HELSINKI — An upgraded Tianzhou cargo spacecraft docked at China’s Tiangong space station Wednesday ahead of a new crewed mission to the orbital outpost.
A Long March 7 rocket lifted off from the coastal Wenchang Satellite Launch Center at 9:22 a.m. Eastern, May 10. The rocket inserted the Tianzhou-6 spacecraft into its planned low Earth orbit around 20 minutes later.
Docking at the Tiangong space station’s aft docking port occurred at 5:16 p.m., completing the rendezvous and docking process nearly eight hours after launch, according to China’s human spaceflight agency.
The Tianzhou-6 spacecraft carries supplies for astronauts, science payloads and propellant for the space station and features improvements over the previous five spacecraft. Its pressurized volume has been increased by 20 percent, from 18.1 to 22.5 cubic meters, with its cargo capacity rising to 7.4 tons, up from 6.9 tons. The spacecraft’s mass at liftoff has also increased by 500 kilograms to around 14 tons.
Tianzhou-6 carries supplies to last a crew of three for 280 days. Also aboard are 714 kilograms of science experiments in the areas of space life science and biotechnology, microgravity fluid physics and combustion science, space material science, and space application technology tests, Lv Congmin, deputy chief designer of the Tiangong’s application system, told CCTV.
A further 160 kilograms are dedicated xenon ion thruster components, according to the China Aerospace Science and Technology Corporation (CASC), China’s main space contractor. Tianzhou-6 also carries 1.7 tons of propellant, of which 700 kilograms will be transferred to Tiangong for maintaining its orbit.
China completed construction of the three-module Tiangong in late 2022. Tianzhou-6 is the first mission of the operational phase of Tiangong. The country aims to keep the station permanently occupied for at least a decade, with crews of the three astronauts spending six months aboard at a time.
The Tianzhou-5 cargo spacecraft, launched in November 2022, undocked from Tiangong on May 5, making way for the arrival of Tianzhou-6. Tianzhou-5 will dock at Tiangong’s forward port following the departure of the Shenzhou-15 spacecraft later this month.
The Shenzhou-15 crew have almost completed their six-month-long mission and will greet the Shenzhou-16 astronauts aboard Tiangong in the new future. Shenzhou-16 will launch from Jiuquan in the Gobi Desert on a Long March 2F in coming weeks, according to earlier schedules.
The expansion in capacity of Tianzhou-6 means China will need to launch a Tianzhou mission once every eight months, instead of every six months, as previously.
The flight was the seventh of the 53.1-meters-long Long March 7, which was designed specifically to launch Tianzhou cargo spacecraft. A variant with an added third stage is used for missions to geostationary transfer orbit.
The rocket was provided by the China Academy of Launch Vehicle Technology (CALT), while the spacecraft was designed and manufactured by the China Academy of Space Technology (CAST). Both are major entities under the aegis of CASC.
CASC aims to launch a national record of more than 60 orbital flights in 2023. CASC is also working on expanding Tiangong with a “multi-functional module.” The module would allow China to further expand the size of the space station and enhance its capacity, according to officials.