| Abbreviation | Definition |
|---|---|
| TIS | Test Interface Subsystem |
| TISP | Teacher In Space Project |
| TISRS | Tether Initiated Space Recovery System |
| TIW | Test Issue Work-out |
| TJC | TraJectory Chart |
| TJF | Test Jack Field |
| TK | Tank |
| TK | Test Kit |
| TKSC | Tsukuba Space Center |
| TKU | The Known Universe |
| TL | Thrust Level |
| TL | Time Latest |
| TL | Traceability Lot |
| TL | Transient Load |
| TLAN | TPOCC Local Area Network |
| TLC | TeLeCommand |
| TLCE | Transmission Line Conditioning Equipment |
| TLD | ThermoLuminescent Dosimeter |
| TLI | Trans Lunar Injection |
| TLM | Telemetry |