Thanks, guys for being sympethetic towards our(american's) feelings. Being in America and knowing and seeing first hand how "$$big projects$$" put alot of pressure on people to push to stay on schedule due to the enormous expense, I only hope patching, to the skin fractures, wasn't done to keep on schedule, rather than halting things until better solutions could have been made. After reading the papers and articles about how the shuttle had lots of resistance on the left side of the craft, I wonder if tiles were missing or fractures to the skin was causing this craft to try and turn left before breaking up. The speed at which this craft enters the atmosphere must stress the skin enormously. The skin temp must go through a wide heat range as well(severe cold to over 3000F). I wonder if it bends in and ripples as the air is forced to go around it. If this is the case, then fatigue could certainly be the cause of cracking, and as others have stated, welding up these fractures may only cause it to fail elsewhere. Speculation can make your mind run wild sometimes, so I'll stop typing for now, because I too am only speculating. Others on this board are more familiar with aviation and the types of stresses that an aircraft encounters, could possibly give better explanation for the skin fractures. These shuttles are given a life expectancy of 100 trips in and out of orbit, I wonder if NASA will refigure the data or improve on the materials used so these 100 trips could become a reality.
John Wright