Periodic Reporting for period 1 - SPACE USB (SPACE Universal Serial Bus)
Reporting period: 2024-01-01 to 2025-12-31
In space exploration, the maintenance of satellites poses significant challenges due to the lack of standardised interconnects. Currently, disparate systems hinder compatibility, leading to costly and time-consuming procedures. A lack of common recommendations impedes progress towards universal connectivity. In this context, the EU-funded SPACE USB project aims to standardise interconnects for orbital modular robotics. By creating a universal, serial interface similar to the USB, the project seeks to enhance flexibility and interoperability in on-orbit servicing and assembly. With existing European solutions providing mechanical connections and data/power transfer, the focus shifts to establishing common recommendations. Through collaboration, the project aims to design an interface ensuring compactness, docking symmetry and interoperability with other interfaces.
At the start of the project, the team focused on gathering and analyzing the current state of service interfaces (SOTA). The consortium created a benchmarking table to compare the features of existing interfaces, including SIROM, iSSI, and Hotdock, alongside other external solutions. This allowed for a comparative evaluation based on key factors such as mechanical durability, data and power transfer capabilities, and space qualifications.
The project introduced the first version of the Space USB specification interface, aiming to establish a generic and standardized approach. This specification defined a set of common requirements and categories, based on the partners’ expertise and findings from the SOTA analysis. The specification was designed to remain open for updates throughout the project, allowing for the inclusion of results from workshops and technical feedback. After the project’s conclusion, the specification is available as a public version.
Key technical areas addressed in the specification included mechanical load tolerances, electrical power levels per orbit, environmental resistance, and connector/data standards. An applicability matrix was also developed to clarify which requirements applied to each interface category.
To ensure cross-validation, a compliance matrix was created, with each partner aligning their internal designs to the standards. Workshops were held to test bilateral interoperability, laying the foundation for future integration, interoperability, and standardization.
The project followed a methodology based on technical workshops organized between partner pairs. Each session focused on evaluating mechanical and electrical compatibility through simplified design iterations and mutual adjustments. Every partner confirmed their willingness to adapt their interface architecture to achieve convergence, while keeping core functionalities intact. Intermediate models were developed to serve both validation and learning purposes.
After successful outcomes from the pairwise workshops, the consortium decided to merge efforts into a single Common Passive Interface (CPI), replacing the three separate 2-in-1 configurations. The goal was to move toward a unified 3-in-1 interface. This significant decision was agreed upon by all partners, setting the new direction for the project.
The CPI combines the mechanical and electrical features from the three partner interfaces. A 3D-printed prototype was created to demonstrate the integration of the joint design. Partners then began finalizing their “delta designs” to ensure CPI compliance, while also maintaining compatibility with existing systems.
A test plan for validating the CPI was established using the ROBY test bench, operated by Thales Alenia Space. Each partner was responsible for delivering one CPI-compatible active interface and one passive unit. Two full CPI sets were produced for testing both single and Orbital Replacement Unit (ORU) configurations. The ROBY system operates in a position-controlled environment, later enabling more precise and generic validation scenarios, focusing on the SI capabilities unaffected by external robotic systems. Thales Alenia Space coordinated the integration, testing, and logistics.
While misalignment stress tests were excluded for risk management reasons, the planned testing campaign ensured thorough verification of the core interface functionalities. All tests, including direct interconnections and ORU configurations, were successfully conducted as planned and the results were documented in a test report. A complete analysis of the test results, including development plans and future activities for SI and interoperability improvements, is available in the report.
The project introduced the first version of the Space USB specification interface, aiming to establish a generic and standardized approach. This specification defined a set of common requirements and categories, based on the partners’ expertise and findings from the SOTA analysis. The specification was designed to remain open for updates throughout the project, allowing for the inclusion of results from workshops and technical feedback. After the project’s conclusion, the specification is available as a public version.
Key technical areas addressed in the specification included mechanical load tolerances, electrical power levels per orbit, environmental resistance, and connector/data standards. An applicability matrix was also developed to clarify which requirements applied to each interface category.
