7. PROPELLANT OPTION SUMMARY
Apollo & planetary missions have provided early material and property samples identifying potential resources to help support development of In-situ propellants
Propellant selection based on resources available and the enormous amount of propellant development in support of the many programs since the 1960’s can be directed at the space tug operational requirement for near and far space regions.
LOX/LH2 demonstrated on many programs is a good starting place and can enable self pressurization with GLOX/GH2 and provide reaction control propellant. Minimizing fluid requirements in space.

8. Technology and resources exist to initiate propellant development
CONCLUSIONS
Technology and resources exist to initiate propellant development
on the moon and resupply capability for Earth-moon region
Implementation can provide routine space operations throughout
the Earth-Moon region.
LOX/LH2 remains a good propellant to support early Space Tug
functional operation.
A long life durable rocket engine which can accommodate early
LOXLH2 propellants with upgrade capability to alternate space
resource developed propellants would be a huge benefit.
(A pre-plan space tuge design tp accommodate additional tankage/varaiable mixture ratio)