In order to develop and pre-qualify thermal control devices for tests on board the ISS, the present proposal proposes the study of pulsating heat pipes (TCPs) in microgravity through thermal and visual aspects. These types of heat pipes are made from a capillary tube arranged in the shape of a serpentine. They are evacuated and a small amount of fluid is inserted inside. A tube with a small critical diameter is necessary for a regime of liquid and vapor pulses to occur. The movement of fluid in a TCP is, in fact, only activated due to the confinement of vapor bubbles inside it, acting as a driving element when heated. TCPs are characterized by the following basic configurations: tubes in loop arranged to form a closed loop; there is no presence of capillary structure inside the heat pipes; there must be, at least, a heat absorption region, a heat rejection region and an adiabatic region located between the evaporator and the condenser. In order to organize the flow within a pulsating heat pipe, and thus increase heat transfer, some surface treatment techniques and changes in the properties of the fluid will be investigated in the present experiment.