Hi Mark

What's with the sour grapes? Most of us support manned Mars missions, but it's just not the only thing worth doing in space. For me Space Elevators and SPS make more sense, for now, but Mars is the next port of call.

And don't write off Venus either.

Adam

PS Years ago Popular Science did a write-up about the Mars Reference Mission's various revisions, one of which was an all chemical launch option using on-orbit assembly - two booster stages and the habitat/ERV for each launch Mars-ward. I've never been able to track its official NASA description down. Any links you've dredged up?