A comprehensive review of multi-dimensional connection interfaces for the on-orbit assembly of space architectures

The demand for large-scale space infrastructures, such as solar power stations and ultra-large telescopes, is growing rapidly. Consequently, on-orbit assembly has emerged as a critical pathway to overcome launch vehicle constraints and construct next-generation space assets. The connection interface, serving as the core of any on-orbit assembly system, directly determines the performance of the assembled structure, mission reliability, and system scalability. This paper provides a systematic review of the technological developments in on-orbit assembly interfaces. We propose an innovative four-category classification framework: Rigid Structural Connections, Mechanism-Based Connections, Advanced Integrated Interfaces, and Permanent In-Orbit Fixation. This framework clearly delineates the technological spectrum from high-stiffness mechanical joints to material-level integration. By analyzing the design principles, typical examples, and technical characteristics of each category, this paper reveals the trade-offs in task adaptability among different interfaces. It thereby offers a theoretical foundation and technical reference for the future development of standardized, autonomous, and multifunctional interfaces within the In-orbit Servicing, Assembly, and Manufacturing (ISAM) ecosystem.