Modal Tests on the Full-scale Model of a Microsatellite

Microsatellites are suitable to undergo modal test.? by Time Average Holographic Interferometry due to their small dimensions and weight. This technique has been used to detect modal shapes of the small spacecraft both in the free-free condition, and in the constrained configuration expected at the launch. Nodal lines occurring at natural frequencies are visualized as bright interferometric fringes appearing over the holographic image of the structure. Stationary vibrations occurring on the whole surface are detected adopting a holographic optical setup with a thermoplastic holographic camera. The experimental modal patterns obtained on the full-scale model, both by the holographic interferometry and the broad band technique have been used to validate the numerical model for predicting the dynamic behavior of the satellite under development.