MECO (Main Engine Cut-Off)

MECO (Main Engine Cut-Off) marks the shutdown of the first stage's main engines, occurring when the stage has either exhausted its propellant or reached the target velocity for staging. It is immediately followed by stage separation and second-stage engine ignition (SES-1). On Falcon 9, MECO occurs 2.5 minutes after launch at roughly 80 km altitude and 6,000 km/h. The term originated with the Space Shuttle program, where MECO referred to the shutdown of the three SSMEs 8.5 minutes into flight. After MECO, Falcon 9's first stage begins its recovery sequence — boostback burn, re-entry burn, and landing burn.