China-Developed New Tanks to Improve Rocket's Payload Capacity

China recently developed two kinds of new rocket tanks with aluminum lithium alloy and composite materials that reduce the weight of the rocket and improve payload capacity.

The tank occupies more than half of a rocket's structural weight and space; when the fuel is added the weight can account for more than 90 percent of a rocket's total. Lightening of the tanker can do much to improve the payload capacity of a rocket.

The engineering prototype of the 3.35-meter diameter tank is made of third generation high-performance aluminum lithium alloy, the first of its kind in China. Compared to the mainstream rocket tank made of aluminum copper alloy, the newly-developed one has 30 percent better performance in strength and is 15 percent lighter.

It is expected to be used in the last stage of China's new generation carrier rockets including the Long March 5, the Long March 7 and the Long March 8 to improve their structure and payload capacity.

The tank also lays a solid foundation for research and development of heavy rockets with larger diameters and new generation manned rockets.

The composite material plays a main role in reducing the rocket tank's weight.

China completed its first principled sample machine of a 3.35-meter diameter rocket tank made of composite material on Jan 22, 2021.

It is designed for use in a liquid oxygen environment and is 30 percent lighter than a metal tank and also stronger. A new type of light tank, it is expected to greatly optimize a rocket's structure and improve its payload capacity.

What's more, production of the composite material tank is easier and can be done more quickly, which lowers the costs of manufacturing a rocket.

As the primary developer of the two tanks, China Aerospace Science and Technology Corporation will continue to test and assess the composite material tank to improve its performance and promote its application on rockets to help lighten rocket weight and improve payload.

A view of the engineering prototype of the 3.35-meter diameter tank made of third generation high-performance aluminum lithium alloy [Photo/sasac.gov.cn]

A view of the fixture used for disassembly and assembly of the composite material tooling [Photo/sasac.gov.cn]

(Executive editor: Wang Ruoting)