Breakthrough in On-Orbit Construction of Large Space Structures Achieved with CF/PEEK Composite
Source:China Composites Expo  May 21, 2026
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SHENYANG, China - As super-large space infrastructure, including space solar power stations, ultra-large-aperture antennas, and on-orbit service platforms, emerges as a strategic focus in aerospace development, the conventional “ground fabrication plus rocket launch” paradigm is encountering critical constraints. Limited by payload fairing dimensions and severe launch-induced loads, this traditional approach is inadequate for the construction of kilometer-scale structural systems. On-orbit construction, which circumvents launch envelope restrictions by enabling in-space component fabrication, joining, and integration, has thus become a foundational technology for next-generation space systems.

Schematic of the Continuous Pultrusion Prototype for CF/PEEK Tubular Units

In this context, the Shenyang Institute of Automation (SIA), Chinese Academy of Sciences, in collaboration with partner institutions, has achieved a significant technological breakthrough in on-orbit assembly of large space structures. The research team has successfully developed an integrated process combining continuous pultrusion forming with laser transmission welding for carbon fiber/polyether ether ketone (CF/PEEK) composite tubular units. This innovation provides a lightweight, high-strength, and high-reliability solution for the automated on-orbit construction of large space truss structures. The findings were recently published in the peer-reviewed journal Space: Science & Technology.

Addressing two fundamental challenges in on-orbit construction-efficient fabrication of high-performance structural elements and reliable interconnection between components-the team proposed a novel technical pathway. Utilizing CF/PEEK thermoplastic prepreg tapes, hollow tubular profiles were produced via a continuous pultrusion process. The effects of processing temperature and pulling speed on mechanical performance were systematically investigated, leading to the identification of optimal parameters. The resulting composite tubes exhibit superior specific strength, high flexural stiffness, and excellent environmental durability, rendering them highly suitable for extended service in the space environment.

Ground Demonstration of On-Orbit Manufacturing for Space Structures (Left: Truss Product; Right: Mirror Frame Product)

For structural joining, the team innovatively employed 3D-printed high-optical-transmittance PEEK connectors combined with laser transmission welding, achieving high-precision, high-strength monolithic integration between tubes and joints. This non-contact, stress-uniform, and high-efficiency joining method effectively overcomes the limitations of conventional techniques-namely, adhesive degradation over time in bonded joints, as well as excessive mass and insufficient reliability in mechanically fastened connections. The resulting weld seams are stable and fully compliant with the load-bearing requirements for space structures.

To validate engineering feasibility, the team fabricated a scaled-down prototype of a parabolic antenna truss using the developed technology, successfully demonstrating the entire manufacturing chain—from raw material processing and unit forming to joint integration and structural assembly. This ground-based validation confirms the applicability of the proposed approach for automated on-orbit space construction.

The research, titled “Manufacturing and Joining of Composite Units for On-Orbit Construction of Large Structures in Space” was published with Yuxin Li, a postdoctoral fellow at SIA, as the first author, and Dr. Haitao Luo, Professor at SIA, as the corresponding author. The study was supported by the Basic Research Program of the Shenyang Institute of Automation.

The Space Structure Dynamics and Optimization Design Team, part of the Space Automation Technology Research Department, has long been engaged in fundamental and applied research on on-orbit construction of large space structures and the application of advanced composite materials, continuously promoting the interdisciplinary integration of state-of-the-art manufacturing technologies with aerospace engineering.

About Shenyang Institute of Automation, Chinese Academy of Sciences

The Shenyang Institute of Automation (SIA), Chinese Academy of Sciences, is a premier research institution specializing in robotics, automation, and advanced manufacturing technologies. With a strong emphasis on space automation, SIA conducts cutting-edge research in on-orbit construction, space structure dynamics, and composite material applications, contributing to China’s strategic advancement in next-generation space systems and intelligent space manufacturing.