China's three astronauts on the Shenzhou-18 mission have been carrying out a series of scientific experiments over the past month since they entered the Tiangong space station on April 26.
The three Chinese astronauts Ye Guangfu, Li Cong and Li Guangsu were sent to the orbiting Tiangong space station for a six-month mission on April 25.
Four zebrafish and hornwort were brought into orbit by the Shenzhou-18 spaceship for a life science and ecological experiment.
So far, the astronauts have successfully carried out two times of water sampling and one fish food container replacement. They have found some abnormal directional behaviors of the zebrafish in microgravity, such as making rotational movements, going in circles and even swimming upside-down.
The water samples, fish eggs, and videos recording spatial movement behaviors of the zebrafish will be sent back to Earth for scientists to study the influence of space environment on the growth and behaviors of vertebrates, which will provide reference for researches on material circulation of contained ecosystems in space.
The combustion experimental cabinet is one of the eight experimental cabinets carried by Mengtian, the second lab module of China's space station. It can help scientists carry out in-depth research on basic science problems of combustion, space propulsion, fire safety for spacecrafts, combustion pollution control and other basic and applied technologies.
Over the past month, the crew members have completed the installation of the conversion cable of the combustion solenoid valve, which can remotely controlled the switch of the solenoid valve, to accurately control the fuel flow during the experiment.
The Shenzhou-18 crew also carried out burner replacement, vacuumizing, exhausting waste gas and other operations on the combustion experimental cabinet.
The three astronauts also completed the mission to replace samples of the container-free material cabinet. Previously, a number of key research projects had been carried out in the container-free cabinet, and many batches of experimental samples had been brought back to Earth for further tests and researches.
Shenzhou-18 astronauts also assembled and tested material extravehicular exposure of experiment equipment.
The astronauts in space face a series of physiological challenges brought about by the microgravity environment, including changes in the cardiovascular system, muscle atrophy and bone density loss.
They have performed regular weightlessness protection exercises, such as treadmill training and resistance training, so as to maintain good physical condition for the half-year mission.
Shenzhou-18 crew conduct scientific experiments in space
