NASA awarded a trio of companies with contracts to develop private space stations, as the agency prepares for the retirement of the International Space Station.

Jeff Bezos’ Blue Origin, Northrop Grumman, and Nanoracks were awarded a combined $415.6 million under NASA’s Commercial LEO Destinations (CLD) project, the agency announced on Thursday.

Nanoracks won the largest individual award with an $160 million, while Blue Origin and Northrop Grumman received $130 million and $125.6 million, respectively.

Notably, private holding company Voyager Space is the majority shareholder of X.O. Markets, the parent company of Nanoracks.

NASA told CNBC earlier this year that the agency “received roughly about a dozen proposals” from a variety of companies for contracts under the project. With NASA planning to retire the International Space Station by the end of the decade, the CLD program represents an effort to turn to private companies for new space stations — with the space agency expecting to save more than $1 billion annually as a result.

Rather than build and own hardware itself, NASA has increasingly turned to public-private partnerships as a way to achieve its goals in space. The agency has had great success through this model in the past decade, with cargo and crew services provided via vehicles built by SpaceX and Northrop Grumman.

The agency does not expect to foot the entire bill for helping companies build new space stations, with NASA saying “the strategy has to work for both the government and the private sector” from an investment perspective.

Blue Origin previously unveiled its plan for a space station called “Orbital Reef” – in partnership with Sierra Space, Boeing, Redwire Space and Genesis Engineering.

Nanoracks also announced plans to build a station called “Starlab” – partnering with Voyager and Lockheed Martin.