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.

M-46/M-48 (VKA-23): The First Soviet Spaceplane

vka-23-designs-1-and-2

The VKA-23’s two designs, Vladimir Myasishchev third attempt in the 1956-60 period to propose a small spaceplane to Soviet leadership. The one on the left was based on his second try, the M-48, while the second design, on the right, was the ancestor of several other Soviet attempts at a lifting body re-entry vehicle in future years. Based on two images of unknown source, believed to be from the USSR–if you know of their source, please contact the author. Click for a larger view.

What it was: Four interrelated, but different, designs for a small Soviet spaceplane. While almost all Russian spacecraft descend from Sergei Korolev’s R-7 and Vostok, they began as an independent line of approach pre-dating 1957, building up to orbital operations by creating ever more extreme airplanes. Only after Korolev’s crowning achievement of orbiting Yuri Gagarin in a ballistic capsule was it definitively folded into the main line of Soviet space exploration. Even after that its descendants repeatedly threatened to split back off again right up until the collapse of the Soviet Union.

Details: We’ve previously discussed Eugen Sänger’s Silbervogel and how it was the first serious attempt to build a spacecraft by an alternative means to ballistic rocketry—building a plane so extreme that its speed and height qualified it for orbit. After WWII ended there was some interest in his work in the United States, but as designing a spaceplane is relatively difficult as compared to a ballistic capsule, it never went anywhere interesting until the development of the X-15.

In the Soviet Union, however, airplane designers kept their eye on the possibility starting as soon as they discovered Sänger and Bredt’s work. Stalin is reported to have been very interested in the possibility of an orbital bomber, and in 1947 tried to have a Soviet rocket engineer, Grigoriy Tokayev, convince Sänger to come to the Soviet Union or, failing that, have the NKVD kinap him (Tokayev chose to defect to the UK instead). Before this, though, in November 1946 Stalin directed Mstislav Keldysh—arguably his most talented plane designer and one of the three men (along with Sergei Korolev and Mikhail Tikhonravov) who suggested in 1954 that the Soviet Union launch an artificial satellite—to build something like the Silbervogel.

Keldysh concluded that the Silbervogel was entirely too advanced for Russian industry to build any time soon. Nevertheless he went for a somewhat less-extreme ramjet-and-rocket-powered craft that kept the same basic suborbital boost-glide approach suggested by Sänger. What he comes up with is still too sophisticated for Russia to make, so it’s not hard to conclude that it wasn’t a serious proposal and more just a way of getting Stalin off his back.

In the years immediately following this, Vladimir Myasishchev was the most serious of early Russian spaceplane designers. Well before Sputnik I his design bureau, OKB-23, was working on radical weapons like supersonic bombers and the Buran cruise missile. When Korolev demonstrated to the Soviet leadership’s satisfaction that ballistic missiles were the best delivery system for nuclear weapons, Buran was cancelled in November 1957, but Myasishchev was still interested in going faster and higher with his planes. So he continued working on an idea he’d had while working on his missile for a suborbital reconnaissance spaceplane called the M-46. Note the date: he was already working on it prior to the launch of Sputnik I, which makes it one of the select few spacecraft seriously considered before the dawn of the Space Age.

Not a lot is known about the M-46 other than its existence, as the work was done entirely on Myasishchev’s own accord; when he was found out he was sanctioned and told to pay back the funds he had spent. Archive materials on it were apparently destroyed some time thereafter. Nevertheless, there’s reason to believe that it would have been a manned version of the Buran missile, which is to say a ramjet-driven, delta-winged craft some 23 meters long, boosted up to speed by four nitric acid/kerosene rockets. The ramjets would have gone out for lack of oxygen long before it reached space, but it would have had enough speed for a suborbital hop above 100 kilometers with an intercontinental range.

Two years after being slapped down for his initiative, Myasishchev’s situation changed. Early reports of the US Air Force’s Dyna-Soar inspired the Russian military to counter with a spaceplane of their own. Korolev’s OKB-1 worked with Pavel Tsybin to develop one possibility, the PKA, while Myasishchev’s OKB-23 was given the go-ahead to develop a new one of his own, which he called the M-48. Both were designed to be boosted by Korolev’s R-7, just like the Vostok spacecraft for which they were considered an alternative. As it’s much easier to build a ballistic re-entry capsule, Yuri Gagarin made his historic flight in the relatively unsophisticated Vostok 1, but work continued on both the PKA and the M-48 until October 1959 and October 1960 respectively.

