Ray Wheeler

Ray Wheeler
Kennedy Space Center · Surface Systems Division

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346
Publications
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Publications

Publications (346)
Article
Future space missions will likely include plants to provide fresh foods and bioregenerative life support capabilities. Current spacecraft such as the International Space Station (ISS) operate at 1 atm (101 kPa) pressure, but future missions will likely use reduced pressures to minimize gas leakage and facilitate rapid egress (space walks). Plants f...
Research Proposal
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Establishing a sustained presence on the Moon, cis -lunar orbit, and on Mars, will require plant agriculture. Growing plants has both psychological and nutritional benefits (Odeh and Guy, 2017) and has long been held as pivotal to successful long-duration human space exploration. The role of plants as components of spaceflight and planetary life su...
Article
Red Romaine leaf lettuce (Lactuca sativa L. cv. Outredgeous) was grown in ground-based analogues of the Veggie plant-growth units used to grow salad vegetables for astronauts on the international space Station (ISS). Plants were grown for 56 days with three “cut-and-come again” leaf harvests from the same plants. Six Biomass-Production-Systems-for-...
Article
Full-text available
Bioregenerative life-support systems for space have been investigated for 60 years, and plants and other photosynthetic organisms are central to this concept for their ability to produce food and O 2 , remove CO 2 , and help recycle wastewater. Many of the studies targeted larger scale systems that might be used for planetary surface missions, with...
Article
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Background Seed sanitization via chemical processes removes/reduces microbes from the external surfaces of the seed and thereby could have an impact on the plants’ health or productivity. To determine the impact of seed sanitization on the plants’ microbiome and pathogen persistence, sanitized and unsanitized seeds from two leafy green crops, red R...
Article
Full-text available
The establishment of steady-state continuous crop production during long-term deep space missions is critical for providing consistent nutritional and psychological benefits for the crew, potentially improving their health and performance. Three technology demonstrations were completed achieving simultaneous multi-species plant growth and the concu...
Article
Crew time requirements for human space exploration missions is as critical as mass, energy, and volume requirements. However, it has only been sporadically recorded in past analog and space missions for plant cultivation. In this retrospective study on crew time data collected in various analog facilities and on the Veggie hardware on ISS, we propo...
Article
Full-text available
Food and nutrition are critical to health and performance and therefore the success of human space exploration. However, the shelf-stable food system currently in use on the International Space Station is not sustainable as missions become longer and further from Earth, even with modification for mass and water efficiencies. Here, we provide a pote...
Technical Report
Full-text available
Growing food on extraterrestrial surfaces requires the development of efficient lighting technologies to provide photons for photosynthesis. Here we discuss the development and demonstration of LED panels with a high color fidelity index that can achieve a photon efficacy of 3.6 μmol of photons per joule of input electrical energy. As of June 2021,...
Article
Full-text available
Closed environments such as the International Space Station (ISS) and spacecraft for other planned interplanetary destinations require sustainable environmental control systems for manned spaceflight and habitation. These systems require monitoring for microbial contaminants and potential pathogens that could foul equipment or affect the health of...
Technical Report
Full-text available
NASA operated perhaps the first vertical farm in the world, although it was focused on research rather than commercial production. The system was called the Biomass Production Chamber and consisted of four vertically stacked hydroponic shelves with electric light banks. This technical memorandum reviews this research and development.
Conference Paper
Full-text available
Space crop production systems are being developed to grow fresh produce in-situ to supplement the astronauts' diet, but the required ventilation rates for crops in different gravity environments remains poorly understood. The reduction or lack of buoyancy-driven convection in reduced gravity environments leads to impaired gas exchange (CO2 absorpti...
Conference Paper
Full-text available
Direct use of sunlight in greenhouses is common on Earth, but planets without atmospheres do not filter meteorites and cosmic radiation, making direct use of sunlight very difficult. Indirect approaches are necessary. Photosynthesis for food production requires two orders of magnitude more light than is needed for optimal human activity and this re...
Article
Full-text available
The first Veggie plant growth chamber was installed on the International Space Station in 2014. Crop plants can be grown in Veggie using plant pillows, small rooting packets that contain substrate, fertilizer, and germination wicks along with attached seeds. The pillows were designed to interface with the Veggie root mat reservoir watering system t...
