BEIJING -- The first group of Chinese astronauts who have been selected for the mission of building China's space station is currently undergoing training for extravehicular activities (EVA), preparing for the scheduled manned space mission.

According to the China National Space Administration, a total of 11 missions to build China's space station are planned for the next two years, including the construction of the core module that is scheduled to be launched in the first half of this year, two lab capsules, as well as four manned craft and four cargo craft.

At the China Astronaut Research and Training Center in Beijing, Wang Yaping, a female Chinese astronaut who traveled for 15 days in space in June 2013, put on training suits weighing more than 120 kg and entered a large water tank with the help of a mechanical arm.

Water provides the best medium on Earth for simulating weightlessness in space and helps astronauts train for EVA, such as spacewalking and maintenance. The water training tank, 10 meters deep and with a diameter of 23 meters, is the largest in Asia.

During the training session lasting more than four hours, seven divers assisted Wang to complete her tasks, while staff also monitored proceedings from a control room.

Wang Yanlei, a staff member at the center, told Xinhua that to simulate a five-hour mission in space, an astronaut will undergo 50 hours of underwater training on Earth. Each training session lasts four to six hours.

He noted that if it is a complicated task or involves many maneuvers, the astronaut will become exhausted and lose 1 to 2 kg by the conclusion of the session.

Last month, the China Manned Space Agency (CMSA) said the core module of China's planned space station has passed a factory review, along with the project's Tianzhou 2 cargo craft.

On Tuesday, the CMSA said in a post on its official WeChat account that the Long March 5B Y2 rocket, which is scheduled to launch the core module into space, is on the way to the launch site, and the Long March 7 Y3 rocket, the launch vehicle for the Tianzhou 2 cargo spacecraft, is in assembly.

According to Zhou Jianping, chief designer of China's manned space program, the core module will be launched from the Wenchang Spacecraft Launch Site in Hainan province. The launches of the Tianzhou 2 cargo craft and Shenzhou 12 manned craft will come after the core module is sent into orbit.