Charlie Brown (London Science Museum)

[Luke Pemberton]

Some pictures of Charlie Brown. I got quite interested in the heat shield and the ablation. The third image shows two sets of holes that run concentrically around the heat shield. What are they for?

[bknight]

I wonder if they haven't been drilled to investigate the properties after reentry.  I looked at Columbia and there were no holes in it.
http://www.google.com/imgres?imgurl=https://c1.staticflickr.com/9/8547/9025108022_a16291cd9e_b.jpg&imgrefurl=https://www.flickr.com/photos/atkeison/9025108022&h=682&w=1024&tbnid=RSaq8pLZjtry1M:&docid=NkV4KOrKcSzUiM&hl=en&ei=UoLsVeeSN8eiyATyi56wAg&tbm=isch&ved=0CAsQMygIMAg4ZGoVChMI54PWvIHjxwIVRxGSCh3yhQcm

[Luke Pemberton]

I wonder if they haven't been drilled to investigate the properties after reentry.  I looked at Columbia and there were no holes in it.

It's a good thought. I'll begin researching that as a lead.

[Zakalwe]

I think that they are core samples taken from the heat shield.

I wonder if they haven't been drilled to investigate the properties after reentry.  I looked at Columbia and there were no holes in it.
http://www.google.com/imgres?imgurl=https://c1.staticflickr.com/9/8547/9025108022_a16291cd9e_b.jpg&imgrefurl=https://www.flickr.com/photos/atkeison/9025108022&h=682&w=1024&tbnid=RSaq8pLZjtry1M:&docid=NkV4KOrKcSzUiM&hl=en&ei=UoLsVeeSN8eiyATyi56wAg&tbm=isch&ved=0CAsQMygIMAg4ZGoVChMI54PWvIHjxwIVRxGSCh3yhQcm

Columbia had a number of holes as well, but it looked like they have been filled in with some sort of filler material. I also seem to recall seeing photos of other CM heatshields, some also with holes filled in.

http://heroicrelics.org/nasm/apollo-11/dsc33089.jpg.html

[mako88sb]

Gumdrop shows the same type of hole pattern:
http://www.collectspace.com/news/news-052604a.html

Makes sense that they would like to see if the stainless steel behind the ablative heat shield had been affected but you think there would be a NASA report about the results. Or there is but a pdf was never produced from it.

While searching for info about this, I stumbled onto this link that answered one of the questions I was wondering about which is what those larger circular objects in the outer circumference of the aft heat are for. Turns out they are shear compression pads. I noticed the same thing on Orion. Pretty informative link concerning all the seals involved with the Command module:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070025192.pdf

Just wondering if one set of those holes are mechanical attachment points to the substructure as shown in figs 8 & 9 in the above link? This other link shows the Apollo 11 shield raised up for inspection and you can clearly see the smaller holes run along the same circumferential line as the shear compression pads(page 78).

https://books.google.ca/books?id=7k1sawDR-kEC&pg=PA72&lpg=PA72&dq=holes+in+aft+heat+shield+of+apollo+command+modules?&source=bl&ots=w6m67Z7YkL&sig=9pTc3CHNGBJ-66jaAyxl0Ok0Lfw&hl=en&sa=X&ved=0CFUQ6AEwCmoVChMIlda80bblxwIVhZWICh01-wnE#v=onepage&q=holes%20in%20aft%20heat%20shield%20of%20apollo%20command%20modules%3F&f=false