It also explains what the astronomers in CA saw. They were watching and saw debris comming off the aft end of the shuttle. Lightly at first then a chunk.
Either tiles were lost or breached (gouged) significantly by the impact of the debris from takeoff. Once the tiles either "zippered" off or the heat breached the damaged area the wing/hull was compromised since it cannot withstand much more than 300 degrees.
I think you are correct. Debugged that pretty well.
Maybe....Shards of ice and debrie have impacted shuttles leading edges repeatedly in the past...shuttles return with missing tiles..impact damage from space debrie and cosmic whatever all the time...do a run on the net..the data is there.
Info on STS 107 from SpaceRef.com
STS-107 Launch of Space Shuttle Columbia for Spacehab NASA, SPACEHAB, and members of the STARS Academy have been preparing for the STS-107 mission for over two years. Scheduled for launch on July 19, 2002, this research mission of sixteen days is sure to be an exciting event. With the debut of SPACEHAB’s Research Double Module on this flight, over 100 experiments are expected to take place onboard the U.S. Space Shuttle Columbia. The flight inclination for this mission is 39 degrees and the flight altitude is 150 nautical miles. This mission will be launched from the Kennedy Space Center in Cape Canaveral, Florida from launch pad 39B. Seven talented astronauts will be flying this critical research mission. They include Mission Commander Rick Husband, Pilot William "Willie" McCool, Payload Commander Michael Anderson, Mission Specialist 1 Kalpana Chawla, Mission Specialist 2 David Brown, Mission Specialist 3 Laurel Clark, and Payload Specialist 1 Ilan Ramon. For the STARS Academy locker, Anderson, Chawla, and Ramon are the assigned crew. As the 111th shuttle mission and Columbia’s 28th flight, this shuttle just celebrated the 20th anniversary of its maiden voyage. Columbia returned to service, fresh from a year and a half of maintenance and upgrades that have made it better than ever. More than 100 modifications and improvements have been made to make Columbia ready for flight on STS-107. Highlights include a “glass cockpit” with nine full-color, flat-panel displays, reduced power needs, old wire removal, and a user-friendly interface.
Columbia's launch for July was scrubbed:****
June 24, 2002 Ed Campion Headquarters, Washington (Phone: 202/358-1694) James Hartsfield Johnson Space Center, Houston (Phone: 281/483-5111) Bruce Buckingham Kennedy Space Center, Fla. (Phone: 321/867-2468) Release: #H02-117 NASA MANAGERS DELAY STS-107 LAUNCH NASA managers today temporarily suspended launch preparations for Space Shuttle Columbia until they have a better understanding of several small cracks found in metal liners used to direct the flow inside main propulsion-system propellant lines on other orbiters in the fleet. Columbia's launch on STS-107, previously planned for July 19, will be delayed a few weeks to allow inspections of its flow liners as part of an intensive analysis that is under way. Recent inspections of Space Shuttle Atlantis and Space Shuttle Discovery found cracks, measuring one-tenth to three-tenths of an inch, in one flow liner on each of those vehicles. Some of the cracks were not identifiable using standard visual inspections and were only discovered using more intensive inspection techniques. "These cracks may pose a safety concern and we have teams at work investigating all aspects of the situation," said Space Shuttle Program Manager Ron Dittemore. "This is a very complex issue and it is early in the analysis. Right now there are more questions than answers. Our immediate interests are to inspect the hardware to identify cracks that exist, understand what has caused them and quantify the risk. I am confident the team will fully resolve this issue, but it may take some time. Until we have a better understanding, we will not move forward with the launch of STS-107." The impact of the investigation on other upcoming space shuttle launches has not been determined.
So...Columbia see's a complex re-fit...how many systems and alterations....what percentage of errors could occur from that...plus the known cracks in the flow liners.
Data is available on the net as to shuttles returning with missing tiles....with numerous impact damage from man made space debrie....and cosmic strike.
Yes...a burn thru or blowtorch effect could have occured..yes certainly.
But it could be something else...something in all that re-fit and weld repair.