Engine cutoff (ECO) marks the commanded or automatic shutdown of a rocket engine during ascent or a specific burn. It occurs when a vehicle reaches its target velocity, when propellant is depleted, or if a critical fault is detected by the flight computer. Precise timing of the cutoff is required to place a payload into the correct orbit or trajectory.
Heard on the job
We have confirmed nominal ECO on the first stage, standing by for stage separation.