US military crazytech chiefs have cancelled the planned "Blackswift" Mach-6 runway aeroplane, following an almost complete cutoff of funding by Congress.
Aviation Week reports that the challenging Blackswift project has now definitely been closed down, following a reduction of its FY 2009 budget from $120m to just $10m. It appears that the Congresspersons responsible doubted that the aircraft could really be built, certainly to the planned timescale.
That seems reasonable, as the Blackswift (aka Falcon HTV-3X) was to achieve very ambitious goals. It was to take off from a standing start on a runway, accelerate to Mach 6, perform a barrel roll at that speed, and then return to a runway landing - and do all of this without using exotic fuels. Here's a concept vid courtesy of YouTube:
Making the Blackswift work would have required several breakthroughs, not least the use of scramjets - ramjets that can sustain a flame with air passing through them faster than sound - able to burn ordinary jet fuel. Such systems have been tested successfully in wind tunnels, but flight trials have seen problems.
These nifty hyper-engines would need to be combined with ordinary turbojets somehow, as ram/scram jets can't even fire up until they're moving fast. Then a way would need to be found to prevent the whole plane melting under the intense friction heating of hypersonic flight. Tricky problems of turbulence and boundary control would also need to be solved.
A tall order, then, and the immediate military need for such aircraft is far from plain to many observers. So perhaps it's not a surprise that the Blackswift idea came from DARPA, the Pentagon super-nerds who have a positively spartan intellectual diet policy. No low-hanging fruit or pieces of cake for them; at DARPA the bacon must be strictly from flying pigs, the black pudding* from the bleeding edge and every pie fresh from the sky.
Perhaps the most ambitious hypersonics effort left with the demise of Blackswift is the X-51 "WaveRider" project, jointly funded by NASA, DARPA and the US air force. The scramjets for this are now said to be ready. However, WaveRider seems unlikely to turn into a radical new aircraft - it's more oriented towards new missiles or similar one-shot applications, at least in the near term.
NASA and DARPA will both press on with more limited hypersonics work aimed at reusable aircraft, but there's now no real prospect of a runway hyperplane in the immediate future. ®
*Overseas readers: blood sausage, boudin etc.