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Few data are available on biodegradation rates of materials over the long-term (more than 30 days). This information is necessary to conduct trade studies (studies used to make selections between alternatives) comparing various degrees of biodegradation versus combining biodegradation with incineration for advanced life support (ALS) systems. This paper describes the extreme case in which solids are degraded only by biodegradation. Data on biodegradation of insoluble solids from inedible parts of tomato plants are fitted to single and double exponential decay models to obtain half-life estimates for these materials. The data were obtained from batch experiments of material degradation over a 128-day period using mixed microbial cultures including activated sludge and an inoculum of Phanaerochaete Chrysosporium, a fungus known for its ability to degrade lignin.

Determining the fundamental role of gravity in vital biological systems in space is one of six science and research areas that provides the philosophical underpinning for why NASA exists. The study of cells, tissues, and microorganisms in a spaceflight environment holds the promise of answering multiple intriguing questions about how gravity affects living systems. To enable these studies, specimens must be maintained in an environment similar to that used in a laboratory. Cell culture studies under normal laboratory conditions involve maintaining a highly specialized environment with the necessary temperature, humidity control, nutrient, and gas exchange conditions. These same cell life support conditions must be provided by the International Space Station (ISS) Cell Culture Unit (CCU) in the unique environment of space. The CCU is a perfusion-based system that must function in microgravity, at unit gravity (1g) on earth, and from 0.1g up to 2g aboard the ISS centrifuge rotor.

The National Space Biomedical Research Institute (NSBRI), established in 1997, is a twelve-university consortium dedicated to research that will impact mankind's next exploratory steps. The NSBRI's Education and Public Outreach Program (EPOP), is supporting NASA's education mission to, “Inspire the next generations…as only NASA can,” through a comprehensive Kindergarten through post-doctoral education program. The goals of the EPOP are to: communicate space exploration biology to schools; support undergraduate and graduate space-based courses and degrees; fund postdoctoral fellows to pursue space life sciences research; and engage national and international audiences to promote understanding of how space exploration benefits people on Earth. NSBRI EPOP presents its accomplishments as an educational strategy for supporting science education reform, workforce development, and public outreach.

Nutrient recovery and biodegradation of inedible biomass is an integral part of an Advanced Life Support (ALS) system for space travel. This study investigates the mineralization and nitrogen recovery of hydroponically grown crops, namely, tomato, peanut, wheat and a 50:50 mixture of peanut and wheat. Shaker flask studies were conducted under various growth conditions of temperature and incubation times utilizing activated sludge and Phanerochaete chrysosporium (P. chrysosporium) inocula. Incubation temperature ranged from 25°C to 60°C and the flasks were monitored for nutrient recovery and solids reduction at 16, 32, 64 and 128 days. For the activated sludge systems, overall solids destruction during the 128 days of incubation ranged from 56% to 60% for the crops investigated. Similar results were found for the fungal systems indicating no substantial degradation enhancement.

Micronutrient recovery was investigated in two microbial systems, activated sludge and Phanerochaete chrysosporium (P. chrysosporium). Hydroponically grown crops, namely, tomato, peanut, wheat and a 50:50 mixture of peanut and wheat were used in the study. The experiments were conducted in shaker flasks on a 1% solids basis at 25°C for all crops and at 25°C, 40°C, 50°C and 60°C for tomato plant material. The micronutrient content of the leachate was determined initially and after 16, 32, 64, and 128 days of incubation. In order to determine the extent and rate of micronutrient release during the initial stages of incubation, when most of the solids degradation occurs, two separate experiments were conducted in batch reactors for 16 days. The micronutrient content of the batch reactor leachate was monitored on a daily basis. Micronutrients assessed included boron, manganese, iron, magnesium, zinc, copper, calcium, phosphorus and potassium.

Biological processing of grey water in space presents serious challenges, stemming mainly from microgravity conditions. Immobilized cell packed bed bioreactors (ICPB) have been used extensively for the treatment of wastewater on earth and can provide solutions to problems associated with microgravity. In this study two bench scale ICPB bioreactors were operated using synthetic grey water with the objective to develop a gravity independent system. Both reactors were packed with plastic flakes having a surface area of approximately 20 cm2/g, inoculated with activated sludge and fitted with an internal recirculation line to induce mixing and enhance oxygen transfer in the packed bed. One system was operated under ambient conditions with air supplied directly through a bottom port and the second was operated under 20 psi gauge pressure in order to achieve high dissolved oxygen concentration and overcome the problem of phase separation associated with microgravity conditions.