The ESACRACK package is the structural analysis software utilized by ESA for damage tolerance evaluation of spaceflight structures. This package developed and distributed by ESA consists of various analysis tools used to generate load and stress spectra, perform fracture mechanics analysis, generate stress intensity factor solutions and to perform fatigue analysis.
ESA is supporting the continuous development of ESACRACK, the structural analysis tools used for damage tolerance verification of spaceflight vehicles and payloads as well as ground support equipment.

Version 4.3.1a of ESACRACK software package was released in 2012. The ESACRACK 4.3.1a package distributed by ESA includes the following tools:

  • ESALOAD 4.2.2a: to generate load and stress spectra from load curves associated to events,
  • ESAFATIG 5.1.1a: to perform fatigue analysis. It contains fatigue materials database,
  • NASGRO® 7.0: The NASGRO program provided by NASA/NASGRO consortium, containing the following sub-modules to:
    • analyze fatigue crack propagation and fracture mechanics for performing assessments of structural life (NASFLA, NASSIF, NASCCS and NASGLS modules),
    • process and store fatigue crack growth properties (NASMAT module),
    • analyze fatigue crack formation (initiation) (NASFORM module), and
    • compute stresses and stress intensity factors (NASBEM module)

ESACRACK package
ESACRACK package
ESA supports also the development of structural software’s and methodologies in the domain of probabilistic fracture mechanics. The stochastic version of ESACRACK, based on ISPUD (developed by Leopold-Franzens University,Innsbruck,Austria) probabilistic software and NASGRO® crack growth analysis software, allows reliability assessments for systems where the structural performance is mainly driven by fatigue crack growth.

Currently the stochastic version of ESACRACK is not foreseen for direct application to design/verification of space projects, but more as a support tool for the definition of deterministic analysis approaches.
Last update: 17 April 2013

Related links

 •  ESACRACK software (
 •  NASGRO software (