There are no equivalent experiment setups to create comparable changes of gravitation such as during parabolic flights. To determine the initial orthostatic responses of the cardiovascular system under the gravitational conditions of mars and moon is an essential step for a better understanding of 1) the fundamental functions of the human cardiovascular system (basic research) 2) specific impact of partial-g on the human heart, lungs and vessels in a spaceflight-context 3) approaches for countermeasure development against orthostatic intolerance on moon and mars (applied research).