As spacecraft architectures evolve toward distributed, high-throughput systems, the On-Board Computer (OBC) is no longer just a controller—it is the central data router, processor, and reliability backbone of the mission.

The OBC-Hypr-Polar, developed by Cavu Aerospace UK, is designed around this philosophy. By combining a PolarFire SoC FPGA with six 1Gb Ethernet interfaces and a high-reliability power subsystem using Glenair Micro-D connectors, the system achieves both performance and mission-grade robustness.

The OBC-Hypr-Polar is built around the Microchip Technology PolarFire SoC FPGA, which integrates:

• Multi-core RISC-V processors for software-defined control
• FPGA fabric for deterministic, parallel data handling
• Low-power architecture ideal for space platforms
• Radiation-tolerant design suitable for LEO and deep-space missions

This hybrid approach allows:

• Hardware-accelerated Ethernet switching and packet handling
• Real-time payload interfacing
• Software flexibility for mission updates

High-Speed Networking: 6× Independent 1Gb Ethernet Ports

The OBC-Hypr-Polar provides six isolated Gigabit Ethernet interfaces, enabling:

Distributed Spacecraft Architectures

Each subsystem (payload, ADCS, communications, storage) can operate as a network node, reducing centralized bottlenecks.

Redundancy and Fault Tolerance

Multiple Ethernet links allow:

• Cross-strapping between subsystems
• Ring or mesh redundancy
• Graceful degradation under failure

FPGA-Based Networking

Using the PolarFire FPGA fabric, the OBC can implement:

• Deterministic Ethernet switching
• Custom packet routing
• Time-Sensitive Networking (TSN)

Multi-Interface Support

Beyond Ethernet, the system integrates:

• LVDS for high-speed sensor interfaces
• Serial I/O for legacy subsystems and housekeeping
• ADC interface for analog telemetry acquisition
• JTAG-USB debug for development and diagnostics

This ensures compatibility across a wide range of spacecraft subsystems.

Power Subsystem: FMEA-Driven Reliability Engineering

A comprehensive Failure Modes and Effects Analysis (FMEA) identified the power subsystem as the highest-risk element in the OBC.

Failures in power delivery can result in:

• Complete system shutdown
• FPGA latch-up or reset
• Data corruption or mission loss

To mitigate these risks, the OBC-Hypr-Polar incorporates:

1. Radiation-Tolerant DC/DC Conversion

• • Stable operation across temperature extremes
  • Protection against transients and single-event effects
  • High efficiency to reduce thermal load

2. High-Reliability Power Interconnect

Glenair Micro-D Connector (IGMPM2-B112R-CBRT-SU-.109)

The OBC uses a Glenair Micro-D combo connector, specifically designed for power and signal integration in harsh environments.

Why This Connector Matters

a) High Current Capability in Compact Form

• Approximately 13A per contact
• Enables reliable power delivery without bulky connectors
• Ideal for compact spacecraft avionics

b) Combo Micro-D Architecture

The connector combines:

• Power contacts
• Signal contacts
• Compact Micro-D footprint

This reduces:

• Connector count
• Harness complexity
• Potential failure points

c) Ruggedized PCB Mount Design

• Right-angle PCB mounting with encapsulation support
• Epoxy-sealed contacts improve:
  • Resistance to vibration
  • Resistance to thermal cycling
• Ensures mechanical integrity during launch conditions

d) Space-Grade Materials

• Beryllium copper contacts for high conductivity and durability
• Gold plating for corrosion resistance and low contact resistance
• Aluminum alloy shell with protective finish for strength and EMI shielding

e) Wide Operating Temperature Range

• Typically −55°C to +150°C
• Suitable for:
  • Low Earth Orbit thermal cycling
  • Deep space missions

f) Mechanical Reliability

• High mating cycle durability
• Secure locking mechanism
• Strong resistance to vibration and shock

Engineering Impact of Using Glenair Power Connectors

Improved Reliability

By reducing connector-related failure modes such as:

• Intermittent contact
• Mechanical wear
• Thermal degradation

Reduced System Risk

The power interface becomes:

• Mechanically stable
• Electrically robust
• Environmentally resilient

Optimized Mass and Volume

Compared to traditional circular connectors:

• Smaller footprint
• Lower mass

Higher integration density