NASA has issued a 360-page request for proposals inviting US commercial space companies to develop private space stations that could succeed the International Space Station as early as 2030.
In a cover letter accompanying the solicitation, NASA said the effort "will ensure NASA has a sustained human presence in LEO for crew members to perform science and exploration."
The release, which came after years of anticipation, gives companies that have spent years designing and developing station concepts their first clear picture of what capabilities NASA is seeking. The agency said it plans to select "two or more" contractors in this phase of the competition.
Industry responses are due back to NASA on December 8, and the agency intends to make a final decision in April.
The request marks a formal step in the transition from the government-led International Space Station program toward commercially owned and operated stations in low-Earth orbit. With the ISS nearing the end of its operational life, NASA has indicated it expects to become one customer of commercial facilities rather than the owner and operator of the only crewed station in orbit.
Details of the agency's requirements, including technical specifications and anticipated contract terms, are contained in the full proposal document, which NASA has made publicly available.