Sidebar: The Langley Water Lander

langley-water-lander

A diagram of the Water Lander if it were full sized, as opposed to the one-eighth scale model that was built. Note the curvature of the wings as seen from the front, not coincidentally like the hull of a boat. Public domain image via NASA from Model Investigations of Water Landings of a Winged Reentry Configuration having Ourboard Folding Wing Panels. Click for a larger view.

There are two fundamental dichotomies in spacecraft design (or three, if you count the types of fuels used for their rockets). You have ballistic capsules in opposition to winged craft/lifting bodies, and you have water landings as opposed to coming in on solid ground. Three of the four possible combinations have been used by crewed spacecraft but one hasn’t: a water landing of a winged vehicle.

That’s not to say it hasn’t been examined, though. NASA studied the ramifactions of an emergency ditching of a Shuttle Orbiter (conclusion: a lot of damage to the underside, but it would stay afloat for a while as long as the wings weren’t badly holed), and the Australians famously photographed the USSR retrieving a BOR-4 test article from the Indian Ocean in 1983. Even earlier, the American ASSET, originally conceived for testing the alloys earmarked for the X-20’s heat shield, splashed down off Ascension Island after a suborbital jaunt from Cape Canaveral.

lander2

The Water Lander model in its tank. Public domain image from same source as previous. Click here for a larger view.

As far back as 1959, NASA was testing the concept using a water tank at Langley Research Center in Virginia. They had a chicken-and-egg problem, though. How do you build a water-landing spacecraft without tests to tell you what it will look like? But then how do you do the necessary tests without having it built first? Ultimately they had to just go ahead and build it based on first principles and common sense. What they came up with never had a name, so for convenience’s sake we’ll call it the Langley Water Lander.

The re-entry vehicle they posited was a light one, just 3600 pounds (1.6 tonnes), which is only a few hundred pounds more than a Mercuty capsule. Given that much of it was wings, it would have definitely seated only one astronaut, perched in a slim fuselage.

And it really was a lot of wing for its size, 27 feet from tip to tip and with an area of 263 square feet (7.0 meters and 24.4 square meters); it had no tail at all, though it did have a large vertical fin. The wing was gently curved, making a cross-section something like a boat so that the craft could rock from side to side on the surface of the water without the tips of the wings dipping below the surface. This was made even more unlikely by the fact that the wingtips were designed to fold up once the craft had gone subsonic.

On its underside were two retractable 4.7-foot × 0.67-foot (1.4m × 0.20m) water skis and a smaller triangular skid aft, roughly a foot to a side, for drag; this was found to be more stable during the final run-out than anything involving a single nose ski.

Thus configured, a one-eighth scale model was built and tested, with the conclusion that the landings were not so bad at all. The Water Lander wasn’t too sensitive to a little yaw in the touch-down, and even with small waves (eight inches high and fifty feet long, or 20 cm and 20 meters,to scale) the run-out was only three to four hundred feet with a maximum of 5.1 g deceleration. On smooth waters, it came in at under 3.0 g and 100 feet further travel after touchdown.

The Water Lander was never intended to be built for actual use, but rather was a reflection of where NASA was in late 1959. They examined a great many basic possibilities for the crewed space program, many of which have fallen into obscurity. In the case of winged water landers, the reason likely was that there’s no advantage to them. A ballistic capsule, almost uncontrolled, can benefit from a target as big as the South Pacific Ocean. But the whole point of a winged re-entry vehicle is that it can be directed once in the atmosphere, and if you can do that you might was well direct it towards a runway.

Source

Model Investigations of Water Landings of a Winged Reentry Configuration having Ourboard Folding Wing Panels, William W. Petynia. Langley Research Center. December 1959.

M-19 “Gurkolyot”: Grab the Problem by the Throat, Not the Tail

Myasishchev M-19 Gurkolyot schematic

A schematic of the M-19. Despite its great width and length, it was to be very flat, and mass only 500 tonnes. Image by the author, released to the public domain. Click for a larger view.

What it was: The Ministry of Aviation’s candidate for a Soviet shuttle, an apparent attempt to wrest control of the Soviet crewed space program away from the Ministry of General Machine Building. It was a runway-launched, single-stage-to-orbit spaceplane using a hydrogen propellant-based nuclear engine, designed by the Myasischev bureau that had previously worked on the VKA-23.

Details: After the first Myasishchev bureau was dissolved 1960 and many of its people moved to OKB-52, Vladimir Myasishchev didn’t lose his interest in spaceplanes. He became head of TsAGI, the Soviet experimental aviation bureau, then in 1967 was allowed to refound his own bureau, at which point he picked up from where he left off. A few years later the Soviet Shuttle project began, and Myasishchev was in the large camp of designers who were skeptical of the American design which slowly became the favorite behind the Iron Curtain.

Many years earlier, responsibility for the development of rockets in the USSR had been disavowed by the Ministry of Aviation and fallen instead to the Artillery wing of the Red Army. When ballistic missiles and rockets became the glamorous thing in the late 50s the aviation types came to regret their decision and repeatedly tried to barge into the business—Vladimir Chelomei came from the aerospace side of things, for example. Now that the USSR was in the large, reusable orbiter business, the Ministry of Aviation chose Myasishchev’s new bureau as their new champion and set him to work.

What the V. M. Myasishchev Experimental Design Bureau then proposed was a series of three craft, with several variations on each type, that would start with a high-speed test-bed and end with an orbital spaceplane. The middle craft was a reasonable knock-off of the NASA Shuttle, but the first and third were a radical alternative program. Back in the 1960s an engineer at NII-1 (“Institute of Jet Aviation-1”), Oleg Gurko, had come up with a novel concept for a SSTO, based around a nuclear reactor, the details of which we’ll explore shortly.

His suggestion got nowhere in the 60s despite his approaching both Myasishchev and Mikoyan, representing the Aviation Ministry for which he worked. Once work began on the Soviet shuttle, however, the Aviation Ministry’s interest picked up and the Myasishchev bureau was told to work on a proposal based on Gurko’s idea. Myasishchev himself realized that this SSTO would be a massive leap that would take a long time to develop, but he was uneasy with merely copying the American shuttle as that kind of a project would only be completed several years after the United States was flying (as indeed was the case, with STS-1 occurring in spring 1981 and Buran’s one, crewless flight being in November 1988). If his country was going to be behind anyway, why not work on a project that would at least offer the opportunity to leap ahead during the delay? He reportedly summed up his approach as “Grab the problem by the throat and not the tail, or else you will always have the tail”.

The breadth of Myasishchev’s ambition can be measured by understanding that the first plane in his program was not just a testing ground but, in order to bring the Ministry of Aviation on-side, was intended to double as an operational Mach 6 bomber flying at 30 kilometers up, twice as fast and fifty percent higher than the XB-70. The final plane was considerably more capable than even that.

Weighing in at 500 tonnes with fuel, the M-19 was a very flat, 69-meter long triangular wedge with two small sets of wings, one at the tail and one as canards near the nose. Launching horizontally from a runway, the M-19’s trip to orbit would begin with twin turbofan jet engines burning liquid hydrogen. After getting up to Mach 4, the plane would switch over to scramjet engines, also burning hydrogen. In both cases, though, the engines had Gurko’s idea behind them for a little extra kick.

The M-19 would have had a nuclear rocket engine that would take over in turn once the scramjet pushed the plane to Mach 16 and out of the appreciable atmosphere around 50 kilometers high. As the reactor was just sitting there during the turbojets’ and scramjets’ operation, Gurko reasoned, why not use it to superheat their exhaust to increase thrust? The potential increase in efficiency was considerable, and as the nuclear rocket (already more efficient than chemical rockets) would only be used for the final leg, the low inherent fuel use of the air-fed turbo- and scramjets gave the M-19 a tremendous payload fraction: the 500-tonne fully fueled plane was projected to lift 40 tonnes to LEO in its 15m × 4m cargo bay, which compares favorably to even staged rockets. Consider the Space Shuttle at 2040 tonnes and 28 tonnes of payload, or the Saturn V at 3038 tonnes and 118 tonnes of payload. To move whatever was stored in it, the bay was to be equipped with a manipulator unit, and an airlock from the crew compartment allowed EVA. Behind the bay was a large LH2 tank and, it should be made clear, no oxidizer tank. The rocket would run on raw hydrogen, while the two different types of jet would use the air as their source of oxygen.

After completing its mission in orbit, the M-19 would then fly back home, using the same propulsion systems in reverse order to come into a powered landing at an airstrip somewhere in the USSR, with an astonishing cross-range capability of 4500 kilometers. This completely plane-like return was of considerable interest to Soviet space planners for other reasons too, as it meant that the M-19 would reduce search and retrieval costs to nil as compared to capsules unless there was an emergency. Under those circumstances the cabin was to be entirely ejectable, serving as a survival capsule for the three to seven cosmonauts that might be on-board..

That the M-19 was perfectly capable of flying as an airplane in the lower atmosphere made it much more flexible too, as it could be moved to a different launch site relatively easily. And, as it didn’t drop stages on the way to orbit, it could be launched in any direction without worrying about what was downrange—a problem that’s particularly difficult for the USSR and Russia, and has led the latter to build its newest cosmodrome in the remote Amur region by the Pacific Ocean.

