Bioregenerative L ife Support System (B LSS) for
Long Duration H uman Space M issions
Graduate Team Paper
Submitted to
NASA Revolutionary Aerospace Systems Concepts Academic Linkage
(NASA RASC-AL)
Conference June 18-20, 2013
On the theme of
Advanced Concepts
Matthew Carton, Christine Fanchiang, Griffin Hale,
Heather Hava, Keira Havens, Jordan Holquist
Graduate Students in Aerospace Engineering Sciences
Nikolaus Correll
Advisor, Assistant Professor, Computer Science
University of Colorado Boulder
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 1 of 16
Bioregenerative L ife Support System (B LSS) for Long Duration
H uman Space M issions
Matthew Cartoni, Christine Fanchiangi, Griffin Halei, Heather Havai, Keira Havensii, Jordan Holquisti
University of Colorado, Boulder, Colorado, 80309
A BST R A C T
T he Bioregenerative L ife Support Systems (B LSS) project presents a novel concept for
integrating plants into a space habitat providing a robust and sustainable solution for
supplementary life support on future long duration space missions. T he system was designed to
address three elements missing in many bioregenerative system designs: 1) an integrative and
synergistic approach to leveraging biological systems for multiple life support functions 2)
provide a realistic timeline and concept of operations for implementation and sustainment and
3) provide a technology development roadmap for integration and test ing of this system. In
support of the project, the B LSS team participated in a science and engineering outreach event
in Denver to engage with middle school students. T he event exposed the students to a variety of
hands-on engineering activities that demonstrated the challenges of living in space.
I.
Background
Bioregenerative Life Support Systems (BLSS) will be the cornerstone of successful long duration human space
exploration missions, ultimately enabling a permanent human presence beyond Earth. Biological-based systems provide
the tangible benefits of atmosphere revitalization, water reclamation, food production, and waste processing, in addition
to the subtle benefits of improved crew health, morale, and productivity. Together, these advantages contribute to
increased crew safety, improved system reliability, and reduced overall cost for long duration missions and future space
colonization.
Biological systems have been proposed for many long duration exploration missions, including visits to and
settlements on the Moon and Mars1. Often these studies either envision full-scale agricultural operations to provide the
entire caloric demand of a colony focusing on crops such as wheat and soy, or they look at optimizing one or two
specific life support functions without consideration of the additional benefits derived from plant usage. Additionally,
these studies lack a comprehensive logistical approach for technology integration and testing with the rest of the space
system, and lack plans for deployment, operations, and sustainment of their proposed systems. Without a clear plan,
projects incorporating highly intensive research components can be easily side-tracked, ultimately endangering future
space mission funding. The goal of this project is to address each of these three gaps with a mid-scale supplementary
biological life support system. This concept analysis provides the following:
1) A detailed description of the integrated system and a comprehensive analysis of its performance
2) A realistic implementation and deployment strategy for the system
3) Plans for advancing technology readiness levels (TRL) and its anticipated costs.
The BLSS concept is designed to be a stepping stone for a near-term application and research of biological systems
for space missions. It is understood that it will take several years of research before biological systems can be relied on
as a primary subsystem for space operations. The following paper describes a proposed concept of a BLSS design and
how to leverage its benefits on a large scale exploration mission.
I I.
Benefits of Bioregenerative L ife Support Systems
There are three major benefits that can be leveraged with a BLSS:
1) reduced need for consumable resupply,
2) enhanced diet (fresh food, palatability, variety, and crew nutrition)
3) gained psychological/physiological benefits of having plants integrated in the habitat.
i
ii
Graduate Student, Aerospace Engineering Sciences, University of Colorado Boulder, 429 UCB, Boulder, CO, 80309
Graduate Student, Plant and Biological Sciences,, Colorado State University, Fort Collins, CO 80523
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 2 of 16
The benefits of having a BLSS increase with increasing mission duration. The average time of return on investment
(often characterized as launch mass) for a biological system is estimated to be around two years.2 While a BLSS can
improve overall system efficiency, they can be large, heavy, and complex; therefore, it is important to do a detailed
quantification and analysis of the projected costs and advantages compared with current physical-chemical systems
providing all functions. With the proposed mid-sized supplementary system, costs can be recovered more quickly, but
with reduced benefits when compared to a larger system.
A . Reduction of Long-T erm Resupply
Two major limitations of current space technology for long duration missions are lack of sustainable and substantial
food production and limited waste management systems. One of the primary benefits of incorporating a BLSS into a
space habitat is its ability to provide resource resupply (producing food, removing CO 2 from the air, and purifying
water), in addition to waste regeneration. With crewmembers expected to consume 0.617 kg of food, 3.91 kg of water,
and 0.84 kg of oxygen each per day3, and produce waste at a rate on the order of 5.361 kg per day3 (including liquids,
solids, and CO2), it is clear how long duration missions, especially those to Mars on the order of 730 days, can incur
high consumable mass penalties. The BLSS regenerates these consumables with biological processes from crewmember
metabolic waste, establishing a use for human waste rather than venting or dumping the waste into space.
