Engineering topics
Publications and source records attributed to Wheeler, Raymond M..
An overview of NASA's research in bioregenerative life support will be presented to a college class at the University of Guelph. The talk will review the use of plants for the production of food, oxygen and CO2 removal for life support systems for future space travel.
Growing fresh, nutritious, palatable produce for crew consumption during spaceflight may provide health-promoting, bioavailable nutrients and enhance the astronaut dietary experience as we move toward longer-duration missions. Tending plants may also serve as a countermeasure for crew psychological stresses associated with spaceflight. However, requirements to support consistent growth of a variety of high quality, nutritious crops under spaceflight environmental conditions remain unclear. This study explores the potential to grow crops for consumption on the International Space Station (ISS) using the Veggie vegetable-production system. VEG-04A and B were two flight tests conducted in 2019 with the leafy green crop mizuna mustard. Mizuna was grown in two Veggie chambers simultaneously, with the chambers set to different red-to-blue light formulations; one Veggie was programmed as "red-rich" and the second as "blue-rich." Light quality is known to impact plant growth, nutrition, microbiology, and organoleptic characteristics on Earth, and the Veggie flight tests examined how these impacts might differ in microgravity. VEG-04A, a 35-day growth test with a single harvest, was initiated in June and harvested in July 2019. At harvest, the astronauts froze half of the edible plant tissue to return to Earth and weighed the remaining half using the Mass Measurement Device (MMD). Weighed samples were then cleaned with produce-sanitizing wipes, and consenting crew members participated in organoleptic evaluation of the fresh produce. The remaining sanitized produce was available for crew consumption as desired. Frozen flight samples were returned at the end of August for microbial and chemical analyses to assess food safety and nutritional quality. No pathogens were detected on VEG-04A flight or ground control samples. On average, bacterial and fungal counts were significantly lower on ground control samples than flight samples. VEG-04B, a 56-day test with multiple harvests from the same plants, assessed sustained productivity. VEG-04B was initiated in October 2019 with three harvests at four, six, and eight weeks after initiation. Challenges with the watering program occurred early during VEG-04A, and several plants failed to survive in both the flight and ground control operations. Thus, prior to VEG-04B, an extra test was conducted to tailor water timing and volumes. This test determined that mizuna grew best if the wicks inside the plant pillow were allowed to dry after plants germinated, reducing persistent water around the stem. The wicks changed from being a conduit for water out of the plant pillow to being a conduit for air into the root zone. This test allowed a fine tuning of methods for VEG-04B. It is our hope that these tests on ISS will help mitigate the risk of an inadequate food supply for long-duration missions by adding fresh vegetables to the crew diet. This research was co-funded by the Human Research Program and Space Biology (MTL#1075) in the ILSRA 2015 NRA call.
In a microgravity setting, such as the environment aboard the International Space Station (ISS), an ideal plant water delivery system is one that can grow edible crops with minimal resource consumption and minimal risk to crew members. There are also concerns associated with the ability to control fluid escape and biofilm formation resulting in potential dangers to systems, crops, or crewmembers. To identify an appropriate system, candidate systems were assembled and operated under simulated ISS environmental conditions (T,CO2,and RH) with red romaine lettuce (Lactuca sativa cultivar 'Outredgeous') as a model crop. Fluid reservoirs and randomly selected planting sites were sampled every seven days until maturity at which point edible plant biomass and root samples were also taken. Heterotrophic bacteria and fungi growth patterns throughout each planting cycle were determined by plate counts on appropriate agar media. The candidate systems were compared to a classic hydroponics system as a control and harvested crops were compared to controls as well as Veggie-grown and market produce. Plants harvested from candidate systems yielded lower average heterotrophic bacteria and fungi per gram of plant mass levels when compared to market and Veggie samples as well as those from the control system. Additional studies to evaluate the system sanitation regimen as well as testing additional crops should be considered to aid in the selection of an ideal system.
In-situ food production is a necessary step for human exploration of the solar system and requires a deep understanding of plant growth in reduced gravity environments. In particular, the lack of buoyancy-driven convection changes the gas exchange at the leaf surface, which decreases photosynthesis and transpiration rates, and ultimately biomass production. To understand the intricate relations between physical, chemical, and biochemical processes, the following methodology combines the development of a mechanistic model of plant growth in reduced gravity environments, computational fluid dynamics (CFD) simulations, and experiments in different time frames.The model presented here is a coupled mass and energy balance using the single round leaf assumption, including gravity as an entry parameter, and the leaf surface temperature as an output variable. Measures of the leaf surface temperature using infra-red cameras allow for a computation of the transpiration rate. This approach was followed to design a parabolic flight experiment, which performed 7 flights, and enabled data collection for model validation in different gravity and ventilation settings on a short time frame. Current measures of carbon assimilation and transpiration rate at the leaf and canopy level using an infra-red gas analyzer (Li-6800) in 1g lab conditions on several species will enable a validation on longer time frames and further calibration of the model. CFD studies both on the parabolic flight and on the lab experimental set-up allow the precise assessment of ventilation above the canopy and plants' leaves.Ultimately, this work will provide recommendations for the design of future plant growth hardware, especially on the lowest adequate ventilation for optimal plant growth in reduced gravity environments, as well as assessing biomass and oxygen production rates on planetary surfaces and space stations. This work was funded by CNES, CNRS, Clermont Auvergne Metropole, and NASA Space Biology through NASA postdoctoral program / USRA.
