Many people mistakenly believe that the astronauts who orbit Earth are "above gravity." Earth's mass is 6×1024kg, and its radius is 6.38×106m (6380 km).
Use the inverse-square law to find a height above Earth's surface at that the force of gravity on a shuttle is about 89 % that at Earth's surface.
1 answer
(6.38E6)² / .89 = (6.38E6 + h)²