B. On-Orbit Services Space Logistics Innovation through RPOD, On Orbit Refueling, and Autonomous Technologies

Significance of the Research

• Contributes to addressing the space debris problem and expands the safe, sustainable use of the orbital environment.
• Promotes the commercial deployment of on-orbit services by private-sector operators, strengthening international competitiveness.
• Over the long term, it establishes a logistics infrastructure in space to sustain the development of exploration, utilization, and industrial activities beyond Earth.

Research Objectives

• To establish advanced rendezvous and proximity operations (RPO) technologies for both cooperative and non-cooperative targets, supporting space debris removal and satellite servicing. For cooperative targets in particular, the research aims to achieve higher levels of autonomy through standardized interfaces and to promote the dissemination of RPO technologies among domestic stakeholders.
• To develop evaluation methodologies and foundational technologies for on-orbit propellant refueling systems, thereby promoting their commercial use.
• To acquire key enabling technologies, such as weight reduction and extended operational lifetime, required for reusable inter-orbital transfer vehicles, supporting future space transportation networks.

Reference information

Development of a Charging Detection Method to Support Spacecraft Charging Mitigation Operations During Docking

The Japan Aerospace Exploration Agency (JAXA) has been conducting collaborative research with to develop technologies for predicting when spacecraft charging occurs in orbit.

As part of this collaboration, Japan Aerospace Exploration Agency (JAXA) analyzed approximately 19 years of satellite observation data using artificial intelligence (AI) and developed a new method for automatically detecting satellite surface charging events. The research also made clear specific space environment conditions that make satellites more charge.

Severe spacecraft charging can cause unexpected charge accumulation across a satellite's surface, resulting in large potential differences between different locations on the spacecraft. When these potential differences become sufficiently large, electrostatic discharges, similar to electrical sparks, can occur. Such discharges may damage solar panels and surface materials and can potentially disrupt normal satellite operations.

The newly developed detection method and the findings on charging-prone space environments are expected to improve our understanding of severe spacecraft charging conditions. These results may contribute to more accurate predictions of charging and discharge risks, ultimately helping to prevent satellite anomalies and failures caused by the space environment.

Understanding the charging state of a spacecraft is particularly important for on-orbit servicing missions, such as satellite inspection, maintenance, repair, refueling, and docking operations. Conducting these activities when electrical potential differences are minimized can reduce operational risks. To support the safe execution of future rendezvous and docking missions, Japan Aerospace Exploration Agency (JAXA) will continue advancing research and development of spacecraft-charging mitigation technologies and operational strategies.

The results of this study were published in the peer-reviewed journal Space Weather, published by the American Geophysical Union (AGU), on December 27, 2026.

Publication Information