NASAs Biomass Production Chamber: A Tool For Controlled Ecological Life Support System (CELSS) Crop Studies

摘要

Over the past four years, three Crops each of wheat, soybean. and lettuce have been grown in a large controlled environment chamber to study their use for life support systems in space. The chamber, called the Biomass Production Chamber, or BPC, has an atmospheric volume of 113 cu m and provides up to 20 sq m of growing area. To date, all plants have been grown using nutrient film technique (NFT) with lighting provided by high-pressure sodium (HPS) or metal halide(MH)lamps.Thebest studies with wheat have produced the equivalent of 15 g seed dry weight/sq m/day(using continuous lighting), while the best soybean yields averaged 6 g seed DW/sq m/day (with a 12-h photoperiod). The best lettuce yields averaged over 7 g head DW/sq m/day (16-h photoperiod), or about 185 g FW per head after 28 days. On the basis of carbon analysis of biomass, photosynthesis of the wheat stand removed about 58 g C02/sq m/day (1.31 mol/sq m/day), and produced about 42 g 02/sq m/day. Both food production and gas exchange rates could be increased by increasing the photosynthetic rate with higher irradiance. Results from the BPC tests have shown the plants to be resilient and predictable in their capacity as 'machines' for life support, provided the physical support systems are reliable.