Even in space the M-19 was unprecedentedly flexible, able to make repeated orbital plane changes by diving into the upper atmosphere and maneuvering aerodynamically. Whether performing an inclination change or coming down to land, the M-19 was protected by reinforced carbon-carbon (like the Space Shuttle’s leading wing edges) and ceramic heat tiles.

The rocket for the M-19 was to be be built by the Kuznetsov design bureau, also the builders of the conventional engines for the N1, and would have been the first operational nuclear rocket in the USSR (and indeed the world).

Testing beforehand would involve several flying test beds to develop hydrogen-burning engines and scramjets, drop test articles, and the aforementioned hypersonic test vehicle/bomber. Though Gurko himself did not work for the organization assigned to build the M-19 he consulted on it, and the M-19 gained the nickname “Gurkolyot” (“Gurkoplane”). If given the immediate go ahead, the Myasishchev Bureau predicted that the final craft would be ready for flight in 1987 or ’88.

What happened to make it fail: First, Myasishchev’s bureau was absorbed again in 1976, this time into NPO Molniya, newly founded to make the Buran orbiter. The Soviet leadership had placed their bet on a close copy of the US’ Shuttle.

Second, even Myasishchev called the M-19 his “swan song”, and that his ambition was to set the USSR on the right course, not see it through. He was in his seventies even before preliminary work began on the spaceplane, and his death in 1978 took away the program’s biggest voice. While some testing of a jet engine running on liquid hydrogen took place in 1988 (in the modified Tu-155 jet), and the first Soviet scramjet was tested on top of an S-200 missile in 1991, by 1980 the M-19 had receded into the future as a possible successor to Buran, rather than a competitor.

Then the USSR came apart from 1989-91, and the future of the Soviet space program was forced into radically different channels.

What was necessary for it to succeed: This is an awfully tough one to assess, as the M-19 is by some distance the most technologically sophisticated spacecraft we’ve looked at. It was based around so many novel approaches (a nuclear rocket engine, a scramjet, preheating the jets’ air, SSTO, and so on) that it seems impossible even with current aerospace technology. Scramjets and SSTO in particular are two things which seem to endlessly recede into the future as we come to understand how difficult they are.

However, Myasishchev and his bureau acknowledged that it was a radical departure, that it would take a long time to develop, and that nevertheless they thought it could be done—and they were some of the best aerospace engineers in the USSR, if not the world. Who am I to say they were wrong?

Even so, it does seem like they were. The problem was not an engineering one (even if I’m skeptical that anything like this could fly before the mid-21st century), but rather an economic one. The M-19 needed time, and the USSR had surprisingly little left. How to fix the economic mistake on which that country was based? There are convincing arguments that it could not be fixed, and that at best the Soviet Union could have lasted only another decade or two past 1991 while becoming increasingly pauperized year-on-year—hardly the best environment for cutting-edge aerospace research. The M-19 simply could not fit into the time remaining, even with any reasonable stretch in the USSR’s lifespan.

Sources
Samoletoya EMZ in V. M. Myasishcheva, A.A. Bryk, K.G. Oudalov, A.V. Arkhipov, V.I. Pogodin and B.L. Puntus.

Energia-Buran: The Soviet Space Shuttle. Bart Hendricx and Bert Vis.

Sidebar: The Intercontinental Ballistic Vehicle

Intercontinental Ballistic Vehicle schematic

A schematic of the IBV as printed in LIFE Magazine, March 7, 1955 via Google Books. Artist unknown, possibly Michael Ramus. © Time, Inc. Click for a larger view.

We’ve previously discussed Eugen Sänger and Irene Bredt’s wildly ambitious Silbervogel, a suborbital spaceplane that they worked on in Germany prior to the end of WWII. Mentioned in passing at the time was Stalin’s interest in it after the war, and Mstislav Keldysh’s unsuccessful attempt to scale back its necessary technological innovations so that the USSR could build something similar. What we didn’t look at at the time was the high-water mark of Sänger and Bredt’s craft in the United States.

Their core design paper was translated into English in 1946 as A Rocket Drive for Long Range Bombers (and is readily available today on the web), but otherwise there was not a lot of interest in it in the West. Sänger and Bredt lived in France for several years after 1945, having secured positions there, but worked on other projects.

Grigori Tokaev/Grigori Tokaty

Grigori Tokaty (to use his preferred name) in 2001, more than a half-century after revealing Stalin’s interest in rocket bombers to the West. Public Domain image via Wikimedia Commons.

Then, in November 1947, Soviet rocket engineer Grigori Tokaev defected to the United Kingdom. According to him, Stalin had become aware of the work on Silbervogel, and assigned the trio of Tokaev, Stalin’s son Vasily, and future head of the KGB Ivan Serov to the case. The Germans scientists were to be convinced to come to the USSR (Tokaev’s preferred approach) or kidnapped (Serov, naturally, for a man nicknamed “The Butcher”). The pursuers were unaware that the two they sought were no longer in Germany, though, and none of the three trusted any of the others, so nothing came of it. In 1949, Tokaev became an author under the Ossetian version of his last name, Tokaty, writing several popular articles about Soviet ambitions with long-distance airpower and other then-advanced weapons, then getting into an extended war of words about them with the hard Left in the UK.

Into this furor stepped John Earley and Garret Underhill in LIFE’s March 7th, 1955 issue, with an article named “From Continent to Continent”. Based on their own understanding of Sänger and Bredt’s work, as well as Tokaty’s story, they sounded the alarm. Keldysh’s aforementioned failure would not become known outside the USSR for many years, and the two LIFE authors felt that instead the USSR was probably working on the project with alacrity.

Their particular iteration of Silbervogel was closely based on the German design with a few variations suggesting that the authors didn’t really know what they were doing (for example, changing its trapezoidal cross-section to a circular one, which would be hell on re-entry). Launched from a rocket-propelled sled it would get up to a speed of 10,600 MPH (17,000 km/h) and 113 miles (182 kilometers) in height, then skip/glide its way around much of the planet. On a sortie from the Soviet Union, the authors thought that this craft would fly over the Arctic, bomb the United States, and then make a landing in the Pacific “for recovery by submarine”—which seems a bit optimistic but may reflect the idea in Sänger and Bredt’s original paper that WWII German Silbervogels could land in the Japanese Mariana Islands.

Really, “From Continent to Continent” is a bit of a head-scratcher until one realizes that it’s not a proposal, but is instead largely a con job, presumably written for the purpose of stirring up trouble and increasing circulation. For example, as can be deduced from the previous paragraph, the authors took the particular tack of describing how the IBV would be used to attack the United States even though the ostensible purpose of their article was to suggest that the US build one themselves, by their estimate in three years for a mere $23 million. Its mission as an American craft was left unstated, and was surely not the exact inverse of their favoured blood-curdling scenario of a Soviet attack.

There’s also the way the article’s authors are described: “[John] Earley, a rocket designer, and [Garrett] Underhill, a former Army officer who is an expert in Russian weapons” looks crafted to make unsuspecting readers think that they were insider sources for another, different LIFE correspondent. They’re almost certainly the authors of the piece themselves, even though it’s unbylined. I can find no other references to John Earley, but Garrett Underhill was the military affairs editor for LIFE in 1955 and had been out of the military intelligence business for most of a decade. Incidentally, if you’ve heard of Underhill, it’s as a minor figure in JFK conspiracy circles who committed suicide in 1964.

Taken as a whole, the IBV is more interesting as a snapshot of its time than it is as a quite ill-founded proposal. In a way it’s the flip side of the contemporary Moonship of Wernher von Braun: it was a popularization of the future military use of space, as opposed to its scientific exploration. The major difference between them is that von Braun’s fundamental vision was the one that took hold, making the way it was laid out in Collier’s and by Disney into well-known classics. Meanwhile the IBV has long since dropped into obscurity.

LKS: The Buran Alternative

LKS spaceplane on Proton rocket

An LKS orbiter atop its Proton launcher at the launch gantry. Original source and copyright status unknown, but pre-dating 2004. Note the folded wings: most sources do not mention this feature, with the implication that LKS’s wings were fixed, but the LKS is sufficiently badly documented that even this basic question is not definitively answered.

What it was: A small, 20-tonne spaceplane intended for launch on top of a Proton rocket. From 1979 to 1983, OKB-52 touted it as an alternative to the Energia/Buran shuttle.

Details: Continuing the parallel, military-oriented space program of OKB-52 (previous entries so far being the LK-700, Almaz, and the TKS), we come to the LKS. In late 1973 the Soviet government decided to respond to the prior year’s announcement by the United States that they would be building the Space Shuttle. OKB-1 was given the task of examining a large spaceplane in the same class as the Americans’, while Mikoyan and OKB-52 were ordered to look at something in the 20-tonne range.

The convulsions of 1974-75 pointed NPO Energiya, the former OKB-1, in the direction of responding to the American Space Shuttle with a quite-close copy (though not before sketching out the MTKVP), and eventually the “Buran Decision” was made in its favour in 1976.

Governmental decision or not, the ever-contrary Vladimir Chelomei and OKB-52 carried on with their own spaceplane from 1976-79 to address what they saw as Buran’s deficiencies: it was smaller, lighter, would be quicker and cheaper to develop and, in their opinion, be almost as capable. They called their two-cosmonaut craft the LKS (“Legkiy Kosmicheskiy Samolet”), meaning “Light Space Plane”.

