I've been immersed in a book for about a week, and sff.net has Topsy-ed while I was away . . . two things, David, more or less relevant to the ongoing ramble –
Back in 1965 I wrote a program that could write World War I Flying Ace stories. Two nested programs, actually, one in COBOL inside one in MAD (Michigan Algorithmic Decoder, a sort of Poor Man's ALGOL.) The professor praised the programming and also said something on the order of "You oughta be a writer." Okay.
Have you come across the model of the "beer-can starship"? Basically a kind of low-IQ space probe that uses stacked propulsion systems, essentially redefining v-naught through a dozen different regimes until you have something the size of a beer can screaming toward Alpha Centauri at a significant fraction of the speed of light. Do-able for less than the Apollo Project cost.