Article
Among candidate leafy vegetable species initially considered for astronauts to pick and eat from the Veggie plant-growth unit on the International Space Station (ISS), Chinese cabbage (Brassica rapa L. cv. Tokyo Bekana) ranked high in ground-based screening studies. However, subsequent attempts to optimize growth within rigorous ISS-like growth env...
Article
Full-text available
The ability to grow safe, fresh food to supplement packaged foods of astronauts in space has been an important goal for NASA. Food crops grown in space experience different environmental conditions than plants grown on Earth (e.g., reduced gravity, elevated radiation levels). To study the effects of space conditions, red romaine lettuce, Lactuca sa...
Article
Full-text available
Potatoes (Solanum tuberosum L.) have been suggested as a candidate crop for future space missions, based on their high yields of nutritious tubers and high harvest index. Three cultivars of potato, cvs. Norland, Russet Burbank, and Denali were grown in walk-in growth rooms at 400 and 800 µmol m−2 s−1 photosynthetic photon flux (PPF), 12-h L/12-h D...
Presentation
Full-text available
NASA has identified robust 'Pick-and-Eat' systems for supplementing crew diets with fresh leafy green crops in near-term LEO, cislunar, lunar and martian missions. • New challenges: • develop and demonstrate the performance of substrate-free, gravity-independent, water delivery systems • safely grow salad crops (monitor plant health) • use crops ad...
Presentation
Full-text available
Describes the NASA Mercury Program and the altitude chamber that was built for it. This chamber was remodeled into a controlled environment hydroponic plant growth chamber in the mid 1980s and operated for over a decade, testing techniques for producing a number of crop plants such as wheat, potato, soybean, lettuce and tomato for advanced life sup...
Preprint
Full-text available
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. An aspect of preflight te...
Conference Paper
Full-text available
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 ne...
Article
Light emitting diode (LED) lighting technology for crop production is advancing at a rapid pace, both in terms of the technology itself (e.g., spectral composition and efficiency), and the research that the technological advances have enabled. The application of LED technology for crop production was first explored as a tool for improving the safet...
Article
Full-text available
Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Strategies for the collection of such samples have ranged from “grab and go” acquisition from the surface, to dust collection in the atmosphere, to scientific selection by geologically capable rovers. As comprehension of the comple...
Article
Full-text available
Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Affirmation by NASA and ESA of the importance of Mars exploration led the agencies to establish the international MSR Objectives and Samples Team (iMOST). The purpose of the team is to re‐evaluate and update the sample‐related scie...
Article
Full-text available
This report requested by the International Mars Exploration Working Group (IMEWG). Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Affirmation by NASA and ESA of the importance of Mars exploration led the agencies to establish the international MSR Objectives and Samples Team (i...
Article
Full-text available
To explore lighting strategies for crop production in space, we investigated the impacts of light spectrum on morphology, biomass, and phytonutrients of red pak choi (Brassica rapa var. chinensis, 'Rubi F 1 ') over a 28-day cycle. Light treatments were white light-emitting diodes (WLEDs) as a control, W + red (WR), W + green switched to red at 21 d...
Article
Full-text available
To optimize crop production/quality in space, we studied various “light recipes” that could be used in the Advanced Plant Habitat currently aboard the International Space Station (ISS). Lettuce (Lactuca sativa cv. ‘Outredgeous’) plants were grown for 28 days under seven treatments of white (W) LEDs (control), red (635nm) andblue(460nm)(RB)LEDs,W+bl...
Book
Full-text available
Executive Summary: Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Affirmation by NASA and ESA of the importance of Mars exploration led the agencies to establish the international MSR Objectives and Samples Team (iMOST). The purpose of the team is to re-evaluate and update the...
Conference Paper
Full-text available
The Vegetable Production System (Veggie) is a scientific payload designed to support plant growth for food production under microgravity conditions. The configuration of Veggie consists of an LED lighting system with modular rooting “pillows” designed to contain substrate media and time-release fertilizer. The pillows were designed to be watered pa...
