David Spain wrote:
Robert Clark writes:

The payload bay would be converted to a fuel tank, and the second
stage of the TSTO would be carried on top or below the orbiter.

With that top or bottom mounted 2nd stage using cryogenic fuels?

Ooops, here we go again....

Unless, double hulled?

I can't for the life of me figure out why Robert Clark is constantly
coming up with ideas for so radically modifying something that already
exists that it effectively becomes a entirely different spacecraft, but
without the advantages that a whole new design would offer.

Pat