My co-blogger discussed Blackstar last year when Aviation Week had it on the cover.
I've always had two questions about Blackstar:
1. Why that architecture?
2. Why then?
The second question is the real puzzle. Contrary to popular belief, governments can usually keep this sort of thing secret. We knew absolutely nothing about the F-117 prior to the Defense Department announcing it in 1988. We didn't get a chance to see one up close until 1990.
In the early 1990s, Aviation Week carried a number of stories about exotic aircraft. At that time, the reason was obvious: budgets were getting cut, and while black projects are relatively easy to keep alive (because their natural enemies most likely do not know about them), they're also, ironically, fairly easy to kill when funds get tight (because their natural allies most likely do not know about them). The only way to garner support for such a program is to make some judicious leaks here and there.
No such event militated in favor of revealing Blackstar last year.
Now, to the question of architecture. The Blackstar design requires the mothership to tote the entire spacecraft up to launch altitude; it requires high-speed separation of spacecraft and mother ship (which is hazardous to both); and it requires exotic equipment (mating and demating facilities in particular).
In short, it's for those who want to go to space in the worst possible way.
Now, consider the vehicle described in this link. Size is held to a minimum by using aerial refueling to transfer oxidizer to the vehicle after launch; infrastructure requirements and prelaunch checklists are held to a minimum because the fuel and oxidizer are non-cryogenic; the bird can take off and land from just about any Air Force base worldwide if necessary; and the resulting "Black Horse" spaceplane is about the same size as an F-16.
Consider, also, the fact that this paper is part of a larger study conducted in 1993-1994. That's thirteen years ago--more than enough time to build hardware, validate it, and put it into service.
That's thirteen years ago. The estimated cost for an RDT&E program was $150 million. Allowing for the usual tripling of RDT&E costs, that's about half a billion. Everett Dirksen's quip about "a billion here, and a billion there, and pretty soon you're talking real money" comes to mind. In a national budget of over two trillion dollars, $500 million is a rounding error.
So perhaps we have an aerospace wing based out at Groom Lake, ready to rain "Rods from God" down onto the heads of evildoers and miscreants around the world.
How to cover up the odd sonic boom as a Black Horse boosts into orbit? Simple, blame it on a concept that's borderline unworkable and probably never made it past initial hardware testing.
It's the magician distracting you with his left hand while his right hand palms the card . . .