> SpaceX is attempting to have the rocket's vertical velocity reach zero at the exact moment the rocket reaches the pad It's definitely hard. It's also the fue

> SpaceX is attempting to have the rocket's vertical velocity reach zero at the exact moment the rocket reaches the pad It's definitely hard. It's also the fuel-optimal solution (referred to as a "suicide burn", http://space.stackexchange.com/questions/10307/what-is-a-suicide-burn http://space.stackexchange.com/questions/10307/what-is-a-sui...). So while it's a very difficult control solution to accomplish, being able to do it reliably translates to a significant savings in fuel cost and therefore one step closer to sustainable reusable rocketry.