For the first time in 21 years, Earth has two separate crewed space stations in orbit. One is, of course, the International Space Station (ISS), with a crew of seven, and now , the . There’s ten people in orbit now! Things are getting crowded up there in the infinite void.

back in April, and is , or even the module that serves as the core of the Russian segment of the ISS.

The three taikonauts, Nie Haisheng, 56, Liu Boming 54, and Tang Hongbo, 45, were launched in the Shenzou 12 spacecraft, which was China’s first crewed flight since October of 2016, which is a good reminder that China’s pace of crewed launches has always been quite slow, but steady.

This also brings up the biggest question about their new space station; with the Shenzou 12 crew scheduled for up to three months of habitation in Tianhe, will China replace them with a new crew immediately, or will the station be left unoccupied for a period of time?

Generally, the point of a space station—especially one with multiple docking ports that allows for a seamless handoff from crew to crew—is to keep it occupied and operational. But to do this, CMS (China’s crewed space agency) will need to dramatically increase the frequency of Shenzou launches and produce Shenzou spacecraft much more rapidly, as the previous shortest gap between crewed missions was a full year, between Shenzous 9 and 10.

While on the station, the three taikonauts will be conducting experiments and outfitting the station, and will do two spacewalks.

I’m quite curious to see how this all goes, and especially interested to see if China can ramp up their human space exploration to keep a station permanently occupied.