| Abbreviation | Definition |
|---|---|
| SIAP | System Integrity Assurance Program |
| SIB | Saturn IB Rocket |
| SIC | Spacecraft Identification Code |
| SID | Shuttle Integration Device |
| SID | Simulator Interface Devices |
| SID | Spacecraft Identification Number |
| SID | Standard Interface Document |
| SID | System Interface Document |
| SIDT | Spacelab I/O (Input/Output) Data Tape |
| SIDT | Spacelab I/O Data Tape |
| SIE | Shuttle Interface Equipment |
| SIEM | Systems Integration Effort for MSFC |
| SIES | Supervision, Inspection, Engineering, and Services |
| SIG | Special Investigation Groups |
| SIGCONDR | Signal Conditioner |
| SIL | Safety Integrity Level |
| SIL | Silver |
| SIL | Sound Interference Level |
| SIL | Systems Integration Laboratory |
| SILTS | Shuttle Infrared Leeside Temperature Sensing |