Because biological systems have not been studied or used on the scales necessary for long term space missions, it is
prudent to gradually introduce the BLSS as an extension of existing life support. In this mission concept, the BLSS
would act as a supplemental system in conjunction with physical-chemical systems, such as those currently used aboard
the International Space Station (ISS). This approach will maintain mission safety, improve redundancy, and provide
supplemental benefits, while also advancing the Technology Readiness Level (TRL) of the BLSS.
T able 1. W H O recommended
daily micronutrient intake.3
B. Nutritional Supplementation
Nutrition can affect human performance -without adequate nutrition the crew could be
Daily intake
susceptible to diseases, fatigue, and psychological issues. Packaged space food often has Micronutrients (mg/person)
Zinc
11
degraded nutritional benefits, especially after being stored for extended periods of time.
Calcium
2000
Certain freshly grown foods have the benefit of high nutritional values and therefore will
Copper
9
Vitamin K
0.09
not degrade due to storage. To minimize nutritional deficiencies in the current astronaut
Selenium
0.4
diets, crops that contain micronutrients are highly desirable, especially for missions with
Vitamin C
90
long term durations, where malnutrition effects may become more apparent. The list of
Niacin
16
Thiamin
0.36
plants to be included with the BLSS was largely driven by optimizing a nutritional regime
Folate
0.4
for astronauts and determining specific crops that could meet those needs. In particular,
Vitamin E
15
due to the spaceflight environment and physiological changes on the human body, a
handful of micronutrients are considered more important to monitor including calcium for bone growth, vitamin C and
E for repairing radiation damage. A subset of important micronutrients has been identified, and the recommended intake
for each as determined by the World Health Organization4 is listed in Table 1.
C . Physiological and Psychological Boost
Lastly, direct interaction between the crew and plants has been shown to provide physiological and psychological
benefits as captured in Table 2. These improvements are unlikely to be obtained through other means, as the
psychological benefits are specifically due to the interaction between plants and humans, and the physiological benefits
are due in part to the availability of fresh food.
T able 2. Benefits of human plant interaction
Psychological Benefits
Relieves stress
Increases concentration levels
Increases morale
Provides a sense of ownership
Physiological Benefits
Immune System
Cardiovascular System
Musculo-Skeletal System
Digestive System
Serenity, tranquility and peacefulness
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 3 of 16
I I I. Design D rivers and T rades Studies for B LSS
To achieve all the benefits of a bioregenerative system without compromising system mass and efficiency, several
trade studies were done to identify an optimal system design. The principal system drivers were identified as the
following:
1) Waste management - drives the need for small woody food bearing plants
2) Micronutrients - drives the need for citrus, vegetables and herbs
3) Psychological benefit - drives need to be in same habitat enclosure
The current waste management protocol on the ISS is storing and dumping waste overboard.5 Several alternative
protocols have been considered to address the amount of waste and the inefficient use of resources generated by this
protocol. Pyrolysis, in which the waste is subjected to high temperatures and pressures to create useful by-products
such as activated carbon for filters,6 however, these systems requires large power demands and often only satisfy one
function of waste recovery. More integrative research has proposed using algae for waste water processing and then
serving it as a nutritious snack.7 While innovative, the application is still unable to process solid waste, and pond-scum
like algae may not provide as much psychological benefit as growing a fruiting plant. In addition, the algae is immersed
in waste and may require additional processing prior to crew consumption. The solution that satisfies the three design
drivers is a tree-based system where plant roots contact the waste and food production occurs far from the interaction
with waste. There are several benefits of a tree-based system.
1) Woody plants provide food with minimal risk of pathogen transfer
2) Roots and bacteria breaks down solid waste into nutrient rich material for food generation.
3) Water uptake through the roots and transpiration through the leaves processes wastewater, with
minimal risk of pathogen transfer
4) Photosynthesis accomplishes life support functions (CO 2 scrubbing, O2 generation, water recycling,
food production)
5) Variable life cycles with variable growths (leaves, fruits) ensure continuously changing scenery for
increased psychological benefits
6) All regenerative functions are inherent to the passive natural system, which requires only cyclic
lighting and human waste as input.
Trees form the backbone of the BLSS, providing waste management, air revitalization, and water recycling, but they
are limited in nutritional variation. Supplementary vegetables and herbs and appropriate growing space were identified
with two additional trade studies. The first focused on selection of the plants that would best suit the nutritional and
growing requirements of a long duration space mission, and the second was the architectural design.
A . Dietary Goal
The harsh environment of space imposes several negative physiological and psychological effects on
crewmembers. Examples include bone and muscle depletion in low-g environments, lack of sunlight exposure, and the
psychological stresses of an Isolated and Confined Environment (ICE). In addition, 0-g conditions can decrease appetite
as a result of disruption of the vestibular system and the fluid shift in the hydrostatic column of the body. Other than
periodically resupplied fresh fruits and vegetables with limited shelf lives, spacefaring food must be sufficiently
preserved. This often decreases both palatability and nutrient quality, compounding the problem of heightened nutrient
requirements and lack of appetite. Regardless of
gravity for astronauts to maintain a normal appetite, long duration space crews stand to benefit from a diet high in fresh
fruit and vegetables.