Inevitably the LKS was to be put on top of OKB-52’s workhorse, a Proton rocket—though not man-rated, the intention was to do so for also launching the TKS anyway. This dictated much about the orbiter, starting with its mass. The Proton-K used until recently could lift just shy of 20 tonnes to low-Earth orbit, which is a bit less than a quarter of either a Shuttle or Buran orbiter carrying a full payload. So while the LKS had a similar shape to its larger cousins by design, its launch mass was only 19,950 kilograms, with a length of 18.75 meters and payload of 4 tonnes (compare with 37.24 meters and 27.5 tonnes for an American shuttle). This is, not at all coincidentally, close in mass to the TKS, and the two can be thought of flip-sides to one another as OKB-52 tried to be everything to everyone while also integrating their proposals into the larger space effort envisioned by Chelomei.

The LKS orbiter diverged from the larger shuttles in a number of other notable ways too, even after being redesigned to be essentially a half-scale version of the US Shuttle Orbiter (earlier incarnations had twin tail fins and wings with a straight leading edge). Its in-orbit engines were to burn N2O4 and UDMH, like every other motor of note proposed for use by OKB-52. Its landing gear was peculiar too, with a steerable wheel up front and landing skids under the wings. Chelomei also proposed to use a renewable ablative re-entry shield rather than the ceramic tiles common to the American and Buran orbiters. As aerodynamically similar as it was, though, it still had the same ~2000 kilometer cross-range capability and would glide in to land at a similar speed (reportedly 300 km/h, a bit slower than the Shuttle’s 350).

OKB-52 had made a full-sized mockup of the orbiter by 1981, then Chelomei pounced during the period of Soviet alarm following Ronald Reagan’s “Star Wars” speech in March 1983. In a letter written directly to Leonid Brezhnev he suggested that the LKS could be used to quickly and cheaply deploy counter-missile lasers into orbit. Sources differ on whether this was as satellites in the payload bay, or if he meant a fleet of unmanned LKSes carrying the lasers directly—but most lean towards the latter.

What happened to make it fail: Having raised the profile of the LKS as a counter to SDI, Chelomei’s efforts came under the scrutiny of the Soviet military. A state commission was convened in September of 1983, headed by the deputy minister of defense Vitali Shabanov. It eventually came to the conclusion that the LKS would not be useful for missile defense; Chelomei was reprimanded for working on an unauthorized project. Previous setbacks on his projects never had much effect on the headstrong designer, but the LKS came to a definitive end when Chelomei died in August 1984. The mock-up was apparently destroyed in 1991.

What was necessary for it to succeed: OKB-52 were right that Buran would take too long and cost too much. Originally planned to fly in 1983, the Soviet shuttle made its sole, automated flight in November 1988; even then it was not completely fitted out and was only suitable for a 206-minute flight (and the next was not scheduled until 1993!) Something like 20 billion rubles, at a time when the ruble was officially marked at better than par to the US dollar, were spent on the program.

Even at the time there was resistance to the big orbiter, but NPO Energiya and Valentin Glushko‘s grip on the Soviet manned space program was firm. First you probably have to get it loosened somehow, though not so much that Chelomei and OKB-52 took over for them—as was discussed in the previous post to this blog, that would have left the USSR flying TKS spacecraft and not LKSes.

The difficult thing here is that if a small spaceplane got built there are two other, likelier candidates. Prior to about 1990 it probably would have been the other 20-tonne study mentioned at the beginning of this discussion, Mikoyan’s. The Spiral project got even further along than LKS did, to the point of a subsonic demonstrator and orbital re-entry tests of scale models. After 1990, NPO Molniya, builder of the Buran shuttle, floated the MAKS shuttle, which introduced the wrinkle of being air-launched by the An-225 superheavy cargo plane originally designed to cart Buran around.

As a result, unless one can cook up a Soviet leader circa 1983 who had the desire to save money of Mikhail Gorbachev while also having the willingness to rise to the challenge of the Strategic Defense Initiative, the LKS probably does not fly.

Sources

Light Space Plane, LKS“, Anatoly Zak.

‘LKS’, The Chelomei Alternative to Buran“, Giuseppe di Chiara.

Malysh v teni «Burana»: Sovetskiy legkiy kosmoplan“, Oleg Makarov. Popular Mechanics (Russian Edition) #93. July 2010.

“The Soviet BOR-4 Spaceplanes and Their Legacy”, Bart Hendricx, The Journal of the British Interplanetary Society, vol. 60. 2007.

Energia-Buran: The Soviet Space Shuttle, Bart Hendricx and Bert Vis.

Sidebar: Alexeyev/Sukhoi Albatros

albatros

A conjectural diagram of the Albatros launcher, by Mark Wade of Encyclopedia Astronautica. Click for a link to the associated article. Used with permission.

Rostislav Alexeyev built the latter part of his engineering career on ground effect, which is the demonstrable fact that a wing generates more lift and experiences less drag when it’s in close proximity to the ground than it does while high in the air. In general aircraft don’t take advantage of it when cruising because of the increased risk—the ground is right therein the event of something going wrong, but Alexeyev was an expert on hydrofoil design and felt that the problem was sufficiently mitigated by flying over water to be worth attacking. Between the Khrushchev era and his death in 1980 he built his largest ekranoplan (“screen plane”), the so-called “Kaspian Monster” (KM: korabl maket, “test vehicle”) which met a watery fate in an accident not long after Alexeyev’s demise.

If you’re the sort of person who’s interested in Soviet crewed spaceflight you’re probably the sort of person who finds Russian ekranoplans and hydrofoils interesting too, but you may be wondering where the connection is between the two that would cause the latter to show up on a  blog devoted to the former. The intersection of this particular Venn diagram is the Albatros, outlined in a remarkable letter to the British Interplanetary Society’s Spaceflight magazine, published in 1983.

Long-time readers will recall that the Soviet space program was in disarray for much of the early 1970s, with 1974 being the year of crisis. Vasili Mishin was replaced by Valentin Glushko as the man in charge, and officials higher than him forced a change in focus from Moon missions to a space shuttle and space stations. For a period of time everything was in the air, and as was endemic to the Soviet space effort various other empire builders tried to get themselves a piece of the pie.

The design bureau of OKB-51 lurked on the edges of the Russian space program right from the very beginning, but never managed to convert its expertise in high-performance aircraft into any concrete projects. In 1974 they teamed with Alexeyev’s Central Hydrofoil Design Bureau to make a claim on the shuttle project, as at the time it was not yet settled that the Soviets would emulate the American Space Shuttle closely to produce Energia/Buran (consider, for example, Glushko’s MTKVP, which also dates to the same time). Their proposal was named Albatros, and it’s, so long as the source, space historian and writer Neville Kidger, got his Cold War information right, the only triphibious spaceplane ever proposed, requiring both water and air to get into orbit and land for its return.

One can see what, perhaps, they were thinking: margins are punishing on space vehicles, and it takes only a little inefficiency to turn a potentially useful craft into something that lifts a uselessly small amount of mass to orbit. Using aircraft as airborne launchers has been mooted a few times, why not use a ground effect “aircraft” to squeeze a little more oomph into your package?

The result was a three-stage vehicle, the first of which would have been a roughly 1800-ton, 70-meter long, Alexeyev-built, hydrofoilnot a full-fledged ekranoplan, alasthat could be thought of as a maritime version of the Space Shuttle’s external fuel tank. It would carry 200 tons of LOX and LH2 to feed the initial boost of the second stage’s motors.

Mounted on top of the hydrofoil, the estimated 210-ton second stage would use the first’s fuel to get up the whole arrangement up to 180 km/h over the course of 110 seconds, using the Caspian Sea (or the Aral or Lake Baikal) as a runway. Then it would disconnect and launch itself off the now-empty barge to consume its own propellants. This stage would be a high-speed reusable winged rocket plane/booster from Sukhoi that would lift the third stage—the actual spaceplane, also from Sukhoi—to a high altitude. There the latter would kick itself into orbit while the booster coasted into landing, possibly under pilot control; sources don’t say if the booster was to be manned, but with Sukhoi’s background it likely was.

The final stage was a tail-less rocket plane, about 80 tons in mass and 40 meters in length, so comparable to the American orbiter. It was estimated to have 30 tons of payload to LEO and a crew of two. It would have been larger than but was otherwise similar in appearance to some iterations of the Hermes shuttle, or to a lesser extent the later Russian/European Kliper. It was the most run-of-the-mill part of the whole vehicle, its design actually being closer to the American shuttle than the MTKVP. The air-based launcher was a radical approach, if not unique, but the underlying hydrofoil was the truly surprising suggestion.

It’s not difficult to see why the idea never went anywhere. Even putting aside the two partners’ inexperience with designing spacecraft, their proposed setup is ludicrous on its face, with tons of volatile propellant skimming over the water at triple-digit speeds, regardless of what its engineers might have actually calculated and put to paper. The likes of Dmitri Ustinov would have blanched if asked to sign off on it, as the country’s internal politics made Soviet decision makers inherently conservative. If they were eventually driven to insist on a close analog to the Shuttle over other proposals, one can only imagine what they thought about this one.

Sources:

“Albatros”, Mark Wade, http://www.astronautix.com/a/albatros.html.

Kliper: Russia and Europe Try a Spaceplane

kliper-infographic

A schematic of the “permanent-wing” variation of the Kliper. The adapted Soyuz service module (hemisphere with docking pin at right) can be seen. Creative Commons Attribution-ShareAlike 3.0 Unported image by Julio Perez Suarez, via Wikimedia Commons.

