Common In-Space Assembly Interface Standardization Framework for the United States Space Force (USSF)

The United States Space Force (USSF) is actively pursuing standardized in-space assembly (iSA) and in-space servicing (iSS) interfaces, vital for creating modular, interoperable, and cost-effective future space systems. This initiative, exemplified by the Advanced Space-Based Testbed (XST) concept, directly addresses the "Valley of Death" challenge in TRL 4-7 technology maturation. This paper presents a comprehensive framework for developing these standards, incorporating insights from the XST development process, including its architecture, requirements, operational concepts, potential test candidates, cost analysis, and a proposed standardization roadmap. The paper emphasizes the need for a robust in-space testing environment and leverages XST as a key enabler for validating and refining interface standards. Existing industry solutions and a competitive down-selection approach are advocated for identifying optimal interface standards for future USSF missions. This framework emphasizes the need for versatile interfaces accommodating diverse test article needs, including stiff mechanical connections, high-bandwidth data transfer, ample power supply, and fluid transfer capabilities. The framework also addresses the critical role of robotics in autonomous grappling and assembly, along with the need for standardized docking and robotic arm mobility interfaces. Finally, it advocates for a governmentsponsored competition to identify and promote the most promising interface solutions for commercialization and inclusion in the Defense Industrial Base (DIB).