Space crop production will be important in future long duration exploration missions to supplement the packaged diet with fresh bioactive nutrients. Plant care and the addition of fresh veggies to the diet may also have a role in astronaut well-being. Pick-and-eat salad crops are the best candidates for this near-term supplementation since they require minimal processing or preparation to add to meals. While light quality can strongly influence plant responses on Earth, the impacts of light quality on plant growth and composition in spaceflight remain unclear. The VEG-04 experiment uses two Veggie plant growth chambers on the International Space Station to simultaneously test different red: blue light ratios on the growth of Mizuna mustard, a leafy green salad crop. In addition to plant health and yield, the composition of key nutrients is assessed. Astronauts conduct on-board organoleptic evaluation of the fresh produce. Microbial food safety of returned produce is examined, and a Hazard Analysis Critical Control Point (HACCP) plan has been developed for this crop. VEG-04 consists of two experiments, one lasting 28 days with a single harvest, and the second lasting 56 days, with three cut-and-come-again harvests. These different scenarios provide an opportunity to test two production concepts, examine different fertilizers, monitor microbial changes over time for this crop, and assess potential impacts of interacting with plants on crew behavioral health and performance in spaceflight operations. In ground testing, plant growth was not significantly different across the different light treatments, however nutrient composition did differ significantly. Flight test results will be compared with ground data. This research was co-funded by NASA's Human Research Program and Space Biology in the ILSRA 2015 NRA call.
This presentation will be an introduction and overview of space crop production needs, goals, and challenges in the areas of robotics and automation for the workshop Aug. 6-7, 2019 at Kennedy Space Center. This presentation will be used to start the workshop and set the direction.
NASA's Project Mercury began as a response to the cold war with the Soviet Union and had a number of goals: to place a manned spacecraft in orbital flight around the earth; to investigate man's performance capabilities and his ability to function in the environment of space and to recover the man and the spacecraft safely. One aspect of preflight testing included the use of an altitude chamber to test each capsule and allow the astronauts to engage in simulated missions within a vacuum environment. Flash forward to 1985. The Biomedical Operations and Research Office at Kennedy Space Center proposed to use the chamber for an unusual mission under what was known as the Controlled Ecological Life Support Systems (CELSS)Breadboard Project. During 1985 into 1987, the chamber was converted to an environmentally-controlled, hydroponic plant growth chamber termed the "Biomass Production Chamber" and operated through late 2001.
New technologies will be needed as mankind moves towards exploration of cislunar space, the Moon and Mars. Although many advances in our understanding of the effects of spaceflight on plant growth have been achieved in the last 40 years, spaceflight plant growth systems have been primarily designed to support space biology studies. Recently, the need for a sustainable and robust food system for future missions beyond Low Earth Orbit (LEO) has identified gaps in current technologies for food production. The goal is to develop safe and sustainable food production systems with reduced resupply mass and crew time compared to current systems.
Several dwarf tomato and pepper varieties were evaluated under ISS-simulated growth conditions (22ºC, 50% RH, 1500 ppm CO2, and 300 μmol m(exp -2) s(exp -1) of light for 16 h per day) with the goal of selecting those with the best growth, nutrition, and organoleptic potential for use in a pick and eat salad crop system on ISS and future exploration flights. Testing included six cultivars of tomato (Red Robin, Scarlet Sweet ’N’ Neat, Tiny Tim, Mohamed, Patio Princess, and Tumbler) and six cultivars of pepper (Red Skin, Fruit Basket, Cajun Belle, Chablis, Sweet Pickle, and Pompeii). Plants were grown to an age sufficient to produce fruit (70 to 106 days for tomato and 109 days for pepper). Tomato fruits were harvested when they showed full red color, beginning ca. 70-days age and then at weekly intervals thereafter, while peppers were grown until numerous fruits showed color and all fruits (green and colored) were harvested once at the end of the test. Plant sizes, yields, and nutritional attributes were measured and used to down-select to three cultivars for each species. In particular, we were interested in cultivars that were short (dwarf) but still produced high yields. Nutritional data included elemental (Ca, Mg, Fe, and K) composition, vitamin K, phenolics, lycopene, anthocyanin, lutein, and zeaxanthin. The three down-selected cultivars for each species were evaluated for sensory attributes, including overall acceptability, appearance, color intensity aroma, flavor and texture. The combined data were compared and given weighting factors to rank the cultivars as potential candidates for testing in space. For tomato, the ranking was 1) cv. Mohamed, 2) cv. Red Robin, and 3) cv. Sweet N’ Neat. For pepper, the ranking was 1) cv. Pompeii, 2) cv. Red Skin, and 3) cv. Fruit Basket. These rankings are somewhat subjective but provide a good starting point for conducting higher fidelity testing with these crops (e.g., testing with LED lighting similar to the Veggie plant unit), and ultimately conducting flight experiments.