The BLSS is projected to provide a minimum of 2800g and 35-63 servings per person per week of raw edible plant
mass, per World Health Organization (WHO) and U.S. Department of Agriculture (USDA) recommendations 8. Serving
sizes are typically measured as one cup, though standard serving volumes may depend upon the state of the vegetable
(e.g. leafy greens, which greatly decrease in volume upon cooking). As plant growing requirements are specified in
terms of raw plant masses, we chose to analyze only raw plant nutritional profiles and to vary our serving sizes
ecommendations for International
7
Emphasis on crop selection and serving distribution is given to the top
micronutrients essential for combating the deleterious effects of space flight. Expected nutrient values were calculated
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 4 of 16
by selecting crops rich in thiamin, niacin, vitamins C, K, E, folate, zinc, calcium, and selenium, assuming that crew
members eat each crop on a weekly basis, and iterating the number of servings to ensure micronutrients are amply
provided.
B. C rop Selection
We considered nine criteria underpinning crop selection: key nutrient density, variety, palatability, bioregenerative
integration, space efficiency, grow time, launch mass, visual appeal, and aroma. After selecting desirable crops and
generating a weekly menu for the crew, the menu was then broken down into individual nutrient yields. Serving size
and frequency was then adjusted until the weekly menu maximized the intake of key nutrients while remaining diverse
and not exceeding nine servings per day as recommended by the USDA. Additional iterations were performed to insure
that the bioregenerative goals and mass and volume constraints were met.
The crops selected for this BLSS provide over 100% of the required weekly recommendations for vitamin K and
vitamin C intake, but are insufficient for the remainder nutrients as shown in Table 3. In order for the BLSS to satisfy
the remaining listed micronutrients, the plant growing area would have to increase to unreasonable values. It should be
highlighted here that the BLSS is meant to provide supplemental nutrients, not a full spectrum at optimal dietary levels.
Grains, nuts, seeds, and animal products are better sources of nutrients that are not provided by the BLSS system alone.
These alternate nutrient sources can be stabilized with minimal or no loss of palatability grains, nuts, and seeds may be
stored for long durations through dehydration and vacuum packaging. While the selected fresh fruits and vegetables do
not solely satisfy the desired micronutrients, they provide other nutritive benefits such as phytochemicals, antioxidants,
and fiber which are not analyzed in this paper.
T able 3. M icronutrient amounts satisfied for chosen B LSS crops and expected weekly servings.
C . C rop Y ields and G rowing A rea
Once a preliminary weekly menu was set, the mass of each crop was determined. The needed growing area of each
crop depends on the yield as well as the frequency of the yields of each crop. Two methods were used to calculate
yields. For all of the vegetables,
Support Baseline Values and Assumptions Document (BVAD) 3 with a format of edible biomass in g/m2-day. It should
be noted that broccoli and kale were not listed in the BVAD. Kale was assumed to have yields similar to lettuce and
broccoli similar to cabbage. The second method used for establishing yields took yearly mass yields per individual fruit
plant and divided these values by the number of days in a year, obtaining edible growth on a per day basis per crop.
These yields on a per day basis can be seen in Table 4.
These annual fruit yields come from a variety of sources and are referenced accordingly. It is noted that fruit yields
depend on plant spacing, lighting, temperature, humidity, maturity, CO 2 concentration, soil, plant size, seasonal chilling,
and a plethora of other factors. It is for this reason that all yearly yields of the fruit crops were taken at the low end of
the spectrum. Within a space habitat, volume and mass are in high demand, therefore the chosen trees uses dwarf
species of citrus, cherry, and banana. Each fruit tree is assumed to take up approximately one square meter and have a
soil depth of about 0.6 meters9. The soil depth volume per tree includes the waste management system embedded within
the soil.
While yield models with a gram per day basis allow for convenient calculations, these methods do not correspond
to the availability of the crop at any given time. Both vegetable and fruit yields ripen intermittently and must be
harvested, processed, and stored accordingly. Vegetables with short grow times (e.g. lettuce, radishes) will be planted
on a continuous cycle. It can also be noted that both the cherries and grapes can be considered constant harvest plants in
that they produce fruit year round. Bananas and citrus plants have intermediate harvest periods throughout the year.
Harvesting unripe fruit and letting the fruit ripen at different rates can elongate these harvest periods. It is also critical to
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 5 of 16
have different storage and preservation methods. Many vegetables
and fruits are amenable to dehydration, a simple method of
preservation available with existing ISS kitchen equipment. Table 3
tabulates the predicted inedible biomass generated, this biomass can
either be thought of as a waste stream or it can be incorporated in other
bioregenerative processes for recycling and additional yields including
methane.
T able 4. V egetable and fruit growing areas and
biomass yields.
D. C rop A tmospheric & W ater Usage and Production
Once the approximate growth area for each crop is determined, it
is possible to analyze the atmospheric yields and needs, as well as the
water requirements for each plant. During photosynthesis, plants take
in CO2 and produce O2, which will relieve stress on the ECLSS CO2
scrubbing system. However, plants use water during photosynthesis,
and additionally, lose substantial water through transpiration as part of
normal nutrient transport. These processes both contribute to a large
water requirement per plant, and transpiration increases the humidity
of the space habitat. A breakdown of the O2 production, CO2 uptake,
and water requirements can be found in Appendix A. It is assumed that
the transpired water will be collected, condensed, stored and recycled.
