Biology Internship Program and her sponsor at Kennedy Space Center, Raymond Wheeler. The assistance of Astronaut Dan Bursch with inflight operations on the International Space Station and David Chapman with ground-control operations at Kennedy Space Center
The development of a crop production system that can be used on the International Space Station, long-duration transit missions, and lunar or Mars habitats, has been a part of NASA's Advanced Life Support (ALS) research efforts. Crops that can be grown under environmental conditions that might be encountered in the open cabin of a space vehicle would be an advantageous choice. The production efficiency of the system would be enhanced by growing these crops in a mixed-crop arrangement. This would also increase the variety of fresh foods available for the crew's dietary supplementation. Three candidate ALS salad crops, radish (Raphanus sativus L. cv. Cherry Bomb II), lettuce (Lactuca sativa L. cv. Flandria), and bunching onion (Allium fistulosum L. cv. Kinka) were grown hydroponically as either monoculture (control) or mixed-crop within a walk-in growth chamber with baseline environments maintained at 22 °C, 50% RH, 17.2 mol·m-2·d-1 light intensity and a 16-h light/8-h dark photoperiod under cool-white fluorescent lamps. Tests were carried out at three different CO2 concentrations: 400, 1200, and 4000 μmol·mol-1. Weekly time-course harvests were taken over 28 days of growth, and fresh mass, dry mass, and harvest index were determined. Results showed that none of the species experienced negative effects when grown together under mixed-crop conditions compared to monoculture growth conditions under the range of environmental conditions tested.
Of the many environmental variables, light intensity (PPF) has primary effect on photosynthesis and significantly influences crop yield. With the eventual use of a crop production system on the International Space Station (ISS), Mars transit vehicle, or in a lunar/Martian habitat, there exists certain engineering constraints that will likely affect the lighting intensity available to plants. Tomato and pepper are candidate crops being considered by NASA that were selected based on their applicability to such mission scenarios. To study the effects of lighting intensity, tomato (Lycopersicon esculentum L. cv. Red Robin) and pepper (Capsicum annuum L. cv. Hanging Basket) plants were grown under cool-white fluorescent (CWF) lamps with light intensities of 8.6, 17.2, or 26 mol·m-2 ·d-1, with a constant air temperature of 25 °C, 65% relative humidity, and CO2 supplementation of 1200 μmol·mol-1 in order to duplicate conditions plants might be subjected to in an open environment of a space cabin. Following 105 days of growth, edible and total mass for both tomato and pepper increased with increasing light levels. Fruit development and time to ripening was also affected by light treatments. The effects of lighting when combined with other environmental factors typical of spaceflight systems will help define crop production for future missions that incorporate plant-based life support technologies.
Development of a crop production system that can be used on the International Space Station, long duration transit missions, and a lunar/Mars habitat, is a part of NASA's Advanced Life Support (ALS) research efforts. Selected crops require the capability to be grown under environmental conditions that might be encountered in the open cabin of a space vehicle. It is also likely that the crops will be grown in a mixed-cropping system to increase the production efficiency and variety for the crew's dietary supplementation. Three candidate ALS salad crops, radish (Raphanus sativus L. cv. Cherry Bomb II), lettuce (Lactuca sativa L. cv. Flandria) and bunching onion (Allium fistulosum L. cv. Kinka) were grown hydroponically as either monoculture (control) or mixed-crop within a walk-in growth chamber with baseline environments maintained at 50% relative humidity, 300 μmol·m-2·s-1 PPF and a 16-hour light/8-hour dark photoperiod under cool-white fluorescent lamps. Environmental treatments in separate tests were performed with either 400, 1200, or 4000 μmol·mol-1 CO2 combined with temperature treatments of 25 °C or 28 °C. Weekly time-course harvests were taken over 28 days of growth. Results showed that none of the species experienced negative effects when grown together under mixed-crop conditions compared to monoculture growth conditions.
