The Douglas ASTRO: An Air Force Launcher

douglas-astro

The ASTRO, as pictured in the September 3, 1962 issue of Missiles and Rockets. Image artist unknown and copyright status uncertain, but believed to be in the public domain. Via the Internet Archive.

What it was: A lifting body craft proposed to the USAF by Douglas Aircraft. It would initially be used as a suborbital trainer then, after up-scaling and being paired with a second lifting body in an unusual nose-to-tail arrangement, evolve into a fully reusable vehicle with a nine-tonne payload capacity to LEO.

Details: In late 1962, the USAF was on the cusp of deciding how it would go forward with its plans to put military men in space. The X-15 had made its first flight mid-year, and the X-20 program was ramping up. Doubts about the latter were getting stronger, though, and would ultimately result in the Air Force deciding to work on the Manned Orbiting Laboratory instead.

It was at this point that an article was published in the now-defunct Missiles and Rockets magazine outlining a proposal from Douglas Aircraft that was supposedly being evaluated by the USAF. What it outlined was a two-part development program that would check the usual laundry list of military applications for space as perceived in the early 1960s.

The core of the ASTRO (Advanced Spacecraft Truck/Trainer/Transport Reusable Orbiter) was the answer to a question the USAF had proposed to North American Aviation and Douglas, as well as Boeing, Vought, and Republic: how to train pilots for the X-20 on actual flights prior to the X-20 being built. North American had come back with what they called the STX-15, which was a way of reconfiguring an X-15 to have the projected flight characteristics of an X-20 (except for, of course, the highest speed and orbital parts). The Phase I of Douglas’ ASTRO was their significantly more ambitious counter to the NAA proposal.

astro-schematic

A schematic of the ASTRO’s A2 vehicle, which would be both independent for suborbital hops, or be boosted to the point that it could be lifted into orbit by a derivative of the same vehicle. Note the booster nose’s ghostly presence at the far right of the image. Same source as previous. Click for a larger view.

Unfettered by the previously existing X-15, Douglas wanted to build a completely new craft dubbed A2, which would be capable of suborbital hops of about 5000 miles (8000 kilometers) after taking off from a runway under the impetus of a J-2 engine, the same rocket engine used by the Saturn V’s second and third stages. Pilots would get their space training, the USAF would have themselves a reusable vehicle with intercontinental range which could carry ten people, or a similar amount of payload. Two RL-10s, as used on the Centaur, would provide a little extra oomph.

Phase II was where Douglas diverged from the question being asked. Take the A2, modify it so that it only carried one crew and two extra J-2 engines, then stick it nose to bumper on the end of another A2 built to the Phase I spec. Turn it 90 degrees and launch it vertically, with the two separating from each other at altitude and speed (both unspecified). The sole crew member aboard the booster would glide back to Earth, while the uppermost A2 would ignite its engines, hopefully after allowing a bit of distance to build from the booster, and carry on into orbit. Douglas projected two crew and about a tonne of cargo to LEO in this configuration.

Phase III scaled up the booster, now dubbed B, and equipped it with two J-2s and one M-1, a never-built LH2/LOX engine that dwarfed even the F-1 engines used on the Saturn V’s main stage. Also launched vertically, this would be the ultimate version of the craft.

The full, two-stage Phase III vehicle was to have been 159 feet long (48.5 meters) and while mass was not mentioned the propellant capacity of the stages (165,000 pounds for the A2 and 594,000 pounds for the B) are—this suggests a total loaded vehicle mass at launch of about 380 to 400 tonnes. Total payload, as mentioned previously, was about nine tonnes, including crew, and there’s a sign that Douglas was nervous about this: the article specifically mentions wanting to launch due east from the Equator, which is an odd thing to be suggesting in 1962, well after the US had committed to launching from the continental USA.

If built, the program was expected to run from 1964 to 1970, with the first flight of the Phase III craft at the end of that period.

What happened to make it fail: It’s difficult to fit the ASTRO into the chronology of the X-20. Phase I appears to have been an attempt to come up with a “Gemini” for the X-20’s “Apollo”, giving the USAF the capability of sending pilots on long suborbital jaunts to train them for the environment they’d encounter when aboard the fully orbital X-20. Phase III would then have been a follow-up to the X-20, increasing crew capacity and payload over that craft.

If this is the case, then, it explains why the ASTRO never went anywhere. The craft made its sole notable public appearance in September of 1962, and American Secretary of Defense Robert McNamara was definitely thinking about cancelling the X-20 no later than March 1963—and possibly earlier. When the X-20 was stopped, then ASTRO would go with it. This is particularly true if one assumes, as seems likely, that the USAF was never very warm about the idea at all, and that it primarily existed as a pitch from Douglas leaked through Missiles and Rockets magazine to drum up support. There’s essentially no reports or discussion of ASTRO post-dating the magazine’s unveil.

What was necessary for it to succeed: It’s not easy to see a way forward for this one. X-20 was dead in the water less than six months later (eventually being formally cancelled in December 1963), and the payload capacity of even the Phase III ASTRO was marginal for what would have been an expensive program. There’s also the issue of Douglas vastly exceeding the question posed by the USAF—it’s unclear that there was any interest on the part of the Air Force in anything other than Phase I. This in turn defeated the purpose of building a fully operational craft for pilot training.

Sources

“Air Force Studies Space Trainer”, Missile and Rockets. September 3, 1962.

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MASS: The Manned Anti-Satellite System

MASS

MASS schematic as shown in Transactions of the Eighth Symposium on Ballistic Missile and Space Technology (Vol. II). The launch vehicle was to be a Titan III, while the command module was based on research into lenticular missiles for the B-70 bomber. Public domain image via the USAF.

What it was: A conceptual design for a manned satellite interceptor/killer, floated by General Dynamics in 1963.

