China is poised to accelerate space operations with the debut of the Tiangong 1 docking module to serve as a target for upgraded Shenzhou space transports launched on more powerful and accurate Long March boosters.
The Chinese are also eyeing development of a 28,000 lb. large space cargo transport based on the Tiangong design, set to make its first flight.
Liftoff of the 8.5 ton module from the Jiuquan Launch Center is set for between Sept. 27 and 30. The vehicle was rolled to the launch pad on Sept. 20 and is now undergoing final checks and propellant loading.
The flight operation’s objective is to gain experience in automatic rendezvous and docking to dramatically broaden the capability of China’s manned space program.
There are also international objectives. China hopes this new buildup will provide them entrée to the International Space Station (ISS). The rendezvous avionics and nose mounted docking systems planned for all future Shenzhou spacecraft are identical to those already used by Russia for Soyuz and Progress dockings at the ISS. So China is preparing ISS capable spacecraft flown by experienced crews.
Access to the ISS has been a Chinese goal for at least a decade. During 2001, Luan Enjie, then Director of the Chinese National Space Agency (CNSA) told me over dinner in Beijing that “Without China’s participation, the ISS is not a true international program”.
But he also acknowledged that even as head of “China’s NASA” he knew virtually nothing about China’s manned program because it was blanketed by the stupefying secrecy of the People’s Liberation Army (PLA) . Today the Chinese program is far more open, but the military involvement and human rights violations that turned off the ISS partners a decade ago still exist. And Japan especially would oppose Chinese dockings with the ISS.
The PLA’s internal program objectives are to show leadership over communist party bosses that run national politics. The PLA also wants to prove it can run bigger and bigger programs, and as a side benefit, use the space program to inspire China’s nationalistic youth already highly skilled in math and science.
China has flown only three manned space missions since 2003, so the Tiangong program will accelerate what has been a tepid flight pace.
China will not only be launching a new man tended module, but doing so on an upgraded version of the Long March 2F used to launch earlier manned and unmanned Shenzhou spacecraft.
Designated the Long March 2FG, the 1 million lb. thrust rocket has a larger payload shroud, a new guidance system for more precise orbital targeting and larger second stage propellant tanks to increase the payload mass that can be launched into orbit.
The lessons learned from the docking and habitability exercises could enable the Chinese space program to reach its goal of assembling a 60 ton Soviet Mir class outpost around 2020.
The 35 ft. long 11 ft. diameter module will be heralded by some media as China’s first space station in an attempt to give it parity with the 25 ton Mir and the 500 ton International Space Station. That would be inaccurate.
Tiangong 1, which translates in Chinese to “Heavenly Palace” is not a prototype station module, or space laboratory, it is a sparsely equipped docking target that can be used as a temporary manned habitat, but only when a Shenzhou is present.
Over the next two years first unmanned then manned Shenzhou spacecraft will use Tiangong 1 as a docking target and rudimentary habitat. Two additional Tiangong modules have been built for redundancy and expanded manned operations.
The Tiangong 1 module was first revealed on a Chinese nationally televised entertainment program complete with dancing girls who pranced around the spacecraft. In revealing the Tiangong Project, the Chinese highlighted that it was designed and led by the PLA. This left the impression that it was a military asset, which it is not.
But Tiangong 1 could be a dual use civil/military module. New images of the module have revealed two large port holes placed side by side on the Earth facing side of the spacecraft.
They will undoubtedly be used for land use and other civilian space imagery, but the ports are also placed so that a fairly large stereo military reconnaissance camera system could be mounted in the module on later missions. The aperture size of Tiangong dual ports closely resemble the PLA’s twin port imaging system flown on Shenzhou 5’s orbital module.
As many as two more Tiangong spacecraft could be launched in the coming years.
Tiangong-2 — “It will be a fully-functional space outpost that can support three astronauts for up to 20 days,” according to SinoDefense.com. “The module will test the water recycling and oxygen generation technologies required for short- to medium-term orbit living, and allow the astronauts to carry out various scientific experiments and earth observation missions.”
Tiangong 3—-The third and final, Tiangong module is due for launch in 2016 said SinoDefense. “This will be an improved design that can support three astronauts for up to 40 days. The outpost will be used to test the effects of medium- to long-term orbit living on the human body.”
The Sino Defense site also says that there is another major space development in the Tiangong family, an unmanned cargo resupply spacecraft to carry air, water, propellant, and dry cargo to the future large Chinese space station. Based on the design of the Tiangong modules, the cargo ship will have a total mass of about 28,600 lb. and carry up to 13,200 lb of payload.