One percent of the required water is assumed to leak or be
incorporated into biomass in an unrecoverable manner.
The benefits of a BLSS are accompanied by unique considerations
which must be borne in mind throughout the design and operation
protocols. One such concern is the susceptibility of living systems to
disease and pests. Horticulture demands for optimal and consistent
plant growth are complex and subject to a number of interacting
variables here on Earth. Adding another variable of partial gravity can make the system even more unpredictable and
tenuous. A non-critical supplementary BLSS for a Mars habitat will increase the TRL values for bioregenerative
technologies while providing physiological and psychological benefits to the crew and increasing system redundancy.
E. A rchitecture T rade Study
Three different architectures were compared to determine which would best suit the goals of BLSS. The first
architecture was suggested as a modular, adaptable, efficient approach. Plant production could be maximized in this
approach since ergonomics would take a low priority compared with plant production architecture. Ultimately this
architecture was ruled out because it would reduce crew interaction with plants and the psychological benefits of such
interactions. Additionally, the modularity in this case actually increases design complexity through atmospheric
regulation, habitat interfacing, and other design consideration.
The second architecture increases human-plant interaction by bringing the plants into the habitat, housed in a
centralized structure. The plants are stored on a shelving system and tended as necessary by the crew. While human
operators would have direct access to go into and work in the plant production chamber, the chamber would only be
optimized for plant production. This option provides the best compromise between human-plant interactions and plant
growth capabilities. However, functionally, it is quite similar to the first architecture in that the plants are integrated to
the habitat only inasmuch as they are under the same roof. It minimally addresses the functional objective of providing
psychological benefits through plant interactions.
Architecture 3, maximizes human-plant interaction by distributing the plants throughout the habitat, incorporating
them in common living spaces. This option reaps the most psychological benefits and provides the most convenient
plant maintenance/inspection access for the crew. Distributing plants throughout the habitat will help the crew quarters
more closely resemble a traditional earth dwelling, easing the stress of an ICE. With this implementation, plant
interactions can become an everyday frequent interaction to increase its benefits rather than a formally scheduled chore.
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 6 of 16
Since only fruit and vegetable bearing plants with high nutrient density were selected to be grown, lower production
capability of this architecture was not seen as a major detriment.
Subsequent to nutrient density, plant
selection is based primarily on palatability,
variety, and shelf life. Plants will be
distributed throughout the living space to
provide a variety of plant interaction sites.
Plants will be included in key habitat areas
including meeting/office, recreational,
exercise and dining areas. 'Interaction' need
not be limited to plant maintenance or
harvesting; ubiquitously distributed yet
unobtrusive plant presence is intended to
cultivate a level of comfort within the
habitat simulating a common earth-based
setting. Psychological benefits are expected
not only from direct plant interaction
through maintenance tasks but also
viewing
and smelling the plants on
F igure 1. A rchitecture representation and trade study.
frequent,
unplanned
occasionsfor
example, walking from one area to another, and during relaxation or recreational activities.
The results from these two trade studies identified the following design foundations:
1) Adequate food production requires crop selections of approximately 20 fruit trees, 9 leafy greens, 4 root
vegetables, and 2 fruit plants.
2) To provide maximum psychological and life support capabilities, plants should be integrated with the
habitat, not grown in a separate chamber.
I V.
B LSS Detailed Design Concept
The proposed BLSS concept is composed of three components: 1) a Bio-Wick tree-based waste management
system 2) the potted plant garden system and 3) the biodigester. Each component serves a unique purpose, and together
work as an integrated system to deliver the maximum benefits of a BLSS.
A . Detailed Bio-W ick Design
The Bio-Wick system is adapted from an aerobic pumice wick. Invented by Tom Watson, the wick (aka Watson
Wick), utilizes symbiosis between microbes and woody plants to passively process and cleanse grey and black water
waste streams. A half-cylinder infiltrator creates an open air volume buried under a layer of pumice which itself is
buried under a layer of soil. This allows water and human wastes to surge into the system from an inlet, while
providing an open space for air to infiltrate throughout the pumice bed. The highly porous pumice provides housing for
aerobic and anaerobic bacteria to live in and process the incoming wastes, and acts as a medium through which air,
liquids, and particulates can percolate.
Once processed by the bacteria, nutrients and minerals can then be drawn up through the plant roots, providing
moisture and fertilizer to the vegetation. Plant roots will easily infiltrate the porous pumice bed, drawing water and
nutrients up from the pumice into the woody tissue of the plants. Plants will use 1-5 % of the water for metabolic
processes and growth, with up to 99% of purified water being returned to the atmosphere through transpiration. 10 The
water vapor resulting from transpiration can be captured in an enclosed atmosphere habitat by existing dehumidification systems.11
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 7 of 16
1. Waste Management
Many of the waste processing techniques
studied to date are of the enclosed bioreactor type,
requiring careful balances of input amounts and
12
concentrations with long retention times.