What it was: A 2004-2006 joint project between Russia and Europe to build a small lifting-body/winged vehicle to replace the Soyuz and provide both groups with their own access to the ISS, as well as future stations. It also would have been able to fly short missions on its own without docking to an orbital facility.

Details: The Soviet Union and then Russia have tried multiple times to replace the venerable Soyuz craft—the Zarya capsule, the OK-M spaceplane, and the Buran/Energia shuttles that nearly pulled it off, among others—but never have done so. As of this writing they’re working on the PPTS spaceship, which seems to be making slow, unsteady progress and might fly before 2020. All have foundered on either Soviet politics or post-Soviet money problems and it’s not that the Russians haven’t been innovative in trying to fix the latter. Immediately prior to PPTS, RKK Energiya made a big push to get the European Space Agency on board with Kliper.

Kliper was based on work that Energia had already done in the 1990s, particularly an elaboration of it in 2002 that was the first to be called “Kliper”. But by 2004 Russian relations with the ESA were at a high point: work had just begun on the Ensemble de Lancement Soyouz, a Soyuz rocket launch pad at the ESA’s spaceport in Kourou, French Guiana, and so the Russians proposed expanding their co-operation to include a new spacecraft that would be launched on top of a substantially beefed-up version of the Soyuz, which they called “Onega” and eventually Soyuz-3.

The ESA’s Ariane 5 rocket was also powerful enough to lift a Kliper, but the Europeans were cool to the idea of launching anything but an unmanned ship on top of one. Even a Zenit rocket (derived from the side-boosters of the USSR’s last big rocket) was considered, but they’ve been under the control of the Ukraine since the collapse of the Soviet Union and the Russians have been leery of using them since then. In all likelihood, Kliper would have launched on top of a new Angara rocket—but the Angaras are still years away as of this writing, and the model likeliest to lift a Kliper (the Angara 3A) hasn’t even been begun yet. That was inconvenient to talk about, though, so the Onega it was, despite the fact that the most powerful variant of the Soyuz fired up until the end of 2004 was only about half as powerful as the one that would be needed. This new rocket was given specifications, with the idea being that it would use the N-33 engines that were to have been used in attempt to stop the N1 from exploding before that ill-fated program was cancelled. That said, it was very much a substantial project on its own.

The Kliper itself was, in 2004, a purely biconic lifting body—which is to say it had no wings at all and relied on its fuselage shape for its lift. By 2005, though, it had gained two small wings with large canards—the Sukhoi Design Bureau was brought into the circle to help with this aspect of the project. With the wings extending a mere 205 centimeters to either side of the 390 centimeter fuselage, the Kliper was a small package either way.

Three-quarters of the craft’s length—everything from its nose to the wings—were the re-entry module which would house its crew and passengers on the trip to orbit and during their return. Behind it was a tripartite service module consisting of a repurposed and upgraded Soyuz service module, a collar of support electronics as well as propulsion tanks and rockets for orbital maneuvering, and an Emergency Recovery System (ERS), which would push the Kliper the rest of the way into orbit if the rocket it was on failed near the end of the ascent to space—and give the craft the final necessary kick to high orbit and the ISS when the rocket worked well. While in orbit the Kliper’s service module would deploy two rectangular solar arrays to supply the spacecraft with electricity.

A mission would begin with the rocket stack being assembled horizontally and the Kliper placed on it. The resulting assemblage, some 47 meters in length of which the Kliper took up 12, would be transported to the pad and hoisted into a vertical position next to the gantry. As with a typical Soyuz launch, the Onega (weighing some 700 tonnes fully fuelled, of which the Kliper and its contents would be 15 tonnes for the lifting body version and 16-17 tonnes for the various winged iterations) would fire its four outer boosters alongside the central rocket engine to get the craft underway, then after they had burned through their propellants they would separate. The central rocket would then throttle up to full and get the Kliper most of the way to 100 kilometers up.

Five minutes after launch the central rocket would also be out of fuel and would detach, at which point the Kliper would coast for 10 seconds, jettison the aerodynamic faring around its ERS, and burn those engines for three and a half minutes to climb into the a 130×370-kilometer high orbit. The ERS would then be ejected too. This would get the Kliper’s perigee to within a few tens of kilometers of the orbit occupied by the International Space Station, and one more burn by the service module’s thrusters a half-orbit and 45 minutes later would circularize the path taken by the craft and allow a final approach to the ISS over the course of a day or two.

The final design of the Kliper approached launch slightly differently, so that it could be fully reusable—rather than have an expendable ERS, the craft would be serviced by an orbital tug named PAROM. Kliper would get to a low orbit on top of its Soyuz-3 and the PAROM (which would be docked to the ISS most of the time) would sally forth from the station’s higher orbit, attach itself to the aft end of the Kliper, and then carry up to higher orbit and a station docking.

Upon arrival at the station the Kliper would back into its berth, using the usual Soyuz-style docking pin and station docking rings to bring the two together and establish a solid connection. By itself it could last five days in orbit, but it could linger for a year if attached to the ISS’ systems.

kliper-reentry

The wingless Kliper variant comes in for re-entry and landing. Image source unknown, believed to be RKK Energiya.

For re-entry the craft would reverse the maneuver that lifted the lowest point of its orbit so that now a half-orbit sees it dip into the atmosphere. A final burn at this point would keep the Kliper at that height and the approach to home would begin. From orbital speeds down to Mach 1 the Kliper would act as a pure lifting body, starting at a high angle of attack slowly tilting forward as its speed dropped. The goal at this point was to keep re-entry forces to less than 5g and ideally below 3, and temperatures to no more than 1500 Celsius. The version of Kliper with foldable wings would deploy them when the craft dropped below the speed of sound, and either these or the permanent wings of the other main winged design would make the Kliper considerably more controllable as well as increasing lift and flattening out the ship’s descent as it came into a runway landing—the permanently winged version had a cross-range capability of 1200 kilometers, quite similar to that of the US’ Space Shuttle. The pure lifting body version of the Kliper had it deploy a parawing as it made its final approach, and one way or another it would be down to 65 kilometers per hour or so before its wheeled landing gear touched the tarmac. The pilots and passengers would then exit (or be retrieved, if sufficiently enervated by weightlessness) through the hatch on the tail end of the craft.

When first proposed in 2004, the idea was to have the Kliper flying no later than 2012. The very final versions of Kliper, studied by the Russians as a solo project in 2008, aimed for 2018. Each Kliper would have been good for sixty missions over the course of a fifteen year lifetime.

What happened to make it fail: Reports are that the European Space Agency’s various national factions couldn’t come to an agreement with Russia and RKK Energiya. In particular they couldn’t convince a majority of Europe’s “Big Three” in space (Germany, France, and Italy) because all think that a large part of the ESA’s value is that it lets them develop local high-tech skills and industries. Kliper would have been built on Europe’s dime but be designed and built almost entirely in Russia; while the ESA would end up with a manned spacecraft and the necessary infrastructure to launch it at the end of the process (as well as the prestige value of a manned space program), that it and of itself was not worth the cost. By December 2005 any chance of Kliper being built as a co-operative project had disappeared and Russia simply didn’t have the finances to do it themselves.

The possibility of continuing to work with Russia was maintained in June 2006 when Roscosmos and the ESA reportedly agreed to study the so-called ACTS (Advanced Crew Transport System), but this was a ballistic capsule. By Spring 2008, though, the two had completely gone their separate ways, with the Russians carrying on developing an early design of the ACTS that would eventually become the current PPTS spacecraft project.

What was necessary for it to succeed: As mentioned earlier Russia has moved on to the PPTS, while Europe is in the process of converting their unmanned ATV—currently used to take supplies to ISS, and itself derived from the work on ACTS—into a service module for the upcoming American Orion Crew Module. Whether or not this turns into a permanent arrangement remains to be seen (currently it is only for one Orion mission, Exploration Mission-1, which is scheduled to make an unmanned loop and return around the Moon in 2017), but at the very least the ESA will have developed one half of a manned spacecraft. The contrast with the way they were going to get much less experience and skill development with Kliper should be noted. The ESA had begun talking about adapting the ATV into a manned craft of their own in May 2008, in the wake of the Kliper and ACTS proposals failing.

This is, then, the one way to get Kliper flying: square the circle of Russian ambitions to build a spacecraft that someone else paid for while also getting two of Germany, France, and Italy a sufficiently large chunk of the interesting development work that they would sign on. The wildcard here is Japan, which expressed interest in joining the program if the ESA signed on for certain, but was in the middle of a long, deep recession and so uninterested in giving major financial support unless the ESA did. But other under circumstances they may have supplied a trickle of money large enough to get Kliper going, then stayed with it despite the inevitable money-related delays if the ESA pulled out later.

German illustrator Armin Schieb has made available a free book of computer-generated images (his master’s thesis) of a simple Kliper mission from launch to hypothetical future space station to landing available through Google Books. It gives a good idea of how Kliper might have been.

http://arminschieb.com/tag/kliper/

HL-20/HL-42: The Personnel Launch System

hl-20-leaves-station

An HL-20 leaves Space Station Alpha, while another stays docked as a lifeboat. Detail of a painting by NASA artist Bill Kluge. Click for a larger view.

