China launched three astronauts into space on Thursday, in its first crewed mission in years.A Long March 2F rocket carrying the Shenzhou-12, or "Divine Vessel," blasted off from Jiuquan in northwestern Gansu province mid-morning local time.This is the third of 11 missions aimed at completing China's first full-fledged space station.It's headed to the Tianhe core module - launched in April as the first and largest of the space station's three parts.Astronauts Nie Haisheng, Liu Boming and Tang Hongbo will live and work on Tianhe for three months.There, they'll be testing the future space station's living quarters -- slightly bigger than a city bus.Chinese astronaut researcher Huang Weifen says it's China's longest crewed space mission yet."The three-month flight is a long-term human-crewed space flight, which requires astronauts to stay in a relatively narrow and confined environment. And it takes time to adapt the weightlessness. Astronauts will feel weightless and have to cope with noise and vibration, which is a very complex environment that will make people uncomfortable."The astronauts' physical and mental health will also be monitored.Since 2003, China has launched six crewed missions and sent 11 astronauts into space.An upcoming mission to the space station will last six months.