Back to News & Events Radiation-Hardened Power Solutions for Space Applications: from EM to FM
Introduction: Powering the Final Frontier
Designing reliable electronics for space environments presents one of the most demanding challenges in engineering. From Low Earth Orbit (LEO) satellites to deep-space probes, every component must operate flawlessly amid ionizing radiation (such as gamma rays, protons, and heavy ions), thermal extremes, and vacuum conditions. These radiation types can cause both long-term degradation and sudden functional failures in electronic systems. At the heart of these systems lies a critical component: the space-qualified power supply built to endure and perform under such harsh, unpredictable conditions.
This article explores what electronic engineers need to know about radiation-hardened DC-DC converters, EMI filters, and industry standards. We’ll also highlight proven solutions from VPT trusted worldwide and available through Horizon Electronics.
Radiation Challenges in Space Environments
Space-based electronics must endure constant exposure to:
- Total Ionizing Dose (TID): Long-term exposure to ionizing radiation degrades semiconductor materials.
- Single Event Effects (SEE): High-energy particles (e.g., protons, heavy ions) can trigger latch-up, burnout, or bit flips.
- Electromagnetic Interference (EMI): Without proper filtering, sensitive circuits can malfunction or fail.
These challenges make it essential to use power components that are not just robust but tested and certified for space.
| Challenge | Impact |
| Radiation (TID, SEE) | Functional degradation, catastrophic failures |
| Extreme temperatures | Material fatigue, drift in component behavior |
| Vacuum and thermal design | Cooling difficulties, outgassing risks |
| Mass and size limits | Constrained design choices, limit on redundancy |
| EMI/EMC constraints | Must not interfere with spacecraft systems |
| Reliability and lifespan | No repair possible, must work perfectly for years |
| Power efficiency | Must Maximize energy use from limited power sources |
| Qualifications and testing | High costs, long development cycles |
| Component obsolescence | Supply chain risks, redesign needs |
1. Radiation Effects
Space is filled with ionizing radiation from cosmic rays, solar flares, and trapped particles in Earth’s magnetosphere. These cause:
a. Total Ionizing Dose (TID)
- Long-term accumulation of radiation degrades the performance of semiconductors.
- Effects include threshold voltage shifts, leakage currents, and eventual functional failure.
b. Single Event Effects (SEEs)
- Single Event Upset (SEU): Bit flips in digital circuits (e.g., in controllers or memory).
- Single Event Latchup (SEL): A high-current state that can lead to thermal destruction.
- Single Event Burnout (SEB) / Gate Rupture (SEGR): Permanent failure in power devices like MOSFETs and IGBTs.
2. Extreme Temperature Ranges
- Components must operate reliably across wide temperatures, often from -55°C to +125°C or more.
- Thermal cycling and extreme cold can cause mechanical stress and change component behavior.
3. Vacuum Conditions
- Outgassing of materials can degrade components and contaminate nearby optics or sensitive instruments.
- Heat dissipation is difficult in a vacuum, requiring careful thermal design and conduction paths.
4. Weight and Size Constraints
- Mass and volume must be minimized, especially for small satellites (CubeSats) and deep-space probes.
- Designers must balance performance, redundancy, and shielding without adding excessive weight.
5. EMI and EMC Considerations
- Power supplies must meet strict electromagnetic interference (EMI) and compatibility (EMC) standards to prevent interference with onboard instruments and communication systems.
6. High Reliability and Long Lifespan
- Many missions last 10+ years with no chance of repair.
- Redundancy, fault tolerance, and graceful degradation strategies are essential.
7. Limited Power Budget
- Available power from solar panels or RTGs is limited and must be efficiently regulated and distributed.
- Power supply must operate with high efficiency across a wide load range.
8. Qualification and Testing Costs
- Space-grade components and systems require extensive testing: radiation testing, thermal vacuum testing, vibration, and shock.
- This adds cost and limits the availability of commercial off-the-shelf (COTS) components.
9. Component Obsolescence
- Space-qualified parts are produced in small volumes and may become obsolete quickly.
- Long mission development cycles mean parts chosen early may be unavailable by launch time.
Understanding EM and FM: Engineering and Flight Models
In the development of space systems, two primary hardware models are utilized:
- Engineering Model (EM): These units are designed to be form, fit and functionally representative of the final product but are built using a mix of commercial and flight-grade components. EMs are primarily used for system integration, interface validation, and functional testing. They offer a cost-effective solution for early-stage development without the need for full environmental qualification.
- Flight Model (FM): These are the final, fully-qualified units intended for actual deployment in space missions. FMs are constructed using high-reliability, flight-approved components and undergo rigorous environmental and functional testing to meet stringent space qualification standards.
Understanding the distinction between EM and FM is crucial for efficient project planning and budget allocation. EMs allow for early detection of design issues and system integration challenges, while FMs ensure mission success through compliance with all spaceflight requirements.
Key Standards for Space-Qualified Power Components
For space applications, component qualification is critical. Engineers typically seek products that comply with:
- MIL-PRF-38534 Class K: The highest quality and screening standard for hybrid microcircuits used in space. Class K certification includes rigorous testing for temperature cycling, burn-in, radiation tolerance, and visual/mechanical inspection—ensuring long-term reliability in space environments.
- NASA and ESA requirements for radiation performance and quality assurance. These agencies set strict design and documentation guidelines that mandate traceability, failure analysis protocols, and environmental stress screening aligned with mission-critical use cases.
- Qualification to TID levels up to 100 krad(Si) and SEE immunity up to 85 MeV/mg/cm². These metrics reflect a component’s resilience to long-term radiation exposure and single-event effects, helping engineers select parts based on mission duration and orbit-specific risk factors.
VPT’s Space Power Portfolio Available from Horizon Electronics
VPT has established itself as a global leader in radiation-hardened power systems, with products qualified for LEO, GEO, lunar, and deep space missions.
Horizon Electronics is VPT’s exclusive distributor in Israel, proudly offering their most in-demand solutions, among other products such as:
This isolated converter is Class K certified and radiation-hardened to 100 krad(Si) TID with SEE immunity up to 85 MeV/mg/cm².
- Input: 28V nominal
- Output: 5V / 18W
- Size and weight optimized for satellite systems
An ultra-compact filter that ensures compliance with MIL-STD-461 for conducted emissions.
- 28V input
- Compatible with VPT DC-DC converters
- Helps maintain system integrity and noise immunity
Designed for distributed power systems, this converter is radiation-hardened and ideal for onboard subsystems.
- Output: 5V / 20A
- Small footprint for tight board space
- Supports modern digital payload designs
Part of VPT’s VXR series, it combines radiation tolerance, ruggedization, and high efficiency.
- Up to 87% efficiency
- SEE: up to 85 MeV/mg/cm²
- Input: 28V | Output: 5V
Supporting Every Stage: Horizon’s Commitment
Horizon Electronics is committed to supporting clients throughout the entire development lifecycle:
- EM Stage: Providing cost-effective, functionally representative power solutions for early testing and integration.
- FM Stage: Supplying fully qualified, flight-ready power components that meet the highest standards of reliability and performance.
By offering tailored solutions for both EM and FM stages, Horizon ensures that clients can efficiently progress from concept to launch.
Looking Ahead: Your Space Project Partner
Horizon Electronics combines deep technical expertise with access to leading power technologies from VPT. Whether you’re building satellite subsystems, payload power rails, or propulsion control units, we’re here to help.
Contact Horizon for project-specific recommendations