What it was:  Two closely related spaceplanes and their associated launcher, in turn related to a number of other projects, which were studied in the late 80s and early 90s as a way of getting astronauts to and from Space Station Alpha or the ISS. This included rescue missions in the event the space station had to be evacuated quickly.

Details: On January 28, 1986 the Space Shuttle Challenger exploded and the American manned space program entered a period of reflection. In the end the result was to continue flying Shuttles at the cost of them never approaching the rate or affordability pictured for them in the early 80s, let alone as they were originally envisioned.

The field was wide open for other possibilities, though, and into it stepped the Personnel Launch System (PLS) consisting of the HL-20 and either a Titan IIIC rocket or a Titan IV. Together they were intended to address a number of perceived problems with the Shuttle, particularly in conjunction with a space station: its cost and complexity, its lack of a crew escape system, and its inability to stay attached to the station for very long (partly for technical reasons and partly because it was sheer overkill for most reasons why you’d want to leave one attached).

As designed the HL-20 was a small spaceplane about 7.5 meters long, 7.2 meters in width, and 10,884 kilograms; the HL-42, proposed a few years later, was so-named because it was almost exactly the same design but 42% larger in each direction. At the time they were the latest in a long line of NASA lifting bodies going back to the “Flying Bathtub”, the M2-F2 the HL-10. Furthermore they benefited from what was known about the MiG-105 and BOR-4 lifting bodies, respectively a subsonic test article and an unmanned subscale version of the Soviet Spiral spaceplane, the latter of which had been seen in an overflight by an Australian Air Force plane while being recovered after a re-entry test.

hl-20-on-titan-iiic

To begin the HL-20 was to be mounted on a Titan IIIC, but before long the plan was to use a Titan IV instead. Image from Personnel Launch System Study, Final Report. Click for a larger view.

The initial proposal was that the HL-20 would have been attached to a Titan IIIC, an Air Force rocket that had just enough strength to lift it into low earth orbit; it had the additional advantage that there was a man-rated version which had been developed in the early 60s for launching the never-flown Air Force spaceplane Dyna-Soar. This plan did change quickly, though, as the USAF had moved on from the Titan IIIC—its last flight was in 1982—and started flying the more powerful Titan IV in 1989 just as the PLS was getting warmed up.

The HL-20 was proposed and championed by NASA’s Langley Research Center, but most of the work on it was done by Rockwell International and Lockheed’s Advanced Development Projects (more famously known as the Skunk Works). Their intention was to develop something relatively simple that could be flown ten to twelve times a year, and deliver from eight to ten astronauts and a minimum of cargo to the space station; as time went by an initially speculative mission to serve as a lifeboat for station crews gained in importance too. To that end they came up with a glider which had no main propulsion engines, unlike the Shuttle, and only orbital maneuvering engines. Once paired up with the powerful Titan IV, some of the systems needed for launch were moved into a fairly heavy adapter (4435kg) at the aft end of the craft which attached the HL-20 to its launcher, a strategy similar to that used on the final versions of its contemporary, the Hermes.

Technically the HL-20 wasn’t a winged craft but a lifting body: its curved shape provided its lift. By eliminating actual wings sticking out from the fuselage of the plane it became easier to build and reduced heating complications at the joints between wing and body. Somewhat surprisingly, though, the complication was added back in by making the “wing” tips of the body hinged so that they would fold up over the top of the craft, the intention being to make it easier to transport by making it smaller in this configuration.

The most important difference between the HL-20 and the Shuttle, though, was its abort systems. Once the Shuttle was launched, or when it was re-entering, there were no provisions for emergency escape—either the Shuttle made it where it was going as a whole or it didn’t make it at all. The HL-20 was to have been equipped with emergency escape rockets to push it away from a failing launch vehicle on the pad, and further up in its trajectory it could be brought back to Earth underneath three parachutes. In those cases it wouldn’t have enough speed to land as it normally would—horizontally on a runway of choice—so it would aim for the water tail first and be supported by inflation devices around its aft end until rescue came. There were times where the crew would have no options during an HL-20 missions (often because the Titan IV used toxic UDMH and N2O4 for propellant, which even the Russians baulk at using for manned missions), but unlike the Shuttle the astronauts at least had a chance in some of the ways a mission could go very wrong.

Like the Shuttle the fuselage of the HL-20 was to have been built out of aluminum, but its outer surface was more advanced. Where the Shuttle had ceramic tiles applied to a substrate before being attached to metal, the HL-20 would have had a graphite/polyimide composite outer skin that had the same heat expansion properties as aluminum; this would have let the tiles be directly attached to the hull.

Upon arrival back home the HL-20 had one more potential advantage. If it were returning long-term station crews who were physically weak after being in freefall for months, its hatch was specifically designed to be large enough that astronauts could be retrieved easily from inside. In a joint effort on NASA’s behalf, North Carolina State University and North Carolina A&T University built a full mockup of the craft to test out this and other human factors of the crew area

What happened to make it fail: Both vehicles needed the Titan IV for launching and that meant cutting a deal with the Air Force, which controlled that particular launch vehicle. This was particularly true as the Titan IV wasn’t man-rated, and so would have had to go through an expensive run of upgrades and tests before astronauts could be perched on top of one. The USAF wasn’t interested, perhaps in part because the Titan IV was the result of the Department of Defense wanting to divorce themselves from NASA after the Challenger explosion grounded their satellite launches. Instead they went ahead with the development of the Delta IV and Atlas V rockets.

NASA might have managed to push things forward anyway by offering the Air Force more, or developing their own launch vehicle to tempt the DoD back into bed (a rocket called the NLS was roughed out), but spending more money like that ran into another wall. When Space Station Alpha became the ISS, the hybrid nature of the station opened up another possibility for getting people to and from it: the Soyuz spacecraft and its associated launcher. Simply renting taxi rides on Russian spacecraft and leaving one attached to the ISS as a lifeboat turned out to be a lot cheaper. NASA took this actual route, swallowing their own national pride and (temporarily, at least) leaving the US without a functional manned spacecraft program for the first time since 1981.

What was necessary for it to succeed: This is another one of those projects that needed the USSR to continue for a little while longer, with the added twist that it’s not a Russian program but an American one. Once the Soyuz became available only a considerably more capable American craft would get the go-ahead, and the HL-20 didn’t qualify. The HL-42 was then proposed, the whole reason for its increased size being that it could carry more people than a Soyuz and so allow more crew aboard the station. This approach became pointless when the ISS was upgraded to allow two Soyuzes to be docked at the same time.

If history diverts so that the Russian part of the ISS disappears, though, possibilities open. While it’s conceivable that an all-American station would have gone ahead without any lifeboat capability at all, it’s not likely. And while NASA gave lip service to developing their own ballistic capsule for that purpose, there was much more internal support for a winged craft. This left only two possibilities at the time, either something like the X-24A (an approach that was revived for the X-38 CRV in the late 90s) or something like the HL-20. At that point it comes down to capability: it’s hard to fit fuel tanks into the X-24A fuselage shape, so do you want to be able to maneuver in orbit? If so, you’d be better off with an HL-20 or HL-42.

Given NASA’s inclination to go for more capable (and more complex) projects, it seems likeliest that in the absence of anything other than the Shuttle for station crew return they’d have gone for the full Personnel Launch System rather than a mere return-only lifeboat based on the X-24A.

As it happens, there’s still one more possibility for the HL-20 to fly. It’s a slick little design, and there have been two commercial attempts to revive it. Orbital Sciences Corporation proposed a derivative of it, Prometheus, for the initial phase of NASA’s Commercial Crew Development competition, which is looking for a commercial craft to deliver crew to the ISS; unfortunately for the HL-20 it didn’t make it through to the second round. However, a second HL-20 proposal, this one from Sierra Nevada Corporation, did, and furthermore proceeded on to the third round too. Their Dream Chaser proposal is considered to be the third likeliest to ultimately win the competition out of the three remaining competitors (the other two being the Boeing CST-100 and SpaceX’s Dragon, both ballistic capsules), but stranger things have happened.

Hermes: The European Spaceplane

hermes-spaceplane-cutaway

A cutaway diagram of one of the later designs of the Hermes spaceplane. Like all later versions it has an expendable payload and airlock bell at the aft end. Only the plane itself would re-enter for re-use. Image source unknown. If you know where it comes from, please contact the author. Click for a larger view.

What it was: A project by the French national space agency CNES (Centre national d’études spatiales) beginning as early as 1975—eventually expanding to an ESA-wide effort in November 1987—to produce a small spaceplane. Launched on the then-yet-to-be-developed Ariane 5, it would have given Europe an independent manned space capability sometime around the turn of the 21st century.

Details: The Ariane 5 has been the ESA’s workhorse launcher since 2003, and has been that space agency’s heaviest launcher since 1998, yet it will never fulfill what was its original mission: to be a part of Europe’s manned space program. Hermes began as internal discussions at the CNES in 1975 for a winged re-entry vehicle to be launched on the Ariane 4, but by 1978 it was decided to upgrade the capabilities of the mooted craft. This would push its mass above anything the Ariane 4 could lift, so a brand-new, more powerful rocket was assumed. The French began their work on the Ariane 5 specifically because of the spaceplane they wanted to build.

