by Douglas Messier
Three Chinese astronauts returned to Earth in their Shenzhou-13 spacecraft on Saturday after spending six months aboard the nation’s first permanent space station.
Zhai Zhigang, Ye Guangfu and Wang Yaping landed in the Gobi Desert after 182 days in space. It was the longest Chinese crewed mission to date, nearly doubling the three months the crew of Shezhou-12 spent aboard the space station launched last April.
The astronauts conducted a series of experiments, made two spacewalks to outfit the exterior of the station, and delivered science lessons to students during their six-month mission. They also used a robotic arm to move the Tianzhou-2 cargo ship to another docking port before returning it to its original location.
They lives in the three-section Tianhe core module, which includes living quarters as well as the station’s power, propulsion, life support, guidance, navigation and orientation control. There is also a docking hub that includes ports for visiting vehicles and additional modules.
Tianhe is 16.6 meters (54.5 feet) long with a diameter of 4.2 meters (13.8 feet) and a launch weight of 22,000 kg (48,502 lb). It is longer than the core module of the Soviet Union’s Mir space station, which had a length of 13.13 meters (43 feet), a diameter of 4.15 meters (13.6 feet) and a weight of 22,400 kg (49,384 lb).
China plans to launch the Tianzhou-4 cargo ship next month to automatically dock with the station. Expendable Tianzhou cargo ships are capable of delivering up to 6,500 kg (14,330 lb) of cargo to the station. SpaceX’s reusable Dragon 2 supply ships can carry cargos weighing up to 6,000 kg (13,228 lb) to the International Space Station and return 3,000 kg (6,614 lb) of cargo to Earth.
The flight will be followed by a new three-member crew aboard Shenzhou-14 for a six-month stay aboard the station. China has not publicly identified the astronauts who will fly.
Those flights will be followed later in the year by the launches of the Wentian and Mengtian science modules aboard Long March 5 rockets to complete initial station assembly. The modules are each 14.4 meters (47.2 feet) long with diameters of 4.2 meters (13.8 feet) and masses of 20,000 kg (44,092 lb).
China also plans to launch the Xuntian Space Station Telescope in 2024. The satellite will share the same orbit as the space station and periodically dock with it. It will include a 2-meter (6.6 foot) diameter primary mirror with a field of view 300 times larger than the Hubble Space Telescope. Xuntian will be able to image up to 40 percent of the sky using a 2.5 gigapixel camera over 10 years.
When fully assembled, China’s space station will be similar in size to the Soviet Mir station. It will have a mass of about one quarter that of the ISS.
The facility is China’s third space station and the first one to be permanently crewed. The nation previously launched smaller single module Tiangong-1 and Tiangong-2 that were occupied for relatively brief periods of time.
Launched in September 2011, Tiangong-1 was occupied for a total of nearly 21 days by the crews of Shenzhou-9 and Shenzhou-10. Tiangong-2 was launched in 2016 and occupied for more than 26 days by the crew of Shenzhou-11.