Rusty wrote:

Upgrading the Space Shuttle

http://stinet.dtic.mil/cgi-bin/GetTR...c=GetTRDoc.pdf

In discussing the possible replacement of the Shuttle's SRBs by liquid
fly-back boosters (LFBBs), this report passes on the suggestion from
LFBB proponents that they might reduce turn-around time to three weeks
and permit flight rates of *15* per year (I presume that's for the
whole fleet, not for individual vehicles).

I find this astounding. It was written in the late 90s, when, after
many years' operation, the Shuttle fleet had never demonstrated more
than six flights per year, IIRC. Is it plausible, either now or from a
late-90s perspective, that LFBBs could have had such an impact on
turn-around time? That such high flight rates were feasible?