In
addition, black and grey water normally require
separate processing systems.
The Bio-Wick
eliminates these complications by processing both
waste-streams simultaneously. It has a short
retention time and can accept a wide variety of
waste sources and amounts without specialized
pretreatment.
An important aspect to consider for a BioWick system is its pass-through capacity per plant.
While there are currently a handful of Watson-Wicks in use on Earth today, the systems have no volume or size
constraints. Urine is primarily water, which will be readily taken up by the plant roots. To size for a space-based
system, detailed calculations were done to estimate the amount of fecal material generated per crew member and how
quickly it would be decomposed and taken up by the tree. From BVAD, the estimated amount of solid waste generated
by a crew of 4 per day is about 0.4 kg. An assumed rate of fecal decomposition was about 0.0016 kg/day-tree,13
therefore it would take about 435 days to decompose one day of crew-generated waste. Due to the duration of the
decomposition process, the Bio-Wick would need to store the 435 days of waste build-up which amounts to about 0.22
m3 of waste. The storage capacity of one infiltrator can hold up to 0.1 m3 of waste material. Therefore a minimum of
three trees would be needed to process all the generated solid waste at a rate that keeps the infiltrator from being
overloaded. Based on the crop selection, there would be at least seven trees in the habitat, easily satisfying the waste
management function requirement by a large margin.
F igure 2. Illustration of a Bio-Wick and its sizing.
2. Food Production
Currently, precapability to supply fresh foods is very
limited. Growing fresh foods can improve astronaut diet and health through better nutrition, increasing food
acceptability and variety, and by enhancing dining experience and crew mood. Previous space-based food growth
systems have not looked at incorporating perennial fruit bearing plants, i.e. trees, vines, and brambles, primarily due to
the volume and resources required to independently support these plants. This is despite their high desirability from
dietary and radiation countermeasure via antioxidant perspectives. Horticultural improvements that have miniaturized
fruit bearing trees and plants have now made it feasible to consider these plants for inclusion in a food production
system for space habitats. In addition, woody plants have the potential to bypass a serious concern with using human
waste for food production: the potential for pathogenic contamination. There is conflicting research concerning the
uptake of plant pathogens in some leafy greens 14 the claim that there is no correlation between the pathogens in contact
with plant roots and their presence in edible or foliar tissue, needs to be verified for this particular technology as part of
the technology development roadmap.
2. Water Recla mation, Air Revitalization, and Microbial Ecology
An average dwarf apple tree has a leaf surface area of 14 m2, and, in a humid environment, a transpiration rate of
15
2L/m2/day. Plants transpire more into drier air, and have been shown to increase transpiration by up to 200% at 37%
16
relative humidity and warm temperatures. A conservative estimate of 100% increased transpiration in a drier space
environment yields a transpiration rate of 4L/m2/day, equivalent to 56L of pure water vapor released into the
atmosphere by a dwarf apple tree alone for collection daily. The amount of transpired water for each plant was
estimated and documented in Appendix A.
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 8 of 16
B.
Plant G arden Subsystem
The vegetables and strawberries will be grown in the
potted plant garden system. The garden system is
composed of a rack that stacks 4-6 plants per level.
Different crop types will be placed on different tiers
where their size and horticultural need requirements are
comparable. The image in Figure 3 shows a research
rack currently in use at the University of Colorado which
would be similar to one used for this Mars-based plant
garden system. Robotic operations would be used to
maintain and sustain the system to reduce crew time
demand and also improve the efficiency for crop care.
Crew interaction with the plants is not limited or
hindered if such interaction is desired. For example, the
robotics would account for crew members that want to
water or harvest a plant from time to time.
F igure 3. Demo plant racks for M ars-based garden at the
University of Colorado.
The seeds would be brought from Earth and grown
using the robotic system when the habitat is fully
deployed on the Martian surface. As the vegetables and fruits mature, the robotic system would harvest the plants for
the astronauts to eat or store. Once the plants mature and pass their fruit bearing age, the robotic system would remove
them from their pots and dump the organic material into the biodigestor. The high cellulosic content of the plant
material would not process well through the Bio-Wick, but the leftover soil could be distributed directly to the BioWick. As captured in the crop selection analysis, the potted plant area required is 23 m2 to be distributed around the
habitat. The stacking ability of the racks greatly reduces the floor space required and saves space within the habitat.
F igure 4. Modified schematic of a
large scale biodigestor.
C . Biodigestor
Anaerobic waste reducing biodigesters are frequently used in developing
countries as a renewable energy resource because they are inexpensive,
easily maintained, and simple. Organic wastes, such as food scraps and fruit
peels, mixed with greywater are reduced by methanogenic and other bacteria
that do not require oxygen to reduce organics17. This technology acts similar
to the ruminant gastrointestinal tract and produces a biogas composed
primarily of methane and carbon dioxide, as well as a nutrient-rich effluent
from a wide range of organic inputs18. The biogas product can be used for
cooking, heating, or for methane extraction, and the effluent provides
nutrients, reinvigorating the substrate in which plants are grown. Figure 4
shows a schematic of how a large scale biodigester would function.
