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Tiangong-1
天宫一号

Drawing of Tiangong-1 (left) docked to Shenzhou (right)
Station statistics
COSPAR ID	2011-053A
Crew	3 (expected)
Launch	29 September 2011[1][2] at 21:16:03.507 CST
Launch pad	Jiuquan LA-4/SLS-1
Mass	8,506 kg (18,750 lb)[3]
Length	10.4 m (34.1 ft)
Diameter	3.35 m (11.0 ft)
Pressurised volume	15 m3 (530 cu ft)[4]
Perigee	355 kilometres (221 mi)[5]
Apogee	362 kilometres (225 mi)[5]
Orbital inclination	42 degrees[6]
Days in orbit	271 (as of 26 June)

Tiangong-1 (Chinese: 天宫一号; pinyin: Tiāngōng yīhào; literally "Heavenly Palace 1") is a Chinese space laboratory module,^[7] an experimental testbed to demonstrate the rendezvous and docking capabilities needed to support a space station complex.^[8] Launched unmanned aboard a Long March 2F/G rocket^[1] on 29 September 2011,^[9] it is part of the Tiangong program, which aims to place a larger, modular station into orbit by 2020.^[8] Tiangong-1 will be deorbited in 2013,^[10] and replaced over the following decade by the larger Tiangong-2 and Tiangong-3 modules.

Tiangong-1 will be visited by a series of Shenzhou spacecraft during its two-year operational lifetime. The first of these, the unmanned Shenzhou 8, successfully docked with the module in November 2011;^[11][12] the manned Shenzhou 9 mission is expected to launch to Tiangong-1 in 2012.

Design and development[link]

According to the China National Space Administration (CNSA), Tiangong-1 is an 8.5-metric-ton (19,000 lb) "space-laboratory module", capable of supporting the docking of manned and autonomous spacecraft. In 2008, the official website of the CMSEO posted a brief description of Tiangong-1, along with its larger successor modules, Tiangong-2 and Tiangong-3. A model of the space station was revealed in the Chinese Lunar New Year celebration program on CCTV on 25 January 2009.^[13]

On 29 September 2008, Zhang Jianqi (张建启), Vice Director of the China Manned Space Engineering Office (CMSEO), declared in an interview with China Central Television (CCTV)^[14] that Tiangong-1 would be launched in 2010 or 2011. Xinhua later stated that Tiangong-1 would be launched in late 2010, and declared that the renovation of ground equipment was in progress.^[15] However, the launch did not ultimately take place until 2011.

By mid-2011, the construction of Tiangong-1 was complete, and testing its electronic, mechanical and thermal properties was underway. Testing was also conducted on the Long March 2F carrier rocket on which Tiangong-1 would be launched; technicians undertook particularly extensive safety tests on the rocket in August and September 2011,^[9] following the launch failure of a Long March 2C rocket on 18 August.

Structure[link]

Tiangong-1 has a pressurised habitable volume of approximately 15 cubic metres (530 cu ft), and uses passive APAS-type docking connectors.^[16] Structurally, Tiangong-1 is divided into two primary sections: a resource module, which mounts its solar panels and propulsion systems, and a larger, habitable experimental module.^[17]

Onboard facilities[link]

Tiangong-1's experimental module is equipped with exercise gear and two sleep stations.^[4] The interior walls of the spacecraft have a two-color paint scheme – one color representative of the ground, and the other representative of the sky. This is intended to help the astronauts maintain their orientation in zero gravity.^[4] High-resolution interior cameras will allow manned missions to be closely overseen from the ground, and the two sleep stations have individual lighting controls.^[18] Toilet facilities and cooking equipment for the manned missions will likely be provided by the docked Shenzhou spacecraft, rather than being integrated into the Tiangong module itself.^[18] Similarly, one member of the module's three-person crew will likely sleep in the Shenzhou spacecraft, preventing overcrowding.^[18]

Mission profile[link]

Background[link]

