Some kind of asbestos stripping worked itself loose during launch. This stripping is only necessary during launch; varying aerodynamics make it worthless in return. But now, since it is sticking out, it would cause a huge temperature increase if left in for re-entry. So, the astronauts constructed this little appliance to cut it off if they couldn't rip it off with their thickly gloved hands. The mission was a success. It's just another tribute to the power of Ducktape!