Tiangong 1

Tiangong 1

Computer-generated rendering of Tiangong 1 in orbit (Credit: CMSA)

Chinese man-tended space laboratory, also known as “Target Vehicle”. Intended serve as a ‘target vehicle’ for the perfection of orbital rendezvous and docking techniques, as well as to demonstrate short-term orbital living. A total of three expeditions, including an unmanned and two manned missions, were made to the station between November 2011 and March 2013. Lost communication contact with ground in February 2016. Expected to deorbit in late 2017.

A.k.a.: Target Vehicle. Type: Man-tended space laboratory. Crew size: 3. Programme: Project 921-II. Agency: CMSA. Primary contractor: CAST/CASC. Status: Deactivated. First launch: 2011-09-29. Last launch: 2011-09-29. Number: 1. Designed life: 2 Years. Launch vehicle: CZ-2F. Launch complex: JiuquanSLS2. Orbit: 380—400 km LEO, 42.77º inclination. Length: 10.4 m. Diameter: 3.35 m. Solar panel span: 18.4 m. Pressurised volume: 14 m3.  Mass (orbital): 8,506 kg. Propellants: N2O4/MMH.

“Space Laboratory” is not a term officially recognised by the international spaceflight community as a specific type of spacecraft, and should not be confused with the space module named ‘Spacelab’ that was developed by the European Space Agency (ESA) and flew onboard the Space Shuttle in the 1980s and 90s. Chinese official writings described the Space Laboratory as a temporarily-manned Earth-orbiting spacecraft, which can be visited and tended by astronauts on a short-term basis and fly in automated mode on a 300—400 km low-Earth orbit between visits.

According to some Chinese publications, the Space Laboratory is a crossover between conventional manned spacecraft vehicles (e.g. Apollo, Soyuz, Shenzhou, etc.) and more sophisticated multi-modular space stations (e.g. Mir and the International Space Station). Although a Space Laboratory may well carry some mission payloads for both manned and unmanned scientific researches and experiments, it’s main purpose is to serve as a technology demonstrator to develop the techniques and technologies required for building a ‘real’ space station.

Compared with previous space stations launched by Russia and the United States, Tiangong 1 is much smaller (8.5 t orbital mass), with a shorter operational life (2 years). It only carried 60 man-days worth of food and supplies, and cannot be resupplied. The spacecraft is single-module, and non-expandable, with only a single docking port for the visiting Shenzhou vehicle. However, it provided a prototype design for the core module of China’s future space station, as well as the resupply ship Tianzhou.

Tiangong 1 was delivered to the Jiuquan Satellite Launch Centre in late June 2011 for final checkout and fuelling. However, on 22 August, days before the scheduled launch of Tiangong 1, a scientific satellite Shijian 11-04 failed to enter its intended orbit due to a malfunction of its CZ-2C launcher rocket. The launch of Tiangong 1 was postponed so that a full examination could be carried out on the CZ-2F (T1) launcher to ensure no similar design flaw existed. As a result, the fuelled Tiangong 1 module was left inside the spacecraft hangar in the launch centre for a month.

Finally, on 29 September 2011, Tiangong 1 was launched from the Pad 921 atop the CZ-2F (T1) launch vehicle. About 9 and a half minutes into the flight, Tiangong 1 was separated from the launched rocket and entered its initial parking orbit. After two orbit elevation manoeuvres, Tiangong 1 entered a 360 km near circular orbit, where it was tested remotely by the ground control.

Tiangong 1 was designed for an operational life span of two years. After the departure of the last crew in June 2013, the space module was put into a sleep mode to continue flying in orbit, in order to allow the ground control to collect data on the longevity of key components before the module is commanded to gradually re-enter the atmosphere. Tiangong 1 remained flying normally in orbit for another 2 years and 9 months after the final visit (or 1,630 days since launch).

On 21 March 2016, the China Manned Space Agency (CMSA) announced that the ground mission control had lost all telemetry and communications with Tiangong 1, leaving no ability to safely control its descent. On 14 September, the CMSA confirmed that Tiangong 1 had descended to a 370 km orbit, and was losing altitude at a rate of 100 m per day. The space module is expected to burn up during an uncontrolled atmospheric re-entry sometime in the second half of 2017.

Spacecraft Design

Tiangong 1 is 10.4 m in length and 3.35 m in diameter, and has an orbital mass of 8,506 kg. The module consists of two cylinder-shape sections: a habitable Experimental Compartment with an internal space of 14.4 cubic metres (2.0 x 1.8 x 4.0 m), and an inhabitable Service Compartment that houses propulsion, power, life support, and communications systems. A pair of solar wings each with 4 solar panels are attached to the Service Compartment. Visiting astronauts can enter the Experimental Compartment via the 0.8m-diametre hatch of the docking port on the front end of the compartment.