One advantage of the BLSS is a low maintenance requirement. Plants do not need parts replacements or consumables
as current water recovery systems do.19 Having the plants in the same habitat as humans makes use of energy intensive
systems such as pressurization, lighting, and temperature control, which are already present in the crew quarters. As
described above, integration with the habitat also provides psychological benefits through human-plant interactions.
Astronauts have reported that caring for plants is an enjoyable activity studies have shown plant interaction has stress
relieving and performance enhancing effects on humans. Plants also provide an important link to Earth, preserving the
sensory enrichment of nature in contrast to the stark and sterile machine environment typical of space habitats.
V.
M ars H abitat and Integrated System Design
To ensure design feasibility and understand the logistics and operational demands of a BLSS, a full mission
architecture and concept of operations were created and applied to a human-focused Mars mission. Table 5 lists the key
mission constraints and requirements that were to be met. Although the minimum timeline is for a 2 year mission, the
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 9 of 16
T able 5. Comparison of mission constraints achieved.
expectation is that the BLSS will support a
continuous Mars program where multiple
crew rotations will occur and the surface
habitat will be fully staffed at all times
with four crew members. The benefits of
bioregenerative systems are better
leveraged during much longer duration
operations.
A . H abitat Design
A habitat design for an initial Mars crew of four was established. Several possible habitat designs were considered,
but the most space and volume efficient was a dome-shaped structure. With the highly limited mass-to-surface
constraints of the Space Launch System (SLS), a hybrid structure was designed with an outer skin made from inflatable
tight Nomex® weave material and interior structure and support derived from a mix of carbon fiber struts and bamboo.
To maximize volume usage, the dome was split into two levels, and a third basement level was added to provide a
radiation shelter and increase total habitable volume. Recommendations for total pressurized volume requirement per
crew member are estimated to be about 100m3 for long duration missions. 20 To achieve that required volume, the
diameter of the dome habitat was calculated to be 10 meters. Total pressurized volume for this habitat design amounted
to 442 m3 allowing for ample space per crew member. Several design elements were taken into account for the habitat
layout and integration of the plants throughout the habitat. Figure 5 depicts the dome habitat spacing and layout while
Figure 6 shows the floor plan for each level. The detailed floor plan analysis used a database of items expected for a
long duration space habitat (example list in Appendix A) including items like an oven, kitchen sink etc.
The basement of the habitat is buried under
Mars regolith making it the most radiation
protected area in the habitat. This is where the
crew will sleep, and where bulk food will be
stored to preserve nutrient value during storage.
In addition, the basement will act as a radiation
safe haven. Since the astronauts will spend a
significant portion of each day sleeping,
locating the sleep quarters in the basement
provides a long interval of increased radiation
protection. The functions of radiation safe
haven and bulk food storage are accessed less
frequently than many other functional zones,
F igure 5. Side view of M ars surface habitat.
and will not be obtrusive to day-to-day life.
Each crew member will have their own
private sleeping quarters. This is important to crew physical and psychological wellbeing and also permits staggered
sleep schedules as needed. Beds will be elevated to provide under-bed storage for personal items and clothing. Each
room will have one electrical outlet and light. Reasonable sound proofing between bedroom walls and living quarters is
The main floor of the habitat employs an open-floor concept to maximize functional space while stacking the
functionalities of each area. In addition, an open floor plan can help make the habitat feel bigger because it creates a
visual illusion of looking across longer distances. This effect would not be possible if each area was walled-in
separately. The atrium area acts as a vaulted ceiling, creating the feeling of an expansive vertical space and also allows
volume for the fruit trees to grow into vertically. The large volume feel is an important aspect of the habitat design
because it helps to minimize the feeling of being in a small confined space, contributing to the psychological wellbeing
of the astronauts.
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 10 of 16
All of the Zone-1 (high usage) functional areas that are utilized
multiple times a day are co-located on the main floor as well as the
Zone-2 (moderate usage) functional areas with the exception of the
sleep quarters that are utilized a few times a day. These Zone-1 and
Zone-2 functional areas include the kitchen, plant processing, plant
production, recreation/lounge, exercise, laboratory, office area and
lavatory. The spiral stairs are located above and below each other to
conserve floor space.
The top floor of the habitat houses items and processes that would
need to be used and accessed the least frequently. Locating these on
the top floor ensures that the astronauts will be spending the least
amount of their time on this floor, the floor most exposed to
radiation. The ECLSS equipment, general storage and utility
equipment such as a hot water heating unit, washer, and dryer are
located on the top floor. The shower is placed on the second floor so
the grey water produced can be gravity fed to the toilet. The crew
preference space is an open undedicated area that may be used for
different functions at different times by the crew as needed.
Each subsystem required for all surface and habitat operations
were considered and preliminary concept designs were established to
determine the masses required for a full architecture.
1.
