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European Space Thermal Engineering Workshop 2025
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Europe/Amsterdam
Einstein and Newton (ESA/ESTEC)
Einstein and Newton
ESA/ESTEC
Keplerlaan 1
2201 AZ Noordwijk
The Netherlands
Description
INTRODUCTION
The European Space Thermal Engineering Workshop, organised by the ESA Thermal Division, will be held on:
Tuesday 9 to Thursday 11 of September
at ESA/ESTEC, Noordwijk, the Netherlands.
The event is held live at ESTEC only, not hybrid or on-line!
Aim and scope
The aim of the workshop is:
- to provide a forum for the exchange of views, experiences, best practices and lessons learned from thermal engineers involved in space missions
- to promote and facilitate contact between thermal engineers and thermal technologies and tool developers
- to present recent developments on all aspects related to the thermal engineering domain and to solicit feedback
- to present new approaches and methodologies (e.g. for thermal design, analysis and verification)
Topics covered include in particular
- thermal design (for platforms, instruments etc.)
- thermal analysis and software tools
- thermal testing
- thermal control technologies
- heat transport technology
- thermal technologies and methodologies related to small satellites and CubeSats
- mapping of thermal results to mechanical models and guidelines for thermo-elastic (for thermal part)
- Thermal for surface missions
Organisation
The workshop will consist of presentations only. The working language will be English.
SMILE in LSS model
Contact
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Registration Einstein and Newton
Einstein and Newton
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. Newton
Newton
Conveners: Kalomoira Gklisti, Olivier Pin, Stephane Lapensee (ESA)-
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Opening
Opening of the workshop
Speakers: Kalomoira Gklisti, Olivier Pin -
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ESA Missions and Thermal Technology Development UpdateSpeaker: Stephane Lapensee (ESA)
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ESA Missions and Thermal Technology Development UpdateSpeaker: James Etchells
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Disruptive Innovations InvitationSpeaker: Mr Thorsten Klameth (ESA TEC-MTT)
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1
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11:00
Coffee Break Einstein and Newton
Einstein and Newton
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Heat Transport Newton
Newton
Convener: Victor Cleren (ESA)-
5
Ammonia MECOP LHP for Multi-Kilowatt Thermal Management
Loop Heat Pipes (LHPs) are considered advantageous thermal management systems for various types of spacecraft, capable of transferring heat from source to sink in microgravity with low temperature drop, no external power input, and typical lifetimes of up to 15 years. However, as communication satellites evolve into the high-throughput and very-high-throughput categories, the need arises to dissipate tens of kilowatts of power into space. In this context, LHP technology loses ground to actively pumped two-phase loops (also known as Mechanically Pumped Loops, MPLs), primarily due to limitations in the effective area of capillary pumps and the maximum heat flux (W/cm²) they can sustain.
Higher throughput can now be achieved using a multi-evaporator LHP, in much the same way that multi-core CPUs overcame the limitations of single-core processing power a decade ago. The newly developed type of evaporator, which incorporates multiple capillary pumps and functions as a two-phase cold plate (Multi-Evaporator Cold Plate, MECOP), offers a compelling alternative to MPL.
An LHP equipped with a MECOP evaporator, assembled from 8 rather compact capillary pumps (approximately D15x110mm), 6m transport lines and a cold plate condenser, was stress tested for maximum heat transfer capability within the typical electronics temperature limit of 70°C at the thermal interface. Ammonia was used as the working fluid due to its high performance among a broad range of refrigerants that are compatible with the presented LHP and frequent use in MPLs.
The tests demonstrated that a passive heat transfer system with MECOP evaporator can overcome the typical heat flux limitations of conventional LHPs, transferring kilowatts of thermal power over a distance of 6 meters within the specified temperature range. Additionally, a series of experiments enabled the verification of the MECOP LHP mathematical model used to predict maximum heat transfer capacity and other LHP characteristics, thereby expanding the design capabilities for multi-evaporator heat transfer systems with alternative evaporator configurations.Speaker: Luka Ivanovskis (Allatherm SIA) -
6
Candidacy of cryogenic pulsating heat pipes for space applications
Pulsating heat pipes (PHPs), also known as oscillating heat pipes, are passive heat transport devices characterized by ease of construction, low mass, ability to function as efficient heat switch, multi-fold times higher effective thermal conductivity than metallic counterparts and gravity-independent thermal performance. The on-orbit long-term reliability and operation of room temperature (or non-cryogenic) PHPs has already been established and demonstrated by JAXA and U.S. AFRL. Numerous experiments on ground and on parabolic flights have been commissioned by ESA for understanding the peculiarities of PHP behaviour under microgravity conditions. This work intends to spark investigations on PHPs with cryogens as working fluids particularly for space applications. Cryogenic PHPs retain the advantages of room-temperature PHPs while additionally addressing low temperatures (2.5-100 K).
CEA Paris-Saclay hosts state-of-the-art research facility for experimentally characterizing cryogenic PHPs. The development nucleated in 2015 as part of a novel proposal within the framework of SR2S European project for the future Mars mission which was to utilize nitrogen PHP to cool the thermal shield between superconducting magnets and human habitat. Since then, the research at CEA Paris-Saclay has been broadened to PHPs of different lengths ranging from 3.7 m to just 200 mm. Successful heat transport tests have been conducted with different cryogenic fluids such as argon, nitrogen, neon and helium (as low as 2.5 K) as well. The best thermal performance ever measured for neon PHPs is reported at CEA Paris-Saclay with thermal conductance as high as ~5.9 W/K in gravity-assisted vertical orientation and ~3.7 W/K in horizontal orientation (the closest condition to space environment for PHPs). The same PHP when tested with helium is able to transport heat with thermal conductance of ~1.0 W/K. In fact, it is interestingly seen that the helium PHP operates in spite of breaching the classical Bond number criteria for room-temperature PHPs. Another remarkable challenge accomplished at CEA Paris-Saclay is development of the first demonstrator of neon PHP employed as passive thermal link to cool a HTS magnet using a single cryocooler. This highlights the excellent capability of cryogenic PHPs to be dynamic and serve as heat switch.
With the aim of taking cryogenic PHPs in space, a collaborative project with CNES is under way to experimentally gauge the potential of miniature cryogenic PHPs in replacing metallic braids used for thermal coupling of cryocooler with an IR instrument focal plane in 45 K – 80 K temperature range. Additionally, in absence of cryofluid within the capillaries, the PHP system can inhibit the heat in-leak arriving from the redundant cryocooler. This miniature PHP is being designed to achieve thermal conductance >1.5 W/K with heat loads up to 6 W at a spatial distance of 150 mm. Some glimpses of the design phases for on-ground testing are showcased in this work.
Speaker: Dr Tisha Dixit (CEA Paris-Saclay)
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5
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Small Satellites and CubeSats Einstein
Einstein
Convener: Malgorzata Solyga-
7
Thermal Model Correlation for the OHB-I IRIDE Mission: Optical payload and satellite TVAC tests
The IRIDE mission, managed by the European Space Agency (ESA) with support from the Italian Space Agency (ASI) and funded through Italy’s National Recovery and Resilience Plan (PNRR), is part of a multi-platform Earth observation initiative. The mission aims to deploy a “constellation of constellations” to deliver imaging services across a broad range of applications.
This presentation outlines the thermal model correlation activities carried out for OHB-I’s contribution to the IRIDE constellation, with a focus on both the optical payload and the overall satellite system. The telescope’s thermal model was correlated through dedicated thermal balance tests at subsystem level to improve model accuracy and verify the thermal control system (TCS) performance in maintaining optical focus under worst-case environmental conditions.
The thermal analysis workflow involved the development of Thermal and Geometrical Mathematical Models (TMM and GMM) using Systema Thermica software, followed by a two-stage thermal vacuum (TVAC) test campaign—initially at payload level, then at the integrated satellite level. Post-test correlation efforts refined the models, with particular attention to the optical payload system, which represents a mission critical element.
The final correlated models provided an improved characterization of the satellite thermal behavior and of the payload TCS and its impact on optical performance. The presentation will conclude with insights on how the correlation activities influenced flight temperature predictions and will highlight key lessons learnt throughout the testing and validation campaign.Speaker: Laura Festa (Politecnico di Milano) -
8
Designing for Deep Space: The Thermal Challenge Behind the HENON CubeSat
Exploring deep space with CubeSats pushes the boundaries of small satellite engineering into highly
ambitious and technically demanding domains.
While CubeSats have gained strong heritage in low Earth orbit applications, operating in deep space
introduces a new set of thermal challenges. Designing an effective thermal control system (TCS) under
such conditions—within tight constraints on mass, volume, surface area, and power—requires
tailored and highly efficient solutions.
This abstract presents the thermal design of the HENON mission (HEliospheric pioNeer for sOlar and
interplanetary threats defeNce), a 12U XL CubeSat developed by Argotec. HENON is Europe’s first
stand-alone CubeSat for deep space, targeting a Distant Retrograde Orbit (DRO) to carry out
autonomous heliophysics and space weather monitoring. The mission is currently approaching its
Critical Design Review (CDR) and acts as a pathfinder for future deep space CubeSat platforms.
All the work presented have been conducted with a strong focus on rapid development and analysis
turnaround. The work starts from preliminary ESATAN thermal models (TMM and GMM) and traces
their evolution toward a more detailed configuration, including numerical statistics and reflections on
modelling strategies and computational effort. Description of the orbital thermal environment will be
then discussed, highlighting the modelling approach adopted and the assumptions that shaped key
decisions. The guiding principle has been to maximize representativeness while ensuring fast analysis
turnaround.
The work will then outline the evolution of the Thermal Control System design. Starting from the
basics, a survey of power density across a wide range of satellites, particularly CubeSats, will be
presented to clearly define the context, highlighting the unique characteristics of the HENON project
with the aim to support key thermal design decisions that follow. Considerations of both hardware
solutions and operational strategies will be discussed, guiding through the development of the final
purpose-built Thermal Control System, which will then be detailed and assessed.
After the thermal design, the development of the HENON Structural-Thermal Model (STM) will be
presented, highlighting the engineering choices that guided its design to achieve the highest possible
thermal representativeness, thereby directly enabling a meaningful and reliable upcoming TVAC test
campaign.
The critical challenges encountered and the innovative solutions devised throughout the HENON
project represent a significant step forward in the field of thermal design for Cubesats. These
experiences not only demonstrate the feasibility of ambitious thermal control strategies in constrained
platforms like CubeSats, but also offer a valuable knowledge base that can inspire and guide the next
generation of deep-space CubeSat missionsSpeaker: Mr Liborio Luca Mininni -
9
6S CubeSat Thermal Testing and Correlation campaign: Educational Innovation in Space Engineering
This paper presents the thermal vacuum chamber (TVaC) testing campaign and thermal model correlation of the 6S CubeSat, the first fully student-developed 1U spacecraft designed, integrated, and tested at Politecnico di Milano by Polispace within the ESA "Fly Your Satellite!" programme. This project represents a significant milestone in the academic training of future space engineers. The 6S CubeSat is designed to host two payloads: VOLTA and PESCA. Given the passive thermal control approach, the design strategically leverages internal and external heat fluxes to subject VOLTA—a structural battery under development—to thermal stresses for evaluating its structural performance.