The module is connected to the visiting Shenzhou spacecraft via an androgynous docking mechanism developed by the Shanghai Academy of Spaceflight Technology (SAST). The system is believed to be similar to the Russian APAS-75, consisting of a docking port, radio beacons, transponders, communication antenna, UHF radar, laser rangefinder, and electro-optical tracking system. The inside diameter of the docking port is about 0.8 m.

The Shenzhou spacecraft carrying the visiting astronauts will act as the ‘chasing’ spacecraft, while the Space Laboratory will act passively as the ‘target’. In order to dock successfully, the two spacecraft will need to have a relative velocity of less than 0.2 m/s and lateral deviation of fewer than 18 cm. The rendezvous docking can be controlled manually by the astronauts onboard the Shenzhou spacecraft, under the remote control from ground, or automatically by onboard computer.

While flying unpiloted between docking missions, Tiangong 1 can serve as a platform for a range of Earth observation and scientific research missions using its onboard mission payloads. Its mission payloads included:

  • Earth environmental monitoring – A hyperspectral imager (HSI) developed by the Changchun Institute of Optics, Fine Mechanics, and Physics (CIOMP) and the Shanghai Institute of Technical Physics (SITP) is carried in the non-habitable section of the spacecraft’s Experimental Compartment. The imager can collect image data simultaneously in multiple narrow, adjacent spectral bands to provide a wealth image data of the Earth surface.
  • Material science – The spacecraft also carries mission payload for crystal growth experiments. Images and video data of the experiments are transmitted to ground via the downlink.
  • Space environment exploration – The spacecraft carries instruments to detect and analyse solar energetic particles, atmospheric chemistry and physics, and ionospheric disturbances.

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Associated Topics

Shenzhou 8 – Unmanned mission and the eighth flight of the Shenzhou spacecraft, intended to demonstrate rendezvous and docking between two unmanned space vehicles. The mission provided useful engineering experience for subsequent manned rendezvous and docking missions and the construction of the future space station. Although orbital rendezvous docking was perfected by the United States and Russia in the 1960s, China had to develop the technique almost from scratch. Shanghai Academy of Spaceflight Technology (SAST) began to develop an androgynous docking mechanism in the mid-1990s, but the system was not ready until 2010 due to technical obstacles.

Shenzhou 9 — The ninth flight mission of the Shenzhou spacecraft, and the fourth crewed mission of China’s manned space programme. The objective of the mission was to perfect the orbital rendezvous docking technique, using both automated and manual docking methods. The crew of three astronauts, Jing Haipeng, Liu Wang and China’s first female astronaut Liu Yang, spent 10 days onboard the Tiangong 1 space module to experience orbital living and working. The Shenzhou 9 mission achieved a number of ‘Firsts’ in China’s manned spaceflight history, including the longest mission duration, the first rendezvous docking with crew onboard the Shenzhou vehicle, the first manual docking, the first Chinese woman in space, and the first two-mission astronaut (Jing Haipeng).

small-shenzhou-10Shenzhou 10 — The fifth manned spaceflight mission, and the last of the three Shenzhou missions intended for the test of the rendezvous and docking technique with the Tiangong 1 space laboratory. The mission lasted for 15 days, a new record in mission duration. Shenzhou 10 was also the first operational flight mission, with four main objectives: to ferry the crew and materials between the earth and the Tiangong 1 space laboratory and test the performance of the Shenzhou capsule and its docking system; to further demonstrate the crew’s ability to live and operate in the Shenzhou-Tiangong spacecraft complex; to demonstrate the adaptability and efficiency of the crew in orbit and also to broadcast a classroom lesson to Chinese students; to further perfect the coordination between different systems in the manned space programme.

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Mission History

Date          Mission       Type               Crew             Launch Site    Launch Vehicle
2011-09-29    Tiangong 1    Space laboratory   None             Jiuquan        CZ-2F (T1)
2011-11-02    Shenzhou 8    Unmanned test      None             Jiuquan        CZ-2F (Y8)
2012-06-16    Shenzhou 9    Crewed             Jing Haipeng     Jiuquan        CZ-2F (Y9)
                                               Liu Wang
                                               Liu Yang
2013-06-11    Shenzhou 10   Crewed             Nie Haisheng     Jiuquan        CZ-2F (Y10)
                                               Zhang Xiaoguang
                                               Wang Yaping

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Photo Gallery

Tiangong 1

Tiangong 1 in the spacecraft assembly hall (Credit: PLA Daily)

inside Tiangong 1

Inside view of Tiangong 1

Tiangong 1 docking port

Tiangong 1 docking port (Credit: CMSA)

Tiangong 1 launch b

CZ-2F carrying Tiangong 1 lifted off from Jiuquan

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