Thanks for the post, Ken.  That made for some interesting reading.  I've bookmarked it for future reference, as well.

If you can find a copy available, there's a book from '78 that the AIAA put together showing where the STS program was "supposed" to go.  The title on it is "Space Transportation Systems: 1980-2000," and it was edited by Salkeld and Patterson.  A number of Shuttle follow-ons and interim-upgrades (which we naturally never went with) are covered in great detail.  It's a crying shame that none of the lessons of the Shuttle are being built into its intended successor - and almost a big a shame that we're not looking to fix much of the easier problems on the current equipment, either.

If I may, where did you find the info for the SSV?  Something similar is used as a design study in the AIAA book, but that's the first I've heard of it as something studied in any kind of "official" capacity.

If I may, where did you find the info for the SSV? Something similar is used as a design study in the AIAA book, but that's the first I've heard of it as something studied in any kind of "official" capacity.

I've been following the attempts to develop CATS since 2001 or so (indeed he first blogs I found were space ones link Hobbyspace).

 It does seem that everything it due to happen '3-4 years from now, but I'm still cautiously optamistic that it will happen.

Now that there are a number of individuals putting serious cash into it (Bezos, Musk and so on), It looks more likley than at any time since the 80's. I still recon I'll to be able to retire to the belt (though LEO would be enough)

Thanks for the references.  Another source to scour is always a good thing.

A thought occured regarding the acceleration of the gun-type launch vehicles, I'm curious why  it would be a bad idea to use an electromagnetic mass driver set up in a loop, with a spur-track coming off at a tangent for the final loft.  The loop would be where you could come up to speed over as much time as needed before the final few m/s of vee are added in the spur-track.  Accelerations could then be anything from a few tenths of G up to multiple 10s of G.  The only really difficult part would be designing the "switch" point, which is somewhat amusing - Dr. O'Neill made his fame for writing "The High Frontier," but made his career and earned his Nobel for designing that very "switch" for use with particle accelerators back in the 1950s.  If Ken or Pete or anyone can point out the flaw in this reasoning, I'd be grateful.