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No PALs on last flight of Atlantis?

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I am winding down the Monogram Atlantis portion of the Shuttle Wars project. I am hoping to have it ready for nationals.

I have been doing research, specifically at Atlantis configuration during its last flight. I noticed that on the last flight, there were NO PAL ramps adjacent to the tank cable trays in either the LH or LO2 sections. For those who don't know PAL stands for Protuberance Aerodynamic Load. These are add on foam pieces that are supposed to keep air from getting up underneath the tank control trays that run lengthwise on the tank and control vents and such.

These types of "glue on" pieces, fitted after the tank is sprayed with insulation, have been problematic. There have been periodic separation incidents, including the left bipod mounting ramp which separated and impacted the leading edge of Columbia's wing.

So, did NASA just give up on these pieces as too dangerous towards the end of the program? If so, it makes my job a little easier as the PAL ramps are not included in the kit.

Here are a couple of pics of STS-135:



I also found a pic of Discovery with no PALs on the tank either:


Some with, some without:


Edited by DutyCat
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I can't wait to see the finished Shuttle Wars project!

It seems after the Columbia accident the PAL ramps were discarded. I think they still existed on the return to flight missions, STS-114 & STS-121, but still posed problems so they were eliminated. I'm not 100% sure when they were taken off.

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You mean the big PAL ramps on the tanks? As far as I can recall, those went bye-bye not long after STS-121 given they had a large piece of foam break off of STS-114 (which contributed to the 11 month delay before the next mission). Now what you are seeing in some photos after that is a ghost effect in the foam as some of the ETs had PAL ramps added before the decision was made to remove them. Freshly applied foam (or sanded down foam exposing the inner layers) always looks lighter in color than the surrounding area and while I don't know if the PAL areas got chopped out and resprayed, or if they just got sanded down, the results were the foam still had a "tan line" of sorts that looked like PAL ramps when in reality those areas were smooth. It looks like STS-120 was the last mission to have the tan lines as from STS-122 onwards, there was no tan line for removed PAL ramps.

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