Power Subsystem
A photovoltaic system was considered due to the long insolated
duration when at the equator of Mars but when considering the
variability of the Martian environment a nuclear power plant
provides greater stability. From previously designed Mars habitats
we approximate our power requirement to be 155 kWe (kilowatts
electrical) needed per day and 75 kWe during the night 17. To
provide margin and room for expansion an SP-100 nuclear power
system coupled with 6 Sterling Engines will be implemented and
will provide approximately 300 kWe17. The engines will arrive preconnected but will require deployment by crew or robotic
construction equipment.
2.
Thermal Subsystem
Thermal protection for the habitat will use a light weight fluid
pump with Teflon coated radiators. Additionally, temperature
ranges on Mars at the equator are expected to be about 20°C at noon
during the summer with a nighttime minimum of about -60°C18.
With low temperatures and a large differential between night and
day, the electrical and mechanical devices will need sufficient
radiators to stay within their operable temperature range. To offset
the swing for any sensitive devices a Peltier energy harvesting buffer
will be implemented to store the energy produced by this large
temperature differential.
F igure 6. L ayout design for each floor.
NASA RAS C-AL 2013
3.
Communication Subsystem
The communication subsystem consists of one orbiting Mars
communication satellite and the transit vehicle the crew would live
on headed to Mars. The transit vehicle would stay in orbit around
University of Colorado and Colorado State University
Page 11 of 16
Mars as the crew worked on the surface. The transit vehicle would already have all the required communication
hardware embedded on the vehicle. The Mars habitat would be able to communicate directly to the transit vehicle
and/or the communication satellite, thus providing a redundant capability for communications to Earth.
V I.
Concept of O perations and Integrated System Design
To ensure design feasibility and to understand the logistics and operational demands of a BLSS, a full mission
architecture and concept of operations was created and applied to a human-focused Mars mission. Table 6 lists the key
T able 6. Comparison of mission constraints achieved.
mission constraints and requirements that
are to be met.
Utilizing existing
propulsion
technologies,
specifically
rockets using cryogenic propellants, for
transportation to and from Mars, an ISP of
450s was referenced for delta-V
calculations. A pictorial view of the
Concept of Operations (Con-Ops) can be
found in 8. It should be noted that the projected Con-Ops does not satisfy the 2 Year Maximum Crew mission. A
surface stay of 533 days (1.46) years was selected in order to obtain a optimum trajectory with a minimum transit time,
limiting crew transit radiation exposure, as well as expected delta-V burns21. Additionally the assumption was made that
the Mars base will be a continuous program where multiple crew rotations will occur and the surface habitat will be
fully staffed at all times with four crew members. The benefits of bioregenerative systems are better leveraged for
much longer duration operations.
The first phase in the Con-Ops is robotics mission. This first mission will be launched utilizing one SLS, launched on
2/17/2031. The payload will consist of a communications satellite, excavation robotics, a nuclear power system and a
thermal system consisting of silverTeflon coated flow through radiators.
The excavation robotics shall deploy
the thermal and power system and dig
the foundation for the Mars Habitat as
well as a hole containing the nuclear
power system located 1 km away from
the habitat. The robotics mission has a
flight time of 211 days and shall have
the power and thermal system
operational by the second launch date
of 4/15/2033. The second phase will
incorporate a coordinated launch of 5
SLS Launches that will carry the Mars
Habitat, Crew Transfer Vehicle (CTV),
Ascent/Descent Vehicles, BLSS, and
the Crew into low Earth orbit (LEO).
Once in LEO all launched components
shall be integrated via docking
maneuvers to form the mother ship.
F igure 7. M ars M ission C O N O PS.
During this phase the Mars Habitat will
be inflated and used as additional pressurized volume. It should be noted that the crew shall be launched with the
Ascent/Descent Vehicles and have the option to abort in case of emergency. A more detailed mother ship configuration
and SLS component and mass break down can be found in Appendix B. It should also be noted that CTV has
capabilities for both the transfer to and from Mars with a 20 percent buffer.
Phase 3 Consist of the first Burn that transfers the CTV and Mars Habitat from LEO into the transfer orbit. The crew
shall then spend the following 198 days in transfer inhabiting both the CVT and the Mars habitat with a total of 200 m 3
of pressurized volume per crew member, twice that of the ISS. The crew shall utilize the 4.3 m 3 of soil as well as 3.47
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 12 of 16
m3 of stored water for radiation protection, by created sleeping quarters as well as a radiation bunker underneath the
plants surrounded by the water tanks. Phase 4 consists of the second burn placing the CTV and Mars Habitat into low
Martian orbit (LMO). In Phase 5 the crew moves to the CTV and the Mars habitat is collapsed and readied for descent.
In Phase 6 the Mars Habitat descends to the Landing zone using retro rockets, thermal shielding, and a parachute similar
to the reference mission found in the Human Spaceflight Mission Architecture and Design text. The habitat will land in
the pre-dug foundation and then inflate, while the robotic team will connect the power and thermal system to the Mars
Habitat. During Phase 6, the crew will remain in LMO and await confirmation that the habitat has successfully inflated
with both power and thermal systems successfully integrated. If there are any unforeseen failures with the Mars Habitat
the CTV has the capability of performing a burn and returning home during the optimal transfer window.
