This work has been performed as a follow on to the ESA R&D activity Improvement of Methodologies for Thermo-Elastic Predictions and Verification (I-METER). In the framework of this activity, a thermal test was performed at the facilities of Thales Alenia Space in Cannes, France in early 2019, using the structure of the Iridium Next platform. The objective of this test was to generate thermal gradients on the spacecraft structure in order to capture various thermo-elastic behaviours. Data from this test will now be used to correlate thermal and mechanical models to produce better thermo-elastic distortion predictions. Test data was captured by discrete temperature measurement via thermocouples, infrared camera images of a single panel and two videogrammetry systems to measure the relative displacement of the structure under different thermal load cases. In order to make use of the test data, a number of correlation and data processing steps need to be performed together with the thermal mathematical model to prepare it for mapping to the structural FEM.
This presentation will focus on the correlation of the thermal model of the structure of the Iridium Next Platform used for the thermo-elastic test. More specifically, it will address some of the outstanding issues in the correlation to represent the temperature gradients seen during the test. In addition, it will also discuss the benefit of processing and manipulating the IR image data and mapping it to the thermal model to correlate gradients.