Blackstar two-stage-to-orbit system: real or fantasy?

BoingBoing pal Kazys Varnelis writes:

Late last night I was browsing through sci.space.history, a USENET group that still is a great source for information on the topic when I ran across this thread, referring me to a lengthy Aviation Week and Space Technology story on a secret government space plane called Blackstar.

Now AWST isn't the Inquirer. On the contrary, it's published by McGraw-Hill and its usual readers are people in the industry or the government. But if this piece, by William B. Scott, a senior editor of the journal, is to be believed, a two stage-to-orbit space plane was developed in the 1980s and may have become operational in the 1990s only to be cancelled recently.

As the piece details, the program was built in response to the loss of the Challenger and subsequent military concern about access to space. During an ultra-secret crash development program, the SR-3, a mothership based on the XB-70 Valkyrie bomber and the XOV, a low-Earth orbiter derived from the X-20A Dynasoar were developed.

(…) Pentagon officials, the article reports, think that the project may have been owned and operated by companies, not by the government to ensure plausible deniability of its existence. Top military space commanders remained in the dark about Blackstar, which may have been operated by an intelligence agency. Blackstar's existence would explain the mysterious retirement of the Lockheed SR-71 reconnaissance plane in 1990. Observers have long wondered why this program was cancelled. The article concludes with a discussion of sightings of mystery aircraft.

Link.

Update: accusations of bogosity abound. Reader Fred Kiesche says,

At Space Review, Dwayne Day outlines the number of breathless "about to be revealed" military vehicles at "Aviation Leak" has revealed…only to never have them come into existence. For example: "But what they should realize is that Aviation Week also has a well-deserved reputation for publishing poorly-researched articles about top secret aircraft programs that do not exist, such as the 1958 claims about a Soviet nuclear-powered bomber. In fact, the same author who wrote the Blackstar articles, William Scott, has written several previous articles about top secret aircraft that never existed. It is his specialty, and he repeats the same pattern in all of them."

Link to Space Review item. (Thanks also, Gord Deinstadt, paperplatehead, and others)