[jzila]

Potential energy is energy, so it's not quite correct that New Shepard had 0 joules at 100km. At 100km and 0 velocity it'll have about 1 gigajoule of energy per metric ton of mass.

[lutefisk]

Potential energy is not energy that you can give to a payload unless you want to have it fall 100km back to earth.

[jzila]

Sure, but it's energy that a rocket needs to impart nevertheless.