Long March-5 (left) and Long March-7 (right). [Photo from Sina Weibo]

China's new carrier rockets, Long March-5 and Long March-7, will make their maiden space flights in June and about the end of September or early October, respectively, chinanews.com reported on Sunday.

Long March-5 is currently being tested at a launch site in South China's Hainan Province, according to the China Aerospace Science and Industry Corporation (CASC).

"The new carrier rockets are using non-toxic, pollution-free fuels," said Li Tongyu, head of the academy's aerospace department.

The country's strongest carrier rocket, Long March-5 has a payload capacity of 25 tons to low Earth orbit, or 14 tons to geostationary transfer orbit.

It is scheduled to carry the Chang'e-5 lunar probe around 2017 to finish the last chapter in China's three-step (orbiting, landing and return) moon exploration program.

Long March-7, a medium-sized rocket using liquid propellants, will carry up to 13.5 tons to low Earth orbit or 5.5 tons to sun-synchronous orbit at a height of 700 km. It will carry cargo craft for the planned space station.

"The two carrier rockets' maiden flights will significantly boost our country's ability to enter space and help realize leapfrog development in our space transportation system," said the CASC.

Both rockets were developed by the China Academy of Launch Vehicle Technology under the CASC.