WASHINGTON — The U.S. Space Force awarded $60 million to five companies to demonstrate how satellites from multiple vendors can connect to its Space Data Network, a military communications architecture whose core backbone is being supplied by SpaceX.

Amazon LEO for Government, Lockheed Martin, Northrop Grumman, Rocket Lab and York Space Systems each received $12 million in contracts and prototype agreements, the Space Systems Command said Aug. 13. The work will test connections between commercial satellite systems and the Space Data Network, or SDN, including on-orbit data transport and standardized interfaces that would allow different providers to operate across the same network.

The SDN is a planned mesh communications architecture in low Earth orbit designed to move large volumes of data among satellites and between space and the ground. SpaceX in May won a $2.29 billion contract to build the Space Data Network Backbone, or SDN-B, a proliferated constellation using optical crosslinks to route data from satellite to satellite.

The latest awards address how systems supplied by other companies will connect to that backbone, an important part of the Space Force’s effort to avoid locking the broader network into a single vendor.

The projects are intended to “validate integration methodologies and demonstrate that diverse commercial systems can seamlessly connect to and transport data across the core SDN system,” Col. Ryan Frazier, acting portfolio acquisition executive for Space Based Sensing and Targeting, said in a statement.

“By investing in standardized interfaces, we are creating a clear runway for any capable and innovative company to come in and compete,” Frazier said.

Each company received a $10 million fixed-price contract for work lasting up to nine months to prototype and demonstrate connections among multiple vendors across the SDN backbone. The demonstrations will include ground-to-space and space-to-space data transport, testing whether different commercial systems can communicate through the core network infrastructure.

The remaining $2 million awarded to each company comes through six-month Other Transaction Authority agreements supporting the Space Force’s planned “space exchange point” concept.

Space exchange points would act as orbital routers, providing connection points through which otherwise separate commercial networks and government satellite systems could exchange data with the SDN backbone.

The five companies were selected through the Space Data Network consortium, an industry group the Space Force established to work through the technical and architectural challenges of connecting systems from multiple suppliers.

While SpaceX is responsible for the initial core network, the consortium is intended to help the Space Force establish a broader architecture in which other commercial and government systems can connect to it. A mesh architecture with multiple connections and pathways could allow military data to be rerouted if individual links or satellites are disrupted, while reducing reliance on any single supplier as the network expands.