Carrier to be used in new Kuaizhou series to send payloads into low orbit

China will begin testing the world's largest solid-propellant rocket engine in February, according to a senior space scientist interviewed on Sunday.

Liang Jiqiu, chief designer of Kuaizhou rockets at China Aerospace Science and Industry Corp, the nation's largest missile-maker, described the engine as having a diameter of over 4 meters and a liftoff thrust of more than 1,000 metric tons.

Until now, the largest solid-propellant rocket in the world - developed by Orbital ATK Inc in the United States - has a diameter of 3.7 meters, he said.

Engineers were required to overcome a host of technical obstacles because China had never developed such a large and sophisticated solid-propellant rocket and there were some gaps in their knowledge of structure, materials and mechanics, Liang said.

Tests of components have now been completed and engineers are assembling an engine for ignition tests, he said.

The engine will be used with Kuaizhou 21 and Kuaizhou 31 rockets, both new-generation models under development at CASIC. Kuaizhou 21 will be capable of sending a 20-ton spacecraft to low Earth orbit while Kuaizhou 31 will be able to transport a 70-ton payload, he said.

CASIC began to develop the Kuaizhou series in 2009 as a low-cost, quick-response product for the commercial space market. It has launched three: two Kuaizhou 1s and one Kuaizhou 1A.

In addition to State-owned companies such as CASIC, private entrepreneurs are also targeting China's commercial space market. OneSpace and LandSpace in Beijing and Link Space in Shenzhen, Guangdong province, have announced plans to design and produce carrier rockets.

On Friday, OneSpace conducted a successful ignition test in Jiangxi province of what it said was the first rocket engine designed by a private Chinese company.

The test lasted 35 seconds and validated the solid-propellant engine's overall design and major parts, OneSpace said in a statement on Saturday. It added that the engine will be used on the company's OS-X series of rockets.

Design has been finalized on the first in the series, which will carry out its maiden flight in the first half of next year, the company said.