Myasishchev’s first attempt at this commission produced the M-48 proper, about which again not very much is known. One day the Soviet archives may open enough to give us more details, but for now our best idea is that it was long, flat-bottomed, triangular craft (with the two forward sides of the triangle much longer than the other one,) with a relatively simple faceted crew cabin for one attached to its upper surface. Its flat underside is particularly interesting, as it makes the M-48 one of the first waveriders, which is to say it took advantage of the shockwave on the belly of the craft to provide lift. The whole concept of doing this had only been discovered in 1951, and its discoverer (Terence Nonweiler) was only just developing a plan to use it (in the never-built British Nonweiler Waverider re-entry vehicle) as OKB-23 was doing the same. Waveriding is a difficult and sophisticated technique, and even in the 21st century only one aircraft has ever been built that used it, the 60s-era XB-70.

Perhaps it was that sophistication, as well as the general audacity of designing a spaceplane, that got the M-48 into trouble. When Myasishchev submitted his design for approval, it was savaged by governmental engineer/bureaucrats, and he had to head back to the drawing board. This time he came up with two designs. Though technically still the M-48, they’re sufficiently different from the original (and from each other) that they’re usually referred to by their alternate designations: VKA-23 design 1 and VKA-23 design 2.

The first of the two designs was similar to what he had done with the M-48, but with changes intended to address the objections to the previous design. It would have been 9.4 meters long and built of steel and titanium, which would then be covered with ceramic foam tiles embedded in a frame made of silicon and graphite. It would have been able to carry one pilot and 700 kilograms to orbit, with the entire loaded and fuelled craft weighing an additional 3500 to 4100 kilograms. This is very small, smaller than even SpaceShip One and only a few hundred kilograms heavier than the unmanned X-37 spaceplane. This size was dictated by the fact that it was to be lifted by one of Korolev’s R-7 boosters, which would do most of the work of getting it into orbit.

The second design is the particularly interesting one, though. In contrast with the first design’s faceted appearance, this one was a rounded lifting body, recognizably like almost every small winged re-entry vehicle developed since then. On the Russian side this is not coincidental. The chain of proposed Soviet mini-spaceplanes running from Raketoplan to Spiral to LKS to MAKS are all dependent in one way or another on the work done on it, or the engineers who developed it. Like design 1, it had to be light to go up on an R-7, and so it rang in at 3600 to 4500 kilograms, and its payload was the same—700 kilograms. It likewise used the same ceramic tiles and silicon/graphite frame as a heat shield. It was slightly shorter than its brother, at 9.0 meters.

Both would have been fitted with a small turbojet engine for maneuverability once they had reached the lower atmosphere during re-entry.

Despite its numerous descendants, the VKA-23 was still quite primitive. In both designs its one astronaut actually had to take a trick from the similarly basic Vostok and parachute out from it to safety once he dropped below 8 kilometers (but before getting to 3 kilometers); the plane itself would have had landing skids (design 1) or had a parachute to bring it safely to ground (design 2).

What happened to make it fail: In 1959-60 Khrushchev starting reducing the size and complexity of the Soviet military establishment. OKB-23 was dissolved in October 1960, and many of the VKA-23 engineers were re-assigned to Vladimir Chelomei’s OKB-52, where they became an important part of his Raketoplan spaceplane design team. When that too was cancelled, they were moved to Mikoyan, where they worked on Spiral.

What was necessary for it to succeed: None of the original four designs was ever going to fly. Spaceplanes have turned out to be considerably harder than anyone ever suspected, and even the United States was far away from building one in the late 1950s and early 1960s. The Soviet Union was even less able to do so.

But In a sense, Myasishchev’s little plane came very close to succeeding in the long run. During all their travels through various Soviet design bureaus, a variable group of Myasishchev engineers kept a recognizable core of VKA-23 design 2 knowledge moving forward. A scale testing model of Raketoplan was launched on a suborbital re-entry experiment in 1961, and another model tested the design’s hypersonic maneuverability in 1963. The Spiral spaceplane got to the point of a full-scale subsonic version, the MiG-105, which was used to study its low-speed handling. Two sub-scale versions of Spiral, BOR-2 and BOR-4, were launched into orbit. Even the larger-scale Soviet shuttle that did finally fly in 1988 had its cockpit designed by the Myasishchev bureau, which was reconstituted in 1967. It had the name Buran, which was a nice callback to the manned Buran cruise missile plans that started it all in 1956-7.

Incredibly, the Myasishchev design bureau was still chugging along on their own distant descendant of the VKA-23 (after a long fallow period) as late as 2009—this time with the aim of using the result for space tourism. That dream finally died when they were acquired by the Russian government’s United Aircraft Corporation in that year.