Tiangong Space Station

The name means Heavenly Palace. Its core module, Tianhe, was launched in April 2021, and two laboratory modules were added in 2022 to make a T-shaped station of roughly a hundred tonnes with ships docked, about a fifth the mass of the International Space Station. It orbits at a similar height, a little under four hundred kilometres, and goes around the Earth about fifteen times a day.

Crews of three arrive on Shenzhou spacecraft and stay for about six months, with a short overlap when the next crew arrives so that the station is never empty. China was kept out of the international station and built its own, the first station any single country has assembled alone since the Soviet Mir in the 1980s and 1990s.

The plan is to keep it flying for at least a decade, to add a fourth module, and to fly a large space telescope in the same orbit so that it can dock for servicing. The station has hosted experiments in biology, materials and fluid physics, and China has opened it to experiments from other countries through the United Nations.

Like the larger station it can be seen from the ground with the naked eye, as a fainter steady point crossing the sky near dawn or dusk. For anyone watching the sky, there are now two.