EPASS NANO – A COMPACT AND RELIABLE SOLUTION FOR SATELLITE ELECTRICAL PASSIVATION

The growing regulation for satellite end-of-life operations, as outlined in French national law (LOS) and European legislation (EU Space Law), underscores the critical need for robust electrical passivation subsystems. This is particularly challenging for nano-satellites, where strict reliability requirements, compact design, and budget constraints must be balanced.

In response, the French Space Agency (CNES) and Ascend Beyond Space have developed EPASS-NANO, an innovative prototype offering a reliable, compact, and low-cost approach to ensuring deactivation of power systems at mission’s end.

EPASS-NANO meet six key objectives: Definitive disconnection of power supply preventing reactivation, immediate passivation triggered on command, controlled and efficient battery discharge, reliability over 95%, minimal form factor, low recurring costs.

The device employs a novel solid-state architecture using MOSFETs, providing advantages over traditional relay-based systems, including compact size and high current density. Mitigations address limitations such as non-latching behavior and radiation sensitivity, ensuring operational reliability.

EPASS-NANO integrates into the satellite’s power infrastructure, between battery, solar array sections and PCDU. It operates across a wide voltage range, accommodating various satellite configurations. The system features two primary functional blocks: a high-current power section for passivation tasks and a low-level logic section for control and autonomous operation. The electronic design maintains passivation until complete battery depletion, preventing any risk of recharging. Activation can be triggered manually via ARM and FIRE commands or automatically by an internal watchdog timer, ensuring fail-safe operation. Periodic timer resets prevent premature passivation, while deliberate commands at mission’s end initiate controlled battery depletion and spacecraft inertness.

The EPASS-NANO solution is currently undergoing a competitive selection process to finalize the design and qualify the system.

This solution supports the competitiveness of emerging French companies while adhering to regulatory standards. By promoting safe deorbiting, EPASS-NANO contributes to global sustainability goals and reinforces the resilience, agility, and autonomy of space systems.