A Long March 2F rocket transporting the Shenzhou-12, or "Divine Vessel", bound for the space station module Tianhe blasted off at 9:22 a.m. Beijing time (0122 GMT) from the Jiuquan Satellite Launch Center in northwestern Gansu province.
Shenzhou-12 is the third of 11 missions - four of which will be crewed - needed to complete China's first full-fledged space station. Construction began in April with the launch of Tianhe, the first and largest of three modules.
The astronauts Nie Haisheng, 56, Liu Boming, 54, and Tang Hongbo, 45, are to work and stay on Tianhe, the living quarters of the future space station, for three months. During their sojourn on the cylinder-like Tianhe, slightly bigger than a city bus, the three men will test the module's technologies including its life-support system.
The men will also be monitored for how they fare in space physically and psychologically for an extended period of time. An upcoming mission to the space station will last six months.