Post-Columbia there was some examination of repair options that could have been used if the crew had known about the damage. Some engineers considered it feasib

Post-Columbia there was some examination of repair options that could have been used if the crew had known about the damage. Some engineers considered it feasible to repair the hole in the wing using material scavenged from Columbia [1] but this was apparently considered very high-risk. The shuttle re-entered at Mach 25 and the leading-edges of the wings were made from titanium because of the extreme thermal and aerodynamic stresses they were subject to, so stuffing a tile (assuming it could be removed, which would have been unlikely) into the hole wouldn't have helped at all. Some repair techniques and tools were developed part of the process of returning the shuttle fleet to flight after the loss of Columbia. These included a caulk-gun to allow in-situ repairs to thermal tiles [2] and a device for plugging holes in leading surfaces such as the wings. These were tested in space but were never needed. [1] http://spaceflightnow.com/columbia/report/rescue.html http://spaceflightnow.com/columbia/report/rescue.html [2] http://www.newscientist.com/article/dn13521-shuttle-heat-shield-repair-test-a-success.html http://www.newscientist.com/article/dn13521-shuttle-heat-shi...