Thermal management in space DC-DC converters represents one of the most critical engineering challenges in aerospace power electronics. The extreme temperature environment of space—ranging from the deep cold of planetary shadows to the intense heat of direct solar radiation—demands power conversion solutions that maintain full operational capability across a 180°C temperature span. Crane Aerospace & Electronics has developed comprehensive thermal management strategies that enable their space-qualified DC-DC converters to deliver consistent performance from -55°C to +125°C, ensuring mission success across diverse space environments from low Earth orbit to interplanetary missions.
Space presents unique thermal challenges that fundamentally differ from terrestrial applications. The absence of atmospheric convection means heat dissipation relies entirely on conduction and radiation. Temperature swings occur rapidly during orbital transitions, subjecting components to severe thermal cycling. Additionally, the vacuum environment eliminates traditional cooling methods, requiring innovative approaches to thermal management that maintain performance while ensuring long-term reliability.
Figure 1: A comprehensive temperature range chart displaying the operational temperature capabilities (-55°C to +125°C) for all Crane DC-DC converter series.
The thermal environment in space missions varies dramatically depending on orbital parameters and mission profile. Low Earth orbit missions experience temperature cycling every 90 minutes, while geostationary satellites face more gradual but equally challenging thermal variations. Interplanetary missions encounter even more extreme conditions, with temperatures potentially reaching -200°C in deep space or exceeding +200°C near solar radiation sources.
The foundation of Crane's thermal management strategy lies in the use of high-temperature ceramic capacitors that maintain stable electrical characteristics across the full -55°C to +125°C operating range. These specialized components represent a significant advancement over conventional capacitors, which typically exhibit substantial capacitance drift and equivalent series resistance (ESR) changes with temperature.
According to the catalog specifications [1], high-temperature ceramic capacitors enable full power operation across DLA's Class H and K temperature range. This capability is crucial for space applications where power conversion efficiency and stability must be maintained regardless of thermal conditions. The ceramic capacitor technology ensures consistent switching behavior, stable output voltage regulation, and predictable transient response across the entire temperature spectrum.
Crane's implementation of all-metal thermally-conductive cases serves multiple critical functions in space thermal management. These cases provide optimum protection for components while ensuring efficient heat dissipation in the vacuum environment. The all-metal construction offers superior thermal conductivity compared to traditional plastic or ceramic packages, enabling effective heat spreading across the package surface.
Figure 2: A detailed thermal cycling performance chart showing the temperature cycling test profile (-65°C to +150°C, 10 cycles minimum) and converter performance throughout the cycling. The chart illustrates failure analysis data and how Crane's thermal management maintains performance throughout cycling.
The thermal conductivity of the all-metal cases enables efficient heat transfer from internal components to the package exterior, where heat can be dissipated through radiation or conduction to spacecraft thermal management systems. This design approach is particularly important for higher power converters where heat generation becomes a significant factor in maintaining operational stability.
All Crane DC-DC converters undergo rigorous thermal cycling testing as part of their space qualification process. The environmental screening requirements specify temperature cycling per MIL-STD-883 Method 1010, Condition C, with 10 cycles from -65°C to +150°C ambient temperature. This testing regime exceeds the operational temperature range, providing margin for reliability and ensuring consistent performance under actual mission conditions.
The temperature cycling test profile demonstrates the converter's ability to maintain electrical specifications throughout thermal stress. During cycling, converters must meet all performance requirements including output voltage accuracy, efficiency, and transient response. This comprehensive testing validates the thermal management design and ensures long-term reliability in space applications.
The burn-in process represents a critical component of thermal qualification, with converters operating at +125°C case temperature for extended periods. According to the screening tables, burn-in duration varies by qualification level: 96 hours for basic screening, 160 hours for enhanced screening, and 2×160 hours (including mid-burn-in testing) for the highest reliability levels.
