I mentioned a month or so ago that I'd been told that NASA was developing a new launcher called Magnum, and that I was going to investigate. Here's where I've got to.
Firstly, searching for the keyword "Magnum" in a space-related context brings up a lot of results referring to NASA launching a series of ELINT satellites in the late 1980s, which isn't very helpful. It's also hard to filter out references to the Colt Magnum series of pistols.
A document from 1998 provides some interesting information:
- Design is derived from that of the space-shuttle (this could be a replacement for the Shuttle-Z programme)
- Performance is 80 tonnes to ~400 km altitude LEO at 28.5° inclination
- Core is 8.4 m diameter to allow Magnum to launch from existing shuttle facilities (cost-cutting measure, I guess)
- Target cost is $1000 per kg (and if you believe that you'll believe anything)
Quite a lot of these details are corroborated by this Space.com article, which also contains some snazzy publicity imagery - including Lockheed-Martin and Boeing concept renders of what the fly-back boosters might look like.
Earliest information I've found is a set of 1997 lecture slides which, although interesting, are probably hopelessly out-of-date by now.
I've also found some comments from various people, many of which run along the lines of, "Why are we spending all this money on massive launchers so we can send spacecraft straight to Mars Apollo-style, when we could use [insert name of current, low performance launcher here] and assemble at ISS?" The fact that the ISS is in a hopeless orbit for insertion into a Martian transfer orbit, and the fact that we don't have the know-how to be able to assemble large structures in microgravity, makes this viewpoint rather an odd one.
And that's pretty much it. I've been able to find very little or no useful information dating more recently that 2000. I'm going to try e-mail MSFC directly, and see what they can tell me. It's worth a try.