The craft they wanted to design in 1978 was given a few basic specifications. It would weigh approximately 10 tonnes and be less than 12 meters long. It would carry five astronauts, two of them pilots, or with just the two pilots have a cargo capacity of 1500 kilograms to low Earth orbit with maximum mission duration of two weeks. Launched vertically, it would land horizontally on a runway.

This, like every other Hermes configuration, didn’t last for very long. For the rest of its existence as an active program, Hermes would suffer from repeated cycles of feature creep and then a battle to get its weight and cost back down to something its budget and the Ariane 5 could handle. In March 1986,  having come to the conclusion that they could not afford the spaceplane by themselves, the French government informed the ESA that they were going to formally push for the “Europeanization” of the project. In the meantime Dassault and Aerospatiale in France were given the go-ahead to start designing and building.

Unfortunately opening up spaceplane to the rest of Europe brought in too many stakeholders. The first (and longest lasting) problem stemming from this approach came with Ronald Reagan’s State of the Union Address on January 24, 1984. In it he proposed that the United States build a permanent space station, and the ESA fell into factions: one wanting to build an independent European presence in space and one looking to continue their partnership with the United States on the Space Shuttle and do the same on the space station project. There was even the possibility of trying to find a hybrid path between the two. Hermes was pulled in different directions depending on which of the possibilities it was supposed to supplement.

In the complicated setup of the ESA, there was a constituent for every possible way to move forward. Of the ESA’s “Big Four”, the French were the most devoted to Hermes as an independent system, while Germany was willing to go along but inclined to work on space station Freedom; their major concern came with an understanding that the station might not be built out of Spacelab-derived components, that program being Germany’s main space science effort. Italy was inclined to the space station as well, while the UK was cool to Hermes as they were considering a spaceplane of their own, HOTOL.

The Challenger Disaster in 1986 brought many doubters on-side, as Europe’s access to space was affected as much by it as the United States’, then NASA’s political faux pas of introducing a US$14.5 billion first design for Freedom brought even more to the table when Congress decided that it was far too expensive for their blood. While a cheaper station re-design was soon underway, the uncertainty over relying on the US finally convinced the ESA to come to Hermes completely as part of a three-pronged compromise plan in November 1987. The Ariane 5 would continue; Hermes would be put on top of it and be capable of missions to Freedom and on its own; Europe would also develop a space station module, Columbus, but hedged its bets as to whether or not it would be specifically associated with Freedom or be a small, independent, European space station in association with another project (the Man-Tended Free Flyer) maintained by Hermes launches.

This was Hermes’ high water mark: fully funded with political backing from all of the ESA’s players, and the cornerstone of a fairly impressive little manned space program that made Europe a strong #3 in space behind the US and USSR. Politics and engineering began to complicate the picture, though.

What happened to make it fail: The politics were two-fold. The US’ gyrations over Freedom kept the Hermes coalition together, but complicated the compromises that had been made. NASA managed to get a plan approved and formally arranged for Europe to be part of the station with the MTFF free-floating nearby with Columbus being attached to the rest of the station modules. This made it harder to design, as now it had to cover three possible outcomes instead of the already difficult two.

Meanwhile the US Congress kept interfering with the budget for building Freedom, slowing and even temporarily stopping the allocation of funds. By 1990 it had become clear that the redesign itself was overambitious and the project was halted until a second, smaller redesign (the sarcastically named “Space Station Fred”) could be made. Finally in 1992 “Fred” itself came within a whisker of dying before being turned into a hybrid of Fred and Mir-2, the latter not getting built either because of the collapse of the Soviet Union. While all the turmoil gave the independent-Europe-in-space coalition more steam—the ESA committed to pairing up the MTFF and Columbus as a completely independent station—it piled more and more redesigns on top of all three components of the plan in order to save the compromise deal. This made the work even more long and complicated—and expensive.

The second political difficulty was a combination of the USSR’s end and the increasing expense. With the collapse of the Soviet Union Germany was free to re-unify, but at the cost of dragging the former East Germany up to West German economic levels. Combined with a coincidental recession in 1990-91, none of the ESA’s Big Four were willing to pay for the Hermes’ ever-increasing expenses, and even had difficulties coming up with the money they had promised in the first place. Germany itself stayed with Hermes only because the MTFF was their baby just as the spaceplane was France’s, and building it would have been pointless without some way of getting astronauts to it.

hermes-detachable-cabin

A version of the Hermes’ detachable cabin. Later the whole nose would come off, then that was replaced with ejection seats.

Finances aside, the ultimate killer was the engineering side of things. Partly to accommodate the necessary compromises and partly because they didn’t know any better, Hermes’ weight kept increasing past the limit of an Ariane 5’s lifting capacity, launching yet another redesign to bring it back down again. Payload capacity suffered more often than not, and as Hermes’ payload was never large to begin with it was constantly flirting with an inability to carry anything to orbit at all. This led to one major redesign: the deletion of a detachable crew cab for emergency escape and its replacement with lighter ejection seats derived from those used on the Soviet space shuttle, but other safety concerns in the wake of Challenger had brought the vehicle’s safe re-entry weight well below the launch weight they were already having trouble meeting.

In an attempt to fix both problems, 1989 saw a major redesign of the spaceplane. Most of Hermes’ payload and the airlock to exit the craft were moved into the adapter that attached the spaceplane to its Ariane 5. Upon reaching orbit the adapter, now renamed the MRH (Module de ressources Hermes) would remain attached to the aft end of the Hermes, then be jettisoned at the end of each mission before re-entry. While clever, this once again increased costs as the system was no longer completely re-usable.

The Hermes program was designed from the beginning to have a second “go forward/stop” decision made at the end of 1990, and as the deadline approached it was clear that the spaceplane was in a lot of trouble. France negotiated with rest of the ESA for a one year extension to the initial phase of the program, and then when that didn’t prove to be enough a one-year “period of reflection” before the final decision was made. In the interim the building schedule for the first launch was extended from 1999 to 2000 (having been pushed back from its initial 1995 several times already), and the number of Hermes to be built was cut from two to one. It wasn’t enough.  At the end of 1992 the ESA formally decided that it was not technically possible to build Hermes with the necessary capabilities without a radical increase in budget. Hermes was cancelled and the ESA moved on (for a while) to partnering with the Russian space agency Roscosmos to develop new ways of getting astronauts into orbit such as Kliper.

What was necessary for it to succeed: This program was the most serious effort by any group or nation to put a man into space outside of the US or USSR before the Chinese succeeded in doing so in 2003. Even so, it’s a cautionary tale for any space program as even if the politics worked out (and they were such a morass it’s a bit hard to see how they possibly could have), the engineering was never going to work.

Even if Hermes’ design had been locked down at an early stage (and an inability to come up with something and stick to it was a proximate cause of the failure), the problem was more fundamental. Europe was trying to do something that had never been done before even though this was their very first attempt at building a spacecraft. The US Space Shuttle and the Soviet Buran were considerably larger than Hermes would have been, which at first would seem to make it easier to build. While true to a certain extent it meant there was less room for error as the spaceship’s weight grew. The Shuttle, for example, was initially projected for about 30 tonnes to LEO and when built instead could carry 24.4 tonnes at best—an unfortunate loss, but not a show-stopper. On Hermes losing five tonnes like that, or two (or even one) pulled the craft into the red. And European inexperience in space technology made this kind of problem inevitable,

In the early 1980s there were proponents of a capsule for Europe’s first spaceship, to the point that the British pushed one from British Aerospace for a while. They didn’t go ahead because spaceplanes were “in the air”: STS-1 had flown from 12-14 April 1981, and it was well-known that the Russians were building one too. Even the Chinese were not far away from considering their own.

In going this way, though, Europe doomed themselves. The Ariane 5 was built, as was the Columbus module (sans MTFF); this makes the ESA’s effort by far the most successful failed attempt to build a manned space program ever. But the Hermes was the cornerstone of it, and so sowed the seeds of that overall failure from the start.

STAR: The USAF’s “Everything” Spacecraft

STAR-cutaway

STAR, the Space Technology and Research Vehicle. Based on a Poseidon missile MIRV (though upscaled), by the 1980s it was a candidate to be a research spaceplane in the mold of the X-15 as well as a cheap, re-usable operational craft for the USAF. Public domain image from the DARPA document Spaceplane Technology and Research (STAR). Click for a larger view.

What it was: An early 1980s proposal to build a research spaceplane along the lines of the X-15 program of the 1960s. To defray costs it would also have been an operational system, designed to do as many things as possible as a supplement to the relatively limited Space Shuttle. It was a slim, small spaceship capable of taking one crew and would have been taken to orbit in the cargo bay of the Shuttle, on top of a modified Peacekeeper missile, or eventually part of an air-launched stack fired from underneath a heavy-lift version of a 747.

Details: In the early 1970s the US Navy looked at a submarine-launched manned spacecraft intended to attack Soviet spy satellites in the event of a war—the idea being that it could be launched from an undetected submarine, perform its mission in less than one orbit, and then return to Earth before being picked up by Soviet radar.

The basic concept foundered on fitting the so-called “Space Cruiser” into a Poseidon missile tube aboard a sub: even a much stripped-down design was hard pressed to fit into one. Anything that could fit wasn’t even going to get to orbit on its own. There’s not a lot of detail available about this early phase of STAR, but one presumes that a submarine looking to send one into space would have to surface, and then have the sub crew remove it from one tube and place it on top of a warhead-less missile in another.

