"Jeff Findley" wrote:

You're trying to re-write history. Originally the shuttle was to be a
manned space vehicle to *service* a LEO space station, which would be
launched by the Saturn V. Funding for both wasn't forthcoming...

Can't be emphasized enough: this is materially different from the flip
(and widespread) version Revision advances. (NB also that the
1955-vintage Von Braun station was to have been built by a "shuttle"
itself larger than the Saturn V... so multiple components of the
over-all agenda were shifting, without enough clear thought about the
shifting dependencies.)

Furthermore, the shuttle morphed into the much larger vehicle we see today
in order to gain political support for the program (i.e. DOD payload and
cross-range requirements).

That was the largest single factor at work, but there were at least
two others.

One was a reluctance to accept just how much the mass costs of
reusability (wings, TPS, landing gear, heavier airframe) were cutting
into payload -- both in the early architectural debates and as the
chosen architecture turned into hard specs. One way to deal with that
was to keep increasing the projected flight rate, but there was also a
tendency to think "OK, if we have to go bigger at least we claw back a
little more payload."

Another, as it gradually became clear that we wouldn't come up with a
robust metal skin, was that a bigger planform with a bigger empty bay
*did* at least ease the heat loads on re-entry.

I'm not saying either of those, or both plus gaining USAF support, was
a *good* argument. In retrospect, it's clear that "reusability" plus
"robust operations" plus "much cheaper $/kg to orbit" in one iteration
was a bridge too far with *any* architecture or *any* budget (and IMHO
still is, even with "magical New Space efficiencies and markets" added
to the mix.) But I was talking to those involved as it happened from
1972 on, and all three were part of their thinking.



Monte Davis
http://montedavis.livejournal.com/