This started in science fair.
In my freshman year of high school, in 2018, I started my research as a science fair project in my physics class. Over the course of 4 years (4 phases of research), I studied both biological and engineering approaches to the system, and ended with a system prototype.
Phase 1:
"Mock Martian Atmosphere and Its Effect on Algae"
2018-2019
Summary:
Phase #1 studied how a mock Martian atmosphere with high CO levels affects the growth of Selenastrum capricornutum algae. This study was primarily conducted to determine the feasibility of producing oxygen in high concentrations of CO2. The question was “how does the amount of CO2 affect the viability of algae?” My hypothesis was “as the amount of CO2 increases, the growth of the algae will also increase because algae rely on CO2 for photosynthesis and survival.” The data supported the hypothesis to an extent. According to the data, the algae colony grew substantially more than the control with a slightly increased CO2 amount, but the tests with a higher CO2 amount caused the algae to die off quickly.
Results:
Overall, the data shows that an atmosphere with an increased 100 ml (~100,000 ppm11) of CO2 positively
benefited Selenastrum capricornutum algae, while 200 ml (~200,000 ppm) and 400 ml (~400,000 ppm) actually was
too much for the Selenastrum capricornutum to handle, and made the algae die off. With the Martian atmosphere 12
CO2 levels being roughly 950,000 ppm , Selenastrum capricornutum algae would likely not survive without protection. Its containment system would need a damper or special airlock to provide enough CO2 to where the algae would thrive but not too much to where the algae would suffocate. I improved this experimental design by making a better airlock system in Phase 2 and Phase 3, as the tubes in this Phase were subject to leakage.
Phase 1 Awards & Honors:
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3rd Place Microbiology - Aardvark Science Exposition (regionals/school-wide competition), Oregon Episcopal School
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NASA Earth System Science Award - Aardvark Science Exposition, NASA Langley Research Center, Oregon Episcopal School
Phase 2:
"RuBisCo Concentrations and Its Effect on Algal Photosynthetic Oxygen Production in a Mock Martian Atmosphere"
2019-2020
Summary:
The purpose of Phase 2 was to investigate the relationship between ribulose-1,5-bisphosphate carboxylase- oxygenase (RuBisCo) concentrations and oxygen production in a contained high-CO2 environment comparable to Mars. After studying Selenastrum capricornutum green algae the previous year, I wanted to find out what type of algae would be optimal for my overall project. This phase of the study is important because RuBisCo is essential in the carbon fixation process of photosynthesis and varying concentrations of the enzyme can affect CO2 consumption as well as oxygen production rate . The question was how do different RuBisCo concentrations affect the photosynthetic oxygen generation in a mock Martian atmosphere? My hypothesis was that the algae with more RuBisCo (Chlamydomonas reinhardtii) would produce more O2 than the algae with less RuBisCo (Coleochaete scutata). The experiment was done by separating two types of green algae with varying RuBisCo concentrations based on sizes of their pyranoid. The pyranoid is a structure, or pocket, near or inside the chloroplasts that largely consists of RuBisCo . The pH was recorded to monitor CO2 intake because CO2 reacts with water to make carbonic acid . It was also tested to observe how the algae would react to a more acidic pH. The oxygen air displacement was also recorded to monitor oxygen production. Chlamydomonas reinhardtii algae, which had more RuBisCo, produced more oxygen than Coleochaete scutata, which had less RuBisCo.
Results:
Overall, the results were conclusive in supporting my hypothesis, where Chlamydomonas reinhardtii produced 5.5% more oxygen than Coleochaete scutata. If the trendline stayed consistent when extended over a longer period of time than the six days tested, the Chlamydomonas would still be the most productive in regards to oxygen production. When finding algae for the Martian in-situ oxygen generation system, an algae type with a larger pyrenoid would likely positively influence the oxygen production.