Ultimately the Navy lost interest, but one part of the initial design lived on. The Space Cruiser was a very long, thin cone, taking advantage of work that had been done on the hypersonic characteristics of the MIRV warheads for the Poseidon missile—though much larger, the Space Cruiser would have encountered the same conditions during re-entry.

The designer of the alpha version of the craft, Fred Redding, was a civilian contractor and so by the late 70s he had managed to extract his work from the Navy and revive it under the auspices of DARPA and the US Air Force. Now the Space Cruiser—redubbed Spaceplane Technology and Research (STAR)—would be launched more conventionally, but otherwise was very similar: long and pointed, with only a minor change from a circle-based cone to one with an elliptical base. This had the twin advantages of increasing its internal volume (as the STAR was always starved for propellants) and turning the craft into a lifting body: the original Cruiser needed small aerodynamic strakes, which were difficult to make in a way that could withstand re-entry, but STAR would have stability and cross-range capability solely as a consequence of the shape of its fuselage.

The bigger change in STAR was its goal. Reading the project’s final report from 1984, one gets the sense that Redding felt burned by the Navy withdrawing funding. Accordingly this time he spread STAR’s purpose as far and as wide as possible. For DARPA he was proposing a research craft, specifically modelled on the X-15, that would provide insight into flight into hypersonic travel in the atmosphere, in low Earth orbit, and even as high as geocentric orbit. Paired with this were suggestions from a large number of defense contractors for research questions, with the goal of demonstrating that private industry might pony up some or all of the necessary money for flights that investigated them.

The Air Force got a research vehicle too (Redding specifically mentions a mandate from the Air Force’s Aerospace Medical Division to gather biometric data on humans in microgravity), but for them and the Department of Defense STAR was more an operational vehicle. While the idea was that at first it would be primarily for research it would be extended in a variety of ways as more was learned about flying it. STAR was also specifically tuned to address a number of failings in the Space Shuttle both from the standpoint of the American military and the Shuttle’s overall capabilities, such as lack of maneuverability in space, inflexible launch schedules, and the vulnerability of its launch facilities to military attack.

The basic STAR was intended to be as small and cheap as possible. It would take only one man to space, and do it in Spartan style. The crew compartment would be unpressurized and was only big enough to sit in: the astronaut would have to stay seated in a spacesuit for the duration of his mission. The craft would have no hydraulics, or an ejection seat, or even landing gear. Instead it would finish its ride home under a parawing, like the one originally planned for Gemini. As it would usually end up on land in the US and was relatively simple in design, refurbishing costs and turnaround time would be kept at a minimum. As the lack of an ejection seat suggests, Redding was also a bit contemptuous of the safety culture that had evolved in NASA since the mid-60s, and spec’d his proposal to the test-as-you-fly/fly-as-you-test standards of years earlier.

STAR itself wasn’t intended to get into space under its own power, and is best thought of as an orbital runabout. It would have been eight meters long and only a meter and a half tall at its aft end, tapering down to a fine point at its nose. The nose itself was designed to fold back at a hinge four meters down from the tip of the STAR, producing a compact package just four meters long. While it wasn’t the primary reason for the folding nose, Redding points out that the cost of shipping something in the Space Shuttle’s cargo bay was the greater of two numbers based on length and mass (a mere 4500kg in the case of STAR, folded or unfolded), and so the compacted version would save quite a bit of money at a time when NASA’s carriage fees were rising dramatically.

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The more-capable STAR/Centaur-SP combination, which would have been capable of getting to geosynchronous orbit. The Centaur tank could be left behind for use as a small space station module. Public domain image from Spaceplane Technology and Research (STAR).

At first the Shuttle would be used to lift a STAR into orbit, and potentially even two or even three at a time, and deploy them from its cargo bay. Once there it could tool off on its missions and either return to the Shuttle when done or head back to Earth on its own. In situations where the STAR needed to go higher than its on-board propellant would allow (a figure of about 1650 kilometers is quoted), the Shuttle could instead lift a STAR mated to a truncated Centaur stage with a single RD-10 engine, dubbed the Centaur-SP, an arrangement which would just fit into the NASA craft’s cargo bay lengthwise. On top of one of these, a STAR could travel as far as geosynchronous orbit and return, plus the plan was to keep the emptied Centaur tank in orbit to use as the base of a small space station if so desired.

Being able to divorce themselves entirely from NASA was apparently one of the Air Force’s goals, because the plan was to eventually move STAR on top of its own launch vehicle. Mid-term, the idea was to put it on top of a man-rated three-stage MX Peacekeeper missile, then the newest and hottest rocket in military hands (the first of them had been test-fired the year before the STAR proposal was published). One wouldn’t be able get a STAR to orbit by itself, but the STAR could do the rest of the work and reach LEO with some internal propellant remaining.

This was less than ideal, though, as the STAR’s peculiar shape didn’t allow for much fuel on-board and ideally you wanted its tanks full after leaving the atmosphere. This led to the long-term solution, developing an air-launched launch vehicle. Nose folded, the STAR would be put in an aerodynamic fairing on top of a two-stage rocket. The first stage would be a Titan III derivative and burn LOX and LH2, while the second would be one of the aforementioned Centaur-SPs. The Titan III stage would be assisted by two recoverable strap-on boosters again derived from a Titan III, but not as tall and so carrying less fuel.

This whole works would then be strapped to the underside of a 747-200F, the freighter version of the then-current intercontinental 747, with its landing gear increased in height by four feet and fixed into place to make room for its spacebound passenger. The jet would take off normally and lift the STAR stack to an unspecified height and then drop it, at which point the stack’s engines would fire and the astronaut aboard begin his climb to orbit.

However it got there, once the STAR was on its own in space it would burn N2O4 and a blended fuel based on UDMH located in two tanks immediately to fore of the pilot. In front of that, just past the nose hinge, was the payload bay. As can be imagined, the bay was not large: just eight cubic feet, or 0.2 cubic meters.

While it was up and moving around, STAR was intended to have a variety of operational missions. It was proposed to use it as a repair craft for satellites, a way of getting a man close up to a satellite just for inspection purposes (including potentially for objects not belonging to the US), and even as a weapons platform for shooting them down. It could be used as a rescue craft, and was cheap enough and small enough to engage in “buddy system” missions needing two STARs in orbit at the same time.

Once its mission was done, the STAR would return to Earth. As mentioned previously the craft would have an elliptical conical shape, which would give its pilot some control as it re-entered. This reveals one more interesting detail: the original Space Cruiser design, with its circular cone, was largely retained in the STAR vehicle and re-named the “substructure”. The external shape was maintained by a removable aeroshell, which had the advantage of greatly decreasing the turnaround time of a STAR: the internal “spacecraft” part could be extracted from the aeroshell and the latter replaced. While whatever necessary work was done on the bits that had actually been exposed to re-entry heat, the guts of the STAR could fly again in new clothes.

Once the STAR landed under its parafoil, it would be retrieved—and at 4500 kilograms, it wouldn’t be hard to retrieve from almost anywhere on land. If the mission was in the latter days of the program when the 747-based launcher was available, the jumbo jet could also serve as a carrying craft to get it back to base.

If the STAR program had gone ahead, three Shuttle payload opportunities in 1987, 1988, and 1989 were targeted for initial flights.

What happened to make it fail: The ground was shifting quite rapidly under STAR. When Redding made his final report to DARPA, the Air Force, and the Department of Defense in August 1984, the Soviet Union was seven months away from getting Mikhail Gorbachev as its new leader.  The US and Soviet Union would soon sign the INF Treaty, Eastern Europe would break free of Soviet domination, and SDI became a dead letter. The US military suddenly lost much of its interest in space.

After that STAR was left with only its worth as a research test bed. The USAF and the Department of Defense decided not to go ahead with it. DARPA apparently demurred too, though the reasons there are less obvious. One presumes that without military money the defense contractors which had expressed an interest in the program backed away too, and DARPA didn’t want to be entirely on the hook for funding the project.

What was necessary for it to succeed: Besides a change to the wider course of US/Soviet relations, you can also argue that STAR ran into trouble because it was at the tail end of a long-existing argument in space operations: “do we need a man on this, or can we get what we need with an automated system?” As a result, it’s difficult to get it to fly unless you can come up with some way to have it follow on to the X-15 more closely than it did, back into the era when a pilot was more necessary, or keep it in the 80s and get rid of the man on board.

It’s interesting to compare STAR to the current X-37B. So far as can be told from its classified flights the latter spacecraft covers much the same ground for the Air Force as STAR would have: testing spaceplane technology, apparently making dry runs of orbital rendezvouses, and landing horizontally on a regular landing strip. The major difference is that it does so unmanned, the state of the art having advanced even further than it had in the mid-80s—and it can do so for much longer periods of time (the two missions flown to date having been 224 and 469 days long). Something like STAR, with a one-man crew on board, was too extravagant for any time after the late 60s or early 70s.

Tianjiao 1/Changcheng 1/V-2/H-2: The Chinese Spaceplane

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An artist’s rendering of Changcheng 1, the likeliest of four spaceplane options considered by China in 1989. Image source and copyright status unknown, please contact the author if you know either. Click for larger view.