Tiangong-1 was originally intended to be launched in August 2011, and was delivered to the Jiuquan Satellite Launch Center on 23 July, successfully passing a launch rehearsal test on 17 August.^[19] However, following the failed launch of a Long March 2C rocket in August 2011, the launch was postponed. Following an investigation into the August launch failure,^[9][20] Tiangong-1's launch was rescheduled for late September 2011,^[21] partly to coincide with the Chinese National Day on 1 October.^[22]

Launch[link]

On 20 September 2011, the spacecraft was again rolled out to Pad 1 of the South Launch Site at Jiuquan in preparation for the rescheduled launch attempt.^[23] The launch occurred at 13:16 UTC on 29 September, successfully placing Tiangong-1 into low Earth orbit.^[19] Chinese television broadcast the launch animation accompanied by an instrumental version of the American patriotic song America the Beautiful, a choice of music for which it later offered no explanation.^[24]

Orbital transfers and testing[link]

On 2 October 2011, Tiangong-1 completed the second of two orbital transfer maneuvers, reaching an apogee altitude of 362 kilometres (225 mi).^[5] This was the precursor to a week-long program of orbital testing, conducted from the Beijing Aerospace Command and Control Center, to prepare the module for future orbital docking operations.^[5] On 10 October, Tiangong-1 released its first orbital photo, showing a view of its outer hull and satellite relay antenna.^[25]

Autonomous orbital docking[link]

The unmanned Shenzhou 8 mission successfully docked with Tiangong-1 on 2 November 2011 GMT, marking China's first orbital docking.^[11] Shenzhou 8 undocked from Tiangong-1 on 14 November, before successfully completing a second rendezvous and docking, so as to test the reusability of the docking system.^[26][27][12] Shenzhou 8 deorbited on 17 November 2011, and landed intact in Siziwang Banner in Inner Mongolia.^[28] After the mission, the CNSA reported that Tiangong-1's systems were in optimal condition.^[29]

Manned missions[link]

Preparations[link]

The manned Shenzhou 9 mission is planned to dock with Tiangong-1 in 2012.^[30] In December 2011, the Tiangong-1 module began automated internal checks for toxic gas, to ensure that its interior would be safe for astronauts to enter.^[31] In January 2012, reports emerged alleging that the American X-37B robotic spaceplane was shadowing Tiangong-1 for surveillance purposes.^[32] However, former United States Air Force orbital analyst Brian Weeden later refuted this claim, emphasizing that the X-37B occupied a different orbit to Tiangong-1, and would not be able to closely observe the module.^[33]

In March 2012, it was reported that China had finished the initial crew selection for the Shenzhou 9 mission. Niu Hongguang, the deputy chief commander of the China Manned Space Engineering Project, stated that Shenzhou 9 would dock with Tiangong-1 by August 2012.^[34] The Shenzhou 9 spacecraft was delivered to Jiuquan Satellite Launch Center for launch preparations on 9 April 2012,^[35] while its Long March 2F carrier rocket arrived a month later on 9 May.^[36]

Future applications[link]

Tiangong-1 is intended as a testbed for key technologies that will be used in China's large modular space station, which is planned for launch in 2020. Furthermore, modified versions of Tiangong-1 will be used as robotic cargo spacecraft to resupply this station. The launch mass of the Tiangong-1-derived cargo spacecraft is expected to be around 13 metric tons (29,000 lb), with a payload of around 6 metric tons (13,000 lb).^[37]

Visibility from Earth[link]

Tiangong-1 may be visible to the naked eye only at lower latitudes, since it has an orbit inclination of 42 degrees.^[6][38]

See also[link]

• Chinese space station – a multi-module orbital station, planned for launch around 2020
• Chinese space program
• International Space Station
• Tiangong-2 – a planned successor to Tiangong-1, launching in 2013
• Tiangong-3 – a larger successor module, launching in 2015

References[link]

External links[link]

• Launch video with commentary in English on YouTube