Details: The B-70 bomber was conceived to fly high enough and fast enough that it could out-run any possible intercepting aircraft, but before the program was well underway it became clear that surface-to-air missiles posed a problem, and that the USSR was good at building them. In December 1959 the USAF decided to build only one prototype (two were eventually built) for experimental purposes and that was that for the B-70.

There was a short interval before cancellation where the USAF explored putting anti-missile missiles on board the B-70, under the unusual code name of Pye Wacket (probably taken from Kim Novak’s feline familiar in the 1958 supernatural comedy Bell, Book, and Candle). The B-70 flew at such great heights and speeds that making a conventionally shaped missile that could attack on any vector away from the craft proved to be problematic. The Pomona Division of General Dynamics assigned to the project instead settled on a lens shape for the body of the missile, which would make it more maneuverable than the conventional “long-and-thin” approach.

When the B-70 was cancelled so was the missile project, but here the story of the MASS begins. Lenticular shapes were one of the three early contenders for manned spacecraft in the early American space program (along with ballistic capsules and winged re-entry vehicles) and Pomona Division got the idea to scale up the Pye Wacket body into something an astronaut could ride. This was written up and proposed to the USAF in March of 1961.

There’s not a lot of public information about Pye Wacket, given that it was developed as a defense for a cutting edge nuclear bomber, and the larger manned, version was classified too: it seems to have been a dark horse running for the role proposed for the X-20. Much of what we know about the craft comes from a single unclassified paper called “Manned Anti-Satellite System” (MASS), published in October 1963, presumably because it had been definitively ruled out by then. The X-20 itself was cancelled outright in December of the same year.

What General Dynamics proposed was a boost-glide craft, perched atop a Titan IIIC for the climb to orbit. It consisted of a 16-foot in diameter (4.9 metres), 8500-pound (3855 kilograms) lens-shaped command module, which seated three, and a 6200-pound (2812 kilograms) mission module, the latter of which would store a little over 7 US tons (6500 kilograms) of propellant—N2O4 paired with 50/50 hydrazine and UDMH.

The most interesting part of the mission module was its “inspector/killer” modules, four of which studded the sides of the orbiting vehicle. These were protected during launch by “wind shields” or, in modern parlance, payload fairings. Once in orbit the fairings would be dropped and the craft as a whole maneuvered into proximity of a target Soviet satellite. At a standoff distance of 50 miles (80 kilometers), the crew would order one of the inspector/killers to detach and then it would close with the target using its two restartable engines.

Each inspector/killer would be 47″ x 38″ x 38″ (about 1.1 cubic meters) when folded up, but once detached it would unfold a two-foot antenna so that it could send a video signal back to the command module, as well powering up a tracking radar with two antennas (one to lock on the target and one to lock on the command module), a TV camera, a flood lamp (in case the target was in the Earth’s shadow) and an IR detector.

ik

An I/K closes in for a an attack on its target, while the manned section of the MASS lurks at a safe distance. Public domain image from Transactions of the Eighth Symposium on Ballistic Missile and Space Technology (Vol. II).

After inspecting the target, the crew of the MASS then had the option of detonating the shaped charge aboard the inspector/killer so as to destroy the target. As well as its two rocket engines, the I/K was outfitted with six attitude control motors, and using all of these it could even chase after a target that was designed to evade an attack; the I/K’s main motors could push it at 12g if needed.

With up to four satellites destroyed, and potentially more inspected depending on how the targets’ orbits were arrayed, the command module would disengage from the mission module and return to Earth. Its lenticular shape allowed for a very high angle of attack (60 to 75º) to bring its ablative heat shield into play while still giving it a good lift-to-drag ration (∼2 as compared to the 1.0 of the Shuttle Orbiter). Once it was down to transonic velocity it would deploy two horizontal stabilizers/small wings, which were necessary due to the craft’s instability at these speeds as well; they also improved the command module’s L/D ratio considerably.

What happened to make it fail: The MASS is a perfect storm of ideas that seemed promising in 1960 but that turned out to be dead-ends. Lenticular craft have never promised enough advantages to be built, the proposed customer—the USAF—never did get its own manned space program, and its proposed mission to intercept, inspect, and potentially destroy satellites has never been worthwhile in practice. In the X-20, it was also up against a strong competitor that had already got underway when MASS was proposed.

What was necessary for it to succeed: It’s awfully hard to get this one to fly. Perhaps if Eisenhower hadn’t been so insistent on giving space to a civilian agency, and if the USAF had been able to fend off the Army to gain it for themselves (far from a foregone conclusion even in the absence of NASA), MASS might have moved further. Even under those circumstances we would have been much likelier to see something like the X-20 or the Manned Orbiting Laboratory rather than the MASS.

When it comes down to it, this proposal placed bets on too many things that, in retrospect, never worked out. It’s interesting as a concrete example of how much we didn’t know in the early 1960s but, with the exception of the Project Horizon Lunar Base, it’s the least likely of all the post-Sputnik projects we’ve examined.

On the other hand…for those of you who (like the author) enjoy stories about conspiracy theories, black projects, UFOs, and the like without actually giving them any credence, I’ll direct you to a strange Pye Wacket-related article published in Popular Mechanics’ November 2000 issue. It makes the case that the MASS wasn’t cancelled but instead went black and turned into a vehicle called the LRV. Fair warning, though: the words “Roswell”, “Nazi”, and “flying saucer” are used in all seriousness.

Sources

“Manned Anti-Satelllite System”, E.E. Honeywell; Transactions of the Eighth Symposium on Ballistic Missile and Space Technology (Vol. II); Defense Documentation Center, Alexandria, Virginia; 1963.

“Pye Wacket”, Mark Wade, http://www.astronautix.com/p/pyewacket.html.