Why can't NASA create a proper shield to install over all of the sensitive areas of the shuttle that could be jettisoned after it is in space? It would land in the ocean like the SRB's and be recycled. Think of it like gloves you would wear when handling barbwire, you take them off when you're done. (the heat resistent tiles appear to be like that stuff that is 99.99% air and .001% heatproof material. Very good at what it does, but very fragile too, structurally speaking)
Or maybe they could cover the outside of the shuttle with reverse magnifying glasses (concave) and check valves to bleed off the excess heat, so that upon re-entry the heat build-up would be turned to ice on impact with the hull.
Or, re do the shuttle so it is like the F117 or B2 stealth, so the heat can't find it.
Or, nail some turkey feathers on the shuttles ass so that it will go faster than the speed of light and therefore out run the heat before it gets a chance to *stick*. (hmm...when the shuttle lands the eventual shockwave that catches up would propel the shuttle into the next co-linear dimension, effectively causing the astronauts to die before they were born (so who was driving the shuttle then).....hmmmm....hate it when that happens.....)