Water Cycle and Its Management for Plant Habitats at Reduced Pressures

Plants survive rapid decompression: Implications for bioregenerative life support

“…But dry mass values for radish storage roots and total plant dry mass were not affected by the native pressure (Table 1). This contrast in fresh mass being different and dry mass not being different may be related to the increased transpirational demand at 33 kPa versus 98 kPa (Rygalov et al, 2004), which resulted in higher percentage dry matter under the 33 kPa environment. It was interesting to note the during the decompression event, leaf flutter and movement due to air circulation gradually disappeared.…”

“…This is not surprising since evaporation rates increase at reduced pressures, even at a fixed vapor pressure deficit (Rygalov et al, 2004). Although precise environmental control was difficult during the rapid decompression with the vacuum pumps running, water vapor pressure deficits actually decreased, which was likely due to the adiabatic drop in temperature with pressure and the increased evaporation of water from the hydroponic troughs.…”

“…Although precise environmental control was difficult during the rapid decompression with the vacuum pumps running, water vapor pressure deficits actually decreased, which was likely due to the adiabatic drop in temperature with pressure and the increased evaporation of water from the hydroponic troughs. Thus the driving potential for evaporation should have been less, but the gas diffusion rates were higher and the resistance to transpiration was reduced at low pressure, which likely explains the loss of turgor in the few wheat leaves (Rygalov et al, 2004).…”

Agriculture for Space: People and Places Paving the Way

“…As noted earlier, several groups in Europe and Japan conducted studies on the effects of atmospheric pressure on plants, as did several NASA researchers (Schwartzkopf and Mancinelli, 1992;Corey et al, 1997Corey et al, , 2002Rygalov et al, 2004;He et al, 2007;. Pressure is not a typical concern for terrestrial agriculture, yet it is critical for space settings.…”

Food and Nutrition for the Moon Base

“…The atmosphere of the Moon base will probably have a higher percentage of oxygen and carbon dioxide (CO 2 ) than on Earth, at an atmospheric pressure between 8 and 10.2 psi rather than the 14.7 psi on Earth. 38,39 Plants for food production on the Moon would likely be grown in their own chambers so that the atmospheric mixture of oxygen, CO 2 , and humidity, along with temperature, light levels, and light cycles, can be controlled. 36,37 Although the percentage of oxygen might be high because of reduced overall pressure, this should not interfere with photosynthesis so long as the absolute partial pressure of CO 2 is greater than 0.1 kPa, or the equivalent of 1,000 ppm at 14.7 psi total pressure.…”