Thermal Analysis Developments for the Large Platforms Mission Program

Status date

Alphabus, built jointly by ALCATEL SPACE and EADS ASTRIUM, will cover a payload power range from 12 to 18 kW corresponding to a solar array power between 15 and 25 kW. . Its main objective is to develop a high-performing satellite platform family in this enhanced power range, which will integrate most advanced equipments from world class suppliers.  

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Several pre-developments are currently being kicked-off, in order to develop advanced technologies in critical areas. In particular, thermal analysis software tools used to support the development of these large platforms must include some key features as described hereafter. These will be developed within a short time frame (14 months):

  • Capability for both ALCATEL SPACE and EADS ASTRIUM to perform alternatively the AlphaBus system thermal analyses in the different development phases.
  • Exchange of experience in telecommunication spacecraft thermal control analysis techniques and, where possible, common development of modules which are not available on a commercial basis e.g two phase and single phase fluid loops modules.
  • Improvement of overall productivity thanks to better data interfaces between tools.

As required by ESA and the Alphabus Project, ALCATEL SPACE and EADS ASTRIUM thermal software shall use ESATAN as the reference solver.


Not Applicable.


A brainstorming between ALCATEL SPACE, EADS ASTRIUM, CNES and ESA allowed to define a work strategy for this pre-development taking into account that tools developed by each of the two prime contractors is fully part of their own know how and analysis process. The thermal analysis software pre-development philosophy is then the following:

- to ensure compatibility and standard data exchange solutions for existing modules, i.e. radiative modeling software, panels conductive modeling tools and solvers,

- to develop common modules for the system thermal modeling of fluid loops.

The expected main benefits are to develop key functionality required by ALCATEL SPACE and EADS ASTRIUM to jointly develop the Thermal Control System of Large Platform Missions and to improve the overall efficiency of the collaborative design process.


The study includes the following work packages:

  • Package 1: Development of a standard interface between ALCATEL SPACE and EADS ASTRIUM conductive modules, these tools allowing to generate a thermal conductive representation of telecommunication panels. More specifically this includes:
    • an adaptation of ALCATEL SPACE's CORATHERM modules to interface with ESATAN, so that ALCATEL SPACE can use ESATAN for this project
    • the development of standard data exchange format interfaces for conductive modules that will automate panel data exchange between ALCATEL SPACE and EADS ASTRIUM.
  • Package 2: Common module for the analysis of capillary two-phase fluid loops at system level:
    • follow-on to a previous CNES R&D activity which had permitted to develop an advanced prototype
    • includes a study of the interaction between LHP (Loop Heat Pipe) model and panel modelling to ensure full compatibility of these specific tools that are to be used together in future telecommunication Spacecraft models. In parallel, an optimisation of LHP system model thermal solution will improve thermal analysis productivity and flexibility
    • a model for single evaporator / multiple condenser LHP will be developed, and validated according to COM2PLEX ground/flight results, and direct condensing fluid loop (DELPHRAD).
  • Package 3: Common module for the analysis of single-phase fluid loops at system level:
    •  the baseline is to develop a solution based on the ESA thermo-hydraulic solver ESATAN/FHTS.
    • a pre-evaluation of ESATAN/FHTS will assess compliance with the Large Platform project needs.
Current status

Package 1 :

  • End of activity of CORATHERM modules adaptation to interface with ESATAN
  • End of activity to transfer a geometrical conductive model between GENASSIST and CORATHERM via STEP-TAS.


  • Furniture of prototype of LHP modelling at system level
  • Validation in progress


  • Characterisation of System thermal analysis requirements for single phase fluid loops
  • Validation in progress

The deliverables are the following:

  • TN01 Adaptation of Coratherm modules to Esatan inputs
  • TN03 Specification of standard data exchange format between CIGALII/Plateau/Equivale and Genassist
  • TN04 Step-Tas interface between CIGALII/Plateau/Equivale and Genassist User's manual
  • TN05 Step-Tas interface between CIGALII/Plateau/Equivale and Genassist User's manual
  • TN10 Two phase fluid loops transient thermal solution optimisation
  • LHP module including also source code and all software documentation in-line with PSS-05 lite (URD, SSD, SVVP, SUM, STD)
  • TN11 Two phase fluid loops single evaporator multiple condenser Esatan module user manual
  • TN15 Summary report on past Alcatel & Astrium single phase fluid loop studies and experiments at system level
  • TN16 Single phase fluid loops components characterisation for thermal modelling
  • TN17 System requirements on single phase fluid loop modelling