The paper details pre-test thermal predictions, the Thermal Balance Test (TBT) setup within the TVaC campaign, and the parameter tuning methodology employed to enhance model accuracy in compliance with ECSS standards. Simulation results are compared with experimental data, highlighting key discrepancies, corrective measures undertaken, and the evaluation of the thermal design solutions’ effectiveness. Test data analysis is also presented, with particular focus on the justification of unexpected thermal behaviours observed during the campaign. Beyond technical findings, the paper discusses the educational impact of executing a complete space qualification process within an academic environment, emphasizing the innovative character of student-led missions and the crucial support provided by ESA in fostering practical experience within the space sector.
Speakers: Mr Diego Fascendini (Politecnico di Milano), Dr Giulia Bianchini (Politecnico di Milano), Dr Ludovico Bernasconi (Politecnico di Milano)
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7
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13:00
Lunch ESTEC Restaurant
ESTEC Restaurant
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Thermal Analysis Einstein
Einstein
Convener: Arthur Dunlop (ESA (ESTEC))-
10
From Experimental Models to Daily Simulations: Advancing Thermal Reliability Assessment for Spacecraft
We present a comprehensive, high-fidelity framework for long-duration thermal reliability simulations, initially developed and validated on a geostationary telecommunications satellite. Traditional methods relied on experimental formulas using minimum and maximum temperatures at specific mission phases. In contrast, our approach performs detailed thermal simulations for every single day of the satellite’s entire 17-year operational lifespan (over 6,200 cases).
Recent improvements to the radiative solver, including optimized and parallelized view factor calculations, enable the full simulation to be completed in approximately 12 days using 10 CPU cores, or 6 days with 20 cores on a standard workstation. A key technical advancement lies in the efficient parallelization of the heat transfer solution, even when daily simulations are interdependent (i.e. when the output of day d becomes the input for day d+1).
The framework accounts for time-dependent thermo-optical degradation by modeling material property evolution, allowing accurate prediction of long-term aging effects. It also incorporates transient thermal phenomena, such as localized heating due to thruster firings during station-keeping maneuvers. Additionally, realistic mission dynamics are captured through varying payload operation modes.
All these features are integrated into the modular architecture of the eTherm software, enabling seamless coupling between orbit propagation, attitude dynamics, and detailed thermal analysis. This physics-based methodology paves the way for a shift from experimental reliability assessments to simulation-driven evaluation of insurance costs, enhancing confidence in thermal margin predictions across the satellite's lifetime.Speaker: Vincent Vadez (Dorea Technology) -
11
Advancements in thermal co-simulation using FMI (EISTAM follow-on)
The "Efficient Integration of Space Thermal Analysis Models" (EISTAM) R&D project investigated the feasibility of using FMI co-simulation to enhance the exchange of thermal models. Although promising results were obtained, several aspects required further refinement. The EISTAM CCN2 follow-on project successfully addressed these issues.
Firstly, EISTAM use-cases revealed that numerical convergence could be a significant hurdle for deploying FMI co-simulation. A comprehensive background study identified state-of-the-art stabilization solutions, some of which were successfully implemented in a test case.
Secondly, the co-simulation between Systema and other software, such as ESATAN, was successfully demonstrated.
Finally, an additional case was set up to validate the scalability of the FMI co-simulation approach. A detailed EOS satellite model was split into two FMUs to perform co-simulation with mixed timesteps. This approach significantly reduced simulation duration while demonstrating the robustness of the process.
This presentation summarizes the achievements, challenges, and lessons learned from this R&D follow-on, as well as discusses potential avenues for future developments.
Speakers: Antoine Caugant, Mr Matthieu Rodriguez (Airbus Defence and Space) -
12
First steps with Generative AI in thermal analysis workflows
The European Space Agency (ESA) has released an AI Harmonisation roadmap, with a focus on "Enabling Artificial Intelligence for Space System Applications." One of the key strategic objectives is to enhance space mission design with the use of AI assistants. Recently, the rapid development of generative AI, has led to significant advancements in automation in various engineering software with the use of AI Agents. Agents use natural language processing via Large Language Models (LLMs) to perform complex reasoning and autonomous interaction with software.
At the same time, there has been significant ongoing work to develop Application Programming Interfaces (APIs) for space thermal analysis tools to support custom workflows. Two notable examples are the ESATAN-TMS Python API which uses a plugin approach and the Thermal Desktop's OpenTD API. This presentation demonstrates initial steps towards using AI Agents to enhance thermal engineering workflows in space thermal analysis tools. Furthermore, the roll of open standards is discussed, particularly with the rise of the Model Context Protocol (MCP) and its use in tool calling.
An initial prototype is presented, merging these two technologies to show an AI Agent taking control of ESATAN-TMS with the engineer in-the-loop to enhance productivity. These examples include parametric geometry construction, electronic unit and honeycomb panel construction, model data access (thermo-optical properties), and automated sensitivity analysis. Several advantages of this approach are highlighted, such as AI enhanced workflows and speed up of repetitive tasks. The approach also permits non-experts to define, access and summarise information from the thermal model through a familiar chat interface.
Finally, some future thoughts are discussed on the use of Agents with respect to testing and verification, non-deterministic results, API development, and data security.
Speaker: Matthew Vaughan (ESA) -
13
ESATAN-TMS
ESATAN-TMS provides an advanced thermal modelling environment for the thermal analysis of spacecraft and launch vehicles. The suite is continually being enhanced to meet current and future requirements of space projects, and to support the specific needs of thermal engineers. This presentation will focus on the latest development to be included in the coming ESATAN-TMS 2026.
Speaker: Henri Brouquet
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10
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Thermal Design Newton
Newton
Convener: Mr Vito Laneve (ESA)-
14
A long way home – thermal challenges in ESAs Plasma Observatory”
The ESAs Plasma Observatory is a mission that will study plasma energization and energy transport in Earth’s Magnetospheric System. This task is going to be performed by constellation 7 Sister Space Crafts (SSCs) with specialised equipment. The thermal aspects of this mission are of interest of this study.
The most dangerous elements of this mission, from thermal perspective, are raising while in coasting phase (stacked in Ariane 6 ULPM module) and then after deployment in Nominal Science Phase (NSP). While in NSP the SSCs are expected to not only maintain required relative position but also keep constant rotation for payload to operate correctly.
Unfortunately environmental conditions for both mentioned phases are different. During rising the SSC is mounted to hub in ULPM module and will experience cold case with limited heat generation (turned off equipment). This is our cold survival case, where maximum possible insulation from environment would be beneficial.
While in the NSP the SSC is rotating with solar arrays periodically in direct sunlight and shadow. Due to that the preferred thermal solution is the maximum thermal contact of electronical equipment with radiators. Possible tilt of the spacecraft, that would expose top or bottom to sunlight with some inclination, is another difficulty to be tackled, since slight tilting cannot be completely prevented.
To satisfy those opposite needs the thermal trade-off analysis was performed considering different possible solutions: thermal switches, deployable panels, freezing-and-thawing heat pipes, phase change material connectors. Drastically simplified 1D analysis was extensively used to analyse temperatures and heat fluxes.
Afterwards feasibility study was done to select optimal with respect to market availability and manufacturability of the desired solutions.Speaker: Kacper Kuta (Creotech Instruments) -
15
Thermal design and analysis of the ARIEL MGAMA.
The Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) mission, led by the European Space Agency (ESA), aims to significantly advance our understanding of the chemical composition of exoplanetary atmospheres. The mission will deploy a single spacecraft operating at the second Lagrange point (L2), equipped with a suite of remote-sensing and in-situ instruments for high-precision spectroscopic observations of transiting exoplanets across our galaxy.
Within this highly ambitious scientific framework, the communication subsystem plays a crucial role in ensuring the reliable transmission of scientific and housekeeping data back to Earth. The ARIEL communication architecture includes among others one Medium Gain Antenna (MGA) and this work focuses specifically on its thermal behavior, which is critical not only to ensure mechanical and functional integrity, but also to guarantee the pointing accuracy required during communication windows.
The current talk aims to outline the evolution of the thermal design of Medium Gain Antenna Main Assembly (MGAMA), which has been driven by the various challenges encountered throughout mission development. It traces the improvements obtained with each design iteration and highlights the limitations imposed by the presence of certain critical components exposed to an environment that, while not extremely restrictive, contrasts with the high-performance demands placed on the antenna’s operation.
Speaker: María Páez López (SENER) -
16
Thermal design of an External Antenna Pointing Mechanism for an Interplanetary Mission
The Earth Return Orbiter (ERO) is a key element of the Mars Sample Return (MSR) Mission, a joint effort by NASA and ESA to achieve the physical return of samples from Mars. One of the critical systems on MSR-ERO is the High Gain Antenna (HGA), responsible for direct-to-Earth communication of the highest data volume, which will be pointed towards the ground station using an Antenna Pointing Mechanism (APM). The size of the HGA and external location on the satellite are leading to a challenging thermal environment of the APM including interface temperatures between -122°C and 86°C.
The highly varied scenarios that are part of the MSR-ERO mission (journey to Mars, orbital operations around Mars and the return journey) yield a diverse set of boundary conditions of over 50 thermal cases to be adhered to with both critical cold and hot cases driving the design choices. To accommodate these boundary conditions a multitude of thermal design measures had to be combined with particular attention on the actuators, which are highly sensitive to temperature variations.
The demanding technical requirements were further intensified by the project being based on pre-existing designs to limit the development efforts. The presentation outlines the development of the thermal design of the APM, with a specific focus on the accommodation of the actuator’s thermal needs.
Speaker: Antonia Grethen-Bussmann (Beyond Gravity Schweiz AG) -
17
Rosalind Franklin Mission – Challenges and trade-offs to minimize heater power consumption in harsh environments
PLACEHOLDER William Bontemps/Augustin Jacques/Claudia Asteggiano/Vito Laneve
The ExoMars Rosalind Franklin Mission (EXM-RFM) aims to send the first European Rover to Mars with the objective to search for evidence of past and present forms of life. The spacecraft architecture consists of a Carrier Module and an Entry Descent and Landing Module (EDLM) composed of an Aeroshell and a Landing Platform, which hosts the Rosalind Franklin Rover. In the current mission design, the cruise to Mars will take approximately 26 months, and during this time the Lander is only allowed to use a limited amount of power provided by the Carrier Module. The Lander is intending to land in the Oxia Planum site and shall survive for at least two Martian days to allow the rover's safe deployment and egress. As the Lander is not equipped with solar arrays, after separation from the Carrier Module it only relies on secondary batteries to provide power to the Rover and to maintain its key units under thermal control. This results in one key challenge for the thermal design of the Landing Platform: minimizing the heater power/energy consumption during all the phases of the Lander's life, while ensuring that no overheating occurs in the hot phases of the mission. From the Cruise phase to the Entry of the Martian atmosphere, the Lander is in a vacuum environment. It can therefore rely on well-known passive thermal control technologies, such as multi-layer insulation (MLI), low emissive surface finishes, and radiators to reject excessive heat. Only electrical heaters will be used as an active thermal control. Upon entering the Martian Atmosphere, MLI blankets are filled with air, making them less thermally efficient to insulate the Lander. The presence of air also results in the presence of convective heat exchange. In order to avoid high heat losses of the on ground operating units, convection suppression tents have been implemented. As the heat losses through convection are still a major unknown factor in the Lander design, a number of other options have been investigated to allow tuning of the thermal insulation on the Lander in response to the results of the thermal test planned in 2026.
