The taikonauts from Shenzhou-14 began their first spacewalk, or extravehicular activity (EVA), at 6:26 p.m. Beijing Time (1026 GMT) on Thursday, which is expected to last about seven hours.

Taikonaut Chen Dong opened the airlock cabin of the Wentian lab module of the China Space Station. Chen and Liu Yang got out of the space station to perform tasks while Cai Xuzhe provides support in the core module.

They will install additional pumps and raise the omnidirectional camera on the lab module.

EVA streamlined

This long and demanding EVA has come to be a carefully planned process.

Wu Bing, the lead designer of China Space Station with China Academy of Space Technology (CAST) ran through a regular EVA process for taikonauts. "Before the taikonauts head out, they will first pass through the airlock cabin. They need to check their equipment and space suits, relieve the pressure inside the airlock cabin, and go through the pre-oxygenation process."

The second part, or the main operation out in space includes various activities. "It could entail crawling on the surface of spacecraft, going on and off the robotic arms, and installing and operating equipment in space," Wu said.

Then on their way back, they must "make sure doors are sealed, and the airlock cabin is re-pressurized." They also need to "take off their spacesuits properly."

A spacewalk usually takes 8 hours. "It's a team-effort that requires coordination between all taikonauts, the ground team and the spacecraft," Wu said.

Airlock cabin accommodates spacewalk, experiment needs

Shenzhou-14 crew had their first spacewalk by way of Wentian lab module's airlock cabin. Wentian joined the space station assembly this July.

Experts told CGTN that Wentian's airlock cabin accommodates taikonauts' EVA process both inside and out. And taikonauts would first see the planet Earth when heading out of the space station.

"When taikonauts first leave the space station, there could be a brief spell of disorientation," Wu said. "With the exit hatch facing the Earth, the taikonauts can position themselves very clearly. And smoothly take the next step."

"Moreover, coming out from this exit hatch means shying away from direct sunlight – which can be really glaring in the vacuum. This helps taikonauts have a better vision."

Wentian's airlock cabin is compact and good for experiments too.

"The cube we see is the experiment platform exposed to space. Wentian lab module has 22 payload adapters, and all of them would be equipped with standard interface. So, every payload going up will conform to the same standards," Jin Weiwei, lead designer of the Mechanical General System for Wentian lab module, also with China Academy of Space Technology (CAST), told CGTN. "This means we could partner with international parties for experiments in the future."

There are spotlights and high-resolution cameras attached to Wentian, so that the ground team can track EVA activities better. The lights and cameras will also film Earth and space better.

Robotic arm tested out

The robotic arm that went to space with Wentian lab module, a smaller one compared with the previous one attached to the space station, is known as a multitasker.

After a five-day testing session in orbit, the small robotic arm has been vetted fully, for its tasks.

Jin said a range of functions have been fully tested. "There would be a large amount of experiment payload to look after, and that cannot be all done by taikonauts going out each time"

"That's where the small robotic arm comes in handy: it fetches and moves and places the payload to where it's needed precisely. That's what we call tending-retrieving-and-replacing."

"Moreover, the small robotic arm is where taikonauts stand on when they operate around the airlock cabin," Jin said. "The small arm can also link up with the bigger robotic arm on the Tianhe core module for their assignments."

Jin confirmed with CGTN that the small robotic arm "is good to go with all the things lined up for it next."

The small arm is nimble. The bigger robotic arm can lift 25 tonnes of equipment, that's heavier than either of the existing modules.

And the two combined could reach as far as 15 meters.

Assembly in great shape, anticipating future tasks

Wentian met and docked with the China Space Station assembly in late July, and the expanded assembly is operating "as one" and "in great shape," Jin said.

"In the last month, Tianhe core module, Wentian space lab module, the cargo ship and the manned spaceship have been flying together in great shape. The assembly is performing as we expected and will maintain its stable status in anticipation of future arrivals."

(CGTN's Sun Ye contributed to the story.)