Tiangong (Chinese: 天宫; pinyin: Tiāngōng; literally: "Heavenly Palace") is a space station program of the People's Republic of China, with the goal of creating a third generation space station, comparable to Mir. This program is independent and unconnected to any other international space-active countries. The program began in 1992 as Project 921-2. As of January 2013[update], China moved forward on a large multiphase construction program that will lead to a large space station around 2020.
China launched its first space laboratory, Tiangong 1, on September 29, 2011. Following Tiangong 1, a more advanced space laboratory complete with cargo ship, dubbed Tiangong 2, was launched on September 15, 2016. Tiangong 3 will continue to develop these technologies. The project will culminate with a large orbital station, which will consist of a 20-ton core module, 2 smaller research modules, and cargo transport craft. It will support three astronauts for long-term habitation and is scheduled to be completed just as the International Space Station is currently scheduled to be retired.
In 1999, Project 921-2 was finally given official authorization. Two versions of the station were studied: an 8-metric ton "space laboratory" and 20-metric ton "space station".
In 2000, the first model of the planned space station was unveiled at Expo 2000 in Hanover, Germany. This was made up of modules derived from the orbital module of the Shenzhou spacecraft. Overall length of the station would be around 20 m, with a total mass of under 40 metric tons, with possibility of expansion through addition of further modules.
In 2001, Chinese engineers described a three-step process toward the realization of Project 921. The original target date for the fulfillment of the project was 2010.
- First, crewed flight itself (Phase 1); this successfully occurred in 2003.
- Second, the orbiting of a space laboratory (Phase 2, a scaled back version of the initial model) that would only be crewed on a short-term basis and left in an automated mode between visits.
- The third phase would involve the launch of a larger space laboratory, which would be permanently crewed and be China's first true space station (Phase 3).
Originally, China planned to simply dock Shenzhou 8 and Shenzhou 9 together to form a simple space laboratory. However, it was decided to abandon that plan and launch a small space laboratory instead. In 2007, plans for an 8-metric ton "space laboratory" being launched in 2010 under the designation of Tiangong 1 were made public. This would be an eight-ton space laboratory module with two docking ports. Subsequent flights (Shenzhou 9 and Shenzhou 10) will dock with the laboratory.
On September 29, 2008, Zhang Jianqi (张建启), Vice Director of China crewed space engineering, declared in an interview of China Central Television  it is Tiangong 1 (i.e. not Shenzhou 8) that will be the 8-ton "target vehicle", and Shenzhou 8, Shenzhou 9, and Shenzhou 10 will all be spaceships to dock with Tiangong 1 in turn.
On October 1, 2008, Shanghai Space Administration, which participated in the development of Shenzhou 8, stated  that they succeeded in the simulated experiments for the docking of Tiangong 1 and Shenzhou 8.
On June 16, 2012, Shenzhou 9 was launched from Jiuquan Satellite Launch Center in Inner Mongolia, China, carrying a crew of three. The Shenzhou craft successfully docked with the Tiangong-1 laboratory on June 18, 2012, at 06:07 UTC, marking China's first manned spacecraft docking.
Space laboratory phase
Tiangong 1 "target vehicle"
The Chinese docking target consists of a propulsion (resource) module and a pressurized module for experiments, with a docking mechanism at either end. The docking port of the experiment section supports automated docking. Its length is 10.5 metres (34 ft), diameter is 3.4 metres (11 ft), with a mass of 8,000 kilograms (18,000 lb). Launched on September 29, 2011, it is intended for short stays of a crew of three.
Tiangong 2 "space laboratory"
A second and a third test station were originally planned to precede the eventual modular station. These would be 14.4 metres (47 ft) long, with a diameter of 4.2 metres (14 ft), and weigh up to 20,000 kilograms (44,000 lb). The second one would provide life support for a crew of 2 for 20 days, and the third one a crew of 3 for 40 days. However, all the objectives of these two stations were later merged into one project, and the size scaled down to less than 10,000 kilograms (22,000 lb).
The resulting Tiangong 2 space laboratory was launched on September 15, 2016.
Large orbital station
Drawing of Shenzhou and Cargo ship docked to the large orbital station
|Length||~ 20.00 m|
|Diameter||~ 3.00 m|
China plans to build the world's third multi-module space station, to follow Mir and the ISS. This is dependent upon the Tiangong 3 launch date, and the date of OPSEK's separation from the ISS. The previous separate components will be integrated into a space station, arranged as:
- Core Cabin Module (CCM) — based on the Tiangong 3 "space station" and analogous to the Mir Core Module. The 18.1-meter-long core module, with a maximum diameter of 4.2 meters and a launch weight of 20 to 22 tons, will be launched first.
