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.
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.