To ensure cross-validation, a compliance matrix was created, with each partner aligning their internal designs to the standards. Workshops were held to test bilateral interoperability, laying the foundation for future integration, interoperability, and standardization.
The project followed a methodology based on technical workshops organized between partner pairs. Each session focused on evaluating mechanical and electrical compatibility through simplified design iterations and mutual adjustments. Every partner confirmed their willingness to adapt their interface architecture to achieve convergence, while keeping core functionalities intact. Intermediate models were developed to serve both validation and learning purposes.
After successful outcomes from the pairwise workshops, the consortium decided to merge efforts into a single Common Passive Interface (CPI), replacing the three separate 2-in-1 configurations. The goal was to move toward a unified 3-in-1 interface. This significant decision was agreed upon by all partners, setting the new direction for the project.
The CPI combines the mechanical and electrical features from the three partner interfaces. A 3D-printed prototype was created to demonstrate the integration of the joint design. Partners then began finalizing their “delta designs” to ensure CPI compliance, while also maintaining compatibility with existing systems.
A test plan for validating the CPI was established using the ROBY test bench, operated by Thales Alenia Space. Each partner was responsible for delivering one CPI-compatible active interface and one passive unit. Two full CPI sets were produced for testing both single and Orbital Replacement Unit (ORU) configurations. The ROBY system operates in a position-controlled environment, later enabling more precise and generic validation scenarios, focusing on the SI capabilities unaffected by external robotic systems. Thales Alenia Space coordinated the integration, testing, and logistics.
While misalignment stress tests were excluded for risk management reasons, the planned testing campaign ensured thorough verification of the core interface functionalities. All tests, including direct interconnections and ORU configurations, were successfully conducted as planned and the results were documented in a test report. A complete analysis of the test results, including development plans and future activities for SI and interoperability improvements, is available in the report.
The SPACE USB project is a major initiative aimed at boosting Europe's position in the global space industry. By developing cutting-edge technologies in robotics, autonomy, and rendezvous systems, the project focuses on the growing On-Orbit Servicing (OOS) market, which involves maintaining and repairing satellites in space. SPACE USB provided a high-tech solution designed to meet the specific needs of this market, positioning Europe as a leader in flexible, modular, and smart satellite designs.
The project creates key outcomes that could revolutionize the space sector. First, it produced a detailed review of existing space connector standards (Standard Interfaces or SIs), helping partners optimize current solutions and develop new ones. Second, it created a universal, USB-like interface for space systems, making it easier to develop and integrate different space technologies. This standardization will reduce market barriers and speed up the adoption of new innovations. Third, the project worked to ensure different European space connectors can work together seamlessly, which will improve collaboration and competitiveness.
The project also aims to meet the growing demand for satellite servicing, targeting key markets like GEO telecommunications and cislunar space exploration. A clear commercialization roadmap is set to lead to the development of prototypes, certification, and international licensing by 2032. Future Strategic partnerships will help validate the technology and ensure it gains widespread use. Additionally, the project is protecting its intellectual property through proper management and NDA keeping the information is accessible on demand.
The project creates key outcomes that could revolutionize the space sector. First, it produced a detailed review of existing space connector standards (Standard Interfaces or SIs), helping partners optimize current solutions and develop new ones. Second, it created a universal, USB-like interface for space systems, making it easier to develop and integrate different space technologies. This standardization will reduce market barriers and speed up the adoption of new innovations. Third, the project worked to ensure different European space connectors can work together seamlessly, which will improve collaboration and competitiveness.
The project also aims to meet the growing demand for satellite servicing, targeting key markets like GEO telecommunications and cislunar space exploration. A clear commercialization roadmap is set to lead to the development of prototypes, certification, and international licensing by 2032. Future Strategic partnerships will help validate the technology and ensure it gains widespread use. Additionally, the project is protecting its intellectual property through proper management and NDA keeping the information is accessible on demand.