Bob Christy: What's Next for China in Space?
The completion of the Shenzhou-10 mission and crew visits to the Tiangong-1 space station naturally raises the question of what's next for China's human spaceflight program. Robert (Bob) Christy, founder and editor of zarya.info, offers his analysis of China's program to date and what may be in store for the future in this guest column for SpacePolicyOnline.com.
Christy, FBIS, started observing space events in the mid-1960s as a student at Kettering Grammar School in Kettering, England. The team eventually evolved into the internationally-renowned Kettering Group of amateur observers and analysts led by the late Geoffrey Perry that focused on tracking Soviet satellites and analyzing the Soviet space program. Christy is the author of the zarya.info website, dedicated to recording and analyzing space events. Follow him on Twitter (@zarya_info) or Facebook.
China in Space - What Next?
By Robert Christy, FBIS
With the successful wrap-up of the Shenzhou 10 mission, China has completed another step in its march to a long-term, permanently-crewed space station.
Shenzhou 10 was the third “production” spacecraft in the series where the first seven all represented development stages. Shenzhou 1 was kitted out with test equipment and had no life support system. By the time of Shenzhou 5, the life support system had been tested to the point it could be trusted to support a human being and Yang Liwei set off on a one day mission to prove it. On successive missions, China tested Shenzhou up to its maximum crew of three and, on Shenzhou 7, two astronauts depressurized the orbital module and stepped briefly outside.
Shenzhou 8 was flown unpiloted to prove the docking unit by joining up with Tiangong 1. It tested the whole system using “crash test dummy” astronauts and a package of biological experiments provided by DLR, Germany’s space agency. Shenzhou 9 repeated the experience, but with a crew that spent time aboard Tiangong 1.
One by one, the flights pointed to a structured approach toward the goal of keeping crews in space for extended periods, and being able to handle the logistics of piloted missions to China's future 60-tonne modular space station. Alongside, work was going on to develop a new range of launch vehicles for the station and future support vehicles.
China was also building up its tracking and support infrastructure with ground stations in Chile, Namibia, Pakistan and Australia and construction of the Tianlian data relay satellite constellation. Locations of the ground stations were carefully chosen to support launch and landing of missions using the Shenzhou/Tiangong 42.8° inclination orbit. For Shenzhou 10, China was confident enough in the network's capabilities to see no need for any of the Yuan Wang ships to back them up. For the first time, all ships remained within the confines of the Pacific Ocean to support only the most critical stages of the mission.
Taken together, all these jigsaw pieces point to China having a clear goal and that it is working patiently towards it. Unlike the Space Race of the 1960s, China is not in competition so it can afford to take steadily-paced, careful steps towards its ultimate goal. It is doing the same with its other space programs, witness the well laid out lunar exploration program currently en-route from a lunar orbiter to a soil-sampling mission.
Shenzhou has flown ten times with no obvious major problems. There will have been some issues, but none seems to have delayed or deflected the program. By the time Soyuz had flown ten times it had lost two test vehicles on re-entry, killed Vladimir Komarov with a parachute failure on Soyuz 1, narrowly avoided losing the crew of the intended Soyuz 2 to the same problem, and had a near-disaster with the Soyuz 5 re-entry. In a similar time frame, Apollo killed three astronauts on the ground and, but for the ingenuity of NASA's engineers, would have had a full-on disaster in Apollo 13.
China has clearly learned from the mistakes of others.
On the ground at mission end, Shenzhou looks remarkably like Soyuz, but it would be a mistake to suggest that the resemblance goes any further. By buying the Soyuz aerodynamic design from Russia, China showed great shrewdness and avoided the effort of starting from. Beyond the visual similarity and some borrowed mechanical systems there is no comparison between the two. Shenzhou is almost pure Chinese. It has its own, versatile, Orbital Module and the Service Module is home-grown. The avionics, computers, communications systems and rendezvous system are Chinese in origin.
With completion of the Shenzhou 10 mission, the vehicle is a proven, tested and mature spacecraft ready to serve as a crew carrier for any mission China might want to perform in low Earth orbit.
One feature of both the Shenzhou 9 and 10 flights is the lack of detailed information on crew activities while aboard Tiangong 1. Shenzhou 9 was probably a pathfinder with its goals more on the technical side. We know that the Shenzhou 10 visitors brought with them lightweight, rigid floor panels to replace the original flexible floor of Tiangong in order to make moving around easier. Then we had the broadcast space physics lecture to school/college students by Wang Yaping. It was three quarters of an hour of digital TV transmission from space with no interruptions. The event was carried via the Tianlian 1A communications relay in geosynchronous orbit over the Indian Ocean. For some reason, possibly technical, it switched seamlessly to a ground station for about five minutes while over China.
China has tended to focus on the fact that the crews were working aboard Tiangong 1, but the lab has very little in the way of internal equipment to be tended or operated so they may have had tasks aboard Shenzhou 10.
The Shenzhou 2 through Shenzhou 6 flights carried OMs that were actually autonomous spacecraft. Left in orbit at the end of the main mission, they used thrusters to move to higher orbits, maneuvered in orbit and stayed in space for up to half a year. Little is known of their purposes although some independent analysis has been done, like this piece by Sven Grahn, on the external equipment that suggests Earth observation and surveillance missions. Apart from the possibility of them carrying out long duration tests of equipment, their missions do not seem to be related directly to the piloted program. They probably represented platforms of opportunity.
