Introduction
Nowadays reliability qualification tests for space applications are based on MIL, NASA or ESA standards, the purpose being to ensure that a device will perform nominally for a specified lifetime. Those tests can help to understand which are the root-causes of the failure, in order to mitigate them. However almost every testing procedure relies on the survival rate while considering a single external constraint.
It is useful to point out, in a first discussion, that in their standard form they might fail to accurately represent real operation conditions, where loads of different nature can simultaneously stress the device. For example, the storage and then preparation on the launch pad in French Guiana (the European spaceport) consists in a heterogeneous set of tests, from a sequence of temperature and humidity oscillations, to intense vibrations and shock in order to simulate the launch and the separations of the different rocket's stages .
This work therefore provides a first view of the 8-runs 7-factors application of the Plackett-Burman design. Two models are considered to represent the experience: the first takes into account the main effects and the second takes into account the interactions. The aim is to observe any possible effect of the succession of thermal and mechanical stress tests. A matrix of alias is computed in order to reveal any hidden interactions. Finally, a selection of effects and secondary interactions is performed as well as an evaluation of their possible random behavior. Figure 1 depicts the strategy used: