The International Space Station will soon no longer be the only operational station in orbit around the Earth. China is about to launch Tianhe (which means “celestial harmony”), the first module of its future space station. It should take off tomorrow, April 29, aboard a Long March 5B rocket, already installed on the launch pad of the Wenchang launch base, on the island of Hainan. A manned mission is planned for the month of June.
The complete structure, of around 66 tonnes, will consist of a minimum of three modules. Tianhe, the main module, includes all the navigation control commands; it is also the living space of future taikonauts. The station will also have two laboratories (Wentian and Mengtian), dedicated to scientific experimentation.
The installation, called Tiangong (“heavenly palace”), will therefore succeed the two prototypes previously put into orbit, Tiangong 1 (2011-2016) and Tiangong 2 (2016 – 2019), developed by the Chinese Space Agency (CNSA) . Both had hosted a crew for a few days, for testing purposes. China plans to complete the construction of its new station by the end of 2022. A particularly tight schedule, even for the third space power in the world.
An “express” blend in just two years
The first 20-tonne module, the station’s control center, will be put into orbit this Thursday, April 29. It has a mooring port and will make it possible to control the trajectory and the attitude of the station. With a length of 16.6 meters, for a diameter of 4.2 meters, this cylinder will also serve as a living space for future Chinese taikonauts. The station was designed to accommodate a crew of three, for up to six months.
China Human Space Flight Agency (China Manned Space Agency, CMSA) plans that the first crew will join Tianhe on June 10, aboard the Shenzhou-12 spacecraft. The team will consist of Nie Haisheng, whose third flight will be, Deng Qingmin and Ye Guangfu who will fly in space for the first time. This is the first manned flight carried out by the Chinese agency since 2016, when Shenzhou-11 had led two taikonauts aboard Tiangong 2. Before that, the station should be refueled via a cargo vessel, the Tianzhou-2, on the 20 may.
The two labs – the Wentian and Mengtian modules – are expected to be added to the structure in June and August 2022 respectively. In total, the Chinese space agency plans eleven launches, including four crewed missions, to complete the construction of this station in 2022. It will operate in low earth orbit, at an altitude of 340 to 350 km, with an inclination orbital between 42 ° and 43 °.
Initially, construction of the station should have started in 2018. However, the failure of the second qualification flight in July 2017 of the Long March 5 rocket – the only Chinese launcher capable of propelling such a large load – resulted in the postponement of assembly. The first flight of version 5B took place successfully in May 2020; this version is capable of placing more than 22 tonnes in low orbit.
A new space telescope from 2024
Note that if this new station is of Chinese origin, it will also be accessible to any other UN member country wishing to conduct scientific experiments on board. It is also expected that the Tiangong station will definitively succeed the International Space Station in a few years. The ISS, whose assembly began in 1998 and was completed in 2011, is indeed at the end of its life and represents an annual cost of several billion dollars for NASA, which has repeatedly considered ceasing its operation. The United States would also like to devote itself fully to its plan for a space station around the Moon (the Lunar Gateway).
For its part, Moscow announced last week its intention to withdraw from this scientific collaboration program in 2025. The spokesperson for Roscosmos, the Russian space agency, also revealed that Russia wanted to set up its own space station project, with an orbit scheduled for 2030. An announcement that some consider “the extension to space of tensions between Russia and the West”. But maybe Russia just doesn’t want to contribute to the costs of deorbiting the ISS to come …
Once the assembly of its station is completed, China will launch a space telescope named Xuntian, comparable to Hubble. Equipped with a mirror two meters in diameter, it must be placed in orbit in 2024. Its wide field of vision (300 times greater than that of Hubble) will allow it to observe up to 40% of the sky over a decade, in the near ultraviolet and visible light. It will operate independently of the station, but will moor there periodically for refueling and various maintenance operations.
Four research centers are already being built to analyze the data that will be collected by Xuntian. The latter will be particularly dedicated to the study of the properties of dark matter, the formation and evolution of galaxies. The telescope is also expected to assist in the detection and monitoring of transneptunian objects and near-Earth asteroids.