Components for the Long March 5B rocket that will launch the core module of China’s space station. Credit: CASC
The core section of China’s space station is scheduled to launch in the next several months, the first of 11 missions carrying lab elements, cargo, and astronauts to the fledgling outpost over the next two years, according to Chinese space program officials.
The launch of the first element of the Chinese station is one of more than 40 missions scheduled this year by China Aerospace Science and Technology Corp., or CASC, China’s largest state-owned aerospace contractor.
CASC’s subsidiaries build China’s Long March rockets, manufacture satellites, and oversee construction of the Chinese space station.
The China National Space Administration, the country’s space agency, said last month that the third phase of the Chinese human spaceflight program will begin in earnest in 2021, building on earlier missions testing out the human-rated Shenzhou space transport vehicle, spacewalk procedures, and docking systems needed for building the full-scale space station.
The heavy-lift Long March 5B rocket assigned to launch the space station’s Tianhe core module has completed testing at its factory in Tianjin, China, and will soon be delivered by transport ship to the Wenchang launch base on Hainan Island.
At Wenchang, the Long March 5B rocket will be stacked on its mobile launch platform and mated with the Tianhe module, which measures more than 54.4 feet (16.6 meters) long, has a maximum diameter of around 13.8 feet (4.2 meters), and has a launch weight of roughly 49,600 pounds (22.5 metric tons).
Manufacturing and testing of the Tianhe module has also been completed in preparation for its launch this year.
Previous Long March 5 launch campaigns required about two months from the time of the rocket’s arrival at the Wenchang spaceport until liftoff. If Chinese teams follow that precedent, the Long March 5B launch with the Tianhe module could occur as soon as this spring.
The Long March 5B rocket is a variant of China’s Long March 5 rocket family tailored to haul heavy payloads into low Earth orbit.
Flying without a second stage, the Long March 5B will carry its payloads into space using just its core stage and four strap-on liquid-fueled boosters. Large payloads will occupy the second stage’s volume on the Long March 5B, which can deliver up to 55,000 pounds (25 metric tons) of payload to low Earth orbit.
The Long March 5B configuration completed its first demonstration flight in May 2020, following delays stemming from a Long March 5 launch failure in 2017 that also pushed back the schedule for launching the first element of the Chinese space station.
The Long March 2F rocket assigned to the Shenzhou 12 mission, China’s next human spaceflight, undergoes final assembly. Credit: CASC
The 11 missions to kick off assembly of China’s space station include the three launch of three pressurized modules on Long March 5B rockets, resupply flights using Tianzhou cargo freighters launched on Long March 7 rockets from Wenchang, the Shenzhou crew capsules launched on Long March 2F rockets from Jiuquan, an inland spaceport in the Gobi Desert in China’s Inner Mongolia region.
The fully-assembled outpost will be about one-sixth the mass of the International Space Station, and is closer in size to Russia’s retired Mir station than the ISS.
China launched two Tiangong prototype space labs in 2011 and 2016.
The Tiangong 1 space lab hosted two Shenzhou crew in 2012 and 2013, and China’s most recent human spaceflight mission — Shenzhou 11 — docked with the Tiangong 2 module in 2016.
China also launched a test flight of the Tianzhou supply ship, similar in function to Russia’s Progress or SpaceX’s Cargo Dragon capsule supporting the International Space Station. The first Tianzhou freighter took off on a Long March 7 rocket in 2017 and docked with the Tiangong 2 space lab, proving out automated docking and in-orbit refueling technology.
After the Tiangong pathfinders verified key technologies for the Chinese space station, officials are moving ahead with integrating the complex in low Earth orbit a few hundred miles above Earth.
The Long March 7 rocket for the Tianzhou 2 mission, the first cargo delivery flight to the Chinese station, is undergoing final assembly in its factory, according to CASC. The Long March 2F launcher for the Shenzhou 12 crew flight is undergoing final factory tests, which should be completed soon after the Chinese New Year in February, officials said.
A specific schedule for the launches of the Tianzhou 2 and Shenzhou 12 missions were not disclosed by Chinese sources.
Chinese officials have said they have selected crew members for the Shenzhou 12 mission, and astronaut training is underway. The astronauts will carry out multiple spacewalks on their mission to link up with the Tianhe module in orbit.
CASC described the space station missions as “the top priority” on the organization’s schedule this year. Other major activities in China’s space program this year include the arrival of the Tianwen 1 robotic mission in orbit around Mars in February, setting the stage for landing of a Chinese rover on the Red Planet in the May timeframe.
Artist’s concept of China’s planned space station. Credit: CASC / China Manned Space Engineering Office
In a statement previewing Chinese space program in 2021, officials also hinted at further planning for exploration of the Moon by Chinese astronauts. But the statement offered no details on the lunar mission planning, which follows China’s successful robotic sample return mission to the Moon in late 2020.
Other Chinese launches expected to add up to the more than 40 missions in CASC’s schedule this year include Long March rocket flights to deploy weather satellites, research payloads, and Chinese military spacecraft in orbit.
There are also a handful of commercial launches in CASC’s backlog, including missions to deliver batches of small Earth-imaging satellites for the Argentine company Satellogic.