Blackswift hyperplane hits trouble in Washington
DARPA Mach 6 porkbarrel logroll dash cash slashed
The main justification for a new generation of super-Blackbirds is "prompt global reach", the ability on America's part to scramble hypersonic bombers, spy planes or even troop transports and have them anywhere in the world within hours. But Blackswift is only expected to be able to stay hypersonic for one minute, in large part due to the constraints of a practical fuel load. It will be at least as thirsty as its illustrious predecessor. It's a prototype demonstrator, sure; but any future operational hyperplane would need to have at least a couple of hours' endurance to be much use.
This seems rather unlikely, and causes the senators and congressmen to suspect that simpler hypersonic programmes might be more militarily useful. Rather than Blackswift, with its various kinds of never-been-done kit, the politicians favour simpler efforts aimed more towards short-range, one-shot hypersonic missiles.
These would be useful for imaginable tasks such as shooting up very sophisticated enemy warships. They'd be easier to build as they could use rocket boost to get up to ram/scramjet speeds, and it wouldn't matter if their airframes had quite short service lives due to speed heating.
In a strictly military, short-term sense, the Washington beancounters are probably right; the Blackswift is in some ways a mad pork-hungry aerospace project of little use. (Lockheed are very keen on it, by the way.) But on the other hand, you could argue that humanity needs reusable hypersonic planes - many space enthusiasts might so argue, anyway. Mach 6 isn't orbital speed, but it's a lot better than Mach 2 or 3, which is the speed limit at the moment for reusable craft. Blackswift's technologies, once developed, would make piggyback reusable orbiters and/or their first-stage lifters a lot easier to achieve.
Blackswift's successors might not be competing with orbiting spacecraft, then - they might be more in the business of getting a lot more stuff up there, a lot more affordably.
Surely that's worth a measly billion dollars or so? ®