It is interesting how the B-52 keeps being reinvented for new roles. There is speculation that they might not be fully retired until they are about 100 years old. Really amazing.
Do they have the original airframes? Amazing if they do.
The first time I saw a B-52, I was a teenager walking in the street of a European capital during the Berlin Air Bridge.
Brought to mind something I remember from the old TV series "Battlestar Galactica"
A line of dialog explained that the Galactica was over 300 years old.
A good military platform can last at least 100 years and will be replaced only when constructing a new replacement becomes cheaper than maintenance on the old equipment.