Tuskegee University is conducting research on salad crops as part of the National Aeronautics and Space Administration's (NASA) goal of supporting humans on near-term space missions, such as on the International Space Station. Small areas of salad crops are ideal candidates for growing in limited volumes, and would provide a source of fresh food to enhance the crew's nutrition. Baseline controlled environment studies were initiated to evaluate the response of eight carrot cultivars (`Baby Mini', `Nantes Touchan', `Danvers 126', `Kundulus', `Nanco Hybrid', `Thumbelina', `Early Nantes', and `Juwarot') to growth and yield in hydroponics. Seeds were sown in moist arcillite and transplanted into growth troughs (0.15 × 0.15 × 1.2 m) after 18 days in reach-in growth chambers, and nutrients continuously supplied by a half-Hoagland solution. Growth chambers conditions included 300 μmol·m-2·s-1 photosynthetic photon flux, 16/8 photoperiod, a constant 25 °C and relative humidity of 50%. Plants were harvested at about 80 days. All eight cultivars grew well in the hydroponic system. Seven cultivars produced greater shoot fresh than root mass except `Baby Mini', which showed the reverse. `Danvers 126', followed by `Nanco Hybrid' and `Nantes Touchan', produced highest root yields. The β-carotene content varied by cultivars. The highest level of 10,400 IU/100 g was obtained for `Thumbelina', followed by `Baby Mini' (8040 IU/100 g), `Juwarot' (6160 IU/100g), and `Early Nantes' (5210 IU/100 g), and the lowest by `Nantes Touchan' (3510 IU/100 g). These results show that while carrots adapted well to growth in hydroponics, carotene, a major nutrient, was at relatively low levels.
NASA has intensively studied the use of plants to regenerate the atmosphere, purify water, and produce food within a bioregenerative life support system for many years. A unique aspect of growing plants in a controlled environment is chronic exposure to low levels of atmospheric volatiles. Alcohols are one of the most common classes of atmospheric contaminants currently detected onboard the International Space Station. A series of experiments were performed in specialized volatile organic compound analysis (VOCA) chambers in order to determine sensitivity of three Raphanus sativus L. to atmospheric exposures of ethanol. Three radish cultivars, Sora, Cherry Belle, and Cherry Bomb Hybrid II, were grown under continuous exposure to 0, 50, 100, 300, 500, or 1000 ppm ethanol for 21 days in the VOCA chambers with environmental setpoints of 23 °C, 75% relative humidity, and 18/6 photoperiod under T8 triphosphor fluorescent lamps at 300 μmol·m-2·s-1 PAR and 1200 μmol·mol-1 CO2. These concentrations corresponded to 5%, 10%, 30%, 50%, and 100% of the human exposure limits established by NASA and OSHA. Exposures to less than 10% of the legal exposure limit resulted in a 30% reduction in total biomass, 12% reduction in leaf area, and a 6% reduction in harvest index. Extreme stunting, chlorosis, and plant death were observed at only 50% of the exposure limit. All three cultivars were sensitive to ethanol exposure, with Cherry Bomb Hybrid II being slightly less sensitive than either Sora or Cherry Belle.
.S. Agency for International Development, U.S. Dept. of Agriculture, National Aeronautics and Space Administration, and National Science Foundation. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal
Matand Kanyand for their technical assistance. Research supported by grants from U.S. Dept. of Agriculture (ALX-9201871), U.S. Agency for International Development (DAN 5053G0000580 C), and National Aeronautics and Space Administration (NAGW-2940). The
. (2005) evaluated seed storage reserves and glucosinolates in Brassica rapa L. grown on the International Space Station and reported that deposition of storage reserves was more advanced in ground controls, whereas glucosinolate accumulation was
developed by the International Potato Center (CIP) in Peru by controlled crossing between the elite orange flesh sweetpotato (OFSP) clone (CIP101048.1) and the advanced OFSP clone (CIP194583.2). This clone will be released by Embrapa as a cultivar for Brazil