The three astronauts aboard China's Shenzhou-21 spaceship have entered the country's space station and met with another astronaut trio early Saturday morning, starting a new round of in-orbit crew handover.

The Shenzhou-20 crew opened the hatch at 4:58 a.m. (Beijing Time) and greeted the new arrivals, according to the China Manned Space Agency (CMSA).

The six crew members then took group pictures for the seventh space get-together in China's aerospace history.

They will live and work together for about five days to complete planned tasks and handover work, the CMSA said.