BEIJING, March 30 (Xinhua) -- Comprehensive training for astronauts on China's future space station missions is underway, according to the Astronaut Center of China (ACC) Friday.

The missions for the space station will feature long in-orbit stays, regular extra-vehicular activities, in-orbit assembling and repair of the station, which means more challenges for the selection and training of astronauts, the center said.

Currently, astronauts have begun the study of space station technology, mechanical arms and extra-vehicular activities. They have also gone through diving training for adaptation, and intensified their strength and stamina training, according to Huang Weifen, deputy chief designer at the ACC.

"Next, they will undergo desert survival tests and underwater examination of the procedure for capsule exits," she said, adding that the selection of the third batch of astronauts was in steady progress.

China is developing and building parts of a manned space station and plans to start assembling it in space in 2020. The station is scheduled to become fully operational around 2022.

Sunday will mark the 50th anniversary of the founding of the ACC.