When it orbited the Moon, the Apollo 11 spacecraft's mass was 8640 kg, and its mean distance from the Moon's center was 2.53743 106 m. Assume its orbit was circu- lar and the Moon to be a uniform sphere of mass 7.36 1022 kg. Given the gravitational constant G is 6.67259 10-11 Nm2/kg, what is the min- imum energy required for the craft to leave the orbit and escape the Moon's gravitational field? Answer in units of J.