Figure 3: A comparative analysis of thermal conductivity for different Crane converter case designs and materials. Show thermal resistance values (°C/W) for various case types (A1, A2, C, E, G, H, K, S, S1, U, V), surface area calculations, and heat dissipation capabilities.
The burn-in temperature is specifically designed to bring the case temperature to +125°C minimum, representing the upper limit of the operational temperature range. This powered test ensures that all components can operate reliably at maximum temperature while maintaining full electrical performance. The burn-in process also serves as an accelerated aging test, identifying potential thermal reliability issues before deployment.
The SLH series, delivering 1.5W in a 0.980" × 0.805" × 0.270" package, represents optimal thermal management for ultra-compact applications. With a package volume of only 0.213 in³, the thermal management challenge focuses on efficient heat spreading rather than high heat flux management.
Key thermal characteristics include:
The SLH series demonstrates how effective thermal management enables high efficiency (up to 88%) even in ultra-compact packages. The all-metal case provides sufficient thermal conductivity for the 1.5W power level while maintaining hermetic sealing integrity.
The SMSA series scales thermal management to 5W output in a 1.075" × 1.075" × 0.270" package. The square package geometry provides efficient thermal distribution with a larger surface area relative to volume compared to rectangular packages.
Thermal management features include:
The SMSA series maintains 65-74% efficiency across the full temperature range, demonstrating effective thermal management for the 5W power level. The inhibit function capability also provides thermal management benefits by allowing complete shutdown during non-operational periods.
The mid-power range represents a critical transition point where thermal management becomes increasingly important for maintaining performance. The SMHF series (8-15W) and SMTR series (18-30W) implement advanced thermal management strategies to handle higher power densities.
Figure 4: A comprehensive derating curve analysis showing power output capability vs. ambient temperature for different converter series. The curves illustrate various power levels (1.5W to 100W) and demonstrates how thermal management enables full power operation across the entire temperature range.
SMHF series thermal characteristics:
SMTR series thermal features:
Both series maintain full power operation across the complete temperature range through optimized component placement, enhanced thermal interface materials, and advanced case designs that maximize heat dissipation.
The high-power converters represent the pinnacle of space thermal management, with the SMFLHP series delivering up to 100W while maintaining full operation from -55°C to +125°C. These converters incorporate the most advanced thermal management technologies to handle power densities up to 55.1 W/in³.
SMFLHP series thermal management features:
The SMFLHP series maintains 72-87% efficiency across the full temperature range, representing a remarkable achievement in high-power thermal management. The unique dual-loop feedback technique provides enhanced thermal stability by improving transient response and reducing thermal stress on components.
The integration of hermetic sealing with thermal management represents one of the most challenging aspects of space converter design. All Crane converters must maintain hermetic integrity while providing efficient thermal conduction. The hermetic sealing testing includes gross leak testing per MIL-STD-883 Method 1014, with both helium and Kr85 testing methods employed.
Hermetic sealing thermal considerations include:
Figure 5: A technology evolution timeline showing the advancement of thermal management technologies across Crane's product generations.
The hermetic sealing process must maintain thermal performance while ensuring complete environmental protection. The all-metal case design provides the optimal solution by combining excellent thermal conductivity with reliable hermetic sealing capability.
The thermal interface between components and the case represents a critical factor in overall thermal management effectiveness. Crane's approach includes optimized thermal interface materials that maintain low thermal resistance across the complete temperature range while remaining compatible with hermetic sealing requirements.
Thermal interface considerations include:
All Crane DC-DC converters undergo extensive temperature testing to validate thermal management performance. The testing regime includes steady-state operation at temperature extremes, thermal cycling, and accelerated aging at elevated temperatures.
Temperature testing protocols include:
The thermal management validation process ensures that all electrical specifications are maintained across the complete temperature range. This includes output voltage accuracy, efficiency, transient response, and EMI performance at all temperature conditions.
