by Morris Jones
Sydney, Australia (SPX) Oct 03, 2008
The success of China's first spacewalk on the Shenzhou 7 mission paves the way for greater things. For China, the next great task will be its first space station. Much reportage has been circulated on this, but ironically, the more we read, the more confused space analysts become. What is China really planning?
It all seemed so simple just a month ago. China would launch a space laboratory on the Shenzhou 8 mission. Despite its name, this would not be a Shenzhou capsule spacecraft, but a new type of vehicle.
This would be followed by the unmanned Shenzhou mission, a conventional Shenzhou, which would dock with it. Finally Shenzhou 10 would carry a crew of three astronauts to the Shenzhou 8-9 complex.
This report seemed reliable for a long time, but this is apparently not the real plan. China has since revealed plans for a small space laboratory module called "Tiangong 1". The name is apparently a reference to a castle or fortress in the sky.
Tiangong 1 will be launched around 2010 or 2011, depending on the source used. Then, the unmanned Shenzhou 8 spacecraft will be launched to dock with it.
In this version of the story, Shenzhou 8 is a conventional Shenzhou, albeit without a crew. Afterwards, Shenzhou 9 would also fly to an automated docking with Tiangong. Finally, Shenzhou 10 would be launched to Tiangong 1 with three astronauts aboard.
The first version of the space station fable sounds a lot like the second, with references to Tiangong removed. It's possible that this was caused by a security blackout on mentioning the Tiangong spacecraft. Somebody could have simply edited and re-hashed the text to compensate for a series of blacked-out regions in a censored report.
The new version is more enlightening, but it does not clear up all the mysteries surrounding the space station program. In fact, we now have more unanswered questions than before! A Chinese official was questioned in a lecture on the Shenzhou 7 at the recent IAF Congress in Glasgow, but could not provide any detailed information.
What does Tiangong look like? China has revealed full-scale mockups of a "space laboratory" that look like the European Spacelab module, designed to fly in the payload bay of the US Space Shuttle. Spacelab was like a miniature space station that never left the Shuttle. The Chinese version is a short, stubby cylinder, like its European counterpart.
Artwork circulated on the Internet shows Chinese space stations that resemble early Soviet Salyut space stations. Are these alternative designs for Tiangong?
The reports suggest that three Shenzhou spacecraft are destined to dock with Tiangong-1. Why? China could probably test its docking technology on one unmanned launch, then send up a crew. This is one reason why the original space station story seemed so plausible.
China's artwork has suggested that no candidate design for Tiangong has more than two docking ports. At some point, one of the first two docking vehicles will have to leave to make room for Shenzhou 10 and its crew. Which one will depart? When will it come back?
It's possible that the first Shenzhou to dock (Shenzhou 8) will be an endurance test of the Shenzhou spacecraft. The Russians certify their own Soyuz spacecraft as reliable for six months, when docked to a space station. Will China try for a six-month test mission for Shenzhou 8?
One plausible scenario would see Shenzhou 8 and Tiangong 1 docked together for roughly six months. Then Shenzhou 8 would stage an automated return to Earth. Experimental samples could be stored on board the Shenzhou 8 descent module, where they could remain in space for a long period. Other experiments would run automatically on board Tiangong 1.
Alternatively, Shenzhou 8 could stay aloft for just a couple of months. This would be enough to satisfy concerns that a Shenzhou spacecraft could support the first manned space laboratory mission, which would probably only last a few weeks.
After Shenzhou 8 had returned, China could launch the Shenzhou 9 to Tiangong. This time, there would be no crew, but supplies would be carried on board. Shenzhou 9 would dock with Tiangong, and sit waiting for a crew. Soon afterwards, Shenzhou 10 would fly, carrying Tiangong 1's first crew.
They would unpack supplies (such as food) from the Shenzhou 9 spacecraft, and retrieve long-duration experiments from the Tiangong space station. The crew would also perform experiments in real-time during their stay. Shenzhou 9 could offer an alternative return vehicle for the crew. They may elect to leave Shenzhou 10 attached to Tiangong after they depart.
The three Shenzhou plan seems confusing unless one mission is counted as a semi-independent test of long-duration flight, and another sees Shenzhou being used as a cargo and logistics vehicle, similar to the Russian Progress spacecraft. Both tasks are important to sustaining a long-term space station, which is a goal of the Chinese program.
This objective of launching a larger space station in the future could explain some of the artwork we have seen. The Salyut-type space stations are apparently larger than the space laboratory. These could be prototypes for the next-generation station, to be launched by the Long March 5 launch vehicle. Several modules are expected to be joined together, much like the Mir station.
Dr Morris Jones is the author of "The Adventure of Mars" and "When Men Walked on the Moon", now available at online bookstores. Email morrisjonesNOSPAMhotmail.com. Replace NOSPAM with @ to send email.
the missing link The Chinese Space Program - News, Policy and Technology
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