The astronauts' physics lecture was open to the public through a livestream, and focused on how the weightless environment affects the movement of objects and optics.

Wang Yaping, the only woman aboard the station, served as the main instructor, while Ye Guangfu assisted.
Wang Yaping, the only woman aboard the station, served as the main instructor, while Ye Guangfu assisted. (AP)

Chinese astronauts have beamed back a science lesson from the country’s under-construction space station.

The lecture on Thursday focused on physics, aiming to illustrate how the weightless environment affects buoyancy, the movement of objects and optics.

Students from five cities, including Beijing and the semi-autonomous region of Hong Kong, peppered the astronauts with questions about living conditions in space and were treated to a virtual tour of the station. 

The event was also open to the public through a livestream.

Wang Yaping, the only woman aboard the station, served as the main instructor, while Ye Guangfu assisted and commander-in-chief Zhai Zhigang worked the camera. 

Wang had taught a similar lesson while aboard one of China’s earlier experimental stations in 2013.

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(AP)

China's longest space mission

The three arrived at the station in October for a six-month stay, charged mainly with preparing the main Tianhe module for the arrival of two additional modules named Mengtian and Wentian ahead of completion by the end of next year.

Wang last month became the first Chinese woman to conduct a spacewalk when she and Zhai spent six hours outside the module to install equipment and carry out tests alongside the station’s robotic service arm.

Their Shenzhou-13 mission is China's longest since it first put a human in space in 2003, becoming only the third country to do so after Russia and the US.

The three are the second crew on the permanent station, which upon completion will weigh about 66 tons, much smaller than the International Space Station, which launched its first module in 1998 and weighs around 450 tons.

Along with installing equipment in preparation for the station’s expansion, the crew is assessing living conditions in the Tianhe module and conducting experiments in space medicine and other areas.

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Source: AP