Cancelled space stations

planned lunar international space station

cancelled United States Air Force space station

proposed American space station, predecessor to the International Space Station

'''Mir-2' was a Soviet space station project which began in February 1976. Some of the modules built for Mir-2 have been incorporated into the International Space Station (ISS). The project underwent many changes, but was always based on the DOS-8 base block space station core module, built as a back-up to the DOS-7 base block used in the Mir station. The DOS-8 base block was eventually used as the Zvezda'' module of the ISS. Its design lineage extends back to the original Salyut stations.

private spaceflight company

Tiangong-3 () was a proposed Chinese space station that was part of the Tiangong program. The China National Space Agency (CNSA) initially planned to launch Tiangong-3 around 2015, following the launch of the Tiangong-2 test laboratory, which was originally planned for 2013. However, the goals for the Tiangong-2 and Tiangong-3 laboratories were merged, and the latter was not ordered. Eventually, the first module of the third station of the Tiangong program, Tiangong space station, was launched in 2021.

Proposed Russian space station

TransHab was a program pursued by NASA in the late 1990s to develop the technology for expandable habitats inflated by air in space. TransHab was intended as a replacement for the existing rigid International Space Station crew Habitation Module. When deflated, inflatable modules provide an 'easier to launch' compact form. When fully inflated, TransHab would expand to in diameter (compare to the diameter of the Columbus ISS Module).

proposed second US space station similar to Skylab

Sundancer was the proposed third prototype space habitat intended to be launched by Bigelow Aerospace—and the first human-rated expandable module based on TransHab technology acquired from NASA. It was to have been used to test and confirm systems used in the company's commercial space station efforts during the early 2010s, and if successful, would have formed the first piece of the proposed commercial space station.

The B330 (previously known as the Nautilus space complex module and BA 330) was an inflatable space habitat privately developed by Bigelow Aerospace from 2010 until 2020. The design was evolved from NASA's TransHab habitat concept. B330 was to have of internal volume, hence its numeric designation.

Conceptual deep space mission architecture