Release of ESPSS 3.8

Empresarios Agrupados announces the release of the new ESPSS Version 3.8, a simulation toolkit for modelling space propulsion systems. ESPSS is an ESA Open Source library for helping the European Industry in the area of simulation of propulsion systems for rockets and satellites.

The version 3.8 is the evolution of previous releases with inputs from many european partners for adding additional capabilities for supporting:

  • Simulation of ground, spacecraft and launch vehicle propulsion systems under transient and steady conditions.
  • Propulsion system with two-fluid mixtures under gas, liquid and two-phase flow regimes for a wide database of working.
  • Studies of water hammer, pressure drop, priming processes, etc. in fluid networks.
  • Hydraulic and pneumatic systems, equipment and combustors, with heat transfer and controls loops coupled together.
  • Transient simulation of liquid, solid and hybrid rocket engines.
  • Simulation of ramjet engines.
  • Orbital and attitude motion of satellites.
  • Performance analysis and design of space engines.
  • Electrical propulsion systems.
  • Modeling of combustors, heat-exchangers, turbo-machinery, pumps, tanks, etc.


Today ESPSS is a common platform in Europe for this purpose. ESA is the responsible of the new updates and gathering all requests from industry.

There are two versions:

  • 3.8.0 ready to work with EcosimPro 6.4
  • 3.8.1 ready to work with EcosimPro 7.0

Both versions are identical, the only difference is the installer. You can select the one you want to use.

The new version provides among others:

  • New pointer to function is added to several components to allow the user to impose specific values to the heat.
  • Transfer coefficient using a custom function.
  • Added new real fluid HFE7000 and potassium and perfect liquids NaK and Li.
  • Modifications in junction and pipes for molecular flow simulation.
  • Added molecular flow test case.
  • Added to cooling jackets.
  • Added thermal port to HTP combustor components.
  • Removed Injector Monoprop, added equations to Injector Loss. Modified PreburnerPlate in accordance.
  • Updated the tanks to include initialization of the liquid and vapour nodes’ temperature using vectors.
  • Updated models and added new experiment to test the new variable nozzle area feature.
  • Etc.

If your company has up to date the maintenance contract, you can download it now from your cloud area. If you have any problem downloading it from the cloud, please contact the support team (, for maintenance contract issues contact