Tiangong-2 (Chinese: 天宫二号; pinyin: Tiāngōng èrhào; lit. 'Celestial Palace 2') was a Chinese space laboratory and part of the Project 921-2 space station program. Tiangong-2 was launched on 15 September 2016.^[7] It was deorbited as planned on 19 July 2019.^[8]

Tiangong-2 was neither designed nor planned to be a permanent orbital station; rather, it was intended as a testbed for key technologies used in the Tiangong station (Chinese large modular space station) of which the first module launched on 29 April 2021^[9] and the remaining modules of which launched in 2022.^[10]

The China Manned Space Engineering Office published a brief description of Tiangong-2 and its successor Tiangong-3 in 2008, indicating that at least two crewed spaceships would be launched to dock with Tiangong-2.^[2]

Tiangong-2 was originally expected to be launched by the China National Space Agency (CNSA) by 2015 ^[11] to replace the prototype module Tiangong-1, which was launched in September 2011.^[12] In March 2011, Chinese officials stated that Tiangong-2 was scheduled to be launched by 2015.^[11][13] An uncrewed cargo spacecraft will dock with the station,^[11] allowing for resupply.^[14]

In September 2014, its launch was postponed to September 2016.^[15] Plans for visits in October 2016 by the crewed mission Shenzhou 11 and the uncrewed resupply craft Tianzhou were made public.^[16] The station was successfully launched from Jiuquan aboard a Long March 2F rocket on 15 September 2016.^[17] Shenzhou 11 (Only Expedition) successfully docked with Tiangong-2 on 19 October 2016.^[18]

Aboard the Shenzhou 11, launched from Jiuquan Satellite Launch Center in the Gobi desert, were Commander Jing Haipeng and Chen Dong who formed the inaugural crew for the space laboratory.^[19] It was China's first crewed mission for more than three years.

During the 30 days the two astronauts were aboard Tiangong-2, they conducted a number of scientific and technical experiments on the physiological effects of weightlessness, tests on human-machine collaboration on in-orbit maintenance technology and released an accompanying satellite successfully. Accompanying photography and near-distance fly-by observation were also carried out. They collected abundant data and made some achievements in programs of gamma-ray burst polarimeter, space cold atomic clock and preparation of new materials.^[20]

Shenzhou 11 separated from the orbiting Tiangong-2 space laboratory on 17 November 2016, reentry module landed successfully at the expected site in central Inner Mongolia Autonomous Region at about 13:59 Beijing Time.^[20]

On 22 April 2017, the cargo vessel Tianzhou-1 successfully docked with Tiangong-2 marking the first successful docking and refuelling with the orbiting space laboratory.^[21] It subsequently performed a second docking and refueling on 15 June 2017. On 12 September 2017, Tianzhou-1 performed the third and final docking and refuelling with Tiangong-2, with what is termed a fast docking which took 6.5 hours, rather than 2 days, to complete.^[22]

In June 2018, Tiangong-2 performed orbital maneuvers lowering the orbit to 292 × 297 kilometers, likely in preparation for deorbiting. It then returned to its usual orbit.^[23][24]

In July 2019, the China Manned Space Engineering Office announced that it was planning to deorbit Tiangong-2 in the near future, but no specific date was given.^[25] The station subsequently made a controlled reentry on 19 July 2019 and burned up over the South Pacific Ocean.^[26]

The dimensions of Tiangong-2 were:

• Crew size: 2, with 30 days of life support resources.^[13] The crew (from Shenzhou 11, October 2016) consists of two astronauts.
• Length: 10.4 m (34 ft).^[2]
• Maximum diameter: 4.2 m (14 ft).^[2]
• Mass: 8,600 kg (19,000 lb).^[4]

Tianhe is the core module of the Chinese space station. The core module and its other parts launched between 2021 and 2022.

• Chinese space program
• Chinese space station – a successive multi-module orbital station
• Shenzhou program
• International Space Station
• List of space stations
• Salyut programme – a similar Soviet space station