The European Space Agency Thermal Analysis Network software (ESATAN) was first made available to users in August 1985. Since that time it has been gradually replacing SINDA as the mainstream tool for thermal analysis applications in spacecraft developments for the European Space Agency and ESATAN is now the accepted standard for ESA projects.
The approach of ESATAN is similar to that of SINDA, but the user input is completely revised. Additionally there are major new features including the very powerful hierarchical submodel structure, which enables independent development of sub-models and integration at a later stage, without any restriction concerning node or conductor numbering, or even any other model-specific entity.
The paper reviews the development of the software from the original distribution (version 1.1) through to the current production version (3.3), and discusses the upgrade activity being performed to further enhance this software.