What it was: A set of studies in 1988 that looked to commit China to a spaceplane by no later than 2015. Four different approaches were examined:  am engine-less small spaceplane lifted by expendable boosters that would need to be designed, a craft similar to a scaled-down Space Shuttle lifted by then-current boosters and it’s own new engine, a Shuttle-sized orbiter of original design launched vertically on a flyback booster, and finally an advanced re-usable horizontal takeoff plane in which the first stage would be air-breathing and the second a spaceplane which would launch off the first’s while in mid-air.

Details: Following the cancellation of Project 714 the manned Chinese space program lay fallow for at least ten years. There are some signs that there was an attempt to revive it in the late 1970s, but the evidence for this is circumstantial: China successfully launched and recovered its unmanned FSW reconnaissance satellites, which were large enough to serve as a basis for a one-man space capsule, and there was a public reveal of an astronaut cadre in January 1980. There are rumours that the sudden cancellation of that training program in December of the same year was due to the loss of a taikonaut on a suborbital flight, but they’re probably just that: rumours. It’s much likelier that the program ended due to economic weakness and the political uncertainty between Mao’s death in 1976 and Deng Xiaoping’s consolidation of power in 1981.

By 1986 the issue had come to the fore again. As part of a general drive toward economic progress China had established Project 863 (863计划), a government program to develop advanced technical skills, similar to its contemporary MITI in Japan. Project 863 recommended seven scientific/engineering projects of which two were space related: 863-204, for the development of a manned space program, and 863-205, which looked to build a space station. The latter rose and fell with the space transport system and so didn’t get very far, but over the next few years several simultaneous studies were made in aid of 863-204. By 1988 the panel of experts assigned to evaluate the studies and synthesize them into a way forward had decided that the correct approach would be to aim for a manned ballistic capsule by 2000, with a spaceplane to follow by 2005-2015 depending on which of four approaches was taken—there was also a fifth, leasing Hermes shuttle technology from France, but that possibility was cut off by European sanctions following the Tiananmen Square Massacre.

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Tianjiao 1. Image ©Mark Wade of astronautix.com, used with permission.

The simplest of the four approaches suggested was Tianjiao 1 (“First in Space 1”), jointly proposed by the Shanghai Academy of Spaceflight Technology (SAST—the later developer of the Shenzhou capsule) and the aircraft division of the Ministry of Aerospace Industry. This was virtually an exact copy of the American shuttle or Buran’s aerodynamic shape, with only upturned wingtips, but a copy that was greatly scaled down: about half-size in length and width and a quarter of the mass. It could be launched into orbit on top of three expendable boosters—two smaller (and probably using N202 and UDMH) on the sides of a larger LOX/Kerosene rocket. The orbiter itself would have had no engines.

It’s reported that Tianjiao 1 would have had a crew of three, which is surprisingly large for its size, and had a payload of two or perhaps three tonnes to LEO. Had it gone forward, it was to have been launched for the first time in 2005.

Next in complexity was Changcheng 1 (“Great Wall 1”), which was suggested by the China Academy of Launch Vehicle Technology (CALT), at the time part of the Ministry of Aerospace Industry. It too closely resembled the US Space Shuttle, with just a few modifications. It would have no tail fin and two small wing-tip stabilizers, while a jet engine would have been added at the tail end for low-speed flight. To get to orbit it would have been lifted by three expendable boosters based on Long March technology and burning N2O2 and UDMH. The shuttle itself would be perched in the centremost of the three boosters and complete the burn to orbit after separation from the first stage rockets using its own engine running on the same two propellants.

The Changcheng 1 orbiter would have been about two-thirds the size of the US Shuttle or Buran, being 24.7 meters long, having a wingspan of 14 meters, and a landing mass of 32 tonnes . It would have carried five taikonauts (two of them pilots) and had a payload of 5 tonnes to LEO. If all went according to plan, the first flight would have been in 2008.

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The unfortunately-named V-2 spaceplane. Image ©Mark Wade of astronautix.com. Image used with permission.

The next proposal was for a spaceplane similar in concept to the US Space Shuttle but a little more advanced. Dubbed V-2, it was suggested by a third division of the Ministry of Aerospace Industry. Like Changcheng 1 this was a two-stage vertical takeoff system, the difference with the first stage being that it was recoverable like that of the US Shuttle and Buran. The proposal took the concept further, however, making the entire first stage recoverable (the STS lost its main fuel tank, while Buran expended its central Energia rocket) through a strategy that’s been considered several times but never developed: it would have been a flyback booster. Essentially the idea was to develop two shuttle-like bodies, the second of which would be the actual orbiter and which would side-mount on the first “shuttle”—this one being responsible for the original launch on a plume of burning O2 and kerosene. At separation partway into space, the orbiter would continue on upwards, propelled by its own LH2/LOX engines, while the booster shuttle would separate and fly back unmanned to a landing strip. There it would touchdown, roll to a stop, and be refurbished.

The V-2 orbiter would have been about the same size as the US Shuttle, and would have mounted a twenty meter long, three-meter in diameter pod on its back. Unfortunately it’s not known if the pod was intended for cargo and the main portion of the orbiter was for crew, or if the pod was for both crew and payload. As a result we’ve no good idea how many taikonauts it would have carried and how much it would have got to orbit. Whatever it would have done, though, it would have done it sometime around 2015.

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The horizontally launched H-2 spaceplane. Image ©Mark Wade of astronautix.com. Image used with permission.

The final possibility was the most advanced of all, a completely reusable two-stage-to-orbit spaceplane proposed by yet another division of the Ministry of Aerospace Industry. This one would take off horizontally at a paved strip by having its first stage fire eight LOX/LH2/CH4 tripropellant engines. At about Mach 2 the first stage would have fired up an air-breathing scramjet powered by liquid hydrogen and between that and its rockets would get to hypersonic speeds. The orbiter would then separate from its position on the first stage’s back and would have climbed to orbit on four LH2/LOX engines. Both the first stage and the orbiter would have been able to fly back to base and land on a landing strip for re-use.

This H-2, as it was called, would have been a monster. The first stage would have been 85 meters long, would have had a wingspan of 36 meters, and would have massed 79 tonnes when landing—lighter than but otherwise bigger than an Tupolev Tu-160, the largest supersonic plane ever built. The orbiter was slightly larger than the American and Soviet shuttles, at 40 meters by 12 meters by landing mass of 25.3 tonnes, though it had a lower maximum orbital height of 500 kilometers. Furthermore all that effort would have led to a fairly small payload: only six tonnes, as compared to 24 tonnes for STS and 30 tonnes for Buran. Its crew would have been two or three. Like the V-2 it was supposed to have flown sometime in 2015, though this seems optimistic. Had they pulled it off by then, or even somewhat after, it would have catapulted China to the forefront of reusable space technology.

After considering the possibilities, the final report of the 863-204 committee chose a ballistic capsule for the initial manned space program, to be followed by Changcheng 1.

What happened to make it fail: Deng Xiaoping was unpersuaded by the arguments made in favour of a spaceplane, or even a capsule, and refused to let either go forward. Ultimately he was pragmatically interested in economic development only, and saw the long-term nature of both programs (ten years to the ballistic capsule and up to twenty-five to the plane) as being too long a time frame to be useful in that regard.

What was necessary for it to succeed: Timing is everything. Deng began loosening his hold on power in 1989 when he resigned as Chairman of the Central Military Committee, thus giving up control of the Chinese military. In one of the first signs of their independence, the People’s Liberation Army Air Force decided to support the proposed manned ballistic capsule, possibly as part of their general modernization push in the early 90s. By 1991 the Ministry of Aerospace Industry formally re-established a Chinese manned space program and in 1992 got approval for a space capsule Premier Li Peng—the number two man in the government post-Deng, after Jiang Zhemin. This rapidly evolved into Project 921, which is to say the successful Shenzhou spacecraft that China has been launching with taikonauts aboard since 2003. Note the timing there: in 1989 Project 863 was aiming for a manned capsule launch in 2000, while three years later Project 921 was founded and got its launch three years after its predecessor predicted. Project 921 can be fairly interpreted as just being a new name for the first part of its immediate ancestor.

So with just a slightly different order of events it’s not too difficult to see the spaceplane going ahead. If 863-204’s final report had been made a year or two later than it was, Deng would have been in the lull of his informal control that followed his resignation (he managed to re-assert his soft power in 1993). Li Peng was a fan of state control and planning—he was also the godfather of the Three Gorges Dam—so he seems like just the type to think that working towards a 25-years-distant spaceplane would be the way to go. What would actually got built on that decompressed timeline is an open question.

The other route to Changcheng 1—Deng resigning a few years earlier—depends on how much you think Premier Li was instrumental to getting the Chinese manned space program running. If you think another figure in the Communist Party would have stepped into his shoes on this then it’s also a plausible route to a world where a Chinese spaceplane would be flying now or in the next couple of years. On the other hand, if you think he himself was necessary it’s likely that this wouldn’t have worked: Li ended up in the high position that he did because of his role in suppressing the Tiananmen Square protests in 1989. Furthermore his political longevity can be partially attributed to the CPC wishing to assert their own correctness in the face of world opinion condemning their actions. Without June 4, 1989, Li likely would not have been in the position he was, or remain in it as late as 1998 when his power waned.

And while it did not go ahead as planned in 1989, the Chinese dream of a spaceplane is not entirely dead. While Western observers have had a hard time figuring out what to make of it, in 2007 the Chinese media publicized a few images of what appears to be an air-launched, sub-scale, and sub-orbital spaceplane prototype, similar in appearance to the US Air Force’s X-37B.