The Shenzhou-13 spaceflight crew conducted their first emergency evacuation drill aboard China's space station on Sunday.

The three taikonauts practiced an evacuation to the Shenzhou-13 return capsule while simulating an extravehicular object collision with the space station's Tianhe core module.

The trio – Zhai Zhigang, the commander, and Wang Yaping and Ye Guangfu – is expected to carry out their first extravehicular activities in the coming days, and the drill is part of the preparations.

In the complex space environment, the impact of external debris is one of the main threats to the space station. The primary purpose of Sunday's drill is to make sure that the taikonauts can safely evacuate in case of a pressure loss.

There is a criterion for corresponding treatment, which depends on the scale of the pressure drops and the decline rate, Wang Chunhui, deputy chief designer of the astronaut systems at the Astronaut Center of China, told Chine Media Group.

The taikonauts should also make preliminary judgment where the leak is and close hatches afterward, Wang said.

The drill started with an alarm sparked by a simulated pressure drop. Zhai quickly made judgment through the instrument, and Ye opened the emergency gas cylinder to sustain internal pressure. Then Ye and Wang closed hatches of Tianzhou-2 and Tianzhou-3 cargo ships.

The whole process was handled quickly and properly with the help of the ground crew. Within minutes, the trio smoothly evacuated to the Shenzhou-13 return capsule.

"Actually, the overall design of the space station puts taikonauts' life safety as the top priority," said Wang. "Various malfunction plans have been considered in the design, including pressure loss and fire, with the core to ensure their security."