ACTS: Europe and Russia Try Again


A somewhat notional view of the ACTS as envisioned once its capsule shape was selected in 2008. By developing a command module with relatively steep walls, the ESA and Roscosmos hoped to solve the problem of cramped quarters aboard the Soyuz, and handle up to six crew. Adapted from an image by Jérémy Naegel, used under a Creative Commons ShareAlike 3.0 license. Click for a larger view.

What it was: A traditional capsule-based spacecraft to be developed jointly by the European Union and Russia, after those two failed to reach agreement on the Kliper lifting body (and further on Europe failing to the get the Hermes spaceplane off the ground).

Details: It’s been interesting the last twenty years or so to watch the gold standard for new crew return vehicles move away from small spaceplanes and lifting bodies back to capsules, as had been the preference through the 1960s. The watershed was sometime around 2006, when mockups of NASA’s Orion ceased to show a lifting body and changed to a capsule, and right about when the tandem of EU/Russia stopped looking at the Kliper and started talking about the Advanced Crew Transportation System (ACTS).

At the end of 2005, the Kliper foundered on the fact that Russia was to design and build it almost entirely. Despite that failure, the ESA was still fetching about for a crewed space project as they had also been rebuffed in approaches to the United States about sharing development of Orion’s capsule prior to Kliper. And so Russia came back into the picture within a few months.

As it happened, the EU had been working on the ATV, an unmanned supply spacecraft for the International Space Station, and it had already been noted that it bore a certain resemblance to a spacecraft service module. “Why not,” the thought ran, “have Russia develop a crew capsule to put on top of an adapted ATV?” Do so and you’d end up with something usable in Earth orbit for short missions, such as going to the ISS.


The so-called “EuroSoyuz” first envisioned for the ACTS. This image is even more notional than the previous, based as it is on ideas being considered at the time and not any actual plans. The habitation module at the left, in particular, never progressed beyond an intent to make one eventually. Image by Jérémy Naegel, used under a Creative Commons Attribution 3.0 License.

Initially the craft was envisioned by RKK Energia as sort of “Soyuz, Mark 2”, which Energia called the Soyuz-2, with a Soyuz-shaped re-entry module, if not the one from an actual Soyuz. Rather it would be oversized, perhaps derived from work down on a mid-80s Soyuz replacement called the Zarya. This had stuttered along as late as 1995, when it was jointly proposed by Energia, Khrunichev and Rockwell as a lifeboat for the ISS. The ESA and Russia committed to a two-year study of the idea, with the ultimate intention of producing a spacecraft that could orbit the moon. This configuration was still in the lead as of August 2007.

The study’s mid-2008 deadline coincided with that year’s Farnborough Air Show, and the details that were announced then had moved on from the initial concept. Now the upper half of the ACTS was a conical capsule, built by the Russians and integrated by them onto the European service module. Many sources describe it as Apollo-like, but it was fairly different in being much more vertical, a mere twenty degrees from vertical on its side walls. This was a throwback to a proposed European capsule, Viking, which had popped up for a while immediately post Hermes before fading out after one subscale, suborbital test (the Atmospheric Reentry Demonstrator) in 1998.

Though the craft was not designed to the point of precise specs, we know that it would have probably have been under 18,000 kilograms, as one of the proposed ways of getting one to orbit was via Kourou Space Centre on top of a crew-rated Ariane-5, though figures bounced around from as low as 11 tonnes and as high as 20. The Russians also talked about launching the ACTS from Vostochny, probably for use on an Angara A5 (though that rocket is still under development even as late as December 2016); a Proton was also a possibility if the difficulties of launching cosmonauts on top of rocket fueled with nitrogen tetroxide and UDMH, and there was nebulous talk of a Zenit derivative (a rocket that had not been Russia as the dissolution of the USSR left its manufacturer in Ukraine).

The capsule would have been five meters across the base and with its high vertical angle would have been roomy enough for six astro/cosmonauts (or four, if going to the Moon); one source reports 2.5 cubic meters of space, but this is no larger than a Soyuz and seems unlikely.

Ultimately the plan was to have a habitation module too, and the responsibility for this was assigned to Europe, but until the core ACTS spacecraft was much further along this was little more than a planned future commitment, with no details at hand. At the forward end, ACTS would at first have a Soyuz-style docking arrangement to take advantage of the matching ports on the ISS. Once it began its lunar missions, though, the plan was to have a common active/passive system with the Americans’ future craft so that joint missions would be easier.