The “Tiangong cargo ship”, which has not yet been named, will be used to transport three types of cargo to the space station: air, water, and propellant which are required for the maintenance of the station itself; food and other materials for the astronauts onboard the station; and equipment for scientific researches and experiments. The ship may also be capable of assisting the space station for orbit maintenance using its own propulsion system.
Tiangong 1 has only a small science cargo, a Belgian thyroid cancer investigation. “We plan to investigate the thyroid carcinoma cell line ML-1,” says Dr. Daniela Grimm with the Laboratory of Molecular Pharmacology in Belgium.
The docking missions for Tiangong 1 are:
—-Unmanned Shenzhou 8 set for launch in late 2011 or early 2012. It will perform an automatic docking with the Tiangong 1 module and, while doing so, collect a huge amount of data on the performance of rendezvous avionics, and docking systems. The Shenzhou will be the vehicle that maneuvers during all the dockings. The module has attitude control thrusters and two orbit adjust engines, but can not be the chase vehicle in any docking. It must always be the passive element.
Shenzhou 8 also marks the first of an upgraded line of Shenzhou vehicles all equipped with docking hardware and new rendezvous avionics. Shenzhou 8 will also function as a test flight around with to freeze the advanced model’s design enabling Shenzhou assembly to be conducted on an assembly line basis.
—-Manned Shenzhou 9 set for launch by mid 2012. It will be crewed by three astronauts that will also make an automatic docking and spend 1-2 weeks essentially camping out in the module. It has a life support system and possibly a food heating and drinking water supply, but no toilet facilities, forcing the crew to use their Shenzhou orbital modules for habitable needs as well.
—–Manned Shenzhou 10 set for launch late in 2012. Its three crewmembers will dock and likely spend additional days at the module possibly conducting an extravehicular activity and making more than one docking.
The Shenzhou 9 and 10 missions will also create a core of six Chinese astronauts, one likely a woman, who have advanced space experience, just like the NASA Gemini program flew astronauts that became future Apollo mission commanders. A 21-member Chinese astronaut team, including two females, is currently undergoing training for the docking flights.
As with Russian Soyuz flights to the ISS, automatic dockings are the preferred method of approach and linkup, but manual dockings are also trained for and conducted for use when the auto system has problems.
The new Shenzhou spacecraft will also be equipped with avionics to enable manned dockings. These other new Shenzhou systems include miniature television cameras placed around the outside of the vehicle to see in multiple directions. In addition to television cameras, the more significant upgrades to this next generation Shenzhou include:
—–Rendezvous avionics: The addition of rendezvous radar and associated avionics to the Shenzhou 8 spacecraft represents a major electronics upgrade for it and other Shenzhous to follow under the frozen design production plan. The Shenzhou vehicle will broadcast radar pulses from multiple antennas. The variation in strength between the antennas on the Shenzhou and those on the Tiangong will allow the system to compute relative position, attitude, and approach rate.
The system is the same as the Russian/Ukrainian “Kurs” used by Russian Soyuz and Progress vehicles to dock with the ISS. The Chinese likely obtained the Kurs system in the major sale of Russian space hardware and design information to China in the late 1990s Initial Shenzhou versions did not need such systems since they never engaged in a rendezvous chase.
The new avionics suite involves major additions to the basic Shenzhou, including rendezvous radar emitters and receivers, digital guidance computers, Inertial Measurement Unit (IMU) sensors including rate gyros and accelerometers and optical devices for sensor alignment . Coupled with the Shenzhou’s glass cockpit these components should provide mission commanders and copilots with a multi-source picture of their rendezvous state.
—Docking system: Once the rendezvous is over emphasis shifts to physical contact and mating. All new Shenzhou and Tiangong modules will be equipped with APAS Androgynous Peripheral Assembly System docking systems designed originally by the Soviets for the 1975 Apollo Soyuz Test Project.
Equipped with specially tuned springs and shock absorbers the APAS systems have structural petals that can muscle spacecraft into proper alignment. The APAS is very forgiving to use when a docking is misaligned or likely to face high contact forces between several ton spacecraft.
The Chinese have announced that they are using a modified APAS-89 docking unit, the same unit used by Russia and the U. S. to dock with the International Space Station.
That is a further indication that the Chinese are still every bit as interested in joining the ISS, as spending the next 10 years developing their own outpost—which could have greater military space implications.