By chance, came across something this week that made me go look for previous postings on the U-2 -- and found this thread. Speaking of trussed wings, there is mention of a similar Northrop proposal considered by the CIA as a possible U-2 replacement because of concerns regarding its detectibility by Soviet radar. The reference is in the CIA's history of the U-2 and Oxcart:
"In the late summer of 1956, [Richard Bissell and his Air Force assistant] visited a number of airframe contractors in a search for new ideas. Among the more unusual was Northrop Aviation's proposal for a gigantic aircraft with a very-high-lift wing. Because it would not be made of metal, the wing would require a type of bridge truss on its upper side to give it rigidity. The proposed aircraft would achieve altitudes of 80,000 to 90,000 feet but only at subsonic speeds, just enough to keep it airborne. The slow-flying Northrop design did not solve the problem of radar detection, and in 1957 the emphasis switched to supersonic designs..."
Anybody know anything more about this proposal?