[Characteristics of several artificial substitutes of soil for space flight greenhouses].

The analysis of the study associated with cultivating the leaf cabbage, small radish in the Russian-Bulgarian greenhouse "Svet" aboard Mir orbital space station in 1990 has demonstrated that under microgravity conditions the zeolite substrate "Balkanin" with particles dimensions of 1-3 mm placed in the root modules of the greenhouse "Svet" did not ensure the sufficient transfer of the water from moisture-saturated wicks to the periphery of the vegetation vessels what is attributable to the peculiarities of hydrophysical characteristics of the substrate used. There presented the results of experimental research on the hydrophysical and agrochemical characteristics of the ion-exchange substrates of two other types--"Biona 312" and "Biona V" prepared on the basis of the artificial ion-exchange resins: cationite--CU-2 and anionite EDE-10P. For these substrates there found the estimates of humidity correlating with the loss of gassy pores as well as there measured the specific weight of the solid phase and the volumetric weight. There presented data on the content of the nutrients as well as the results of assessing the biological productivity potential of the tested substrates in the "Svet" greenhouse root modules. The characteristics obtained are indicative of the possibility to use the mentioned substrates in space greenhouse of the "Svet" type.