Article
Full-text available
Agricultural systems for space have been discussed since the works of Tsiolkovsky in the early 20
Article
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Mechanical stimuli or stress has been shown to induce characteristic morphogenic responses (thigmomorphogenesis) in a range of crop species. The typical mechanically stimulated phenotype is shorter and more compact than non-mechanically stimulated plants. This dwarfing effect can be employed to help conform crop plants to the constraints of spacefl...
Article
Full-text available
The Veggie vegetable production system was launched to the International Space Station with three sets of test plants for an initial hardware validation test, designated VEG-01. VEG-01A and B featured the crop ‘Outredgeous’ red romaine lettuce, while VEG-01C tested ‘Profusion’ zinnia plants for longer duration growth and flowering characteristics....
Conference Paper
Full-text available
The NASA Advanced Plant Habitat (APH) is configured as a quad-locker payload to be mounted in a standard EXpedite the PRocessing of Experiments to the Space Station Rack on the International Space Station. It is envisioned to be the largest plant growth chamber yet to be developed for ISS. The APH is designed to support commercial and fundamental p...
Poster
Full-text available
>Plants are a key component of Bioregenerative Life Support Systems; they provide food, remove CO2, generate O2 and contribute to the production of potable water. >CO2 concentrations in environments, such as the International Space Station (ISS) and future crew cabins, can be extremely high (3000-10,000 μmol mol-1). >Super-elevated (SE) levels of C...
Presentation
Full-text available
Prunus domestica (plum) trees have been developed that ectopically express the Flowering Locus T-1 (FT1) gene. The resulting phenotypes overcome the barriers that have prevented the use of tree fruit species as candidate crops in bio-regenerative life-support systems, thereby opening the door to a new class of candidate crop species. In addition to...
Article
The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED lighting, and those capabilities continue to expand. The 'Veggie' vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of hort...
Article
Full-text available
The objective of this study was to evaluate root restriction as a tool to increase volume utilization efficiency in spaceflight crop production systems. Bell pepper plants (Capsicum annuum cv. California Wonder) were grown under restricted rooting volume conditions in controlled environment chambers. The rooting volume was restricted to 500 ml and...
Book
Full-text available
This report provides a general overview of the results from spaceflight studies and identifies the unique aspects of the spaceflight environment that lend themselves to scientific investigation and understanding of space plant biology. Book can be downloaded from: https://www.nasa.gov/sites/default/files/atoms/files/np-2016-06-016-jsc_plant_resear...
Article
Full-text available
Tree fruit (e.g., apples, plums, cherries) are appealing constituents of a crew menu for long-duration exploration missions (i.e., Mars), both in terms of their nutritive and menu diversity contributions. Although appealing, tree fruit species have long been precluded as candidate crops for use in plant-based bio-regenerative life-support system de...
Article
Full-text available
Significant advances in controlled-environment (CE) plant production lighting have been made in recent years, driven by rapid improvements in light-emitting diode (LED) technologies. Aside from energy efficiency gains, LEDs offer the ability to customize the spectrum delivered to a crop, which may have untold benefits for growers and researchers al...
Conference Paper
Full-text available
Greenhouse modules and regenerative life-support systems are critical for long-duration space missions and future settlements on the Moon and Mars; understanding their mechanisms and issues on Earth in remote areas is a first step towards their space adaptation. To follow up with studies performed in NASA‘s Deep Space Habitat and deployed at NASA D...
Article
Full-text available
Bioregenerative life-support systems involving photoautotrophic organisms will be necessary to sustain long-duration crewed missions at distant space destinations. Since sufficient sunlight will not always be available for plant growth at many space destinations, efficient electric-lighting solutions are greatly needed. The present study demonstrat...
Article
Full-text available
Spaceflight imposes several unique stresses on biological life that together can have a profound impact on the homeostasis between eukaryotes and their associated microbes. One such stressor, microgravity, has been shown to alter host-microbe interactions at the genetic and physiological levels. Recent sequencing of the microbiomes associated with...
Conference Paper
Full-text available
Tree fruit, although desirable from a crew nutrition and menu diversity perspective, have long been dismissed as candidate crops based on their long juvenile phase, large architecture, low short-term harvest index, and dormancy requirements. Recent developments in Rapid Cycle Crop Breeding (RCCB) have overcome these historical limitations, opening...
