April 25, 2023

— China has launched a new mission to its space station, including three taikonauts and four aquatic "crewmates."

Ye Guangfu, Li Cong and Li Guangsu lifted off on China's Shenzhou-18 spacecraft on Thursday (April 25), together with two male and two female zebrafish as part of their country's first in-orbit underwater research project. The crew rode atop a Long March-2F rocket from Jiuquan Satellite Launch Center in northwest China at 8:59 a.m. EDT (1259 GMT or 8:59 p.m. Beijing Time).

Ye, Li and Li are scheduled to spend six months on the three-module Tiangong ("Heavenly Palace") as the station's seventh expedition crew. In addition to trying to establish a self-cycling ecosystem using the fish and hornwort plants, they will conduct the world's first in-space stem cell study on a plant's stem tips, as well as perform spacewalks to install additional shielding after the station's solar wings were damaged by space debris.

Ye, Li and Li are also tasked with to overseeing the arrival of the Tianzhou-8 cargo spacecraft, which will bring supplies.

Launch of China's Shenzhou-18. Click to enlarge video in new pop-up window. (CCTV)

When Ye, Li and Li arrive at the station about six and a half hours after their launch, they will be met by the Shenzhou 17 crew of Tang Hongbo, Tang Shengjie and Jiang Xinlin, who have been in space since Oct. 25 of last year. After completing a brief period working as a six-person crew — the fourth such direct handover in China's history — Tang, Tang and Jiang will undock on Shenzhou-17 and return to Earth at the Dongfeng landing site in the Gobi Desert on April 30.

Ye, 43, previously logged 182 days on the Shenzhou-13 mission to the space station. A pilot in the People's Liberation Army Air Force, he was selected to train for space in 2010. He was the first Chinese cosmonaut to undergo training with other nations' astronauts — including NASA and ESA (European Space Agency) crew members — as part of a three-week spelunking (cave exploration) course and is now the youngest from his nation to command a crew.

"My two crew members and I, as well as the entire space mission team, are fully prepared and confident (in our ability) to complete this spaceflight mission," said Ye during a pre-launch press conference held on Wednesday.

Li Cong, 34, and Li Guangsu, 36, are on their first flights into space. Both are members of China's third class of taikonauts chosen in 2020. Both are former fighter pilots.

"I am looking forward to the experience of traveling at 7.9 kilometers per second [5 miles per second], the unique sensation of weightlessness and the remarkable feeling of soaring through space without wings," said Li Guangsu.

Though not the youngest of China's crews to date, Ye, Li and Li are of similar age and background.

"To ensure the smooth running of the space station with complicated operation systems, all the operations must be precise," said Li Cong, "and the mutual trust of the crew members is required."

Shenzhou-18 is the 32nd mission of China's human space program, the 13th to fly with a crew and the tenth to include three taikonauts.