This paper describes the design and features of a Scalable Orbital Propellant Depot
Design tool. The purpose of the tool is to enable others to easily test the effectiveness of
adding a propellant depot to an exploration architecture. Several options are available
including zero boil-off technology, usable propellant and depot geometry. It is assumed that
the depot is refillable with a total service life of 10 years and resides in low earth orbit.
Examples of depots created with the tool are shown. Application to existing exploration
architectures is also discussed.