X-43 Test Failure (Score 2, Informative)

I haven't seen that particular report, but just to clarify what I know, the failure wasn't in the X-43 hypersonic vehicle but in the Pegasus launch booster, built by Orbital Sciences. Apparently the Pegasus was built to be launched at 40,000 feet, however in the first test it was launched at 20,000 feet. The increased air density and aerodynamic loading at this altitude caused a structural failure in a stabilising fin on the booster, not the X-43 craft itself, which remains unproven.