While low-Earth orbit (LEO) has become an increasingly crowded space in recent years, it currently contains only two habitable space stations: the International Space Station (ISS) and China’s Tiangong station. The ISS is considerably older than Tiangong, with its initial modules launched in 1998. By comparison, Tiangong’s first components entered orbit in April 2021. After decades of service, the ISS is currently scheduled to be decommissioned in late 2030, when it will be de-orbited. Given the immense geopolitical and scientific importance of the station, the status of its replacement has become a matter of international debate.

In keeping with a broader shift toward commercial space activity, NASA has announced plans to develop the new station in partnership with private space firms. Accordingly, has awarded funding to several commercial firms, including Voyager Space and Blue Origin, to develop their own space station concepts. In 2020, one of these companies, Axiom Space, received a contract from NASA to design the first privately built modules for the ISS. Before the ISS reaches the end of its mission, Axiom plans to detach its modules, using them as the core of an independent station that could potentially serve as the ISS’ replacement.

Despite modest progress, many of these commercial endeavors remain behind schedule. With the conclusion of the ISS mission fast approaching, it remains unclear if a replacement will be in orbit before the ISS de-orbits. If NASA’s commercial partnerships fail to meet their timelines, it is possible that Tiangong will be the sole habitable station in orbit by 2031.

This question will resolve positively if the Tiangong station is the only habitable space station in low- Earth orbit by December 31, 2026.