Concept for a lunar He-3 transporter using an in-orbit modified shuttle external tank

A concept is presented for the transport of gaseous He-3 in temperature equilibrium with the liquid hydrogen and liquid oxygen in a modified lunar shuttle external tank. The concept first describes the internal modifications to accommodate He-3, and then, the external modifications to incorporate a propulsion system and an aerobrake. Estimates of the system masses and an assessment of propulsion requirements show the round trip capability. The concept also includes a description of the lunar orbit servicing and transfer operations.