Jaap Wijker retired from Dutch Space B.V in 2009. As associate professor he lectured from 1992-2010 Spacecraft Structures at the Technical University Delft, the Netherlands. He was member of several working groups within the frame of the European Cooperation for Space Standardization (ECSS) creating several standards and handbooks; Structural Requirement, Buckling of Structures, Spacecraft Mechanical Loads Analysis Handbook. He is still a member of the IHS-Markit (ESDU) committee “Vibrations and Acoustic Fatigue”. He wrote four books with Springer: “Mechanical Vibration in Spacecraft Design”, “Spacecraft Structures”, “Random Vibrations in Spacecraft Design” and “Miles’ Equations in Random Vibrations”. Simon Appel has 35-year experience as senior structural and thermal engineer in spacecraft engineering of which already 20 years as a consultant of ATG Europe to the European Space Agency. He has been supporting several spacecraft and technology development projects for the European Space Agency. Thermoelastic problems were a recurring topic in the career of Simon Appel. Besides his work on general spacecraft structural engineering simulations, he presented several papers on thermoelastic problems during conferences and workshops. Simon Appel is the main coordinator of the “European Working Group on Thermo Elastic” aiming to develop guidelines for the European space industry for thermoelastic verification.