China is expected to launch a new crewed mission into space this week, as Beijing takes steady steps toward its goal of putting astronauts on the moon.

China has launched three astronauts to replace the crew on the Chinese Tiangong space station. The Shenzhou 20 spaceship took off as planned atop China’s workhorse Long March 2F rocket at 5:17 p.m. local time (0917 GMT).

China sent three astronauts to its permanently inhabited space station on Thursday, in its 15th crewed spaceflight and the 20th overall in the Shenzhou program that started over three decades ago.