The Optimization of Root Zone Substrates (ORZS) for Reduced Gravity Experiments Program (ORZS) - 07.15.14
ISS Science for Everyone
Science Objectives for Everyone ORZS was developed to provide direct measurements and models for plant rooting media that will be used in future Advanced Life Support (ALS) plant growth experiments. The goal of this investigation is to develop and optimize hardware and procedures to allow optimal plant growth to occur in microgravity.
Science Results for Everyone
Long-term space missions will likely use plants to provide food and recycle waste products. This experiment assists in developing hardware, media, and procedures for optimal plant root growth in microgravity. Validating calculations of how plants transport oxygen and other gasses in space is a key step, but it’s difficult to collect accurate measurements in microgravity. Initial samples are currently undergoing analysis on the ground, and data from different substrates will be compared with results from similar ground control cells to describe how plants move oxygen in microgravity.
Utah State University, Space Dynamics Laboratory, North Logan, UT, United States
Johnson Space Center, Human Research Program, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
September 2006 - April 2009
Previous ISS Missions
ORZS is a new investigation for microgravity research.
- The goal of ORZS is to develop and optimize hardware and procedures to allow optimal plant growth to occur in microgravity.
- The ORZS will provide direct measurements and models for plant rooting media that will be used in future Advanced Life Support (ALS) plant growth experiments for long duration missions to the Moon and Mars.
Many long-term space flight life-support scenarios assume the use of plants to provide food supplies for crewmembers, as well as to recycle waste products. To date, Brassica rapa (field mustard plant) and Triticum aestivum (super dwarf wheat), and four species of salad plants have grown in microgravity throughout their useful life cycles, with Triticum and Brassica producing viable seeds in nearly normal amounts and quality. These successes came at the end of nearly a decade of repeated efforts using the same equipment to arrive at the optimal settings for substrate moisture and oxygen.
Optimization of Root Zone Substrates (ORZS) for Reduced Gravity Experiments is managed at the Space Dynamics Laboratory (SDL) as part of SDL's Space Plant Technology program and was developed to provide direct measurements and models for plant rooting media that will be used in future Advanced Life Support (ALS) plant growth experiments. The goal of this program is to develop and optimize hardware and procedures to allow optimal plant growth to occur in microgravity for future space exploration beyond low Earth orbit.
The key to this effort is validating wet substrate oxygen diffusion calculations in microgravity. While the measurements appear simple and well studied in agricultural soils on Earth, collecting repeatable results at high water contents in the coarse-textured growth media required for microgravity requires a modified approach, due to the dominance of capillary rise in microgravity and the greater root zone density of plants grown in space. Collecting accurate data under both one-g and microgravity conditions and correctly interpreting these data at reasonable cost requires careful management and organization, and expert technical microgravity experience. Only a few microgravity substrate water management experiments have been conducted. ORZS will be the first experiment to directly measure oxygenation parameters in wet substrates.
ORZS data collection will utilize two existing flight programs to meet experiment requirements:
- Institute of Biomedical Problems' (Moscow, Russia) "Growth and Development of Higher Plants through Multiple Generations" program authority, utilizing the "Substrate Technology Development Section".
- The Lada Space Growth Chamber developed jointly by SDL and IBMP.
The experiment will develop and optimize hardware and procedures to allow optimal plant growth to occur in microgravity to support long-term space flight life-support scenarios assuming the use of regenerating green plants to provide food supplies for crewmembers, as well as to recycle waste products.
As less fertile land becomes available to grow food, alternative agricultural systems that efficiently produce greater quantities of high-quality crops will be increasingly important. Data from the operation of the ORZS will advance greenhouse and controlled-environment agricultural systems and will help farmers produce better, healthier crops in a small space using the optimum amount of nutrients.
The research will be conducted for two experiment modules, with a series of downlinks for each, followed by sample returns. Operations will require crew time and Ku-band availability for data downlinked.
Crewmembers will tend the ORZS equipment monitoring plant growth and downlink files related to equipment operations.
Initial samples from the ORZS investigation have been returned to Earth and are currently undergoing analysis by the investigator team. Data from the flight system of gas diffusion cells with different substrates will be compared with results from similar ground control gas diffusion cells in order to describe gas diffusion in microgravity (Jones et al. 2005). (Evans et al. 2009)
Ground Based Results Publications
Jones SB, Bingham GE, Or D, Morrow RC. ORZS: Optimization of Root Zone Substrates for Microgravity. SAE Technical Paper. 2002; 2002-01-2380.
Jones SB, Bingham GE, Topham TS, Or D, Podolsky IG, Strugov OM. An Automated Oxygen Diffusion Measurement System for Porous Media in Microgravity. SAE International Journal of Aerospace. 2003 July; 2003-01-2612. DOI: 10.4271/2003-01-2612.
Jones SB, Or D, Bingham GE. Gas diffusion measurement and modeling in coarse-textured porous media. Vadose Zone Journal. 2003 Nov; 2(4): 602-610. DOI: 10.2136/vzj2003.6020.
Space Dynamics Laboratory - Utah State University Research Foundation
NASA Image: ISS006E27426 - View of Lada Leaf Chamber and Light Module on panel 218 in the Service Module, Zvezda during ISS Expedition 6. The Lada growth chamber currently in use on ISS will be used in the ORZS investigation.
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NASA Image: ISS016E027955 - Astronaut Peggy Whitson, Expedition 16 commander, checks the progress of plants growing in the Russian Lada greenhouse in the Zvezda Service Module of the ISS.
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