Bob Truax
Robert C. Truax proposed cheap liquid boosters for the Shuttle. He was way ahead of a lot of others on the commercial space front, and was looking to pop a single person into space many years ago.
One of his papers on access to space can be found here.
His last web page I have on file seems to be dead, and he also seems to have faded out of the history what used to be American Astronautics. Embarrassed to say I've lost track.