On re-entry, the Russian-made capsule would have borrowed a trick from previously mentioned Zarya: a re-entry to land under a minimal parachute, with primary responsibility for landing being passed on to 12 solid rocket motors that would begin firing at about 300-800 meters up. Retractable landing legs were also mooted, as part of a general desire to make the capsule re-usable (with one Russian official hopefully suggesting ten flights in a lifetime). Rumor had it that this hair-raising retro-motor approach was made necessary by the Russians insisting on their historical requirement that their crews return to land in Russia, and with much of Central Asia now thoroughly Kazakh, the area they had to hit was much smaller than before—and parachutes normally cause one to drift quite a bit.

What happened to make it fail: Europe started showing signs of cold feet in the spring of 2008, just as the ACTS was making its splash at the Farnborough Air Show. The reasons are bureaucratically murky, but seem to have reflected the ascendance of a faction in the ESA that wanted to focus on “ATV Evolution”, a more ambitious approach where they’d upgrade the ATV so that it could return cargo, then upgrade the return module into a capsule, and then even turn it into the core module of a small space station. All this would be indigenous to Europe, with no Russian involvement.

ACTS might have survived this, but two competing financial tides worked against it. The Great Recession kicked off in late 2007, and for the next six years Europe had to deal with repeated sovereign debts crises that made money scarce. Not only was ATV Evolution shelved, even a shared spacecraft with the Russians was too expensive.

In the other direction we had a surging price for oil and gas (bar a severe but short drop near the start of the recession), reaching $140 per barrel in June 2008. Replete with petrodollars, Russia came to the conclusion that they didn’t need to put up with European waffling any more and could go ahead with their own, solo version of the ACTS. Political opinion at home favored this course anyway, and local laws on technology transfer made it difficult for Roscosmos and Energia RKK to come up with a legal framework for transferring technical information on Soyuz and other ACTS-related work out of Russia. This last issue is what is generally cited in official ESA documents as the main cause of ACTS’ failure.

Then in August 2008, Russia invaded Georgia in support of separatists there, followed by a gas pipeline dispute with Ukraine in January of 2009 that affected several EU countries. European confidence in Russia as a partner nosedived, and it became politically distasteful for the ESA to continue working with their Russian counterparts on such a high-profile project. Both sides quietly went on their way.

What was necessary for it to succeed: ACTS as such could have gone ahead in the face of most of the difficulties just listed. Certainly the financial crisis could have been ridden out for a few years, and the Russia oil boom didn’t last. What’s been the real killer has been the frosty relationship between Europe and Russia, kept chilled by further events like the latter’s clandestine invasion of eastern Ukraine. It’s difficult to see ACTS restarting any time after 2008, despite occasional French noises about re-establishing partnership with Russia.

Unlike most other projects discussed here, though, ACTS didn’t lead to no flying craft, or even to one. Rather it’s changed into two, and that’s not even counting the ATV Evolution which the ESA bravely claims is still on the table despite little sign of movement for about eight years. The Russian ACTS derivative was first called the PPTS, then it became the PTK. While that project has faced a long and slow road, it was formally dubbed Federation this year and, is still looking like it will fly in the 2020s.

On the European side, NASA announced in January 2013 that the previous design of the Orion service module was being replaced with an ATV-derived service module for at least the EM-1 unmanned test out past the Moon, currently scheduled for a year next September. Whether it will be used again after that mission is an open question, but so far it looks like it’s going to be used once. The initial idea that the ATV would work if someone else supplied a capsule for it was right, they’d just picked the wrong partner at first.

So the ACTS has survived after all, and did so by being cut in two. As mentioned, the Russian half has a name already, but seems fitting to name the as-yet-anonymous American/European half after King Solomon.


“Advanced Crew Transportation System”, Anatoly Zak.

“Collapse of ESA-Roscosmos Crew Vehicle Partnership Holds Lessons”, Peter B. de Selding. SpaceNews.

“Potential European-Russian Cooperation on an Advanced Crew Transportation System”, Frank De Winne. Belgian Science Policy Office.

Sidebar: Sonnengewehr, the “Sun Gun”


Illustration of the Sonnengewehr “Sun Gun” as published by Life magazine on July 23, 1945. Image copyright status unknown, possibly owned by Time, Inc.. Click for a larger view.

At the end of World War II the United States famously snapped up as many German scientists as it could with Operation Paperclip. While they were from a wide variety of disciplines, the ones most remembered today were the rocket designers and, as London and Amsterdam were still sporting spectacular V-2 craters, public interest in them was high at the time.

