From: snidely.too@gmail.com   
      
   On Thursday or thereabouts, JF Mezei asked ...   
   > I know SLS doesn't have much love.   
   >   
   > But watching the second test fire, prompts this question:   
   >   
   > Does the SLS core stage tank use the same foam as for the Shuttle's ET?   
   > Would all the post-Columbia research and refinements still be considered   
   > to be "current" or would much progress have been made since resulting in   
   > new significantly different foam formulation?   
      
   Quite possibly the same foam.  Which is unlikely to damage any tiles   
   even if it sheds.   
      
   > In terms of the Shuttle ET, it was mostly smooth except for perhaps 1/5   
   > that had ridges on the surface. What was the purpose/reason for only   
   > that portion having ridges? SLS doesn't appear to have such a zone.   
      
   That may have been a reflection of what's underneath.  Consult a good   
   shuttle book.   
      
   > Does the foam have an expiry date? Since SLS has been delayed and   
   > delayed and delayed, I wonder if at one point they would have to ditch   
   > the tank/core because the foam has started to decompose?   
      
   The booster joints are a shorter term issue.   
      
   /dps   
      
   --   
   "First thing in the morning, before I have coffee, I read the obits, If   
   I'm not in it, I'll have breakfast." -- Carl Reiner, to CBS News in   
   2015.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)