This presentation will provide an overview of the Landing Platform thermal design and detail the trades-offs performed in the process of achieving a thermal architecture that minimizes the heater power and energy consumption in all the phases of the Lander's life.Speaker: William Bontemps (Airbus Defense and Space Ltd)
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14
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16:00
Coffee Break Einstein and Newton
Einstein and Newton
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Heat Transport Newton
Newton
Convener: Paula Prado Montes-
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Integration simplification of capillary driven heat transport systems
To meet customer’s needs, new payloads are needed such as digital payload. These payloads reshape totally the accommodation of S/Cs and thus the philosophy of its thermal control. The new dissipative units are more numerous and dissipative as well as often far away from cold source. This represents a new constraint for the design of future LHP product as the pipework is foreseen to be more complex to link an evaporator which would likely be inside the S/C toward the condenser which would likely be on the exterior side of the S/C.
The historic MAIT flow is not adapted to such applications. The design of the LHP routings and the needed MGSEs would indeed be very complex to ensure compatibility with a complex integration sequence of a LHP as a single block. The cost of such product is then foreseen to increase significantly, assuming it is still possible to design an LHP coping with all the constraints.
This study aims at defining the new approach needed to simplified the integration of capillary driven heat transport systems. The LHP use case has been used for this study.
The study has been discretized into 3 different phases.
- phase 1 : new LHP architecture have been proposed to ease integration sequence. This new architecture implements new components (valves & connections solutions). Existing On-The-Shelf components (COTS) have been traded off to selected those compatible with previous requirements.
- phase 2 has consisted to perform test on the selected components.
- During Phase 3 representative EM based on a LHP implementing the new architecture and the selected components have been tested and mounted on a MGSE representative of the most critical accommodation scenario encountered on real spacecraft.
The performance of the LHP have been tested before dismounting and mounting cycles and after to validate that the simplified integration does not hinder LHP performances. Three analyses were performed to validate the LHP performances and no impact have been measured on the LHP evaporation and condensation efficiency nor the internal heat leak from evaporator to reservoirSpeaker: Mrs typhaine coquard (airbus defence and space) -
19
Demonstration of methods for adding heat switch function to loop heat pipe
Spacecraft such as lunar rovers need to control onboard temperatures within an allowable range in response to the large temperature changes between day and night on the lunar surface. The high temperatures during the day require a large enough radiator to dissipate heat from the equipment, which takes a high heat transport capacity. On the other hand, equipment with the same heat transport capacity as daytime would require considerable heater power and battery to keep the equipment warm during the long cryogenic night.
To achieve efficient heat transfer during the hot day and minimize power consumption by a heater at cold night, it is effective to add a heat switch function to the loop heat pipe. The heat switch controls the temperature of equipment by changing the thermal conductance at high and low temperatures.
This workshop presentation will describe three methods of adding heat switch function to loop heat pipes: one is to heat the reservoir, the second is to install a bimetallic passive valve in the vapor line, and the third is an electrohydrodynamic (EHD) active valve in the liquid line. These methods were compared in thermal vacuum tests where the environmental temperature varied significantly. The EHD active valve is a new method proposed by the authors, and thermal vacuum tests confirmed that each method, including the EHD active valve, can control the equipment temperature at low temperatures. In this workshop, we introduce the proposed design of the EHD active valve and report the results of a comparative evaluation of the power consumption and additional pressure loss associated with the installation of each method.Speaker: Mr Takeshi Miyakita (JAXA) -
20
Loop Heat Pipe operating between 100K to 150K for detector cooling
The LHP100K project focuses on the following temperature range of interest: 100-150 K. It encompasses the current NIR/SWIR detector operational temperature as well as the future MWIR one that could work around 100-120 K (Figure 1). Above all, this project aimed at designing, building and testing a breadboard (BB) of a LHP suitable for these uses. The whole project has been divided into 4 main steps:
1. LHP design, definition and justification
2. Breadboard manufacturing, assembly and verification tests
3. TVac test
4. Test result analysis
First of all, it has been necessary to identify the best working fluid. Out of the several candidates, methane has been retained as the most suitable working fluid for the considered use case. Namely, the LHP was expected to be operated at 5 W / 100 K and 70 W / 150 K (see Figure 2 for the Clapeyron curves of every preselected working fluid). Oxygen and argon, while having an interesting Clapeyron curve, have their critical temperature point too close from the 150 K hot operational temperature.
Methane is not in a two-phase state between 190 K and 320 K. In this range of temperature, a methane LHP will have its working fluid fully gaseous. This implies two major design drivers. First, a voluminous tank shall be added, on the vapour line, to increase the LHP overall volume and to limit the internal pressure when all the fluid is gaseous. This tank has been called “Pressure Reduced Reservoir” (PRR). Second, a secondary evaporator shall be implemented to perform the preliminary cool down of the main evaporator. As a matter of fact, above 190 K, the main evaporator is not able to run since the working fluid is fully gaseous. The secondary evaporator is thus use to cool down the main evaporator below the methane temperature critical point. To do so, the secondary evaporator shall be thermally linked to the heat sink (radiator for instance).
on the overall the LHP100K worked well.
1. First the LHP was successfully operated between 5 W / 111 K and 40 W / 150 K which is a wide range of temperature and power; although it is a reduced range in comparison with the requirements.
2. Second the heterogenous heating was tested, assessed and validated. Power has been injected on both evaporator tubes, then only one, back on two and again on only one, the other one, without significative change of operation on the overall LHP.
3. Moreover, the secondary evaporator was proven efficient: increasing the power on the secondary evaporator rapidly reduce the saturation temperature. Several watts were enough.
4. Besides the inhibition heater also was proven efficient: increasing the power on the reservoir quickly increase the saturation temperature. A few watts were sufficient.Speaker: Mrs typhaine coquard (airbus defence and space)
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18
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Thermal for surface missions Einstein
Einstein
Convener: Alexandre Darrau (ESA)-
21
Thermal modelling for the Martian environment using the ESATAN-TMS Python API
Currently, the specific Martian thermal environment isn't fully automated and addressed within many space thermal analysis software, hence often critical parameters are simplified and dismissed. The Application Programming Interface (API) in ESATAN-TMS, first released in 2022 and updated in the 2025 release, provides a plugin interface and has been used to model configurable environments to support future lander and robotic studies.
This presentation showcases a plugin created to understand and model all types of phenomena on the Mars surface, such as transmissivity, convection, diffuse fluxes, sky and atmospheric temperatures. The script uses the Laboraroire de Météorologie Dynamique (LMD) 1D tool and offer guidelines toward using the Martian Climate Database (MCD) to provide inputs to the ESATAN-TMS model.
The diffuse solar fluxes are considered in a separate plugin that uses the UV Radiative Exchange Factors (UV REFs) of model shells to define the flux on each external shell via a boundary condition. A similar methodology is applied when considering the optical depth factor which is used to calculate the attenuation of solar fluxes, which creates a different solar flux at the surface compared to the top of the atmosphere. Finally, a convective heat transfer is defined between surface geometries and the sky, to consider the Martian wind for different scenarios.
Several landing sites from the phoenix lander and ExoMars rover were used as study cases to validate and correlate the model.
Speaker: KENZA BATTAGLIA -
22
Thermal Modeling and Environmental Analysis of 99942 Apophis for Surface Mission Applications
The growing interest in missions targeting small bodies and near-Earth asteroids, driven by planetary defence, exploration and resource-utilization objectives, calls for space systems capable of operating in asteroid environments that are often not well characterized, or that present large uncertainties during the mission design phases.
In this presentation one interesting example of such asteroids is considered, 99942 Apophis, mainly known for its 13th April 2029 Earth Closest Approach (ECA). The thermal environment of the asteroid is analysed, with particular emphasis on the ECA period, to identify the challenges of a possible surface landing mission.A parametric Python-based framework for conducting preliminary assessments of the environments of Non-Principal Axis tumbling asteroids is developed, with a flexible approach to uncertainties in dynamic, physical and thermal properties.
An application to the Apophis case study, considering its peculiar spin state, is shown, with the objective of deriving high level thermal constraints and requirements for a surface mission. A first manual search of the domain space of the principal unknowns is conducted, based on the selection of worst-case scenarios in terms of illumination conditions and surface temperature distribution; then a parallel computing (GPU accelerated) Monte Carlo stochastic search is implemented, to understand the most influential parameters related to the thermal operability of a landed spacecraft.Ultimately, the integration of more powerful third-party software within the developed framework is discussed, with special attention to Thermal Desktop modeling.
Speaker: Davide Cosenza (Tyvak International) -
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Lunar Thermal Environment Modelling and Thermal Design Trade-Offs for Lunar South Pole Landers
In recent years, there has been a renewed interest in both robotic and human missions to the Moon. This resurgence brings renewed focus to the thermal challenges of the Lunar surface environment, such as wide temperature fluctuations, risks associated with the lunar regolith, and especially at the poles, highly varying illumination conditions, characterized by prolonged lunar night.
First, several moon surface models of different complexities were established in ESATAN- TMS, including the radiative environment, the surface meshing definition and the regolith thermo-physical models. Furthermore, a simplified thermal model of a lunar lander descent module was established. Following this, several thermal design concepts, and hardware, for the "Passenger” element of lunar lander were considered. Various radiator configurations have been explored, as well as different techniques for achieving a variable thermal link, given the wide differences in day and night conditions. In this context, loop heap pipe with by-pass valve, thermal switches and variable conductance heat pipes were considered. In support of this analysis, an Excel-based tool for radiator sizing on the moon surface was also developed, enabling the assessment of radiator performance under a wide variety of conditions such as different latitudes, environmental conditions, different moon terrain and radiator inclinations, and different optical properties, including degradation due to lunar dust. Moreover, lunar dust effects on thermal hardware were also assessed, exploring different strategies to model the degradation due to lunar dust as well as its effects on thermal performance.
The selected approach for modelling the lunar environment as well as the selected thermal design solutions will be presented. Eventually, several best practices and lessons learned from the thermal modelling and design process will be shared, providing insights for future development of lunar lander thermal control systems.
Speaker: Matteo Ruvolo (OHB System AG / KTH Royal Institute of Technology)
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18:00
Cocktail Wintergarden
Wintergarden
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Thermo Elastic Newton
Newton
Convener: Matthew Vaughan (ESA)-
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Thermo-Elastic Antenna Depointing Analysis Workflow
This paper outlines a detailed workflow for calculating the depointing of an antenna due to thermos-elastic effects. The process starts with a thermal analysis to determine the temperature distribution across the antenna structure in orbit. These temperature data are then mapped onto a structural model. Accurate mapping results are ensured through mesh visualization and mapping constraints. Following this, a thermo-elastic distortion case is conducted. The antenna depointing is assessed using the displacement of a coordinate system and the displacement compared to the undistorted antenna reflector. We will discuss how this workflow allows for precise evaluation of thermal-induced distortions, and potential avenues for automation.
