| Abbreviation | Definition |
|---|---|
| SIU | Signal Interface Unit |
| SIV | Saturn IV Rocket |
| SIV | Sieve |
| SIV-B | Saturn IV-B Rocket |
| SIVE | Shuttle Interface Verification Equipment |
| SIW | Space Internet Workshop |
| SKD | Singer, Kearfott Division |
| SKE | Schwarzchild Kinematical Explorer |
| SKIRT | Shuttle Kientic Infrared Test |
| SL | Sea Level |
| SL | Seal |
| SL | Service Level |
| SL | Shelf Life |
| SL | Sound Level |
| SL | Spacelab |
| SL&I | System Load and Initialization |
| SLA | ERNO Spacelab Product Assurance Department |
| SLA | Shuttle Laser Altimeter |
| SLA | Super Light Ablator |
| SLA | Support and Logistics Areas |