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.
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.
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.
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.
False Steps 
I suspect what’s needed is a convincing argument for a spaceplane over capsules – some sort of mission that really needs the reusability. Maybe the technology is now good enough that a modern equivalent of the Shuttle could be made genuinely reusable… but it would still be a hard sell after the failure of the American programme to produce the low costs to orbit that it promised.
Advances in technology have to be embodied/embedded in engineering, and that takes (1) repeated design/test/learn/redesign loops and (2) accumulated operational experience. The Shuttle was remarkable, but to expect the *first* reusable system to be an all-purpose “space truck” was like expecting to get from a 1910 aircraft to the DC-3 in a single iteration.
The central chicken-and-egg problem of space access is that you need a lot of designs and a lot of flights to bring down costs, while the costs of each design and each flight are too high to do it a lot. It’s inevitably going to be a long, slow bootstrapping process.