Speaker: Nayli Hayi-Slayman (Maya HTT) -
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Thermo-mechanical analysis of a satellite’s electronic box with Thermal Desktop and Ansys Mechanical
Electronic boxes are a critical part of a satellite, housing several heat-dissipating components with strict thermal and structural constraints. Their design is one of the focal points of the overall thermal behavior of the satellite, while also needing to withstand significant mechanical loads during launch, as well as fatigue and thermal stresses throughout the mission lifecycle.
The aim of this work is to simulate thermal stress on one of such electronic boxes, presenting all the different steps. The process begins with preparing the geometry for both thermal and structural models. The thermal model is then configured by importing the meshed geometry, applying appropriate contactors, and defining heat loads based on operational conditions. Subsequently, the structural model is prepared using the same geometry, incorporating bolted connections and relevant boundary constraints. The final step involves mapping the thermal results directly onto the structural mesh, enabling the calculation of thermal stresses as external loads.
This workflow enables accurate assessment of thermal-induced stresses using coupled thermal and structural analysis. It supports early design decisions and improves the reliability of satellite electronic units under operational conditions.Speaker: Daniel Navajas Ortega (Ansys)
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Thermal Analysis Einstein
Einstein
Convener: Romain PEYROU-LAUGA (ESA)-
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Coupling Orbit Propagation and Abaqus FEA for Spacecraft Thermal Control Design and Innovation
PLACEHOLDER: Authors:
Puyu Shi, Nicholas H. Crisp, Katharine L. Smith, Ciara N. McGrath, Belen Lopez-Pardo and Andrey P. Jivkov at The University of Manchester
Andrew Gibson at ESR Technologies LimitedThermal modelling is a critical aspect of satellite design, ensuring subsystem performance and overall mission success under the extreme conditions experienced in space. While industry-standard satellite thermal tools provide efficient solutions for common scenarios, these tools often have limitations including simplified thermal interfaces, restricted material libraries, and limited support for structural-thermal coupling. In contrast, general-purpose finite element analysis (FEA) tools, such as Abaqus, offer robust handling of nonlinear material behaviour, integrated thermo-mechanical coupling, and high-fidelity meshing and geometry handling. The availability of automation, scripting interfaces, and APIs also offers a high degree of customisation and integration with wider interdisciplinary simulation environments. However, the lack of native support for orbital thermal conditions requires external coupling to provide input of the radiative and orbital thermal environment.
This presentation describes an industry-academic collaboration focused on the integration of orbit propagation models with Abaqus FEA to provide a flexible thermal modelling workflow. Initial case studies have focused on assessing the performance of a novel thermal control shutter designed for nanosatellites. By enabling simultaneous variation of the thermo-optical properties of the device and time-varying boundary conditions from orbit data, our approach enables an exploration of the benefits for thermal control and overall system power. The developed workflow offers a flexible solution for integration with iterative design and optimisation whilst also showing promise for wider analysis of innovative thermal control methods, complex thermo-structural interactions, and missions across diverse space environments.
Speaker: Puyu Shi (The University of Manchester) -
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Thermal Analysis and Testing of the Enfys Electronics Box
Enfys is an IR reflectance spectrometer for ESA’s Rosalind Franklin Rover (planned for launch in 2028), which has undergone rapid development since 2024 to replace the previous ISEM instrument. RAL Space is responsible for the design, analysis and test of Enfys’s electronics box. This has an unusual thermal configuration within the lander, sitting on insulating stand-offs with a dedicated thermal strap for heat rejection.
This presentation will explore the thermal development of the Enfys electronics box. This includes initial feasibility studies to assess the necessity of the thermal strap, the development of the thermal modelling approach (particularly regarding the representation of the convective heat lift from the Martian atmosphere) and the inputs of the thermal model to the instrument CONOPs. More recent test verification of the EQM and FM will also be presented, which has included simulating the thermal configuration within a thermal balance test.Speaker: Nivraj Chana
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Thermal Testing Newton
Newton
Convener: Arthur Dunlop (ESA (ESTEC))-
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SMILE Thermal Testing in the Large Space Simulator
The Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) mission, a joint venture between ESA and the Chinese Academy of Sciences, aims to investigate the interaction between the solar wind and Earth's magnetosphere. This presentation details the spacecraft’s environmental verification campaign, with a focus on the thermal vacuum (TVAC) test conducted in ESA’s Large Space Simulator (LSS) at ESTEC.
Both the Payload Module and Platform underwent successful and independent TVAC campaigns demonstrating robust thermal performance under mission-representative conditions and correlated, confirming thermal design margins and system stability.
The SMILE FM thermal test campaign performed in the LSS included one full thermal cycle covering Hot Operational and Cold Operational conditions. Two thermal balance phases were executed: a Hot Operational balance representative of the mission's High Elliptical Orbit (HOT HEO), and a Cold Survival balance.
The presentation will highlight key aspects of the test setup, correlation methodology, and performance verification. It concludes with lessons learned and recommendations for future international cooperation missions undergoing spacecraft-level environmental qualification in ESA test facilities.
Speakers: Andreas Mussger (ESA), Matthew Vaughan (ESA) -
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PROBA-3 TCS from Dual-Spacecraft Thermal Testing to Flight Performance
PROBA-3 is an ESA mission designed to demonstrate high-precision formation flying using two spacecraft flying in close configuration to form a large-scale solar coronagraph. The industrial development of the mission is led by SENER Aerospace (Spain) for ESA, coordinating a consortium involving 14 ESA Member States and Canada. Key partners include Redwire Space (Belgium), in charge of the avionics, final assembly and spacecraft operations; CSL (Belgium), which developed the ASPIICS coronagraph; Spacebel (Belgium), which developed the on-board and ground segment software; GMV (Spain), responsible for the formation flying system and flight dynamics; and Airbus DS (Spain), responsible for the mechanical, thermal and propulsion platforms of both spacecraft. The two satellites were launched in stack aboard a PSLV-XL rocket from ISRO and are operated from ESEC in Redu, Belgium.
This presentation provides an overview of the thermal control systems verification campaign, including the thermal tests, the model correlation activities, final flight thermal predictions and final hardware adjustments. It also presents the result from the LEOP and IOC with a focus on the correlation between the predicted and actual thermal performance. The unique thermal challenges associated with the mission’s highly flying elliptical orbit and precision formation flying are discussed, along with the lessons learned throughout the development, testing and early operations of the mission.
Speaker: Jesualdo Ros Arlanzón (Airbus DS Madrid)
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11:00
Coffee Break Einstein and Newton
Einstein and Newton
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Heat Transport Einstein
Einstein
Convener: Dr Paolo Ruzza (ESA)-
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Heat Pipe and Hybrid Radiator/Single-Loop Technology for Exploration Missions
Exploration missions have to cope with stringent reliability requirements, large thermal rejection needs and complex attitude with respect to sun orientation. The common solution for large dissipation systems is a single mono-phasic Mechanical Pumped Loop (MPL) running from the cabin/equipment to external piping lined radiators. These systems face redundancy and reliability issues due to their sensitivity to Micrometeoroids and Orbital Debris (MMOD), where a single impact hole will lead to the risk of losing the entire loop. These issues are then exacerbated when extended to long-term duration exploration missions and outposts. This study aims to develop hardware technology capable of interfacing with standard fluid loop thermal control systems, improving the reliability of the architecture and improving the performance with a two-stage heat transport system. By keeping a crew-safe fluid in the MPL primary loop, avoiding direct exposure to space, this addition of a novel high-performance heat exchanger with integrated Heat-Pipe evaporators, ensures a safe method of spreading heat along MMOD exposed radiator surfaces.
Mechanical Pumped Loop and Loop Heat Pipes are widely used in space application to collect the heat inside a spacecraft and transfer it to external radiators. As presented in the first Figure, the radiators used for MPLs are based on panels with the condenser lines embedded (or surface mounted) and snaking throughout the radiator surface to enable complete coverage. This approach leads to a significant surface of the loop exposed to the external environment, increasing the risk of micrometeoroid and debris induced damage, and lowering the overall reliability of the radiators, especially for very long missions. This risk is be reduced using the proposed configuration of the radiators, with a Compact Heat Exchanger used to transfer the heat from the cooling line to a network of heat pipes used to spread the heat uniformly over the radiator surface. In this case, a possible impact with a micrometeoroid would lead to the failure of only a single heat pipe reducing performance of the system but a small amount but ensuring the function of the overall radiator system.
The design of this 3D printed hybrid heat exchanger has been narrowed down from a variety of different design concepts. The final design is the result of compromises between performance, manufacturability, design compactness, ease of integration and equality in nominal/ redundant line pressure drops. This design also incorporates lessons learned from manufacturing and test results on coupons which enabled the derisking of certain processes (orbital welding between ALM part and extruded aluminum HP) and establish backup solutions.
The test realised on this Breadboard have done successfully (pressure cycling, thermal performance). Generally, the power evacuated increases with the thermal gradient ΔT = Tinlet – Tsink (2,9 kW has been achieved with ΔT = 55°C) which is a 45% higher than the specified evacuated power from MPL system.Speaker: Filipe Mancio Reis (Airbus Defence and Space) -
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ALM heat-pipe for compact active antenna
The roll-out of highly dissipative active antennas is now a major and critical challenge which requires efficient thermal control systems. However, the collection and transport of the dissipated power are a tough problem because of several severe constraints: high heat flux density, high number of sources, high total power and complex accommodation. Several two-phase solutions are already used or are usable to overcome this issue, for instance it is possible to have a combination of HPs and LHPs (current Telecom baseline), or heat pipes connected to a standard two-layer stacked heat pipes. Nevertheless, another promising option appears to be interesting: the two-phase heat transport equipment (TPHTE) made by additive layer manufacturing (ALM). Indeed, it presents attractive advantages: the use of additive manufacturing as advanced manufacturing technique extends the possibility both in terms of geometry (for integration and accommodation) and of performances (the equipment can be structural, mechanically speaking, and it is possible to have both grooves and a micro-porous media inside to improve the thermal behaviour).
Concretely, an engineering model (EM) of a two-phase heat transport equipment has been designed, 3D-printed and tested. The present product has been designed for compact active antenna, but the same design philosophy can be adapted for other use cases.
The evaporator side is more or less 30x35 mm in section. It includes a porous media with a pore size lower than 20 µm. The overall TPHTE length is 830 mm (evaporator + condensers on both sides). Such an important length for an ALM part has been made possible by welding. As a matter of fact, two parts of ~415 mm have been welded together. The fluidic continuity has been insured by a dedicated assembly and welding process. Furthermore, there are a total of 3 cavities so as to assess the redundancy. And last, but not least, brackets have been printed at the same time than the TPHTE itself.
