11K views · 142 reactions | Whether it’s before launch, just after liftoff, or deep into the mission, timing is everything in spaceflight. In this episode of “Nerdy Words,” the SLS (Space Launch System) team breaks down three timekeeping terms that help NASA track every moment of a mission. Watch here to learn more about T-minus, T-plus, and Mission Elapsed Time (MET). | NASA's Marshall Space Flight Center | Facebook