | Space Medicine Medical Engineering | In English | → Serial publications, periodicals → Medicine |
| SPN | Shuttle Project Notice | In English | |
| SPO | Spacecraft Program Office | In English | |
| SPO | Shuttle Program Office | In English | |
| SPOC | Shuttle Portable On-Board Computer | In English | → Hardware |
| SPOC | Shuttle Payload Operations Contract | In English | |
| SPORTS | Simplified Payload/Orbiter Thermal Simulator | In English | |
| SPOT | Space Station Proximity Operations Trainer | In English | |
| SPOT | Système Probatoire d'Observation de la Terre | In French | → Earth sciences |
| SPOT | Système Probatoire pour l'Observation de la Terre | In French | → Meteorology, climatology |
| SPP | Solar Physics Payload | In English | → Astronomy |
| SPP | SImulation Planning Panel | In English | → Aeronautics, aircraft |
| SPPIL | Shuttle Preferred Pyrotechnic Items List | In English | |
| SpPol | Space Policy | In English | → Serial publications, periodicals → Astronomy |
| SpPow | Space Power | In English | → Serial publications, periodicals → Energy economics |
| SpRBu | Space Research Bulgaria | In English | → Serial publications, periodicals → Astronomy |
| SPRMD | Space Power Resources and Manufacturing Development | In English | → Serial publications, periodicals → Energy economics |
| SPS | Satellite Power System | In English | → Energy economics |
| SPS | Shuttle Procedures Simulator | In English | |
| SPS | Shuttle Processing Site | In English | |
| SPT | Stationnary Plasma Thruster | In English | → Electrical engineering |
| SPVPF | Shuttle Payload VeErtical Processing Facility | In English | |
| Spvw | Spaceview | In English | → Serial publications, periodicals → Astronomy |
| SQIDS | Satellite Quick-Look Interactive Display System | In English | → Human-computer interaction |
| SRAD | Space Radiator Assembly Demonstration | In English | |
| SRAD | Shuttle Radar Assembly Demonstration | In English | |
| SRAG | Space Radiation Analysis Group | In English | → Astronomy |
| SRB | Solid Rocket Booster | In English | |
| SRBAB | SRB Assembly Building | In English | |
| SRBARF | SRB Assembly And Refurbishment Facility | In English | |
| SRBDF | SRB Disassembly Facility | In English | |
| SRC | Sample Return Canister | In English | |
| SRD | Spacecraft Research Division | In English | |
| SRD | Shuttle Requirements Document | In English | |
| SRD | Shuttle Requirements Definition | In English | |
| SRF | Shuttle Refurbishment Facility | In English | |
| SRL | Space Radar Laboratory | In English | → Research institutes → Astronomy |
| SRM | Solid Rocket Motor | In English | |
| SRMS | Shuttle Remote Manipulator System | In English | |
| SRR | Shuttle Requirements Review | In English | |
| SRSS | Shuttle Range Safety System | In English | |
| SRT | Shuttle Requirements Traceability | In English | → Quality management |
| SRU | Space Replaceable Unit | In English | |
| SS | Space Station | In English | |
| SS | Space Segment | In English | |
| SS | Space Shuttle | In English | |
| SS | Shuttle System | In English | |
| SS&A | Space Systems and Applications | In English | |
| SSA | Shuttle Simulation Aircraft | In English | → Aeronautics, aircraft |
| SSA | Space Suit Assembly | In English | |
| SSAIAF | Space Systems Automated Integration and Assembly Facility | In English | |
| SSAT | Space Shuttle Access Tower | In English | |
| SSBR | Space-Based Radar | In English | → Telecommunications |
| SSBUV | Shuttle Solar Backscatter Ultraviolet | In English | |
| SSBUV | Shuttle Solar Backscatter Ultraviolet (experiment) | In English | → Astronomy |
| SSC | Shuttle System Contractor | In English | |
| SSCB | Space Station Control Board | In English | |
| SSCC | Space Station Control Center | In English | |
| SSCF | Space Station Control Facility | In English | |
| SSCHS | Space Shuttle Cargo Handling System | In English | |
| SSCL | Shuttle System Commonality List | In English | |
| SSCM | Space Station Cost Model | In English | → Prices |
| SSCSP | Space Shuttle Crew Safety Panel | In English | |
| SSD | Space Systems Division | In English | |
| SSD | Spacecraft Software Division | In English | → Software |
| SSDAC | Space Station Data Acquisition and Control | In English | → Data |
| SSDF | Space Science Development Facility | In English | → Astronomy |
| SSDS | Space Station Data System | In English | → Data |
| SSDSAS | Space Station Data System Architecture Study | In English | → Hardware → Data |
| SSE | Space Shuttle Engine | In English | |
| SSE | Space Support Equipment | In English | |
| SSE | Spacecraft Simulation Equipment | In English | |
| SSEOS | Space Station External Operations Simulator | In English | |
| SSEOS | Space Shuttle Engineering and Operations Support | In English | |
| SSF | Space Station Freedom | In English | |
| SSFCS | Space Shuttle Flight Control System | In English | |
| SSFGSS | Space Shuttle Flight and Ground System Specification | In English | |
| SSFL | Santa Susana Field Laboratory | In English | → Research institutes |
| SSFN | Space Station Flight Network | In English | |
| SSFP | Space Station Freedom Program | In English | |
| SSFS | Space Shuttle Functional Simulation | In English | |
| SSGDAC | Space Station Guidance, Dynamics, And Control | In English | |
| SSHA | Shuttle System Hazard Analysis | In English | |
| SSI | Space Segment Integration | In English | |
| SSIBD | Shuttle System Interface Block Diagram | In English | → Human-computer interaction |
| SSIP | Shuttle Student Involvement Project | In English | → Specialized or (poly)technical colleges → Higher education, universities |
| SSIS | Space Station Information System | In English | → Knowledge management |
| SSITP | Shuttle System Integrated Test Plan | In English | |
| SSLV | Standard Small Launch Vehicle | In English | |
| SSM | Spacecraft System Monitor | In English | → Human-computer interaction |
| SSM | Satellite Survivability Model | In English | |
| SSMB | Space Shuttle Maintenance Baseline | In English | → Maintenance and logistics |
| SSMC | Space Shuttle MIssion Control | In English | |
| SSME | Space Shuttle Main Engine | In English | |
| SSMEC | Space Shuttle Main Engine Controller | In English | |
| SSMECA | Space Shuttle Main Engine Controller Assembly | In English | |
| SSMTF | Space Station Man-Systems Training Facility | In English | → Education |
| SSMTF | Space Station Mockup and Trainer Facility | In English | |
| SSO | Space Shuttle Orbiter | In English | |
| SSODB | Space Station Operational Data Book | In English | |
| SSOP | Space Systems Operating Procedure | In English | |
| SSP | Space Shuttle Program | In English | |
| SSP | Space Station Program | In English | |
| SSP | Subsolar Point | In English | → Astronomy |
| SSPC | Spacelab Stored Program Command | In English | |
| SSPD | Shuttle System Payload Description | In English | |
| SSPD | Shuttle System Payload Definition | In English | |
| SSPD | Shuttle System Payload Data | In English | |
| SSPDA | Space Shuttle Payload Data Activity | In English | |
| SSPDS | Space Shuttle Payload Data Study | In English | |
| SSPE | Space Station Program Element | In English | |
| SSPF | Space Station Processing Facility | In English | |
| SSPF | Space Shuttle Programming Facility | In English | → Software |
| SSPF | Sortie Software Production Facility | In English |
|