Initially read this as "US astronauts enter China's space station".
That would have been interesting.
Cosmonauts = Russian Taikonauts = Chinese Astronauts = Western
Let's call them Earth orbitonauts. :-)
As they’re obviously not sailing between stars, but in the cosmos, Cosmonaut is obviously the correct term.
"Astro- a combining form with the meaning “pertaining to stars or celestial bodies, or to activities, as spaceflight, taking place outside the earth's atmosphere,” used in the formation of compound words:"
It sounds like the Greek(?) meaning has been lost now in English, which is fine since it's a different language. Astronomers still sometimes look at other planets afterall.
Sometimes linguistic prescriptivism is necessary to keep a language actually understandable, and to ensure it makes sense, and doesn’t just become thousands of independent statements that you have to learn by heart.
Cosmos, on the other hand, derives from the entire universe. Obviously, the universe surrounds us completely, but if you're willing to call someone in LEO a cosmonaut, I'm not certain you couldn't say the same about someone driving a car on the planet's surface to the grocery store to buy milk. Both are traveling through the cosmos. Where's the cutoff? Earth escape velocity? Solar escape velocity? Galactic escape velocity? People in LEO just aren't going fast enough.
I have no qualms about calling the flight personnel of the Apollo program "astronauts", as their goal was to reach another celestial body, even if it was not literally a star, and several of them actually made it there. "Selenauts" would also have been appropriate.
But since 1972, we have only been sending humans as far as LEO. Maybe "lacunauts" would be better for those in space, but not traveling to other celestial bodies?
They will be called 'Vyomnauts' apparently.
A quick search of matches in actual translated texts returns 'astronauts' as the term in the vast majority, and a few cases of 'spaceman' and 'man in space'. 人 'ren' in Chinese is genderless.
Taikonaut is however used by the Global Times and China Daily, tabloid and broadsheet papers published in the mainland. Am pretty sure the term wasn't termed in China, however. Otherwise the pinyin would be correct.