The EM testing assessed the technology validity over a large range of power (up to 1000 W) and heat flux density (28 W/cm²). In terms of mechanical performances, the TPHTE underwent QS test up to 40 g, Sine test up to 24 g and random test up to 23 gRMS. During the tests the TPHTE bore additional masses to simulate the active antenna amplifiers mass.Speaker: Mrs typhaine coquard (airbus defence and space) -
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Flexible Heat Pipe for Space, Development and Test Validation
With the continuous growth in power demands across space applications, the need for efficient thermal management solutions becomes crucial, spanning a wide range of spacecrafts from large GEO to small LEO satellites as well as deep space exploration and lunar missions. In this context, the design of thermal management systems emerges as a challenge to face to ensure the reliability, performance and longevity of space systems. The complexity and diversity of mission profiles require innovative, adaptable and lightweight thermal technologies capable of handling varying thermal loads and stringent environmental conditions. A typical approach to enhancing heat rejection is to increase the radiator surface area using deployable devices. The thermal efficiency and performance of these deployable radiators are critical enablers for system functionality while the deployable thermal link remains the primary challenge to be addressed.
This presentation aims to outline the development process of a flexible link compatible with aluminum axially grooved heat pipe technology.
The flexible heat pipe is composed of a flexible junction connecting straight extruded aluminum grooved profile portions. The flexible link comprises a capillary structure, a flexible housing and welded connectors.
The design and testing of two Engineering Models will be detailed and analysed. Both models have undergone testing using a dedicated rotating bench designed to replicate microgravity fluid distribution conditions. The results including comparison with conventional extruded heat pipes and correlations with qualification data will be presented to demonstrate that the implemented flexible technology has a minimal impact on overall system performance.
Speakers: Dr Mikael Mohaupt (Lead Design Engineer at EHP), Safia Moussaoui
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Thermal Design Newton
Newton
Convener: Miguel Copano (ESA)-
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MetOp-SG Satellite A Launch and Early Orbit Launch Thermal Performance
The MetOp-SG (Meteorological Operational Satellite - Second Generation) program comprises a series of meteorological satellites developed by ESA in collaboration with EUMETSAT and with the support of a European industrial consortium led by Airbus Defence and Space as the prime contractor. MetOp-SG is designed to provide crucial data for weather forecasting, climate monitoring, and atmospheric research. These satellites are equipped with a range of advanced instruments that collect data related to atmospheric temperature, humidity, wind, cloud cover, and various other parameters, to better understand weather patterns, track severe weather events, and improve long-term climate predictions.
MetOp-SG satellites are constructed in two series: spacecraft A, carrying visible, infrared, and microwave imagers and sounders, and spacecraft B, carrying microwave imagers and a radar. Each series includes three identical satellites. MetOp-SG satellites will fly in a Sun-synchronous orbit at 831km altitude.
MetOp-SG satellite A benefits from the common platform developed for both series, with thermal control managed by cavities, including various subsystems and units. They feature a set of radiators, heaters and multi-layer insulation. The instruments have more complex thermal control to meet stringent low-temperature requirements. The two largest instruments are equipped with cryostats and actively cooled by cryocoolers, while the other instruments use passive cooling, requiring multi-stage radiators and various types of heat-pipes for two of them.
Following the launch, expected in mid-August 2025, this presentation focuses on the initial findings regarding the satellite's thermal performance, from the Launch and Early Operations Phase through the first weeks in orbit.Speaker: Romain PEYROU-LAUGA (ESA) -
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Design and Analysis of ATHENA’s X-IFU Cryostat
Santiago Terrón1*, Sergio Cavia1, Cristina Ortega1, Alberto Merino1, Andoni Rodríguez1, Aitor Pérez1, Leonardo Valencia1, Asier Iglesias1
1. Added Value Solutions, Vitoria-Gasteiz, Spain.AVS is developing the flight cryostat design for the X-IFU instrument of ESA's ATHENA mission. This cryogenic system is responsible for supporting and integrating the instrument's cold core, whose operation depends on its ability to reach 50 mK. The design of this component presents multiple technical and manufacturing challenges as well as multiple trade-offs to manage i.e. thermal conductivity, mechanical resistance, weight, etc. This work shows the efforts made by AVS in order to create and evaluate a first cryostat architecture capable of satisfying thermal, mechanical, manufacturability and high-level assembly requirements. This work has been carried out in the framework of an ESA PRODEX contract.
Speaker: Santiago Terron (avs) -
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THERMAL DESIGN OF HAWK PLUS: A STANDARDIZED AND SCALABLE SMALL SATELLITE PLATFORM
As small satellite production is moving toward industrialized, scalable models, the need for flexible and mission-adaptable thermal management becomes crucial. HAWK PLUS, Argotec’s standardized and modular satellite platform, integrates thermal design flexibility as a core architectural principle to support a wide range of mission profiles and orbital environments.
Although HAWK PLUS is based on a standard platform, its thermal control architecture is fully adaptable and can be configured according to specific mission requirements and payload characteristics. Thermal control strategies on HAWK PLUS are highly configurable to accommodate a broad range of mission profiles, including those with drastically different thermal environments, by combining both passive and active techniques. Passive control may include variable optical surface properties, thermal switches and thermal straps, with material and placement optimized depending on orbital environment and power dissipation of the different sub-systems. Active control may be implemented via heaters, with independent power and logic routing through standardized interfaces.
For the purpose of thermal verification, the payload is simulated as a cubic aluminum box with variable internal heat dissipation ranging from 5 W to 500 W, depending on the mission and on the operative mode. Moreover, the payload is considered in both internal and external configurations relative to the satellite core. The thermal design is evaluated under both Worst Hot Case (WHC) and Worst Cold Case (WCC) scenarios, based on mission-defined orbital conditions as well as different operating profiles and attitudes. These boundary cases are used to assess thermal stability, heater activation needs, and passive radiator sizing.
In addition, extended communication scenarios are simulated to account for transient power dissipation profiles during active uplink and downlink phases. The thermal response of the avionics modules is analyzed to ensure that critical components remain within allowable temperature ranges throughout the mission cycle.A dedicated Structural Thermal Model (STM) is used to emulate different payload configurations and support the characterization of the thermal model. The STM has different dummy masses, to represent the different subsystems, which can be equipped with resistive heaters to reproduce variable internal power dissipation. This approach enables a representative thermal response under mission-relevant conditions, providing valuable insight into the accuracy and robustness of the thermal design.
This work presents the thermal design approach adopted in the HAWK PLUS platform, highlighting the configurability of thermal paths, the integration of passive and active components, and the validation approach for different use cases. The objective is to ensure repeatability across platform instances while maintaining adaptability to variable thermal environments and mission-specific constraints.
Speaker: Claudio Pedrazzini
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13:00
Lunch ESTEC Restaurant
ESTEC Restaurant
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Thermal for surface missions Einstein
Einstein
Convener: Andreas Mussger (ESA)-
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Effects of lunar dust deposition on thermal control surfaces - from measurements with lunar dust simulants to predictions for real lunar dust
Modification of thermal control surfaces due to lunar dust remains uncertain for upcoming lunar missions. While dust deposition rates have been both estimated and measured, significant uncertainties persist. Prior studies established that there is a clear link between lunar dust simulant (LDS) coverage to changes in solar absorptivity (α) and infrared emissivity (ε) of radiator.
However, there are no measurement-based correlations directly connecting dust deposition rates (µg/cm²/year), dust coverage (%) and modifications in α and ε. In an ESA-funded experiments by ONERA 20 thermal control coatings were tested, with varying LDS levels, establishing correlations between dust coverage, deposition, and modification factors.
Utilizing these measurements, an empirical methodology was developed to correlate measurement data from the Lunar Dust Simulator (LDS) with actual lunar dust, taking into account differences in parameters such as density, thermo-optical properties, dust grain morphology, and particle size distribution. This approach enabled the derivation of empirical equations applicable to each of the 20 thermal control surfaces, quantifying how contamination by lunar dust—expressed as mass or deposition rate—impacts their thermo-optical characteristics.Speaker: Dr Philipp Hager (ESA) -
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Pre and Post Mission Thermal Analysis and Operations of the Lunar Outpost Mobile Autonomous Prospecting Platform (MAPP) Rover
Lunar Outpost’s Lunar Voyage 1 (LV1) MAPP rover mission launched from Cape Canaveral, FL on February 26, 2025, aboard the Intuitive Machine 2 (IM-2) lander. The rover included payloads from multiple customers and Lunar Outpost Europe’s (LOEU) Thermal Switch demonstration. Following 6 days in transit from Earth to the Moon, and 3 days in Lunar Orbit, the rover survived a challenging, off-nominal landing on March 6, 2025. The MAPP rover continued to send health statuses through the lander to Earth for 2.7 hours from the lander’s final position in a cold, shadowed lunar crater until the Intuitive Machine lander, Athena, ran out of battery power and cut all communication. This presentation details pre-mission thermal analysis for the rover, leading to rapid response thermal analysis efforts during the mission which supported real-time operational decision-making. Additionally, post-mission data correlation and analysis to enhance future thermal model prediction fidelity will be covered. The talk will also inform lunar night survival for future expanded-scope rover missions including LOEU thermal technology development and flight heritage demonstrations.
Speakers: Alexander Walker (Lunar Outpost), Kaila Pfrang (Lunar Outpost US) -
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Design and Optimization of Convective Cooling System for Mars Flight Vehicle
Thermal management on Mars poses significant challenges due to its rarefied atmosphere, where the low ambient pressure severely limits the effectiveness of convective heat transfer. This study investigates the feasibility and optimization of convective cooling strategies for a Mars flight vehicle, using NASA's Ingenuity Mars Helicopter as a case study. Particular emphasis is given to the thermal control of the motor and electronics enclosure, two components highly sensitive to overheating during flight.
Computational fluid dynamics (CFD) simulations in Ansys Fluent were employed to analyze the local flowfield around the helicopter and identify optimal cooler placement. Subsequently, an adjoint-based solver was used to perform shape optimization, refining the cooler geometry to maximize convective heat dissipation under Martian atmospheric conditions.
The optimized configurations show significant improvements in thermal performance, successfully maintaining critical component temperatures within operational limits during simulated flight profiles. Importantly, the results indicate that enhanced cooling can enable longer flight durations or increased payload capacity, even when accounting for the additional mass of the cooling system.
This work demonstrates that convective cooling can be both effective and practical. These findings provide valuable insights for the design of thermal control systems in future planetary aerial vehicles operating in low-density atmospheres.
Speaker: Jiri Teichman (TechSoft Engineering) -
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Lunar Night Survival technologies originating from the LUX-Thermal development
The next decades will see a growing presence on the Lunar surface. Not only will robotic systems continue to explore the Moon , but they will also assist in establishing a permanent human presence. Various stationary and mobile assets will be needed to enable such a growth in Lunar exploration. Different systems have emerged during the last years that include instruments, vehicles, and habitats. Due to the extreme thermal environment on the Lunar surface, long-term survival constitutes the most important challenge during the designing of these systems as depicted by NASA in their shortfall ranking list .
Lunar Outpost EU (LOEU) is developing LUX-Thermal, an autonomous, self-contained energy storage and generation technology that provides thermal and electrical energy on demand. Its operation is based on the harnessing and storage of heat from multiple inputs during the day. During the Lunar night, it would provide power to customers in proximity, thus enabling their survival without additional internal subsystems.
The survival of LUX-Thermal itself is enabled by a combination of multiple novel technologies, which have been developed by LOEU as part of the LuxIMPULSE contract with the Luxembourg Space Agency:
- The thermal cover system has been designed to adapt LUX-Thermal to the changing external thermal environment of the lunar day-night-cycle. The system deploys MLI on external surfaces that would form heat leakages during the lunar night. Additionally, the system protects sensitive surfaces from lunar dust, when they are not operating.
