TIANJIN - China's new-generation Long March-7 rocket departed for its launch base in Hainan on Sunday from north China's port of Tianjin.

It has taken researchers eight years to develop the medium-sized rocket, which can carry up to 13.5 tonnes to low Earth orbit, said Li Hong, director of the Carrier Rocket Technology Research Institute with the China Aerospace Science and Technology Corporation.

"The Long March-7 launch scheduled for late June will be of great significance as it will usher in China's space lab mission," said Yang Baohua, deputy manager of the company.

China also plans to launch the heavy lift Long March-5 to transport cargo for the planned space station.

China's second orbiting space lab, Tiangong-2, will also be launched this fall, and it is scheduled to dock with manned spacecraft Shenzhou-11 in the fourth quarter.

Yang said that the Long March-7 carrier is more environmentally friendly than earlier Long March models. The rocket will become the main carrier for space launches.