By the end of 1945 most of them would relocate to the United States, but in the period immediately following the end of fighting in Europe they were still in Western Europe and being interrogated by US intelligence personnel keen to learn about a line of weapons development in which the Nazis had jumped far ahead of the rest of the world.

It was in this setting that a few articles were published in major US newspapers and magazines (Time, Life, the New York Times and others) during July 1945 outlining one bit of information the US was getting from the captured scientists. All the articles were based on a single news conference held in Paris at the end of the previous month. While the conference apparently covered a wide variety of weapons that had been under development when the war ended, the articles picked up on one spectacular one and focused on it: the Sonnengewehr, quickly dubbed the “Sun Gun”.

The Sun Gun idea had been brought to the attention of the US by a group of scientists and engineers at Hillersleben, Germany (now part of the town of Westheide in Saxony-Anhalt, which was once part of East Germany). Though mostly unassociated with Wernher von Braun’s more-famous group they too had experience with rocketry, having worked on rocket-assisted artillery weapons and tank shells during the war.

As reported, in an unfortunately garbled way that makes it clear the reporters didn’t understand the underlying physics, the Sun Gun would have been a disc-shaped space station in a 3100-mile (5000-kilometer) orbit; some sources say 5100 miles, but this seems unlikely as German engineers would have expressed themselves in kilometers and that would be an unwieldy 8208 of them. Either way, neither would have been geosynchronous, an oddity pointed out even by some of the reporters in 1945.

Regardless, the station would have been coated with metallic sodium—chemically reactive and so easy to tarnish in the atmosphere, but which would stay clean in vacuum—polished into a mirror. The mirror would be pointed at a receiver off the coast of Europe and used to boil ocean water for power, but when the need arose it could be used on military targets—it had a projected ability to heat anything on the surface to 200 Celsius. Other numbers are scant and not clearly from the scientists themselves, but one that raises an eyebrow is that the mirror would have had an area of 5000 square miles (a round number in non-metric units, which is suspicious, and matches a diameter of 128.4 kilometers). Other sources suggest a much more realistic 9 square kilometers.

Life magazine was the most expansive on the topic, and published several drawings on the construction and operation of the station. Unfortunately their accompanying text and some of the details in the illustrations themselves suggest that the article’s authors were engaging in speculation on both topics. For example, they have the station being built of pre-made sections—cubes, oddly enough, which makes it a bit hard to produce a disk—when there’s reason to believe that it would have been made on a skeleton of long cables reeled out from a central station. Also contrary to this, Life has the inhabitable area around the edge of the disk, though this would have turned the Sonnengewehr into a “filled-in” version of the torus-shaped stations so favoured by von Braun during his lifetime

Immediate post-war reports to the contrary, it’s very unlikely that there was any sort of official work done on the Sonnengewehr beyond some tentative memos and discussions. If nothing else, consider the sheer mass of material that would have to be lifted into high orbit to build it. One source suggests one million tonnes of sodium metal, a figure considerably larger than the mass of everything ever lifted into orbit by all the world’s nations between 1957 and the present day.

Instead it seems to have been at best something batted around as a possible ultimate destination—even the scientists involved were thinking along the lines of the year 2000—in the culture of grandiosity that Nazism embraced and that also produced things like the Landkreuzer P. 1500 and Hitler’s architectural enabler Albert Speer. Even the mainstream rocketry program at Peenemünde was looking to run before it learned to walk, and this was just an extreme example of this attitude in the embryonic German space program. It may not have even been as tentative as that: at worst, it was merely discussions of an idea floated by the father of German rocketry, Hermann Oberth, in 1929.

Any gloss of reality the Sonnengewehr got likely came once the war was over and the Hillersleben group were under the control of the American military. In that precarious situation they would have been searching for anything to impress their captors of their usefulness and the Sun Gun inflated from cafeteria-table discussions to the preliminaries of a project. It did get them a little attention at the time, to be sure, but its sheer fantasticalness made it quickly drop back out of the limelight.

Kliper: Russia and Europe Try a Spaceplane


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.


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.

Sidebar: The Multi-Role Capsule


The only contemporary image of British Aerospace’s Multi-Role Capsule—a competitor to the ESA’s Hermes spaceplane—of which the author is aware. The capsule itself is the larger aft section to the right, while the service module is in the foreground left. Originally published in Flight International magazine, October 24, 1987. Click for a larger view.