A review of NASA's bioregenerative life support research will be presented along with testing related to Mars greenhouse or plant growth systems.
This is our annual "station report" of activities related to controlled environment research to the North Central Education Research Activity (NCERA-101) committee. The committee is sponsored the USDA National Institute for Food and Agriculture (NIFA). Kennedy Space Center has participated in this committee for over 30 years.
Plants can provide a means of life support for space missions. Through photosynthesis, plant can generate oxygen and remove CO2, while generating clean water through transpiration. And, by using edible crops, the plants can also produce. The talk will review some of NASA's testing with plants for life support through the years and show how student teams at the "Growing Beyond Earth" challenge have helped NASA in this effort.
Supplemental safe food production has been an essential goal of NASA to meet the nutritional needs of astronauts on the International Space Station (ISS) as well as for future long duration missions to the moon and beyond. Food crops grown in space experience different environmental conditions than plants grown on Earth (i.e. microgravity and spaceflight physical sciences impacts). To test the growth methods and effects of the space environment, red romaine lettuce Lactuca sativa cv. 'Outredgeous', was grown in Veggie plant growth chambers on the ISS. Microbiological food safety of the plants grown on the ISS was determined by heterotrophic plate counts to assess total microbial load for bacteria and fungi as well as screening for specific pathogens and isolate identification. Molecular characterization was completed using Next Generation Sequencing (NGS) to provide valuable information on the taxonomic composition and community structure of the plant microbiome. Chemical analyses of plant tissue were conducted to understand spaceflight-induced changes in key elements in the space diet, phenolics, anthocyanin levels, and Oxygen radical absorbance capacity (ORAC), a measure of antioxidant capacity. Three growth tests of red romaine lettuce were completed on ISS, VEG-01A, VEG-01B, and VEG-03A. Plants were harvested using two harvest methods, either a single terminal harvest (after 33 days) or cut-and-come-again repetitive harvesting (64 days total growth). Ground controls were grown simultaneously with a delay to accommodate condition monitoring and replication. A comparison of the plant tissue returned to Earth showed leaves from the second grow-out had significantly higher bacterial counts than the preceding or subsequent growth test or any of the ground controls. Fungal counts were significantly higher on the final cut-and-come-again harvest of the third grow out. None of the potential foodborne pathogens that were screened for were detected. Bacterial and fungal isolate identification and community characterization indicated similar diversity between VEG-01A and VEG-01B growth tests, however, there appeared to be subtle differences in diversity and distribution among the three growth tests. Chemical analysis of plant tissue revealed significant variation in a few elemental data, but variation in levels of phenolics, anthocyanins, and ORAC was not significantly different. This study indicated that leafy vegetable crops could safely provide an edible supplement to astronauts' diet, and our analysis provided baseline data for continual operation of the Veggie plant growth units on ISS. This research was funded by NASA's space biology program.
An overview some NASA work and interests in controlled environment agriculture, and how this might overlap with interests in the USDA are presented.
NASA and other space agencies and around the world have had long-standing interest in using plants and biological approaches for regenerative life support. In particular, NASA's Kennedy Space Center, has conducted research in this area for over 30 years. One unique aspect to this testing was NASA's Biomass Production Chamber, which had four vertically stacked growing shelves inside a large, 113 cubic meter chamber. This was perhaps one of the first working examples of a vertical agriculture system in the world. A review of some of this research along with some of the more salient findings will be presented.
The concept of using plants and algae for human life support in space goes back to testing in the 1950s and 1960. The basis for this is harnessing photosynthesis to generate oxygen, remove and fix carbon dioxide, and produce food. For several decades, NASA conducted studies with crops in controlled environments to assess their requirements for optimum growth. This includes tests with wheat, soybeans, potatoes, lettuce, tomatoes, and other crops. In many ways, these studies have paralleled growing interests in controlled environment agriculture on Earth. For example, NASA operated perhaps the first working example of a vertical agriculture facility in the late 1980s. The facility used recirculating hydroponic systems to conserve water and nutrients, with multiple growing shelves and light banks. NASA also pioneered the use LED lighting for growing plants. Findings from these tests suggest that an area of 20-25 sq m of crops could provide all the O2 for one human, and about 40-50 sq m could provide all the O2 and food. But this is dependent on the amount of light provided. Most of these studies targeted surface settings like habitats on Mars or the Moon. Growing plants in weightless settings, like the International Space Station (ISS) requires different approaches to contain and deliver water to plants, but lettuce, mizuna, pea, and other crops have been grown in small chambers aboard the ISS to provide supplemental fresh food for the astronauts.
No abstract available