rcc looked tough in comparison.so nobody, to my memory, ever really talked about it before this accident. and so it was generally thought to be pretty tough stuff. there are also problems with requirements at that time. it turns out that the wing -- none of the rcc panels -- none of the tiles had a requirement to be able to withstand a debris hit of foam or anything. why? the foam wasn't supposed to come off. and so that requirement was never there, it was never qualified for the condition and it was a difference in the different prompts that were independent of each other to some degree. so and also at this point in time, because of the time had gone by since the challenger, the cnn i, the system engineering and integration office had dwindled in size they were not able to do expensive analysis. there was a crater model which was a mathematical model with calibration of testing to indicate what kind of damage can be cone -- done with a piece of debris. that was in place. it was talked about during the period, and t

they don't understand the strength of the rcc. thome is not allowed. number one, the exteriors. okay. so the first thing we said we came up with recommendations that said you have to understand the materials that you are dealing with. second, the launch cameras facilities observations and imaging facilities at the kennedy center had been allowed to degrade slowly as they break or degette obsolete so that was not good imagery of the shuttle launches so the analysts couldn't tell whether or not a serious event had happened or not and so the second group of recommendations was you have to be able to witness and analyze and launched a higher degree of accuracy. third, this is something that struck us privately. we went through the whole sequence of boards and committees and checklists and months and months of signing things am going to meetings and certified in and you have that - ascent the trouble that fire, heat and light, sound and all that energy it gets 17,500 miles an hour but as we know from physics 101 every bit of energy put into that shuttle has to be taken out in order t

rcc look top in comparison., to my memory, every really talked about it before this accident. and so it was generally thought to be pretty tough stuff. there are also problems with requirements at that time. turns out that the wing, none of the rcc panels, none of the tiles had a requirement to be able to withstand a debris hit of foam or anything else. why is that? because the phone wasn't supposed to come off. and so that requirement was never there. it was difficult for the condition and it was a difference between, and of different projects that were independent of each other to some degree. and also at this point in time, because of the time had gone by since challenger, the se&i office had dwindled in size and they were not even able to do extensive analysis. there was something called a crater model which was a model, a mathematical model based on calibration with testing that would indicate what kind of damage could be done by a piece of debris. so that was something that was in place. but it was talked

then we had tile and rcc repair. when we started the journey, we had numerous exports come us that tile repair is impossible. and in fact in the 1970s, they did try very hard to develop it. it failed. we flew for 22 years with no way to repair the heat shield that was damaged in orbit. it was an accepted risk. i remember dr. kraft came to us and said, there's two things you should never do. never attempt to do tile repair. it's impossible. never change the outer mold lineup of the vehicle. we did both of them. and it cost a lot of money to do both. it took a lot of time. we came up with repair and finally if the repair was unsuccessful. we had a wild crew rescue scheme that might have worked if we ever had to call it in. that was the. we staid said how with we doing reducing the risk. 20% of the total risk flying shuttle was due to damaged to the thermal protection system andlet see how we did. well, in a qualitative way we have e eliminated a lot of asset debris. we added orbit inspection repair, we added rescue cap