When the ESA settled on the Hermes spaceplane in November 1987 there was one dissenter from the ambitious space program of which it was part. The British government of Margaret Thatcher was in the process of killing the British spaceplane HOTOL due to its technical difficulties and weren’t keen on supporting another one. As a result one of HOTOL’s designers, British Aerospace, was about to be left out of the European initiative. Without much support from anyone they suggested just prior to the formal adoption of Hermes that Europe might want to talk a look at an expendable capsule for trips to and from the US’ as-yet-unnamed Freedom space station. They also put it forward to NASA as a possible lifeboat if astronauts ever had to leave Freedom in a hurry.

BAe knew that Hermes was the favorite, and so positioned what they called the Multi-Role Capsule (MRC) and being cheaper and quicker to build. It would also have been capable of being lifted by a modified Ariane 4, rather than the new specifically-designed-for-Hermes Ariane 5 on which the ESA was spending so much of its budget.

The spacecraft consisted of two modules, a crew cabin called the Descent Module (DM) and an ejectable Service Module (SM) for any systems that weren’t needed for re-entry and the DM’s splash-landing on Earth. This is the arrangement of many capsule-based designs, built or merely proposed, but the MRC was unusual in that the SM was considerably smaller than the capsule (796 kilograms, versus an unfuelled mass of 6204kg for the latter) and mounted on the nose of the DM instead of its tail. The SM’s low mass did mean that the MRC would not have had much maneuvering capability while in orbit.

After launch the capsule would have held four to six astronauts, or none at all if the mission didn’t need a human touch. One of the latter type would have been docking with the upcoming US Space Station Freedom for use as an escape capsule if the station had to be evacuated. BAe specifically positioned this as the MRC’s first role, hoping that a go-ahead from NASA would overcome Hermes’ momentum, or at least get the MRC developed in conjunction with the spaceplane. British Aerospace sweetened the pot further by making the DM reusable (the SM was to have been expendable) and proposing to build a full MRC for a relatively inexpensive US$183 million—after adjustments for inflation, comparable to an Apollo CSM.

Unfortunately for British Aerospace they couldn’t get the ESA to back their idea, and their fallback of building them for the US didn’t work either. NASA did study return capsules for Freedom and Alpha, but did so in house: as might have been suspected up front, they already had extensive experience building their own space capsules and didn’t see any good reason to have them designed and built out of the country. Even at that, NASA ended up deciding against capsules for rescue missions anyway because they felt that the high g-loads of a capsule re-entry would be a problem in the case of a medical emergency (though in the end not even the Americans ended up building the mini-spaceplane that would be necessary to get around that problem).

It’s also telling of British isolation from the ESA’s mainstream at the time that, after the Multi-Role Capsule had faded away, a coalition of the aerospace contractors Aérospatiale, Deutsche Aerospace, and Alenia Spazio (respectively representing France, Germany, and Italy) went ahead with an independent study of a capsule-based escape craft for the ISS, thus essentially duplicating what the British Multi-Role Capsule was to have done as its first job. The ACRV, as it was called, was also cancelled.

Hermes: The European Spaceplane


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.


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.

MTFF/Columbus: Europe’s Space Station

Columbus docked to Hermes

The initial module of Columbus, the MTFF, docked with the proposed mini-shuttle Hermes. At this point the space station would be unpressurized and unmanned except when astronauts were retrieving its experiments, but the APM (which eventually evolved into the ISS module Columbus) would be attached later to add a small living space. Image source unknown, believed to be the ESA; if you know the source of this picture, please contact the author. Click for a larger view.

What it was: A European effort to turn their contribution to the American space station Freedom into an independent space station of their own, hoisted into orbit by ESA rockets and serviced by an ESA shuttle.

Details: The European Space Agency signed on to Ronald Reagan’s suggested internationalization of the Freedom station right from the moment he made the offer in 1984. They had been developing the pressurized Spacelab module for use in the Space Shuttle’s cargo bay since the early 1970s, and now pushed for the new space station to build on components derived from their work. As part of this they started the Columbus project, which among other goals would have them make one such component—the Attached Pressurized Module (APM)—on their own for inclusion in the completed Freedom.

Another part of the project was to be semi-autonomous right from the initial planning, though. The Man-Tended Free Flying Platform (MTFF) was to have been a two-segment unmanned Spacelab module which would detach from Freedom and move to a nearby orbit. This would allow for sensitive, teleoperated microgravity experiments away from the noisy, manned Freedom and, a round of experiments completed, it would return for maintenance at the main station.

