Search

Stability of Chinese cabbage crop colonization by methanolic bacteria Methylovorus mays, Methylomonas methanica and Methylosinus trichosporium inoculated using a space-applicable method was evaluated. Besides, trends of methane and methanol concentrations in the pressurized chamber with inoculated and uninoculated crops were calculated. Methylovorus mays and Methylosinus trichosporium were shown to establish more stable colonization as compared to Methylomonas methanica. Also, stable association of methanolic bacteria with plants reduced airborne methanol 75% faster owing to its uptake by bacteria. Therefore, inoculation of these microorganisms can be viewed as a promising method of controlling volatile pollutants in space vehicle atmosphere. Methane drop after 6-hour exposure to inoculated control and test crops was not significant.

The authors substantiate the choice of a mobile telemedicine facility (MTLF) configuration for elimination of medicosanitary consequences of emergency situations fit in minibus Sobol. The global competitiveness criterion has been adapted to consider the MTLF cost-quality gain/reduction ratio in comparison with the basic model. This approach permitted determination of the vector of MTLF attributes, indices of user (doctor) satisfaction, and coefficients of significance for each MTLF vector component. The proposed competitiveness criterion and calculation procedure can be applied in optimization of the structure and composition of MTLF and other intricate telemedicine systems.

The laboratory model of space production salad conveyer PHYTOCYCLE SD utilizes the principle of self-opening of plants growing under the light-emitting diodes. A computer model has been proposed to estimate greenhouse productivity as a function of design values. The model was used to compare greenhouses with a cylinder and flat crop surface. Self-opening crops on the cylindrical surface were shown to have a 30% advantage in production per a unit of light energy. Based on the analysis of the dependence of specific productivity on light intensity, the most effective light level is 300-350 micromol x m(-2)s(-1). It was established that PHYTOCYCLE SD productivity per a unit of orbital resources is much better compared with the known research plant growth facilities and can meet the vitamin (A and C) and rough dietary fibers' demand of three crew members.

In order to evaluate the effects of gravity on growing plants, we conducted ground-based long-term experiments with dwarf wheat (cultivar "Apogee USU") and Chinese cabbage (cultivar "Khibinskaja"). The test crop had been grown in overhead position with HPS lamp below the root module so that gravity and light gradients were in opposite direction. Plants of the control crop grew in normal position under the same lamp. Both crops were grown on porous metallic membranes with stable--1 kPa water potential on the surface. Results from these studies allowed us to examine the significant differences in growth and development of the plants as well as the root systems in relation to the gravity force. Nevertheless, the experiments in greenhouse Svet aboard the Mir space station proved that it is possible to compensate the effects of weightlessness on higher plants by manipulating gradients of environmental parameters (i.e. photon flux, water potential in the root zone, etc.). Even in ground studies Svet productivity averaged no more than 14 gm of fresh salad biomass per a day. This does not provide a sufficient supplement nutrients to the ISS crew. A cylindrical design of a space plant growth facility (SPGF) allows for maximal productivity under very tight energy and volume limitations onboard the ISS and a number of operational advantages.

To decide on the light status of plants in space greenhouse, a theoretical study was undertaken to correlate specific productivity of space greenhouse with illumination characteristics including vertical PAR flux density (I), photoperiod (tau), and crop leaf index (L). It was demonstrated that in pace with I the daily productivity per a volume unit tended to monotonously approach maximum at I = Ip, whereas the greenhouse energy efficiency ME peaked at I = IE, IK < IE < IP, where IK is a compensation point of the light curve of crop photosynthesis. Proposed are compromise criteria to optimize illumination as a maximum of linear combination of MV and ME and coefficients which account for the cost of a space station volume unit and a unit of board power supply, and as maximum of product Q = MV.ME. Experimental results serve as the basis for a technique for determination of the best, by the Q criterion, light status parameters for three types of space greenhouses: research growth chamber for synchronous cultivation of leaf mustard, wheat growth chamber with fixed crop density, and green conveyer for cultivation of Brassica pekinensis (Lour Rupor). For the last mentioned Q effective I and tau values differed with the conveyer step. The technique allows design of ground-based experiments aimed at determination of the most effective light status of space-grown crops.

In ground-based experiments reproducing conditions in experiments in the Mir greenhouse Svet super dwarf wheat was raised at water potential (WP) in root modules with pearlite within the range from -0.5 kPa to -3.0 kPa. At -2.0 kPa the number of florets in spikes, mainly the tiller ones, was considerably reduced and the actual spikes were fully barren. With WP equal to 0.5 kPa and -1.0 kPa, the grain component in the mass of a completely ripe shoot made up 46% and only 32% with WP at -2.0 kPa. With WP = 3.0 kPa, spikes of the main shoot and tillers were fully barren. In the WP range from 0.5 kPa to 1.0 kPa plants developed two tillers and no more than one tiller at 3.0 kPa. In the experiment with elevated air temperature mass of tillers at 1.0 kPa was by 39% lower as compared to the data from the experiment at the normal temperature. Degenerated anthers and abnormal pollen grains were again the cause of full barrenness of spikes grown at the normal temperature.