Here's what I would do, and I have said this repeatedly, even just yesterday: Launch cargo on BDBs [Big, Dumb Boosters.] Launch crew on separate man-rated vehicles, which means the crew can escape under any circumstances, and for crew re-entry, use something much smaller and easier to make robust. Forget the wings.
Get to work on this right now and assume the Space Shuttle is headed for mothballs as of today. If any more building is to happen on the ISS, use BDBs to launch the hardware.
It's time to rethink NASA's mission. Moonbase and Marsbase should be the goal. NOW.