China has disclosed details of its future space station following the construction of one of its key parts by engineers.

The Chinese multimodule space station, named Tiangong, or Heavenly Palace, will be mainly composed of three parts－a core module attached to two space labs－having a combined weight of 66 metric tons, said Zhou Jianping, chief designer of the nation’s manned space program. Zhou spoke on April 24 at a space industry conference in Harbin, provincial capital of Heilongjiang.

The station will become heavier with the gradual installation of equipment for experiments and docking by visiting spacecraft. It will be capable of docking with up to three spacecraft at a time, Zhou said.

The designer said once the station begins its operations in orbit about 393 kilometers above Earth, it will be manned by three astronauts in extended shifts that will last several months. During handovers between shifts, the station will accommodate up to six astronauts.

The station will be able to carry more than 10 tons of scientific and experimental equipment and it will have 26 internal payload cabinets, 67 external hatches designed to dock with medium-sized extravehicular apparatuses and four external points for towing large instruments.

The core module, Tianhe, or Harmony of Heavens, will control the station and dock with visiting manned spacecraft and cargo ships, Zhou said. It will accommodate astronauts and contain supplies, and will be used to support astronauts’ extravehicular activities.

The China Academy of Space Technology said this month that engineers have constructed the core module and are testing it.

The two space labs, Wentian, or Quest for Heavens, and Mengtian, or Dreaming of Heavens, will mainly perform scientific and technological experiments.

In addition, a space telescope will fly with the space station in the same orbit to perform observations of deep space and Earth. It will have a viewing angle 200 times wider than that of the Hubble Space Telescope, and will dock with the space station when it needs maintenance or refueling, Zhou said.

The astronauts will carry out experiments inside the space station in more than 10 scientific and technological fields such as space medicine, microgravity fluid physics and combustion and space material sciences, he said. The station also will be open to commercial activities to help foster China’s space economy.

China will start putting together its first manned space station around 2020, according to government plans. First, a Long March 5B heavy-lift rocket, which is being developed by Chinese scientists, will put the station’s core module into orbit that year. Next, about four manned spaceflights will be made to send astronauts to assemble the station.

The space station is expected to be fully operational around 2022 and is set to operate for at least 10 years, according to the China Manned Space Agency. In 2024, it likely will become the world’s only space station if the United States-led International Space Station is retired that year as planned.