MECO is also an acronym for Main Engine Cut-Off
, which is a crucial point during a Space Shuttle
launch. It signifies the point at which the main engines
on the orbiter
stop thrusting; at this point, the Shuttle has enough velocity to reach the planned orbit
either directly (called direct insertion
- ooo!) or using the OMS
Immediately after MECO, the External Tank is jettisoned and begins its fall back into the atmosphere. MECO typically occurs at around 68 or 69 miles of altitude.