BEIJING — China plans to launch its heavy-lift carrier rocket, the Long March-5 Y3, in late 2018, after finding the cause of the failure of the Long March-5 Y2, according to the State Administration of Science, Technology and Industry for National Defense.

The Long March-5 Y2 rocket was launched from Wenchang Space Launch Center in the southern province of Hainan on July 2, 2017, but a malfunction happened less than six minutes after liftoff.

Analysis based on computer simulations and ground tests showed that a problem occurred in a turbine exhaust device in the engine of the first stage of the rocket, the administration said on April 16.

The engine has been improved and has passed many ground tests. The research team is producing the Long March-5 Y3 rocket, according to the administration.

If the Long March-5 Y3 rocket is successful, the Long March-5 Y4 rocket will be used to launch the Chang’e-5 lunar probe, which is expected to bring lunar samples back to Earth.