China's Queqiao-2 relay satellite is now on its way to the moon's orbit, a critical step forward for the upcoming Chinese lunar exploration programs. With a takeoff mass of 356 tonnes, the Long March 8 is capable of transporting various types of spacecraft to multiple types of orbit. This launch vehicle played a key role in Wednesday's Queqiao-2 mission. CGTN's Wu Lei talks to Song Zhengyu, chief designer of the Long March 8 rocket, about the mission.