Passive Components Blog
No Result
View All Result
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • electro-mechanical news
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • inter-connect news
    • Market & Supply Chain
    • Market Insights
    • Medical
    • Modelling and Simulation
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors News
    • Resistors
    • RF & Microwave
    • Telecommunication
    • Weekly Digest

    VINATech Expands Aluminum Capacitor Portfolio with Acquisition of Enesol

    binder Offers Wide Range of M12 Panel Mount Connectors

    Bourns Releases New Shielded Power Inductors

    Supercapacitors Benefits in Industrial Valve Fail-Safe Control Systems

    Wk 21 Electronics Supply Chain Digest

    Samsung Electro-Mechanics Releases High-Capacitance MLCCs for AI Server Applications

    Samsung Electro-Mechanics Releases 165C Automotive 0806 Size Power Inductors

    Coupled Inductors Circuit Model and Examples of its Applications

    Würth Elektronik Introduces LTspice Models for ESD Products

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Circuit Protection Video
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Inter-Connect Video
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos

    Coupled Inductors Circuit Model and Examples of its Applications

    Inductor Resonances and its Impact to EMI

    Highly Reliable Flex Rigid PCBs, Würth Elektronik Webinar

    Causes of Oscillations in Flyback Converters

    How to design a 60W Flyback Transformer

    Modeling and Simulation of Leakage Inductance

    Power Inductor Considerations for AI High Power Computing – Vishay Video

    Coupled Inductors in Multiphase Boost Converters

    VPG Demonstrates Precision Resistor in Cryogenic Conditions

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Who is Who
  • Events
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • electro-mechanical news
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • inter-connect news
    • Market & Supply Chain
    • Market Insights
    • Medical
    • Modelling and Simulation
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors News
    • Resistors
    • RF & Microwave
    • Telecommunication
    • Weekly Digest

    VINATech Expands Aluminum Capacitor Portfolio with Acquisition of Enesol

    binder Offers Wide Range of M12 Panel Mount Connectors

    Bourns Releases New Shielded Power Inductors

    Supercapacitors Benefits in Industrial Valve Fail-Safe Control Systems

    Wk 21 Electronics Supply Chain Digest

    Samsung Electro-Mechanics Releases High-Capacitance MLCCs for AI Server Applications

    Samsung Electro-Mechanics Releases 165C Automotive 0806 Size Power Inductors

    Coupled Inductors Circuit Model and Examples of its Applications

    Würth Elektronik Introduces LTspice Models for ESD Products

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Circuit Protection Video
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Inter-Connect Video
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos

    Coupled Inductors Circuit Model and Examples of its Applications

    Inductor Resonances and its Impact to EMI

    Highly Reliable Flex Rigid PCBs, Würth Elektronik Webinar

    Causes of Oscillations in Flyback Converters

    How to design a 60W Flyback Transformer

    Modeling and Simulation of Leakage Inductance

    Power Inductor Considerations for AI High Power Computing – Vishay Video

    Coupled Inductors in Multiphase Boost Converters

    VPG Demonstrates Precision Resistor in Cryogenic Conditions

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Who is Who
  • Events
No Result
View All Result
Passive Components Blog
No Result
View All Result

Failure Analysis After In Orbit Anomaly On Bimetallic Thermostat

1.5.2025
Reading Time: 4 mins read
A A

This paper Failure Analysis After In Orbit Anomaly On Comepa Bimetallic Thermostat TH47 was presented by Florian Krimmel, ESA/ESTEC, Noordwijk, The Netherlands during the 5th Space Passive Component Days (SPCD), an International Symposium held from October 15th to 18th, 2024, at ESA/ESTEC in Noordwijk, the Netherlands. Published under permission from ESA SPCD organizers.

Introduction

RelatedPosts

High-Density PCB Assemblies For Space Applications

Solid State Polymer Multilayer Capacitors For High Temperature Application

Graphene-Based BOSC Bank Of Supercapacitor Cells

Bimetallic thermostats are integral to spacecraft thermal management systems, ensuring the stable operation of critical subsystems.

The thermostat TH47, employed in the pressure reduction unit of a propulsion subsystem, encountered an in-orbit anomaly after months of nominal operation.

The subsequent failure analysis, conducted at the European Space Agency (ESA), sought to reproduce the anomaly under controlled conditions and identify its root causes to mitigate future risks.

