— China has launched three taikonauts on a six-month mission to expand the country's single-module space station into a complete orbital outpost.

Chen Dong, Liu Yang and Cai Xuzhe lifted off on board China's Shenzhou 14 spacecraft on Saturday (June 4). The three crewmates flew atop a Long March 2F rocket from the Jiuquan Satellite Launch Center in the Gobi Desert at 10:44 p.m. EDT (0240 GMT or 10:44 a.m. local time on June 5).

Chen, Liu and Cai are set to rendezvous and dock with the Tianhe ("Harmony of the Heavens") core module of the Tiangong ("Heavenly Palace") space station within six hours of their launch. They are the third crew to launch to the station and second to be tasked with a six-month stay.

The Shenzhou 14 spacecraft will dock to the radial port Tianhe, where two cargo vehicles, Tianzhou 3 and Tianzhou 4, already await with supplies for the mission.

Update: The Shenzhou 14 spacecraft docked with the Tianhe core module at 5:42 a.m. EDT (0942 GMT or 5:42 p.m. Beijing Time) on Sunday (June 5). Chen, Liu and Cai entered the space station for the first time at 8:50 a.m. EDT (1250 GMT).

"The Shenzhou 14 mission is crucial for the construction of China's space station, with more difficulties and more challenges," said Chen in a pre-launch press conference on Saturday. "Although the three of us are relatively young, we are fully prepared for the mission, we are very eager to undertake it and we have full confidence."

Wentian and Mengtian

During their six months on orbit, Chen, Liu and Cai will oversee the arrival of two new modules for the Tiangong space station, completing the T-shaped complex.

"The crew will work with the ground team to complete the rendezvous, docking and transposition of the two lab modules with the core module," said Lin Xiqiang, deputy director of the China Manned Space Agency (CMSA). "The mission will build the space station into a national space laboratory."

The Wentian ("Quest for the Heavens") and Mengtian ("Dreaming of the Heavens") laboratory cabin modules are scheduled to launch in July and October, respectively. Both 59-foot-long, 14-foot-diameter (17.9 by 4.2 m) modules will support science research, as well as add capabilities to the 54-foot-long, 14-foot-diameter (16.6 by 4.2 m) Tianhe core module.

The Wentian module will include new crew quarters and a new airlock, the latter to support future extravehicular activities (EVAs or spacewalks) from the space station. The Shenzhou 12 and Shenzhou 13 crews, who earlier lived and worked aboard Tianhe, used the core module's docking hub to exit and enter the station.

"The [Shenzhou 14] crew will, for the first time, use the airlock cabin in Wentian to carry out extravehicular activities for two to three times," Lin said.

Chen, Liu and Cai will also carry out functional tests with the station's large and small robotic arms and outfit the interiors of both new modules. They will also conduct science experiments, participate in physiological studies and maintain the station's on board systems.

"No matter technically, mentally or physically we have made all-around preparations," said Cai. "We are fully confident and determined to complete the mission."

'Proud and honored'

Chen, Liu and Chai were all members of China second taikonaut selection made in 2010. They are the first Shenzhou crew without a member of the first class that was recruited in 1998.

A former fighter pilot in the People's Liberation Army Air Force, Chen, 43, logged 32 days on the Shenzhou 11 mission to the Tiangong 2 space lab in 2016.

Liu, 43, is also on her second spaceflight. A former military transport pilot, she was China's first woman in space on the 13-day Shenzhou 9 mission in 2012.

"I was very excited and honored to join the space mission back then," Liu said. "Ten years on, we are again fulfilling our space dream with the expectations of the motherland and the people, which also made me very proud and honored."

Cai, 46, served as a fighter pilot in the People's Liberation Army Air Force before becoming a taikonaut.

The Shenzhou 14 taikonauts will become the first Chinese crew to hand-off to another, greeting the yet-to-be-named Shenzhou 15 crew on board the Tiangong space station at the end of their mission.