This task agreement provides for testing of candidate crops under controlled environments and developing crop production technologies applicable to Advanced Life Support Systems. FY 2002 will include testing alternative lighting sources and systems with candidate salad crops, developing and testing hydroponic trays and crop supports for baseline tests, and monitoring root zone microbial communities throughout growth and development of salad crops for International Space Station and future testbeds. This task also provides for computational and laboratory support and development and testing engineering components of bioregenerative technologies for ALS, plant growth chambers, control systems, and databases.

The primary objectives of this task are to define the environmental conditions and horticultural methodologies to optimize both edible biomass production and life support functionality in candidate crop species and assess how they interact with overall system efficiency. Environmental conditions include carbon dioxide (CO2) concentration, light quantity and quality, temperature, relative humidity, and nutrient media elemental concentrations. An important consideration of this task involves the screening of different cultivars of candidate crops and the compilation of all crop growth data for inclusion in a crop handbook. This effort will use a standardized testing procedure for all candidate crop species selected from the Crop Selection Meeting held at KSC in May 1997. Development of crop management strategies for reuse of nutrient solutions with a special emphasis on biologically active organic materials that may accumulate in the nutrient solution is being addressed. This task includes coordination of NASA-supported tasks at the New Jersey NASA-Specialized Center of Research and Training (NJNSCORT) for tomato and salad crops, at Tuskegee University for peanut and sweet potato, and at Utah State University for wheat, soybean, and rice. Other significant collaborations include Cornell University for dry and snap bean research and Texas Tech University for onion research.

The development of a bioregenerative life support system requires that the horticultural methodologies and the range of suitable environmental conditions for various candidate crops be well understood. This is an integrated activity requiring coordination with several research organizations and ongoing ALS tasks in order to maximize the benefit to the ALS program.

Onion Cv. Kinka Grown for 42 Days

The candidate crop research and technology conducted at KSC during 2001 included:

• Beans: Performed tests in collaboration with Cornell University to determine the growth and yield characteristics of both dry beans (cv. Etna) and snap beans (cv. Hystyle) at varying levels of CO2.
• Lettuce and Radish: Performed tests to evaluate the growth and yield characteristics of both lettuce (cv. Waldmann’s Green) and radish (cv. Giant White Globe) at superelevated CO2 levels.
• Lettuce: Conducted tests to determine the effects of narrow-band spectral radiation provided by light-emitting diodes (LED’s) on the growth and yield of lettuce in collaboration with the ALS lighting task, KSC Center Director’s Discretionary Fund (CDDF), Cornell University, and a NASA Research Announcement (NRA) grant.
• Radish: Performed evaluations of growth and yield characteristics of eight varieties of radish under high-pressure sodium (HPS) lamps.
• Potato: Conducted tests to determine nutrient management approaches for reducing vegetative growth of potato crops.
• Lettuce: Conducted tests in collaboration with the resource recovery/water recovery task to determine the effect of reuse of inorganic nutrients recovered from fixed-film bioreactors.

Key accomplishments:

• 2000: Completed experiments investigating the effects of superelevated CO2 up to 16,000 parts per million on the growth, yield, and stomatal functioning of two cultivars of beans. Completed experiments investigating the effects of narrowband spectral radiation provided by LED’s on the growth and yield of spinach and radish.
• 2001: Completed experiments investigating the effects of superelevated CO2 up to 15,000 parts per million on growth, yield, and stomatal functioning of lettuce and radish. Completed experiments evaluating eight radish cultivars under HPS lamps. Published four peer-reviewed articles and three book chapters. Completed a Ph.D. dissertation as part of a NASA graduate fellowship project.

Key milestones:

• First edition of the crop handbook for ALS candidate crops.
• Complete cultivar trial and baseline testing with radish.
• Begin cultivar trial and baseline testing with onion (collaborations with Texas Tech).
• Track root zone microflora of salad crops.
• Prepare and coordinate ALS planning workshop projecting research goals for next 5 years.

Contact: Dr. R.M. Wheeler (Raymond.Wheeler-1@ksc.nasa.gov), YA-E4, (321) 476-4273
Participating Organizations: Dynamac Corporation (Dr. G.W. Stutte and N.C. Yorio), Utah State University (Dr. B. Bugbee), Cornell University (Dr. D. DeVilliers, Dr. C.F. Johnson, and Dr. R.L. Langhans), Rutgers University (Dr. H. Janes), Tuskegee University (Dr. D. Mortley), and Texas Tech University (Dr. E. Peffley)

Radish Cv. Cherry Bomb II Grown for 21 Days