| Abbreviation | Definition |
|---|---|
| JSA | Job Safety Analysis |
| JSC | Johnson Space Center |
| JSC | Lyndon Baines Johnson Space Center |
| JSCM | Johnson Space Center Manual |
| JSCM | JSC Manual |
| JSFC | Johnson Space Flight Center |
| JSL | Jet Select Logic |
| JSLWG | Joint SpaceLab Working Group |
| JST | Joint Systems Test |
| JSV | Joint Space Vehicle |
| JTA | Job Task Analysis |
| JTG | Joint Training Group |
| JTS | Jet Thrust Stoichiometric |
| JU | Joint Use |
| JULIE | Joint Utilization of Laser Integrated Experiments |
| JUP | Jupiter |
| JURG | Joint Users Requirements Group |
| JWST | James Webb Space Telescope |
| JWY | John Watts Young, Astronaut |
| JXV | Jupiter Satellite 15, Adrastea |