During the mid- to late-1980s, though, Freedom had a rough ride in the US Congress and the ESA started developing contingency plans for what to do with Columbus if the American station was cancelled. Couple this with massive increases in prices to use the Space Shuttle—then the Challenger disaster temporarily making its cargo bay unavailable at any price—and from 1989-92 these plans culminated in an entirely autonomous station that the Europeans would try if remaining part of the now downsized and re-named Alpha (AKA “Space Station Fred”) became too unpalatable.

The initial station would have been the unmanned MTFF, but now the experiments would have been retrieved by the ESA’s Hermes shuttle, which along with the Ariane-5 rocket had been approved as an unrelated project in 1987. In 1991 the three were melded into one big project.


Two suggested expansions of Columbus beyond its initial two modules. Image source unknown, believed to be the ESA. Click for a larger view.

The MTFF, Hermes, and the French launcher were to be joined by a fourth piece of the puzzle: the APM, now divorced from Alpha. Once the unmanned MTFF-based station was proven, the APM would be completed and launched on an Ariane-5 (or possibly in an US Shuttle’s cargo bay, if renting it turned out to be cheaper and more convenient). It would then dock with the MTFF to produce an entirely European manned facility, Columbus. The long-term, if somewhat nebulous, plan was then to add more and more modules as time went by.

Statistics on the Columbus are surprisingly hard to come by. Based on the actual ISS module that was derived from it, though, we can presume that its two working modules would totaled about 14 meters in length, with the power module and station-keeping ion engine at the MTFF end adding about another 5 meters.  Its total mass would have been in the range of 25 to 30 tonnes, which would have made it a bit bigger than the Soviet Salyut stations, but less than 25% the size of Mir and about 6% the size the ISS. Accordingly it probably would have had the same sort of missions as the Salyuts, involving two or three astronauts for a few days up to several months.

The budget for the station was calculated at US$5.3 billion, including operations for five years.

What happened to make it fail: Two trends pulled the APM back to where it started: attached to the ISS.

First, the United States got its act together. The Space Station passed through another session budget shrinkage and soul-searching under Bill Clinton in 1993, but finally stabilized into what is recognizably the ISS that got built. As uncertainty over the American contribution faded away, and the Russians signed on to ISS rather than build Mir-2, it became clear that it would be safe to co-operate rather than go it alone—though the ESA did keep contingency plans for Columbus in place as late as 2001.

The ESA itself was also running into budget difficulties. The collapse of the Soviet Union did open up another possibility, as there was talk for a while of perhaps attaching the APM to Mir-2, but a related event back down on Earth proved to be more important. The costs of German reunification made Germany scale back its contributions to the ESA by nearly a fifth, which brought a budget crunch to the agency as a whole. With Hermes already over-budget, it was cancelled entirely, as was the MTFF, and the APM’s costs were scaled down by committing to the American station project after all—the name Columbus was co-opted for it alone rather than the entire project, and it became the Columbus science laboratory module that was attached to the ISS in February 2008. Only the Ariane-5 launcher managed to emerge from the crisis unscathed. As it turned out, the late 80s and early 90s were something of a Golden Age for European manned space exploration. Not only has the over all ESA budget been declining slowly since then, the percentage of it devoted to manned space travel has dropped precipitously. The ESA’s focus has shifted to more commercial uses of space such as telecommunications satellites and the Galileo satnav system.

What was necessary for it to succeed: The main necessity is the stillbirth of the ISS, which isn’t too hard to engineer. The Challenger disaster had called it into question, repeated budget cuts hit it in 1989 and 1990, and in June 1993 a bill to cancel its immediate ancestor Alpha had failed by only one vote in the House of Representatives.

Given that event, the budgets floated for MTFF even after the Germans had run into reunification money problems had it flying by 1999 so long as the ESA doesn’t make the real world turn into budgeting more for commercial applications that it did. This gives us the first component of the station.

If MTFF did get off the ground, the next component of the program was still very likely to have changed. Hermes was not going to fly on a reasonable budget in a reasonable timeframe, which kicks out one leg of the station’s autonomy. However if the MTFF had gone ahead it’s likely that the ESA could service it with an (relatively) quick upgrade to the simpler Automated Transfer Vehicle they had begun developing in the mid-1990s. It flies in the real world on unmanned missions to the ISS, and its manufacturer EADS Astrium has been floating a proposal to turn it into a manned capsule since 2008. British Aerospace had actually suggested manning and supplying the station using a capsule of their own design in the mid-80s, only to have it squelched in favour of the French mini-shuttle.

The combination of an MTFF serviced by a manned ATV would likely have worked, leading to the attachment of the APM and a completed, manned ESA station Columbus sometime in the middle to late 2000s.