- The thermal capacitor (TCAP) is a phase change material container with a defined melting point. The system stores heat for short periods, while maintaining a stable temperature range.
- The active thermal switch (ATS) is a compact device which actively changes the thermal conductance on-demand between a heat source and sink from a low to a high value and vice-versa.Speakers: Tobias Flecht (LunarOutpost EU), Mr Jan Junker (Lunar Outpost EU), Ms Kaja Dabrowska (Lunar Outpost EU)
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Thermal Testing Newton
Newton
Convener: Mr Gunnar Sieber (European Space Agency)-
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WFI Fast Detector Breadboard Thermal Cycling Test And Learnings
The Wide Field Imager (WFI), one of two instruments aboard the NewATHENA X-ray space telescope, includes a Camera Head comprising a large detector array and a Fast Detector (FD). Both utilize Depleted P-channel Field Effect Transistor (DEPFET) sensors with identical pixel sizes and technology. The large array consists of four quadrants, each containing a DEPFET sensor, while the smaller FD shares the same design. These sensors are operated and read out by FrontEnd Electronics (FEE) application-specific integrated circuits (ASICs) mounted in close proximity to the DEPFET sensors. To manage the differing thermal requirements of the DEPFETs and FEEs, the design separates their respective cooling chains.
To validate this thermal concept, the FD prototype underwent thermal cycling tests in the TVK 5 vacuum chamber at MPE’s X4 test facility. The objectives were to verify the thermal design and assess whether the adhesive bonds in the design and bondwires between the ASICs and DEPFET sensors withstand temperature cycling. The results confirmed the robustness of the thermal design and the mechanical stability of the adhesive bonds and bondwires. This presentation covers the test article, outcomes, and insights gained.
Speaker: Anirudh Mukund Saraf (Max Planck Institute for Extraterrestrial Physics) -
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Thermal Balance Test and thermal model correlation of FLORIS PFM
PLACEHOLDER FOR EDOARDO MARIA BENIVEGNA
The Fluorescence Imaging Spectrometer (FLORIS) is the Instrument of the FLuorescence EXplorer
Mission (FLEX). This is the Earth Explorer 8 (EE8) mission of European Space Agency, whose
objective is to perform quantitative measurements of the solar induced vegetation fluorescence to
monitor vegetation photosynthetic activity.
The FLORIS thermomechanical architecture is based on an optical bench (OB) that provides support
to both the optics and the two focal plane assemblies (FPAs). In order to maintain the required optical
quality and spectral stability, the OB temperature is actively regulated at 22 °C in operational
condition. The cooling of the FPAs is achieved by a passive radiator placed on top of the OB. The
core of the FPAs are three identical CCD detector units, cooled by an interface with the radiator. A
closed loop thermal control maintains the detectors temperature around -35°C with a stability of ±
0.2°C.
The thermal balance test foresaw five phases: one hot non operative, one cold non operative and three cold operative. The
main purpose of the test - and of the consequent correlation activity - was to investigate the modeling
accuracy of both radiative and conductive links of the two FPAs. During the thermal balance of the
STM, in fact, in place of the FPAs there were two dummies, that accounted only for the dissipation
of the active elements inside these assemblies.
Varying the temperature of the instrument radiator was crucial to collect a good set of data for the
correlation of the thermal model. For this reason, a dedicated shroud was placed right on top of the
radiator.
A non-negligible discrepancy between the predicted and the actual temperatures reached by the
various subsystems emerged right from the beginning of the test. To get a better insight of the
problem, two additional thermal balance phases were performed in the same test campaign. The
major differences between test predictions and test measurements concerned the VAU
temperatures and the power dissipated by both the OB and FPA heater lines.
Find the explanation of this discrepancy was part of the correlation activity. Two TVAC phases were
also included in the data set to assess the impact of the changes implemented to both the GMM and
TMM on a broader range of cases.
The several sensitivity analyses performed showed that the overall coupling between the instrument
and the radiative environment was not sufficiently correlated in the thermal model used for the test
predictions. This was mainly due to the MLI efficiency and affects above all the OB, which is the
largest subsystem of the instrument. The OB was cooled more than predicted also conductively,
through the links to the radiator, the nadir baffle and the bottom cover.
The VAUs power dissipations and the linear conductors between them and the OB have been
lowered, while the internal linear conductors have been increased, all these effects led to a drop in
their temperature.
The GMM has been updated too, including new geometries that increase both the view factor
between the FPAs and the OB assembly, and between the OB and the MLI blankets.
As a result of the implemented modifications, the thermal model of FLORIS PFM meets all the
applicable requirements.Speaker: Edoardo Maria Benivegna (Leonardo) -
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A Thermal Instrumentation Study for the Large Space Test Chamber Loading Trolley
A thermal instrumentation study has been conducted for the 6 Tonne Large Space Test Chamber Loading Trolley housed at RAL Space. The loading trolley is a novel piece of equipment designed to suspend the Item Under Test in the chamber. Although the design of the trolley intrinsically minimises the conductive heat flow path to the IUT through the use of an insulating GFRP spacer at the interface, thermal regulation of the loading trolley is required to further conductively decouple it from the IUT. A thermal model of the chamber and loading trolley has been created using ESATAN-TMS, and the results of steady-state thermal analyses were used to determine suitable size and placement of heaters on the trolley structure. A total of 4KW of available heat power (including 2KW redundancy) was instrumented, with a mixture of closed and open loop control systems utilised. Thermal balance test cases were subsequently conducted at both cold and hot steady states, the results of which were correlated with the thermal model. This presentation outlines the thermal model methodology, practical aspects of thermal instrumentation, and thermal vacuum test results.
Speaker: Jack Pleasant -
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Thermal Testing of the Structural and Thermal Model of the HyperSpectral Instrument for the CHIME Mission
The CHIME (Copernicus Hyperspectral Imaging Mission for the Environment) mission is a key component of the European Union’s Earth Observation program, Copernicus. The mission consists of two satellites carrying a unique payload designed to provide routine hyperspectral observations. To perform these observations, the instrument’s three focal planes will be cooled down to 175 K. The cooling of the focal planes is achieved passively, using a large baffled cryogenic radiator connected to the focal planes by a cryogenic chain featuring three graphite thermal straps and two ethane heat pipes. In 2024, the Structural and Thermal Model (STM) of the HSI underwent thermal balance testing, a crucial step towards the Critical Design Review (CDR) in early 2025. In this article, the results of the STM thermal balance test are presented, including the thermal model correlation and the status of the thermal control design at CDR. During the thermal balance test, the cryogenic chain exhibited higher-than-expected temperatures, prompting an investigation into potential additional heat leak sources within the instrument design and the test equipment. The findings of this investigation are detailed, as well as the performance of the ethane heat pipes under gravity conditions, and the overall results of the thermal balance.
Speaker: Victor Cleren (ESA)
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16:00
Coffee Break Einstein and Newton
Einstein and Newton
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Disruptive Innovations Panel Newton
Newton
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18:00
Workshop Dinner ESTEC Restaurant
ESTEC Restaurant
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Thermal Analysis Newton 1
Newton 1
Convener: Duncan Gibson (Telespazio BE for ESA)-
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SYSTEMA – THERMICA
In this presentation, We will provide an overview of the most recent developments in Systema. We will begin with a focus on the latest release, Systema 4.9.4P1, highlighting the key enhancements delivered to end users including improvements in usability, stability, and overall workflow efficiency.
We will then present a preview of the upcoming version, detailing the features currently being finalized, and how they respond to feedback and evolving use cases from our user community.
The final part of the talk will be dedicated to the ongoing development of Systema V5, a major evolution of the software. This new version is being rebuilt from the ground up, with the objective of offering a more modular, scalable, and modern interface. We will share the current status of the project, key design principles and progress made so far.
This presentation will offer a clear snapshot of where Systema stands today and where it is headed in the near future.
Speaker: Léa Galeron -
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Radian: Developments during 2025 for a cloud-based thermal analysis software
Radian is a thermal analysis software conceived to provide agility to engineers, both at modelling and computing processes. Our software is accessible through a regular web browser and counts on a scalable network of computing resources in the cloud.
Over the course of 2025, as part of the ESA BIC Madrid incubation program, our team has compared the results computed by our simulation engine with other tools like ESATAN-TMS, obtaining a successful correlation for steady-state and transient test cases. Moreover, we have deployed our first STEP-TAS exporting capabilities, easing the exchange of thermal data with other vendors. These activities have counted with the support and guidance from the Thermal Analysis and Verification Section of the European Space Agency.
Furthermore, several new features have been included both in the user interface and the simulation engine, with orbital mechanisms and parametric analysis being the most prominent.
Speaker: David Criado (Radian) -
46
Ansys Thermal Desktop new features and coming developments
Ansys Thermal Desktop (TD) is software for heat transfer analysis, thermal radiation, environmental heating, and fluid flow design. With a strong focus on space applications, it includes capabilities like importing and meshing CAD geometries, orbit definition for radiative analysis and 1D multi-phase flow.
The latest releases introduce several innovations like a new template launcher for easier user experience, second order finite elements with higher order thermal solutions, participating media for radiative calculations, quadratic elements and a new integration with Ansys optiSLang, a process integration and design optimization software that automates simulation workflows and uses advanced algorithms to improve product performance through sensitivity analysis, optimization, and robustness evaluation.
Finally, a case study will be presented, using a combination of TD and optiSLang to understand the impact of different thermal parameters on the results.Speaker: Daniel Navajas Ortega (Ansys) -
47
Thermal Modeling for Early Design Phases
In the space industry, thermal modelling typically relies on commercial simulation tools such as ESATAN-TMS, NX Siemens, and Systema Thermica. While powerful, these tools are often expensive and complex, particularly for systems engineers working in the early stages of mission design. To address this challenge, the Concurrent Engineering Centre at CNES has, over the past three years, developed a free thermal pre-sizing tool.
This tool is integrated into the IDM-Editor module, which defines the Integrated Design Model (IDM) of the satellite. It enables users to specify satellite configurations, including mass and inertia properties, and supports the creation of mission scenarios. These scenarios may include trajectory definitions, attitude profiles, power modes, articulation sequences, and corresponding ephemerides.
The IDM-Editor includes the standard Geometrical and Mathematical Model functionalities (2D and 3D modelling, bulk and thermo-optical properties), along with STEP-TAS import/export capabilities for supported shapes, materials, meshing, numbering, and topological features (import only). It also incorporates features for setting up a Thermal Mathematical Model, including standard radiative and conductive links, internal dissipations, applied heating power, and other specific items. Moreover, the tool supports calculations of solar, albedo, and terrestrial fluxes. Finally, one of the objectives of this tool is to allow export and interface with detailed professional softwares for refinement.
This presentation focuses on validating and improving the IDM-Editor’s thermal modelling capabilities by solving the discretised heat equation. Validation has been initiated on a test case relevant to space applications.
