liftoff

noun3

1. •
   The point in the launch of a rocket or an aircraft where it leaves contact with the ground.

   • we have liftoff [in narration of launches]
2. •
   The point at which a person or animal leaves the ground, as for example when jumping.

   • As she was on her approach to the hoop, taking that first Jordanesque liftoff step, her mouth guard fell floorward. Undeterred, she kept going up with the ball in her right hand. — 2011
3. •
   (figurative) The point of launching into success or action.