Key Points

  1. Identification of temperature anomalies in the spacecraft’s propulsion subsystem linked to the TH47 thermostat.
  2. Reproduction of the anomaly on-ground through controlled thermal cycling.
  3. Discovery of contact resistance degradation leading to self-heating and functional failure.
  4. Root cause attributed to silicon-based contaminants causing contact deterioration.
  5. Implementation of an alternative thermal management strategy to maintain mission safety.

Extended Summary

The anomaly was initially detected through in-flight telemetry, revealing unexpected temperature fluctuations deviating from the thermostat’s nominal operating range of 34°C to 39°C.

The TH47 thermostat, part of a specific manufacturing lot, was suspected as the failure source. Controlled thermal cycles were conducted on samples from the same lot and more recent productions to replicate the anomaly.

The reproduction setup involved precise temperature control using Peltier elements, with meticulous monitoring of body temperature, contact resistance, and switching behavior. It was observed that after several cycles, the thermostat exhibited increased closed contact resistance, leading to self-heating. This phenomenon caused premature switching, with the thermostat turning off before reaching intended temperatures.

Further destructive analysis revealed contamination within the thermostat’s sealed environment. Residual Gas Analysis (RGA) and Scanning Electron Microscopy (SEM) identified silicon-based compounds as contaminants. These compounds degraded under electrical arcing conditions during switching events, forming insulating debris that exacerbated contact resistance issues.

The failure mechanism was linked to silicon-induced contact degradation, where arcing facilitated the breakdown of silicon compounds into non-conductive materials.

This degradation led to erratic thermostat behavior, self-heating, and ultimately, premature contact failure. The issue was isolated to thermostats from a specific manufacturing date, with newer units not exhibiting similar failures.

Conclusion

The comprehensive failure analysis successfully identified the TH47 thermostat as the root cause of the in-orbit anomaly.

The degradation of contact resistance due to silicon contamination resulted in self-heating and functional instability.

By understanding the failure mechanism, ESA implemented a revised thermal management strategy, bypassing the thermostat’s switching function while maintaining subsystem safety.

This case underscores the importance of rigorous component testing and contamination control in spacecraft systems, contributing to improved reliability in future missions.

Read the full paper:

ORAL_Day 3_38_ESA ESTEC NL_Failure Analysis on TH47 thermostatDownload

Related

Source: ESA SPCD

Recent Posts

Coilcraft Extends Air Core RF Inductors

20.5.2025
16

Highly Reliable Flex Rigid PCBs, Würth Elektronik Webinar

15.5.2025
28

Vishay Releases Automotive SMD Thick Film Power Resistor for Enhanced Protection Against Short Transient Pulses

14.5.2025
13

Exxelia Power Film Capacitors Support Critical Systems Across Various Industries

13.5.2025
31

Fischer Releases High Vibration Robust Ratchet Locking USB-C Connector System

9.5.2025
12

KYOCERA AVX Releases Compact High-Directivity Couplers

7.5.2025
28

Tariffs Crush Sales Sentiment in April 2025 ECST Results

5.5.2025
91

High-Density PCB Assemblies For Space Applications

2.5.2025
23

Solid State Polymer Multilayer Capacitors For High Temperature Application

2.5.2025
54

Graphene-Based BOSC Bank Of Supercapacitor Cells

2.5.2025
25

Upcoming Events

Jun 4
11:00 - 12:00 CEST

Würth Elektronik PCB Production in Asia

View Calendar

Popular Posts

  • Buck Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Flyback Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Boost Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • What is a Dielectric Constant and DF of Plastic Materials?

    4 shares
    Share 4 Tweet 0
  • Ripple Current and its Effects on the Performance of Capacitors

    3 shares
    Share 3 Tweet 0
  • LLC Resonant Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • SEPIC Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Dual Active Bridge (DAB) Topology Explained

    0 shares
    Share 0 Tweet 0
  • How to Design an Inductor

    0 shares
    Share 0 Tweet 0
  • MLCC and Ceramic Capacitors

    0 shares
    Share 0 Tweet 0

Newsletter Subscription

 

Passive Components Blog

© EPCI - Leading Passive Components Educational and Information Site

  • Home
  • Privacy Policy
  • EPCI Membership & Advertisement
  • About

No Result
View All Result
  • Home
  • Knowledge Blog
  • Premium Suppliers

© EPCI - Leading Passive Components Educational and Information Site

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.
Go to mobile version