Only three space stations have been permanently crewed in orbit in the past quarter century: Russia's Mir, retired in 2001; the International Space Station, a multinational facility of roughly 420 tonnes operated by the United States, Russia, Europe, Japan and Canada; and China's Tiangong, a three-module station completed in 2022. At around 52 tonnes across five modules, the Bharatiya Antariksha Station will be substantially smaller than either the ISS or Tiangong - it is designed as a research and technology-demonstration outpost rather than a permanently occupied laboratory of ISS scale. The choice of an inclination near 51.5 degrees is significant: it matches the ISS orbit, which means spacecraft flying from the world's main crewed-launch sites can reach BAS, keeping the door open to international visits and cooperation. The ISS itself is scheduled to be deorbited around 2030, which is part of why several national programmes, India's included, are building successors for the 2030s.