- Laboratory Cabin Module I (LCM-1) and Laboratory Cabin Module II (LCM-2) — based on Tiangong 2 "space laboratory". Each laboratory module is 14.4 meters long, with the same maximum diameter and launch weight of the core module.
- Shenzhou — crewed vessel
- Tianzhou ("Heavenly Vessel") — a cargo craft based on Tiangong-1 that will have a maximum diameter of 3.35 metres (11.0 ft) and a launch weight less than 13 tonnes (13 long tons; 14 short tons), intended to transport supplies and experiments to the space station. The craft will have three versions: pressurized, unpressurized, and a combination of the two. It is designed to be launched on the new Long March 7 rocket. It has been announced that Tianzhou is set for its inaugural launch in 2017.
The larger station will be assembled in 2020–2022 and have a design lifetime of ten years. The complex will weigh approximately 60,000 kilograms (130,000 lb) and will support three astronauts for long-term habitation. The public is being asked to submit suggestions for names and symbols to adorn the space station and cargo ship. "Considering past achievements and the bright future, we feel that the crewed space program should have a more vivid symbol and that the future space station should carry a resounding and encouraging name", Wang Wenbao, director of the office, said at the news conference. "We now feel that the public should be involved in the names and symbols as this major project will enhance national prestige, and strengthen the national sense of cohesion and pride", Wang said.
After the success of China's crewed space launch, a Chinese official expressed interest in joining the International Space Station program. In 2010, ESA Director-General Jean-Jacques Dordain stated that his agency was ready to propose to the other 4 partners that China, India, and South Korea be invited to join the ISS partnership. China has indicated a willingness to cooperate further with other countries on manned exploration.
- Branigan, Tania; Sample, Ian (2011-04-26). "China unveils rival to International Space Station". UK Guardian. London. Retrieved 2011-04-27.
China often chooses poetic names for its space projects, such as Chang'e – after the moon goddess – for its lunar probes; its rocket series, however, is named Long March, in tribute to communist history. The space station project is currently referred to as Tiangong, or "heavenly palace".
- David, Leonard (2011-03-11). "China Details Ambitious Space Station Goals". SPACE.com. Retrieved 2011-03-09.
China is ready to carry out a multiphase construction program that leads to the large space station around 2020. As a prelude to building that facility, China is set to loft the Tiangong-1 module this year as a platform to help master key rendezvous and docking technologies.
- "China outlines space station plan". Chinadaily.com.cn. 2009-03-03. Retrieved 2013-11-16.
- "China takes first step towards space station". September 20, 2011.
- "Chinese rocket successfully launches mini-space lab". Astronomy Now. 2011-09-29. Retrieved 2011-10-19.
- "China will launch small space station in 2010-2011 (in Chinese)". 2008-09-29.
- "Simulated docking of Shenzhou 8 has succeeded (in Chinese)". 2008-10-01.
- Jonathan Amos (June 18, 2012). "Shenzhou-9 docks with Tiangong-1". BBC. Retrieved June 21, 2012.
- China launches fifth manned space mission
- "China manned space engineering Tiangong-1". Chinese Government. Retrieved 2011-10-26.
- "脚踏实地，仰望星空——访中国载人航天工程总设计师周建平". Chinese Government. Retrieved 2017-04-22.
- "China to launch Tiangong-2 and cargo spacecraft in 2015". GB Times. June 13, 2013. Retrieved 16 June 2013.
- Xin, Dingding (2011-04-26). "Countdown begins for space station program". Beijing: China Daily. Retrieved 28 April 2011.
- Clark, Stephen (3 March 2016). "China to launch new space lab later this year". Spaceflight Now. Retrieved March 8, 2016.
- Jones, Morris (March 3, 2014). "The Next Tiangong". Space Daily.
- "李学勇：中国希望参加国际空间站计划". Archived from the original on July 7, 2008.
- "ESA Chief Lauds Renewed U.S. Commitment to Space Station, Earth Science". Peter B. de Selding, Space News. 2010-03-02.
- "Chinese space Agency statement of international cooperation". Chinese Space Agency. June 4, 2011.
|Wikimedia Commons has media related to Tiangong program.|
- "China Might Be Planning Early Space Station Attempt". SpaceDaily.com. February 19, 2006.
- Article on Project 921-2
- China plans more space missions - October 16, 2003 article
- Details of Project 921
- Orbit of Tiangong 1 at Heavens-Above.com