It does raise the possibility of the Shenzhou 9 and 10 Orbital Modules containing equipment that needed attention by the crew, providing some of the workload while docked with Tiangong 1.
Tiangong 1 is an 8.5 tonne test-bed. Unlike Shenzhou, it does not represent the finalized design of a vehicle to be used with China's future space station. It is a rendezvous and docking target, providing basic accommodation and a means for crew to transfer to/from a transport vehicle. Its expected usable life is two years, the end of which is approaching. The docking unit was rated for six uses and it has reached the limit. That is not to say that it has suddenly become unusable, but China’s space engineers know that wear and tear from repeated operation now makes the risk of a mechanical or electrical malfunction significant enough to result in a potentially aborted mission.
That aside, Tiangong 1 has outlived its usefulness as there are very few, if any, new tasks it can perform. Its rudimentary life support system, that can only function fully when Shenzhou is attached, is contaminated with bacteria introduced through human habitation. China's engineers have speculated that it will eventually become a health risk. It will be kept in orbit until the two-year point. About then a decision will be made whether to fire its thrusters and initiate a destructive re-entry above the “international spacecraft graveyard” of the southern Pacific Ocean. There is talk of it being kept in orbit and that it may still be there when Tiangong 2 is launched, although the two will not dock with each other.
China has been variable in the amount of information released about the Shenzhou missions. A lot of information was relayed real-time during Shenzhou 9, but only of the mission high points like launch, docking and return to Earth. It looked good, but reports on other parts of the mission were thin on substance. Although stories appeared on many Chinese websites, there was much repetition of content and duplication of words, indicating that there was only one real source. There was little independent reporting from mission control and only Chinese national media were allowed inside.
For Shenzhou 10, there was a tight clamp down on information with some major events being reported after the fact. Some days there was nothing at all. When the crew returned to Earth, reporters from China's main TV channels broadcast from the car park in front of the building. The Soviet Union used to provide at least a daily bulletin during its space station missions, maybe about communications sessions or the occasional personal touch like “....they breakfasted with gusto”. A steady drip of information, however inconsequential, gives an “all is well” feeling. Silence leads to thoughts of something having gone wrong although the true reason may simply be that China did not want to reveal what the crew was doing.
Maybe China was trying to portray a “business as usual” and “nothing here to interest you” attitude, but stereotypical Chinese inscrutability fails to recognize the enormous worldwide interest in spaceflight, the well being of the crew and the facts and figures that define the mission. It is probably a forlorn hope that China will change its approach for the next mission.
Presently, the target launch date for the first of the three 20-tonne modules that will comprise China's space station is 2020. Before then, there is more engineering development and testing work to be done.
Tiangong 2 will be another test-bed and seems set to experiment with cargo transport and transfer of propellant between space vehicles, both of which are necessary to sustain long-term habitation of a space station. It will also test a regenerative life support system, an advance on the one aboard Tiangong 1 that has no mechanism for recycling waste products. No firm dates have been mentioned and it could be at least two years before we see it in space.
China may not yet be ready to have crews aboard while more-dangerous operations, like fuel pumping, are going on. Tiangong 1's thrusters, for example, have never been fired for a significant maneuver with a crew inside. It raises the possibility that it may be a long time before we next see a Chinese crew in orbit.
A possible goal for the next Chinese space crew is a significant extension to mission duration, but it would require re-supply missions to Tiangong 2 to do it. It will need a step change like the one from the Soviet Union’s Salyut 4 to Salyut 6 in the 1970s -- where a second docking port with re-fuelling capabilities was introduced. It also may need one of China's new line of Long March rockets to loft it.
Depictions of the three-module, T-shaped, 60-tonne outpost planned for 2020 show that crews will arrive in the production line version of Shenzhou. They also show a Cargo Spaceship that looks exactly like Tiangong 1. It is an equivalent to a Cygnus/ATV/HTV cargo delivery vehicle with Progress-style refueling capability. Omitting the systems that make Tiangong 1 habitable, its mass will be seven tonnes and it will be able to carry six tonnes of supplies.
What seems to be lacking in China’s plans is a vehicle that can bring material back to Earth -- equivalent to Dragon. But is it? Long term, Shenzhou could follow a reverse evolutionary path when compared with Dragon where crew support systems are stripped out to provide a cargo return craft.
What Will Happen?
Only China has an insight to this and its plans may yet not be set in stone, but their foundations are in a five year space plan published in 2011. It talks of launching space laboratories, "manned" spaceships and space freighters, and developing technologies such as a regenerative life support system and propellant refueling to support medium-term stays in orbit.
What is written here is based mainly on the 2011 plan. It shows that we will see a steady evolution from where China is now to the space station. There will be no gigantic surprises and certainly no step change as the one seen between Gemini and Apollo that would permit China to send a crew to the Moon within the next decade.
The 2011 document does mention the Moon, but only in terms of conducting studies on a preliminary plan for a human landing. With its financial resources directed into establishing the space station, it may take several more five-year plans to bring a lunar landing to fruition.
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