JIUQUAN -- The Shenzhou XXI crew will carry out in-orbit scientific experiments involving mice during their stay on China's space station, according to the China Manned Space Agency (CMSA) on Thursday.

Four mice, two males and two females, will be transported to the space station aboard the Shenzhou XXI spaceship and raised in orbit, CMSA spokesperson Zhang Jingbo said at a press conference held one day prior to the launch of the Shenzhou XXI mission.

Noting that this is the first time China will conduct scientific experiments involving rodent mammals in space, Zhang said the in-orbit study will focus on examining the effects of space conditions, such as microgravity and enclosed space, on the behavior of these animals.

Subsequently, the mice will return to Earth via a spaceship, and further scientific research will be carried out to explore the stress response and adaptive changes of multiple tissues and organs of mice in the space environment, Zhang added.

The Shenzhou XXI crewed spaceship is scheduled to be launched at 11:44 pm Friday (Beijing Time) from the Jiuquan Satellite Launch Center in Northwest China. Taikonauts Zhang Lu, Wu Fei and Zhang Hongzhang will carry out the Shenzhou XXI mission.

During their stay in orbit, the Shenzhou XXI crew will conduct a total of 27 new scientific and application study projects.