Years ago my branch was involved in a test flight called Aeroassisted Flight Experiment (AFE). This flight test was a heavily instrumented entry vehicle that would have demonstrated the concept of aerocapture and the raked conic entry vehicle. NASA actually built the heat shield just before the project got canned. AFE was another example of a project sacrificed on the holy altar of the Space Shuttle. Instead of launching AFE with a cheap ELV and then dumping it in the ocean, someone got the bright idea of launching AFE from the Shuttle and then recovering it from orbit. At that point AFE had to be man rated and the costs went exponential. AFE was terminated soon afterwards with more than one career wrecked in the process.

NASA hasn't had a decent flight test experiment since Fire Flight II back in the 1960s (we still use data from Fire-II for CFD validation). There were Apollo CM test flights after Fire-II but the data was compromised due to equipment failure. Columbia (OV-102) was originally rigged for test flights (STS 1-5) but the Shuttle never really got all that hot. Just to rub salt in the wound, when our guys go to visit the folks at Sandia sometimes they'll take us to their "museum". At Sandia's museum, there are many classified entry vehicles on display from succesful test flights. For the longest while, Sandia had almost a "blank check" from the government to test fly any new RV concept that popped into their head (not anymore). The vast majority of what is known about hypersonics is restricted to the black side of the profession.

Gary