The launch sequence is managed through a precise timeline that counts backward to zero, known as T-minus time. It synchronizes hundreds of critical operations across different teams, from fueling the tanks to switching the vehicle to internal power. Built-in holds are often scheduled to allow teams to catch up on tasks or wait for better weather before the final automated sequence begins.
Heard on the job
We're picking up the countdown at T-minus four minutes and the board is green.
Related terms
T-minus
A countdown protocol indicating the time remaining before a scheduled launch or major sequence.
Launch window
The specific timeframe during which a spacecraft must lift off to reach its intended orbit or target.
Liftoff
The exact moment a rocket or aircraft breaks physical contact with the ground.