https://files.catbox.moe/hb01s5.jpg

NASA 804 | Northrop HL-10

likely a precursor design to triangle shaped jet craft.

https://en.wikipedia.org/wiki/Northrop_HL-10

The Northrop HL-10 was one of five US heavyweight lifting body designs flown at NASA's Flight Research Center (FRC—later Dryden Flight Research Center) in Edwards, California, from July 1966 to November 1975 to study and validate the concept of safely maneuvering and landing a low lift-over-drag vehicle designed for reentry from space.[1] It was a NASA design and was built to evaluate "inverted airfoil" lifting body and delta planform. It currently is on display at the entrance to the Dryden Flight Research Center at Edwards Air Force Base.

B52.