Plasma streams flowing from space engines interact with other life-support systems of space stations, in particular with solar panels. The magneto-plasmadynamic motor is a source of rarefied low-temperature plasma and can be used in production of semiconductor devices, integrated circuits and in a number of other areas. At the same time, the optimization of such a plasma source involves the active use of electric probes for diagnosis of plasma formations. In the work the original methods for processing the probe experiments in plasma flows, including the use of flat and cylindrical oriented probes as well as the non-stationary probes, which allows expanding the capabilities of the probe method for plasma diagnostics, have been presented. The optimization of the probe measurement schemes has been discussed. The results of probe measurements in jets, both in the bench conditions and in conditions of the Earth’ ionosphere, have been presented. The study has been carried out using both full-scale and computational experiments. In the work the original methods for processing the probe experiments in plasma flows, including the use of flat and cylindrical oriented probes, as well as non-stationary probes, which allows expanding the capabilities of the probe method of plasma diagnostics, have been presented. The studies have been carried out using the bench and computational schemes. The results obtained are important for plasmadynamic technologies in microelectronics and for radio communication with spacecraft powered by plasmadynamic engines.