 Investigations description Throughout the experiment test subject will be safely attached to a fixation mechanism at its center of gravity hip. This mechanism comprises a climbing harness connected to two lateral vertical guides by two magnetic connection plates at the level of the hips. The test subject will lie down on the floor on a plate equipped with foam pads to create a comfortable lying surface. This mechanism allows free postural movement in microgravity phase and also supports the test subject s lying position during 1,8g- phase. At any stage of the experiment the test subject will be able to exit the fixation alone, by using one hand only. 