Performance validation includes:
Low Earth orbit missions present unique thermal management challenges due to rapid temperature cycling. During a typical 90-minute orbit, converters experience temperature swings from deep space cold to solar heating. Crane's thermal management ensures consistent performance throughout these cycles.
Orbital thermal considerations include:
Interplanetary missions present even more extreme thermal challenges, with potential temperatures far below the standard -55°C lower limit. However, spacecraft thermal management systems typically maintain converter operating temperatures within the qualified range.
Deep space thermal factors include:
Planetary surface missions, such as Mars rovers, present unique thermal management challenges due to diurnal temperature cycling and atmospheric effects. The thermal management must accommodate both the space environment and planetary surface conditions.
Planetary surface thermal considerations include:
Crane's thermal management approach extends beyond package-level design to include component-level optimization. This includes selection of components with superior thermal characteristics and optimization of component placement for thermal distribution.
Component thermal optimization includes:
Advanced thermal design validation tools enable optimization of thermal management before physical prototyping. These tools include thermal modeling, finite element analysis, and thermal cycling simulation.
Thermal design validation includes:
Continued advancement in thermal management technologies promises further improvements in space converter thermal performance. These developments include advanced thermal interface materials, enhanced case designs, and improved component thermal characteristics.
Future thermal management developments include:
Future space missions will demand even more advanced thermal management capabilities. These include missions to extreme environments, extended duration missions, and high-power applications requiring advanced thermal management solutions.
Next-generation thermal management requirements include:
Crane Aerospace & Electronics' comprehensive thermal management approach enables full power operation of space DC-DC converters from -55°C to +125°C, representing a critical capability for space mission success. Through the integration of high-temperature ceramic capacitors, all-metal thermally-conductive cases, and advanced thermal management techniques, Crane converters maintain consistent performance across the extreme temperature range encountered in space environments.
The thermal management strategies employed across the product portfolio—from the ultra-compact 1.5W SLH series to the high-power 100W SMFLHP series—demonstrate scalable solutions that maintain thermal performance while achieving remarkable power density. The proven mission heritage, including successful operation in Mars surface conditions, deep space environments, and long-duration orbital missions, validates the effectiveness of these thermal management approaches.
The comprehensive temperature testing and validation protocols ensure that thermal management performance meets the demanding requirements of space applications. The integration of hermetic sealing with thermal management provides the complete environmental protection essential for space operation while maintaining optimal thermal performance.
As space missions become increasingly demanding and power requirements continue to grow, Crane's thermal management innovations provide the foundation for next-generation space power systems. The ability to maintain full power operation across the complete space temperature range ensures mission success and enables the continued exploration of space environments from low Earth orbit to the outer planets.
As the authorized distributor of Crane Aerospace & Electronics, SAGA Components provides customers with direct access to Interpoint® DC-DC converters and space-grade power management solutions used across satellite, defense, and deep-space missions.
Through our partnership with Crane, we support customers with:
• Technical sales guidance to identify the most suitable converter series for mission-specific requirements.
• Assistance in interpreting datasheet parameters, derating curves, and screening options per MIL-PRF-38534 Class H and K standards.
• Coordination of procurement and qualification documentation to meet aerospace and defense compliance requirements.
• Comprehensive logistics support, including forecasting, inventory management, and scheduled deliveries aligned with customer production timelines.
• Dedicated after-sales support to ensure traceability, long-term availability, and consistent supply chain continuity.
Our team combines aerospace market expertise with Crane’s proven Interpoint® product reliability to deliver seamless technical, commercial, and logistical support from initial inquiry through delivery.
This collaboration ensures that mission designers and system integrators receive trusted, space-qualified power solutions backed by responsive service and supply assurance.
Contact:
📧 Email: contact@sagacomponents.com
📞 Phone: +46 (0)8 564 708 00
🌐 Web: https://www.craneae.com/interpoint
Reference:
1. Crane Aerospace & Electronics Power Solutions - Interpoint® Products Space Catalog Rev AD - 2025.01.27.