(Right: Apparatus of Phase #2 with chamber and algae cultures)
Phase 2 Awards & Honors:
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2nd Prize Internationally - Sophomore Individual, National Space Society International Space Settlement Contest
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1st Place - Plant Sciences, Northwest Science Exposition (state-level competition)
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3rd Place Plant Sciences - Aardvark Science Exposition, Oregon Episcopal School
Phase 3:
"Development of Optimum Design Parameters for an Algae Based Martian Oxygen Production System"
2020-2021
Summary:
Algae, due to the extreme environmental conditions of Mars, would not likely be able to survive without protection. Phase #3 aimed to experiment with environmental parameters for: temperature, ultraviolet, light level, and pressure for engineering an independent photosynthesis-based system. The engineering goal was to find the optimal temperature, pressure, UV, and light level conditions for O2 production and algal viability in an environment as close to ambient Martian conditions as possible. Through my results in Phase #2 and external research, I foundthat using Chlorella vulgaris algae would be optimal for my design, as it has a strong and prominent pyrenoid. After determining the optimal algae in Phase #1 and Phase #2, Phase #3 determines the optimal environmental parameters for a system. The system with these parameters should produce the optimal amount of oxygen, utilize the natural Martian resources, and produce no harmful byproducts- all while limiting the amount of environmental changes relative to the natural Martian environment. This would reduce the amount of protection needed to sustain the algae.
(Left): Close-up of 3D printed sensor-integrated test tube stand. (Right): Apparatus with test tube stand and autonomous data-collecting microcontroller.
Results:
Overall, these experiments show that Chlorella vulgaris is sensitive to each environmental parameter tested. The ideal parameters to produce an optimal amount of O2 from Chlorella vulgaris are: a temperature above 11.3 degrees C, a pressure approaching 100 kpa (at least 89 kpa), 24-hour 100+ lux exposure, and as close to 0 ultraviolet exposure as possible. A future oxygen generator system, using Chlorella vulgaris, would need a containment to support these conditions.
Phase 3 Awards & Honors:
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3rd Place Internationally - Energy: Sustainable Materials and Design, Regeneron International Science and Engineering Fair (ISEF)
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Patty Jeanne Semura Best of Fair Award - Aardvark Science Exposition, Oregon Episcopal School
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1st Place - Engineering: Bioengineering and Materials, Aardvark Science Exposition, Oregon Episcopal School
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Outstanding Exhibit in Materials Science - Northwest Science Exposition, ASM International Foundation
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NASA Earth System Science Award - Northwest Science Exposition, NASA Langely Research Center
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Honorable Mention - Engineering: Bioengineering and Materials, Northwest Science Exposition
Phase 4:
"Prototyping an Algae-Based Martian In-situ Oxygen Generation System"
2021-2022
Summary:
The current mainstream idea for oxygen production on Mars has inefficiencies and produces the dangerous byproduct of hydrogen. I have developed a system that offers a resource-efficient alternative using algae to produce oxygen from the Martian atmosphere. The engineering goal of this project was to design and test a small-scale, algae-habitable system that is able to input in-situ carbon dioxide, produce oxygen, and then separate the carbon dioxide from the oxygen, thus leaving oxygen for breathable use. The intermediate goals include engineering an environmental valve transfer system and evaluating the separation of carbon dioxide chemically using sodium hydroxide. The biological constraint is that the system must be environmentally viable for sustained algae growth and photosynthesis. Key engineering constraints consisted of complexity, volume, power consumption, and scalability. Building the physical system required multiple subsystems including gas flow systems (managing oxygen and carbon dioxide), electrical systems (microcontroller for sensors, data collection, and valve control), algae life support (growth medium and algae growth), mechanical systems (pump, valves, vacuum chamber, piping), and environmental systems (temperature, light control). Through experimentation, my system was found to be successful with both producing oxygen and has a high potential for increased scalability. It also has the potential to provide supplemental resources like nutrition and biofuel for Mars-based astronauts.
Results:
Ultimately, the data showed that the system was successful in producing O2 and separating O2 from CO2 for use. The consistent results in the repeated experiments supports the potential for the system to be scaled-up to support humans. An assumption is made that the amount of algae is proportionate to the O2 production. Considering that the amount of O2 produced on the International Space Station per person is 0.84 kilograms per day, with the rate of O2 production in this system, approximately 10.777 L of Chlorella vulgaris (10,777.06 ml) would be needed to support one human in a controlled Martian sub-environment. Assuming linear proportions, calculations can be proportionally scaled to account for as many astronauts as needed.
Phase 4 Awards & Honors:
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4th Place Internationally - Energy: Sustainable Materials and Design, Regeneron International Science and Engineering Fair (ISEF)
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Patty Jeanne Semura Best of Fair Award - Aardvark Science Exposition, Oregon Episcopal School
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1st Place - Engineering: Bioengineering and Materials, Aardvark Science Exposition