This study focuses on the stiffness controllability of magneto-rheological elastomer (MRE) but also on the damping dependency with the magnetic field. It is well known that elastomer visco-elastic behavior is highlighted by elliptic hysteresis loops. Force-deflection loops of MRE were measured for different amplitudes and frequencies conditions. It results rectangular shape hysteresis loops. Hence, it has to be wondered which dissipation mechanisms are present in addition to the viscous in the MRE. The aim of this study is to have a better understanding of the working principles of MRE in order to evaluate their ability to be used for innovative solutions in damping and stiffness variation devices. This knowledge will confirm or re-orientate, based on the outputs, the applicability of MRE's to Space applications.