The chief designer of the Tianzhou cargo ships for the China Space Station spoke to CGTN exclusively about the new cargo spacecraft, Tianzhou-6, saying it carries the first mission for Tiangong's application and development stage.

"It is the first in the modified group of Tianzhou cargo ships codenamed from 6 to 11," said Bai Mingsheng, chief designer of Tianzhou cargo ships from the China Academy of Space Technology.

The new group of ships has two distinct features that set them apart from their predecessors. First, their sealed cabin has a larger space and carrying capacity. Second, their operation platform has been optimized for low-cost and higher reliability.

"Its previous cargo module was 5.5 tonnes, and now it's 6.7, an increase of 1.2 tonnes and an equivalence of 20 percent capacity. That's a big improvement based on the interior design without changing its appearance," Bai said.

The chief designer said there are no big differences in cargo categories, and there are still three.

One is materials to support the lives and work of the taikonauts. One is to support the operation of the space station, like propellants and maintenance and repair parts, and one is for experimental devices.

But their proportions have obvious changes. The experimental devices, samples and facilities take up a big percentage of the Tianzhou-6 cargo. 

And the supplies for the taikonauts are mainly to meet the needs of the upcoming Shenzhou-16 crew for nine months. Bai said they will also have supplies for one more month as a backup.

He said the Tianzhou family is divided into different groups.

"Among them, Tianzhou-1 and Tianzhou-2 belong to a group with Tianzhou-2 serving as backup. Tianzhou-1 docked with the Tiangong-2 space lab. And Tianzhou-2 made an adaption to the dock with the core module of the space station. Tianzhou-3, 4 and 5 are in the same group, and now Tianzhou-6 to 11 are in the same group," he said.

According to him, in the future, China will make six cargo ships in the same group and not make any big changes because it will increase efficiency.

"We have begun to design the following group, like Tianzhou 12. We are finding what needs to be improved. The planning itself is diverse. For example, we are planning a completely sealed ship, and we will have both half-sealed and open cargo ships," he said.

"We will keep innovation and improve our service. Our position is to serve the space station, and we will make better cargo ships," the designer said.