The answer depends on many factors, including the amount of fuel needed, the moon's orbit and the mission's objectives.

Customers send Ben Bosworth all types of items to be put into custom rings. His business was recently tasked with incorporating a piece of history — part of the Apollo 11 spacecraft — into a ring.

Apollo 17 became the last mission to launch humans on the moon. With two astronauts on board, the lunar module Challenger ...