This is actually the SR-71 “Blackbird” manual which is of the YF-12 design. But since Skunkworks threw out a design for SR-72 it is safe to assume that in principle, the Darkstar would be of similar/same materials and similar/same build. Mostly to withstand the high temperatures of hypersonic.
So if you found this page looking for a technical manual for your SR-72: enjoy the real SR-71 and familiarize yourself with it. (pg 15)
- Wow! I heard it said but couldn’t understand the word; finally found the word in writing to know how it is spelled and properly said: HASTELLOY. A very high temperature Nickel alloy.