The third batch of Chinese astronauts has been selected for the nation's coming space station mission, the China Manned Space Agency said on Thursday morning.

Visitors examine models of various types of Long March rockets in Changsha, Hunan province, on Tuesday. The exhibit highlights China's achievements in astronautics. (Photo: China Daily)

The 18 new astronauts – 17 men and one woman – are in three groups: seven will become spacecraft pilots, another seven will turn into spaceflight engineers, and the last four will be mission payload specialists, the agency said in a statement.

Next, they will start undergoing systematic and sophisticated training before joining spaceflight missions, it said.

Before them, China had 21 astronauts from two generations. Among them, 11 have taken part in spaceflight during six missions.

The selection for the third-generation team began in April 2018 and involved three rounds of tests. About 2,500 applicants participated in the selection.

The new pilots were chosen from aviators from the People's Liberation Army Air Force. The spaceflight engineers are former researchers or technicians in aeronautics, astronautics and other related fields, while mission payload specialists were selected from those involved in space science and applications for China's manned space program, the statement explained.

China opened its manned space program in early 1990s and conducted the first manned spaceflight in October 2003. By now, the nation has conducted six manned spaceflights, which totaled 68 days and orbited Earth 1,089 times, while the nation's astronauts have traveled more than 46 million kilometers in space and conducted more than 100 experiments.

Chinese astronauts have also undertaken extravehicular activity, conducted several extended missions inside the Tiangong I and II space labs, and delivered a 40-minute lecture from space that was watched by more than 60 million students at about 80,000 schools.

According to government plans, the nation will start putting together its first manned space station around 2021 and in the first step, a Long March 5B will put the station's core module into orbit that year. Next, other components and astronauts will be ferried to the core module to assemble the station.

The multimodule station, named Tiangong, or Heavenly Palace, will be mainly composed of three components -- a core module attached to two space labs -- having a combined weight of more than 90 metric tons, according to the China Academy of Space Technology.

The space station is expected to be built and become fully operational around 2022 and is set to operate for about 15 years, the academy said.