put air craft carrier reactors in orbit (after refit to make them a low/no gravity reactor) and surround it with tanks holding multi tonnage of water(for cooling, propulsion, shielding, growing food etc) and then use your steam rocket....with 30 years supply of fuel you could sail out to the Kuiper Belt or closer to Europa for unlimited propellant in water contained there...the massive amounts of electricity produced can also manufacture hydrogen and oxygen(from the h2o) for atmosphere and for chemical rocket engines for maneuvering etc...
forget about the solar BS