Alpha Lifeboat

Big Soyuz, Zarya

Mission Profile

Alpha Lifeboat (Big Soyuz, Zarya) was a conceptual uncrewed orbital rescue vehicle studied in the early ISS planning era as a dedicated Crew Return Vehicle, intended to remain docked at the station and allow crew evacuation to Earth without waiting for a visiting Soyuz or Shuttle. The design evolved from Soyuz heritage and was studied by several contractors under NASA's CRV program in the 1990s, with concepts ranging from small Apollo-like capsules to lifting bodies. The X-38 lifting body vehicle was the most developed CRV candidate before the program was cancelled in 2002, leaving the ISS dependent on Soyuz spacecraft for emergency crew return — a dependency that continues to inform crew rotation planning.