1. In case anyone doesn't know, they use the actual recovered Shuttle casings on SLS, but use an extra "middle" section to make it 5 sections in length instead of the Shuttle's 4 sections. In the future they'll move to "BOLE" boosters which won't use previously flown Shuttle parts.
I think the booster was redesigned after the accident, I guess/hope the opportunity was seized to make a design that would be less sensitive to orientation.
> Are you saying that they are tested horizontally or that they are ONLY tested horizontally?
My understanding is that they are only hot fired horizontally.
Presumably there are many tests done at the component level, although it's questionable whether it makes sense to call those tests horizontal or vertical at that point.
https://www.youtube.com/watch?v=n-wqAbVqZyg
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1. In case anyone doesn't know, they use the actual recovered Shuttle casings on SLS, but use an extra "middle" section to make it 5 sections in length instead of the Shuttle's 4 sections. In the future they'll move to "BOLE" boosters which won't use previously flown Shuttle parts.