Article
Full-text available
Spaceflight environment have been shown to generate reactive oxygen species (ROS) and induce oxidative stress in plants, but little is known about the gene expression of the ROS gene network in plants grown in long-term spaceflight. The molecular response and adaptation to the spaceflight environment of Mizuna plants harvested after 27 days of cult...
Chapter
Extending human activities to outer space has been a major target of space engineering from its inception. We have long dreamed of space flight, been curious about the origin of the universe, our solar system, and life on Earth (Tsiolkovsky in Exploration of world space with rockets. Kaluga Press, Russia). Even with recent discoveries of many extra...
Conference Paper
One of the technologies being tested at Ames Research Center as part of the logistics and repurposing project is heat melt compaction (HMC) of solid waste to reduce volume, remove water and render a biologically stable and safe product. Studies at Kennedy Space Center have focused on the efficacy of the heat melt compaction process for killing micr...
Conference Paper
In preparation for future human exploration missions to space, NASA evaluates habitat concepts to assess integration issues, power requirements, crew operations, technology, and system performance. The concept of a Food Production System utilizes fresh foods, such as vegetables and small fruits, harvested on a continuous basis, to improve the crew'...
Article
Plants will be an important component of off-Earth life support systems for food production and atmosphere recycling. “Veggie” is a small vegetable production unit designed for space flight, with a passive water delivery system. Plants can be grown in Veggie using small bags with a wicking surface containing media and fertilizer, i.e., pillows. Pil...
Conference Paper
Full-text available
NASA has clearly stated its intentions for human-rated planetary exploration in the early half of this century. The duration of such missions presents many challenges; far from least is how to provide the resources necessary to sustain human life on another planetary surface. Mass and energy constraints limit the amount of food, air, and water that...
Article
Full-text available
The relationship between fundamental plant biology and space biology was especially synergistic in the era of the Space Shuttle. While all terrestrial organisms are influenced by gravity, the impact of gravity as a tropic stimulus in plants has been a topic of formal study for more than a century. And while plants were parts of early space biology...
Article
Full-text available
In tightly closed human habitats such as space stations, locations near volcano vents and closed culture vessels, atmospheric CO(2) concentration may be 10 to 20 times greater than Earth's current ambient levels. It is known that super-elevated (SE) CO(2) (>1,200 µmol mol(-1)) induces physiological responses different from that of moderately elevat...
Data
CO2 or developmental responsive low molecular weight compounds with 2 fold or more changes in their steady state levels in mixed effect model analysis (p-value ≤0.001). (XLSX)
Data
A. Corresponding genes of the development-responsive transcripts with 2 fold or more changes in their signals in mixed effect model analysis (p-value ≤0.001). B. Corresponding genes of the CO2 regulated transcripts. CO2 only or development independent and dependent CO2 regulated transcripts with 2 fold or more changes in their signals in mixed effe...
Data
The raw data for metabolite profiling. n = 3 biological experiments each having 3 analytical replicates (XLSX)
Data
CO2 responsive transcripts with biotic abiotic, hormone, and sugar regulation. The transcripts in Table S2 are compared to publicly available microarray data sets. (XLSX)
Data
The raw data for transcript profiling. n = 3 biological experiments. (XLSX)
Conference Paper
VEGGIE is a prototype vegetable production unit for space designed by Orbital Technologies Corporation that is being developed to fly on the International Space Station. A modular plant rooting system “pillow” is being designed to support plant growth in VEGGIE under microgravity conditions. VEGGIE pillows are small self-contained packets of media...
Data
In tightly closed human habitats such as space stations, locations near volcano vents and closed culture vessels, atmospheric CO2 concentration may be 10 to 20 times greater than Earth’s current ambient levels. It is known that super-elevated (SE) CO2 (>1,200 µmol mol−1) induces physiological responses different from that of moderately elevated CO2...
Data
In tightly closed human habitats such as space stations, locations near volcano vents and closed culture vessels, atmospheric CO2 concentration may be 10 to 20 times greater than Earth’s current ambient levels. It is known that super-elevated (SE) CO2 (>1,200 µmol mol−1) induces physiological responses different from that of moderately elevated CO2...