The DEEP Power Processing Unit (PPU) has been developed to reach Critical Design Review (CDR) maturity as a fully integrated electronic system, capable of powering and managing electric plasma thrusters in a large power range. While the current engineering model is designed around the RIT-2X ion thruster, the architecture is intentionally versatile, supporting a broad range of thrusters and voltages (800–1500 V). This flexibility enables multiple operating modes, including both iFROST and iGSP, which are critical for long-duration telecom missions.
A central aim has been to enhance competitiveness by reducing cost and mass. Early assessments show that the design achieves the target of up to 40% cost and volume savings, largely enabled by the extensive and well-managed use of COTS components.
Integrating the Radio Frequency Generator: A Key Added Value
One of the major innovations in the DEEP PPU is the integration of the Radio Frequency Generator (RFG) directly into the unit. Traditionally separate, the RFG’s inclusion brings several strategic advantages:
- Reduced mass and volume
- Lower manufacturing and integration costs
- Simplified spacecraft accommodation
- Improved system integration and harness design
Testing performed with long harness lengths (5–6 m), supplied by AXON, confirmed that the integrated RFG performs reliably, even under challenging spacecraft-like conditions.
System Architecture at a Glance
The DEEP PPU architecture unifies multiple functions under a single control interface connected to the spacecraft’s onboard computer. This centralized control manages:
- A large range of Thruster operating points
- Telemetry reporting
- Operational sequencing
- Autonomous management
- Fluidic regulation management
Key modules include:
High-Voltage Modules
Each module delivers up to 2 kW, allowing scalability simply by adding boards. The broad voltage range supports both nominal and high-thrust modes.
Fluidic Control Module
Responsible for propellant flow control, pressure sensing, telecommands, and communication with the platform’s fluidic systems.
Radio Frequency Converter
Designed to interface with both European and U.S. regulator standards, ensuring broad operational compatibility.
Mission Applications and Market Prospects
The DEEP PPU is designed for GEO and MEO telecommunications missions, with possibilities extending to on-orbit servicing such as docking, refueling, and repairs. The modularity of the system enables multi-thruster configurations—2 to 5 thrusters depending on mission needs.
With the RIT-2X thruster, currently undergoing qualification, the PPU is well positioned to enter the commercial market. Airbus-CRISA plans to finalize development and to initiate industrialization next year, aligning with industry demand for low-cost and high-efficiency propulsion solutions.
Technology Readiness Level Progress
Most functional blocks of the PPU have reached TRL 4–5, with some approaching TRL 6 due to strong heritage. Key achievements include:
- Successful functional testing of the RFG board with representative harness and inductors
- Demonstrated feasibility of managing long harness lengths with very low losses (<100 W)
- Positive evaluation of overall mass, volume, and thermal performance
Next Steps Toward Full Qualification
- Perform thruster coupling tests with the actual RIT-2X (beyond equivalent impedance testing).
- Finalize the PPU design ahead of CDR closeout next year.
- Qualify both the PPU and its harness—particularly the high-temperature, high-voltage thruster interface.
- Optimize harness implementation to ensure long-term operational reliability.
The DEEP PPU development has reached a promising level of maturity, demonstrating a compact, efficient, and highly competitive solution for electric propulsion. With functional performance validated and industrialization on the horizon, this next-generation PPU is poised to support a wide range of commercial missions and emerging applications such as on-orbit servicing.
By combining modularity, integrated RF capability, low-loss harness technology, and cost-effective design, the DEEP PPU stands as a significant advancement for electric propulsion and a meaningful contribution to the European space sector.