Joann Evans wrote:


That's what tanker vehicles (where additional fuel is the payload)
are for....

Googled "tanker space vehicles". Is Argus a typical model?
www.iafastro.com/archives/pap02/ Aabst/IAC-02-V.P.10.pdf
says a 256.3 MT Argus or a 218.6 MT pure tanker Argus could deliver 9.07
MT to LEO. If there were 320 flights/year either version could provide
LEO fuel at $375/kg.

Is 320 flights a year what is hoped for? That'd be a launch most every
day (excepting Sundays).

Hop
http://clowder.net/hop/index.html