Chinese engineers are nearing completion of the Long March-7 rocket and will soon test its compatibility with the launch site, the designers said.

"We will perform the compatibility test for the Long March-7 and the Wenchang Satellite Launch Center in Hainan within a short time, and the rocket to be used in the test has been produced," said Tao Gang, general manager of the Tianjin Long March Launch Vehicle Manufacturing Co Ltd.

"The Long March-2 and Long March-3 families, the backbones of our launches, are scheduled to retire within the next 10 years, so the Long March-7 and Long March-5 will become the pillars of China's space program," he added.

Tao's company is a subsidiary of China Academy of Launch Vehicle Technology, the leading space launch vehicle developer in China. It has been designated by the academy as the development and manufacturing base for China's heavy-lift rockets.

Four Long March-7 rockets have been made to date, and three of them are being used for static and thruster tests, said Zhang Beijun, a senior executive at the company.

The Long March-7 is a liquid-fueled, carrier rocket intended to launch China's first cargo spacecraft, which is under development.

The unmanned cargo vehicle will transport supplies to and refuel China's future manned space station. China Aerospace Science and Technology Corp, one of the major undertakers of China's space activities, said the spacecraft will also retrieve waste from the station and then burn up with the waste when it re-enters the atmosphere.

Zhou Jianping, chief designer of China's manned space program, told Xinhua News Agency in an earlier report that the first launch of the Long March-7 and the cargo spacecraft will be around 2016, to serve the Tiangong-2 space laboratory, which is planned to be in orbit by the end of next year.

Ma Zhonghui, a China Academy of Launch Vehicle Technology engineer who helped develop the Long March-7, said that the rocket has new engines and eco-friendly propellants.

"It can be widely used in commercial launch service," she said. "We have received a lot of orders from domestic users."

Ma said it has the advantage of being able to send payloads into a low Earth orbit or a sun-synchronous orbit, meaning the satellite will always appear to be in the same position relative to the sun.

Luo Xiaoyang, a high-ranking official of the academy, previously told China Daily that the Long March-7 is 53.1 meters long and 3.35 meters in diameter. Its launch weight will be about 593 metric tons.

It can put a 13.5-ton payload into low Earth orbit and a 5.5-ton payload into a sun-synchronous orbit, he said.

Lei Fanpei, chairman of China Aerospace Science and Technology Corp, said earlier this month in Beijing that in addition to the Long March-7, three other new types of rockets - including the Long March-5, a heavy-lift rocket that is more powerful than the Long March-7 - will also fly for the first time in the next two years.

zhaolei@chinadaily.com.cn