[en] During space flights, pyrotechnic devices are widely used for various purposes as booster separation, unfolding solar panels or activation of propellant valves. The firing of these pyrotechnical charges generates severe mechanical shock waves (so-called pyroshocks), characterized by a high intensity and a wide frequency range, which can damage the surrounding electronic equipments. Common damages are relays chatter, failure of electromagnetic components, failure of relays or crystals and so on. Test specifications are imposed to embarked electronic devices. The pyrotechnic shock resistance is always checked experimentally. The equipment is submitted to a shock that has to verify the specifications imposed by the launcher. These test specifications are commonly defined in terms of Shock Response Spectrum (SRS). Alcatel ETCA and FPMs collaborate to develop several shock test protocols, allowing defining testing conditions respecting the test specifications. They are generally made up of suspended plate structures that can be excited by a great variety of impact devices: explosive charges, dropping mass or pneumatic actuator. The magnitude and the shape of the resulting shock can be controlled by different parameters, which are tuned in order to satisfy the launcher's specifications. Otherwise, a specific electric testing device has also been developed in order to check the perturbations induced by shocks on the electrical behaviour of some relays generally used for spatial missions. Microswitches, provisional switches, permanent switches or damage of relay fixtures have been correlated to the magnitude and the shape of different Shock Response Spectra.