Speakers: Katell Le Floch, Noé Bursachi (CNES)
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Thermal Design Newton 2
Newton 2
Convener: Mr Gunnar Sieber (European Space Agency)-
48
PCM passive thermal control for stable structures
Phase change materials have been investigated in order to damp fast but short thermal loads for platform application on specific electronic equipments. Beside thermo-elastic performance reduction could be challenged by combining a very low CTE material like Invar with a PCM material allowing to improve global thermal inertia.
Elementary characterization of different PCMs will be presented as well as potential applications and gain in performances.
Main objectives of thermal design for thermo-elastic purpose will be presented. Breadboard and test sequences will be detailed as well as results of breadboard testing under vacuum to check interest of such solutions from a technical and cost point of view. Preliminary correlation of tests results will be also assessed.Speakers: Mr David Valentini (Thales Alenia Space), Romain PEYROU-LAUGA (ESA) -
49
WIVERN Payload Module Thermal Design and Loop Heat Pipe BB Testing
WIVERN (WInd VElocity Radar Nephoscope) is an Earth Explorer 11 candidate mission currently in Phase A. The thermal design of the payload module (PLM) is challenging due to the combination of high solar fluxes and rotation rates of the PLM combined with accommodation constraints placing high dissipating components at the centre of spin. To resolve this the proposed design relies on a large sun-shield to reduce incoming fluxes and a loop heat pipe (LHP) to work against the centrifugal forces. The correct functioning of the LHP in the rotating environment is a mission critical technology and therefore a BB test was performed comparing the LHP performance at 0rpm and 15rpm.
This submission will describe the overall PLM thermal design concept and preliminary LHP design performed by OHB and the design, manufacturing and testing of the breadboard by Euro Heat Pipes (EHP).
Speakers: Russell Bewick (OHB System AG), Quentin Harivel (Technology Development Manager at EHP) -
50
Thermal design, analysis and test of near infrared and visible cameras abstract - INVAP
The scope of this presentation will be focused on the thermal design and analysis of two cameras: one is a Near Infrared-Short Wave Infrared camera (NIR-SWIR), and the other is a Visible-Near Infrared (VIS-NIR) camera. These two instruments were built, integrated and will be fully tested at INVAP facilities in Bariloche - Argentina.
These instruments are part of a LEO satellite for an Ocean Colour mission, where INVAP is the prime contractor.
NIR-SWIR and VIS-NIR cameras were divided into two main parts; Optical Box and Calibrator. In addition, the optical boxes were separated into thermal enclosures in order to isolate the electronic zone from the optical zone, since the allowable temperatures and thermal stability requirements differ significantly between these zones. One of the most challenging issues was transferring heat from the optical sensor, which has restrictive mechanical and configuration requirements, to the radiators. In order to achieve this, a thermal strategy was used to transport heat involving thermal straps without affecting the performance of the optical module. Since these thermal devices were not originally qualified for aerospace applications, a qualification campaign was also carried out.
This presentation will be divided in two parts. The first part, will show how the design and analysis, were carried out from the point of view of the Thermal Control Subsystem. In particular, it will focus on how different thermal enclosure with sensitive requirements were handled and on the strategies used to overcome various issues. The second part, will cover thermal hardware integration as well as qualification campaigns. Specifically, several TVAC test have been and will be performed from individual component (including thermal straps) to the entire camera.Speakers: Mr Domingo Cattoni (INVAP S.E.), Olivier Martre (INVAP S.E.) -
51
Next Generation Gravity Mission (NGGM) thermal challenges
The Mass-change And Geosciences International Constellation (MAGIC), a joint mission initiative by ESA and NASA, is designed to provide high-resolution, time-variable gravity data to support global monitoring of water mass transport. By tracking changes in Earth’s gravity field, MAGIC will enable improved understanding of critical processes such as ice sheet and glacier melting, groundwater depletion, and ocean circulation—key components of the climate system.
Within this constellation, ESA’s Next Generation Gravity Mission (NGGM) will form the inclined-orbit satellite pair, flying in tandem with NASA’s GRACE-C polar pair to achieve improved spatial and temporal resolution. NGGM leverages advanced technologies including laser interferometry, high-precision accelerometers, and drag-free control, all of which impose strict requirements on spacecraft thermal stability. Ensuring consistent thermal performance is essential to maintain the nanometer-level measurement sensitivity required for inter-satellite ranging and inertial force detection. With strict requirements in terms of temperature stability in the time-domain and thermal noise in the frequency domain, it is critical to accurately assess the satellites' orbital environment and evaluate thermal control across each orbit and in mission-relevant spectral bands.
This presentation presents the key challenges and preliminary solutions in the thermal design of the NGGM satellites, with emphasis on maintaining instrument performance under highly dynamic orbital and environmental conditions, and ensuring mission-critical thermal stability for sub-nanometer measurement accuracy.Speakers: Mr Dylan Feore (Airbus Defence and Space), Mr Erik Hailer (Airbus Defence and Space), Romain PEYROU-LAUGA (ESA)
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11:00
Coffee Break Einstein and Newton
Einstein and Newton
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Heat Transport Newton 2
Newton 2
Convener: Dr Paolo Ruzza (ESA)-
52
Development of an engineering model of an additive-manufactured Electronic Box with embedded heat pipes: from architectural choices to final thermal performances
In the context of the ESA tender "Thermally Enhanced Power Unit Housing using Embedded Two-Phase Technology, ARTES Advanced Technology”, a consortium composed by the Energy (prime) and Mechanical Engineering departments of Politecnico di Milano, Leonardo S.p.A., BeamIT S.p.A. and Apogeo Space S.r.L. has worked on project HPS2 (Heat Pipe Solutions for High Power Systems), aimed at developing an engineering model of an electronic box, containing three single-piece modules with embedded heat pipes, realized mostly by Additive Manufacturing, in particular Selective Laser Melting (SLM) of AlSi10Mg, with the objective to transport waste heat as directly as feasible from the electronic components to an heat sink.
The worst case hot main requirement is to transport a total of 300 W towards a heat sink at 65 °C, while maintaining a maximum temperature below 100 °C, with the box in vertical position and Earth gravity.
The development process included the wick choice, single heat pipes thermal performance tests for various geometries and configurations, the mechanical design and verification of the modules, the fill-tubes and the assemblies, and the fabrication of the final engineering model.
The final tests, carried out with acetone as working fluid, highlight the contribution of the heat pipes in reducing the hot spot temperature by 20 °C in horizontal configuration with respect to the vertical one, while the performance gains are reduced, but still measurable, as the inclination against gravity is increased.
Moreover, tests at 150 W and 300 W of input power have been carried out for baseplate temperatures ranging from -15 °C to 40 °C and climatic chamber temperatures from -20 °C to 40 °C in vertical and horizontal configurations.
This work shows both the roadmap of the developed technologies within the project and the final thermal test results.Speaker: Luigi Vitali (Politecnico di Milano, dip. di Energia) -
53
Enhanced Cooling for Electronic Boxes
Miniaturization and thermal management of electronic systems are critical challenges in spacecraft design. EHP aims to develop a standardized, lightweight, and efficient two-phase cooling solution for high-density electronic boxes (E-Boxes).
EHP proposes a modular concept combining additive manufacturing and porous structures properties, allowing to dissipate at least 10W on any place of a 300mmx180mm structure or 50W for a 100mmx180mm structure. The system ensures passive, two-phase heat transfer from chip-level hotspots to the E-Box walls. The solution aligns with ESA's roadmap goals in advanced manufacturing and miniaturization and offers a competitive alternative to metallic straps and traditional Loop Heat Pipes, targeting a scalable market of over 10,000 PCB units per year.
The first breadboards have been produced, using aluminum for the casing and the porous structure, and ammonia as working fluid. From the temperature perspective, the components must not reach a too large temperature (typically 90°C) while the cold source is at maximum 65°C. The start-up temperature is -35°C. Testing is currently ongoing.
Speaker: Mr Antoine Lonez (Euro Heat Pipes) -
54
Oscillating Heat Pipes for Satellite Electronics Thermal Management
The oscillating heat pipe (OHP), also called pulsating heat pipe (PHP), is a high-performance passive heat transport technology with a wide range of applications in satellite thermal management. The OHP is similar to other heat pipes in that it uses a saturated fluid to transport heat; however, its operational mechanism relies on bubble nucleation within a capillary channel to drive oscillatory flow of liquid and vapor between heat sources and sinks. This mechanism enables the OHP to be constructed in thin, lightweight, structural, and three-dimensional form factors capable of transporting high heat loads and fluxes. These capabilities are well-suited for cooling satellite electronics, where component sizes are decreasing while power densities continue to rise.
This presentation will highlight development and integration efforts focused on electronics cooling in space applications. Experimental data, thermal modeling, and qualification results will be presented to demonstrate the performance, reliability, and design flexibility of OHPs for demanding spaceflight environments.Speaker: Corey Wilson (ThermAvant Technologies)
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Thermal Analysis Newton 1
Newton 1
Convener: Matthew Vaughan (ESA)-
55
Dynamic Thermal Simulation of a Reusable Inflatable Atmospheric Decelerator during Entry and Descent from LEO towards Earth
With the deployment of space-based systems becoming increasingly accessible, the desire for affordable and sustainable return technologies is growing rapidly. Atmospheric re-entry from space presents extreme thermal challenges due to aerothermal heating, so the ability to predict and optimize the thermal performance of conceptual, prototype or production orbital return technologies is critical. In this work we present progress towards a transient thermal simulation of a novel return technology, referred to as an Inflatable Atmospheric Decelerator (IAD). With respect to traditional re-entry devices such ablative heatshields, retrorockets (propulsive landing), parachutes, and air brakes, this inflatable heatshield enhances mass efficiency while reducing cost. We explore here the thermal performance of this disruptive technology that functions as both a reusable radiatively-cooled heat shield and a high-velocity parachute for cargo returning from orbit to Earth.
To evaluate the transient thermal performance of the IAD we simulate a dynamic trajectory that begins near Low Earth Orbit (LEO) and descends from an altitude of 260 km to a much lower altitude of 30 km. Boundary conditions such as an altitude-dependent atmospheric profile, transient spacecraft velocity and changing return vessel orientation with respect to Earth are incorporated temporally. Radiative exchange with the Earth and space are included in the thermal analysis, as are both direct and Earth-reflected solar loading. The dominant heat source experienced by returning spacecraft is aerodynamic heating, and we demonstrate a method for predicting the convective heat flux at stagnation point(s) and distributed across the various surfaces of the re-entry object. We compare the results of this approach to previously-published results to verify the suitability of such a method for transient thermal prediction, ensuring appropriate accuracy while reducing the burden on thermal analysts through the use of a unified, automated simulation workflow.
Speaker: Dr Corey Packard (ThermoAnalytics, Inc.) -
56
Wavelength dependency of thermo-optical properties and their role in testing on cryotemperatures
Going into cryogenic fields is always challenging for reasons such as achieving and keeping desired temperatures and stabilities for suitable time or due to temperature dependent material- and thermo-optical properties. One of the crucial goals of Thermal tests is to qualify the radiator system and with it the cold chain, and other is to correlate the Thermal Mathematical Model. Therefore, the test consists of temperature plateaus several times on such low levels, considered as cryo, where surfaces’ emissivity and absorptivity may change by temperature. This can lead to issues when it comes to implementing two surfaces (e.g. radiator and it’s dedicated cold plate) facing towards each other on different cryotemperatures into thermal software, such as ESATAN. The problem is not a graybody problem anymore.
In flight analysis, radiator planes face towards deep space, represented by artificial node, in which the temperatures are nearly constant. Therefore, the above-mentioned problem does not exist.
On the other hand, the issue does very much exist during modelling a test. OHB recently encountered with such problems during Thermal Test where, on cryotemperatures, emissivity of a radiator panel (white) and of its dedicated coldplate (black) followed their wavelength dependent behaviour. The setup is even more complex as there is a third surface, a radiator shield with highly reflective coating. Thus, the problem translates essentially to three different surfaces with view factors towards each other, one with white, one with black coating with a third reflective surface taking away the possibility of having constant view factors with the value of 1. The setup is depicted on below sketch:(PDF attached)
OHB have found two possible ways of solving, however, none of them could be considered as perfect solution, therefore both have their own advantages and disadvantages.
1.Taking higher uncertainties into account
2.Using ESATAN PWGBR subroutine
First method can lead to conservative approach and, therefore, to an overdesigned system which can lead the engineers to decisions which would increase cost significantly.
Second method leads to tremendous amount of effort and working hours (and, in the end, to extra cost), while the problem would use a grey body assumption still in the solve but only for a given wavelength band. The model uses an effective GR which is based on the temperature dependent emissivities and current temperatures of the emitting and receiving bodies to obtain the same net heat flux that would be calculated in a non-grey body process.
The presentation is dedicated to explaining the original test setup, possible resultant scenarios and the two above mentioned solution methods while such fascinating topics are going to be addressed as effect of coating thicknesses on thermo-optical properties or possible test modifications.
Zsolt Peterbencze, Niels Hendrik SchibillaSpeakers: Mr Niels Hendrik Schibilla (OHB System AG), Mr Zsolt Péterbencze (OHB System AG) -
57
Thermal Correlation of a mechanically driven loop heat pipe for deep space science missions
Two-Phase Mechanically Pumped Fluid Loop represents an efficient technological solution to control temperature of spacecraft equipment because:
• The heat exchange in phase change is high.
• The temperature is stable during the phase change.
• The pump allows to control on the flow and so on the heat to dissipate.
The two-phase flow of fluid loop can be modeled using 3D and 1D flow solvers, but such approaches are not scalable at system-level where the entire satellite thermal model must be represented. For this reason, space thermal analysts and engineers develop spacecraft 3D thermal models without the two-phase flow modeled explicitly to speed up simulation and perform more iteration on the design. However, estimating the heat exchange due to the phase change with accuracy is always difficult to achieve, and it requires thermal correlation between the two-phase flow model of the fluid loop and its associated simplified representation used in the 3D spacecraft thermal model. This thermal correlation procedure is iterative, manual, and time consuming for the thermal analysts.
In this paper, we will show how we can leverage the results of 1D two-phase flow simulations of a mechanically driven loop heat pipe to correlate its simplified representation, which can then be integrated into a 3D thermal model to consider the heat dissipation capacity of the loop heat pipe without modeling it explicitly. An adjoint-based approach speeds up and automates the correlation procedure. The predictions of the correlated model will be validated against the 1D two-phase flow model and reference test data. Finally, we will give some perspectives of work and future use cases of such an approach for conducting thermal correlation on spacecraft equipment.Speaker: Dr Florian Sanchez (Maya HTT)
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55
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Lunch
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Small Satellites and CubeSats Newton 1
Newton 1
Convener: Nektarios Chari (ESA)-
58
Thermal design of the 6U CubeSat using Systema Thermica
This mission represents the 6U satellite for Low Earth Orbit (LEO) developed by TRL Space Systems, targeting the role of Czech satellite system integrator. The satellite is equipped with two key payloads, including a hyperspectral camera capable of acquiring high-quality imagery across up to 32 spectral bands and Data Processing Unit (DPU) running onboard image processing algorithms. These subsystems, together with other critical components, impose significant demands on the satellite's thermal design.
This contribution presents the thermal engineering approach adopted for the 6U cubesat mission, utilizing the Systema Thermica software for detailed thermal modelling and analysis. The design process considered various operational modes, including nominal, transmission, imaging, processing and safe mode, each associated with different power dissipation on components. The thermal control strategy is based primarily on passive thermal design principles, optimized through careful component placement and surface properties [1], complemented by active thermal control applied to the battery unit via heaters to ensure its operational temperature range during eclipse periods and early mission phases [2]. Special focus is given to the thermal management of the hyperspectral camera and the DPU, whose temperature stability is essential for ensuring image quality and system performance.
Acknowledgement
This publication was supported by the project "The Energy Conversion and Storage", funded as project No. CZ.02.01.01/00/22_008/0004617 by Programme Johannes Amos Comenius, call Excellent Research.
References
[1] S. Tachikawa, H. Nagano, A. Ohnishi, and Y. Nagasaka, “Advanced Passive Thermal Control Materials and Devices for Spacecraft: A Review”, International Journal of Thermophysics, vol. 43, no. 6, 2022, doi: 10.1007/s10765-022-03010-3.
[2] Y. -G. Lv, Y. -T. Wang, T. Meng, Q. -W. Wang, and W. -X. Chu, “Review on thermal management technologies for electronics in spacecraft environment”, Energy Storage and Saving, vol. 3, no. 3, 2024, doi: 10.1016/j.enss.2024.03.001.Speaker: Marek Sedlařík (TRL Space Systems s.r.o., Bauerova 10, 603 00, Brno, Czech Republic) -
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Thermal Design and Analysis of an In-Space Manufacturing Demonstrator Payload with Radian
With launch costs per kilogram to low-Earth orbit at an all-time low and projected to fall even further, new use cases have emerged for the next generation of space systems, such as on-orbit data centers, high delta-V Orbital Transfer Vehicles (OTVs) for last-mile delivery, in-space manufacturing of pharmaceuticals and semiconductors, and space-based solar power. A common denominator for such applications is the need for multi-kW power systems, beyond what state-of-the-art deployable solar arrays can provide, especially on small satellite platforms.
Dcubed’s In-Space Manufacturing (ISM) Technology aims to replace conventional solar arrays, consisting of mechanical articulations of rigid panels, with a flexible blanket solar array, rigidized by booms that are manufactured directly in space, using a 3D-printing process based on a UV-cured photopolymer resin. This approach could enable significantly larger structures than traditional deployment methods, as mass and volume of the printing system are eventually offset by the lighter and more compact ISM structure above a certain break-even point. Apart from solar arrays in the kilowatt range, we are also exploring the application of this technology in building large reflect-arrays for communication applications.
To test this technology in a real space environment, Dcubed is flying a demonstrator payload on Exotrail’s spacevan™ orbital transfer vehicle. During this mission, we will attempt to deploy and rigidize a 900-mm-long, 100-W-scale rollout solar array, supported by two parallel resin booms. If successful, this mission will bring Dcubed’s ISM technology to TRL 9 and pave the way for larger structures that fully utilize the inherent advantages of this technology. The payload has been developed and built in an exceptionally short window of 8 months from concept to FM acceptance and is scheduled to launch in Q4 2025.
The thermal control subsystem (TCS) of the payload is centered around protecting the uncured photopolymer against extreme temperatures that might compromise the quality of the printed boom or cause unintended curing prior to the start of the deployment process. A secondary function is managing the heat released during the deployment phase, where multiple stepper motors and a system of UV LEDs are causing a short, but substantial one-time dissipation event.
To dimension the thermal control subsystem, the payload was modelled and analyzed in Radian, a cloud-based thermal analysis software tailored to agile NewSpace projects. Insights from a TVAC test campaign at DLR in Bremen were also applied to the final iteration of the TCS. This presentation provides an overview of the payload’s TCS, shows key results from the thermal analysis, and closes with some lessons learned during this project.Speaker: Benedikt Bauer (Dcubed GmbH)
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Thermal Control Newton 2
Newton 2
Convener: Mr Vito Laneve (ESA)-
60
NanoBLAST, a novel surface treatment for thermal applications
Spacecraft thermal control systems often favour the use of passive elements due to their simpler implementation compared to active systems. When heat is to be transferred via radiation, coatings and paints are typically used on the control surfaces of the items of interest so their thermo-optical properties enable this transfer as required. However, these methods come with their drawbacks such as limited operational temperature ranges, poor thermal conductivity, degradation over the life cycle, contamination issues and export regulations.
In collaboration with the Fraunhofer Heinrich-Hertz Institute and funded by the Zentrales Innovationsprogramm Mittelstand (ZIM), Azimut Space develops the NanoBLAST (or Black Laser Surface Treatment) project, a process capable of altering the thermo-optical properties of a surface through its functionalization using a nanosecond-pulse laser. This functionalization modifies the surface microstructure at the top layer (<100 µm) of the substrate material in question, removing the need of further coating. Because the surface is essentially the same material as the substrate, its thermal conductivity and operational temperature range remain unchanged. Likewise, degradation due to radiation exposure is driven by the properties of the substrate, and contamination is no longer an issue since there is no loss of particulates during the part’s life.
To assess the performance and suitableness of this technology, the project takes a modularly designed, aluminium box for electronics and treats its outer surfaces via the NanoBLAST process. This item was chosen as it is commonly used in many satellite subsystems. Once ready, a series of environmental tests are performed so any loss in performance, as well as cleanliness, can be assessed. This allows determining up to which scale is the NanoBLAST process a fitting substitution for thermal coatings and bring forward its technological readiness.Speaker: Mr Sebastian Ospina (Azimut Space GmbH) -
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Additive Manufacturing for Thermal Management Components: Potential, Best Practices, and Space Applications
Metal Additive Manufacturing, particularly Laser Powder Bed Fusion (L-PBF), is emerging as a key technology for producing high-performance components by overcoming the constraints of traditional manufacturing methods. Its design freedom enables the creation of complex, weight-optimized structures, an essential advantage in the aerospace sector.
Components such as structural brackets, lightweight assemblies, waveguides, and heat exchangers are especially well-suited to L-PBF. Heat exchangers, in particular, benefit from geometries that maximize surface area for thermal transfer, such as internal channels, implicit structures, and fine fins, which are difficult or impossible to fabricate using conventional techniques.
This workshop will showcase practical case studies and technical results, providing a comprehensive overview of the L-PBF process chain. Topics will include design optimization strategies, key post-processing steps, and recommended best practices for achieving high-quality metal parts. A dedicated session will focus on the challenges and requirements of 3D printing for space applications, with particular emphasis on the European Cooperation for Space Standardization (ECSS) guidelines that govern flight-ready hardware qualification.
The session aims to offer a clear introduction to L-PBF for engineers and designers new to the technology, while also providing valuable insights for experienced users. Through both technical and regulatory perspectives, the discussion will highlight how Additive manufacturing can be effectively integrated into current and future space missions.Speaker: Mr Daniele Da Prato (Sales Manager at AM Solutions srl)
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60
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Break
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Disruptive Innovations PresentationConvener: Mr Thorsten Klameth (ESA TEC-MTT)
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ClosureSpeaker: Kalomoira Gklisti
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