In Phase 7 the crew descends to the Mars Habit in the Mars Ascent/Descent vehicle (MA/DV). In Phase 8 the crew
performs its 533 day ground stay, exploring and performing experiments while reaping the benefits of the BLSS and
Mars habitat. BLSS provides antioxidants through fresh fruits and vegetables, and the submerged bottom floor of the
Mars habitat provides additional protection both of which help combat radiation during the crew mission. During Phase
8 the CTV orbits in LMO and acts as a communication satellite. It should be noted that for Phases 5 through 9 the
architecture uses both the original communication satellite and the CTV to help communicate and coordinate landings.
In Phase 9 the crew ascends and docks to the CTV in the MA/DV. In Phase 10 the third burn is preformed and CTV
with crew is transferred from LMO to the transfer orbit. During the return flight the crew lacks the benefits of the
additional Mars Habitat but the CTV still has appreciable pressurized volume. During Phase 11 the crew makes its final
decent in the Earth Descent Vehicle. I
small burns to perform a slow aero capture maneuver, eventually placing the CTV in LEO. In Phase 13 the CTV awaits
resupply from earth for future mars missions.
The above architecture can further benefit if the Mars base is considered to continually operated with a crew rotation
and resupply. It should be noted that the focus of this paper is the advanced topic of BLSS. The above Con-Ops are a
top-level architecture showing th
using RASC-AL guidelines.
V I I.
T echnology Development
Technologies that utilize living systems require long cycle times for testing of robustness and reliability. Therefore, it
is critical to start developing these technologies as early as possible since there are many aspects of biological systems
that are not well understood. The Bio-Wick system can play a key role in advancing long duration mission capabilities
as a
TA06 Human Health Life Support and Habitation Systems and TA07 Human Exploration Destination Systems. It also
directly supports and links to the following Grand Challenges: Economical Space Access, Space Health and Medicine,
Space Colonization. This section analyzes the benefits of having a BLSS for a long duration Mars mission based on
mass savings and illustrates the steps required for maturing the technology to the appropriate TRL with the anticipated
costs.
T able 7. M ass comparison between three habitat concepts.
MARS$SURFACE$MASS$(no$transit$mass$or$communication$satellites)
BASIC$MASS$(includes$
hygiene$water)
ADVANCED$NP/C
Hybrid$Advanced$P/C$
and$BLSS
Mass$(kg):
Power$(W) Mass$(kg):
Power$(W)
Mass$(kg): Power$(W)
Totals: $$$$$$$$$$$$$$$$$$$$145,020$ $$$$$$$$$29,653$ $$$$$$$$$$30,874$ $$$$$$$$$$$$$$$$$$30,818$ $$$$$$$$$$37,400$ $$$$$$$$$$48,044$
Consumables
Habitat.Structure
Power.System.[BVAD.Table.3.2.9]
Thermal.System.[BVAD.Table.3.2.9]
Comm.System
ECLSS.(BLSS.embedded)
Crew.Accommodations.
(include.crew.and.EVA)
Robotics.(preHmissions,.rovers)
Payloads.(tools,.other.experiments).
[HSMAD.p998]
Airlock.(includes.2)
NASA RAS C-AL 2013
!!!!!!!!!!!!!!!!!!!!!!!77,711!
!!!!!!!!!!!!!!!!!!!!!!!!!1,360!
!!!!!!!!!!!!!!!!!!!!!!!!!1,930!
!!!!!!!!!!!!!!!!!!!!!!!!!3,588!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!!!!!49,856!
!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!1,000!
!!!!!!!!!16,212!
!!!!!!!!!!!!5,157!
!!!!!!!!!!!!1,360!
!!!!!!!!!!!!2,006!
!!!!!!!!!!!!3,729!
!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!8,048!
!!!!!!!!!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!!1,000!
!!!!!!!!!!!!!!!!!!17,377!
!!!!!!!!!!!!!5,157!
!!!!!!!!!!!!!1,360!
!!!!!!!!!!!!!3,128!
!!!!!!!!!!!!!5,813!
!!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!11,168!
!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!1,000!
!!!!!!!!!!34,027!
!!!!!!!!!!!!!!!!!!!!!!!!!4,339! !!!!!!!!!11,441! !!!!!!!!!!!!4,339! !!!!!!!!!!!!!!!!!!11,441! !!!!!!!!!!!!!4,539! !!!!!!!!!!12,017!
!!!!!!!!!!!!!!!!!!!!!!!!!4,000! !!!!!!!!!!!1,000! !!!!!!!!!!!!4,000! !!!!!!!!!!!!!!!!!!!!1,000! !!!!!!!!!!!!!4,000! !!!!!!!!!!!!1,000!
!!!!!!!!!!!!!!!!!!!!!!!!!1,436! !!!!!!!!!!!!!!!!!!%!!! !!!!!!!!!!!!1,436! !!!!!!!!!!!!!!!!!!!!!!!!!!!%!!! !!!!!!!!!!!!!1,436! !!!!!!!!!!!!!!!!!!!%!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!800! !!!!!!!!!!!!!!!!!!%!!! !!!!!!!!!!!!!!!!800! !!!!!!!!!!!!!!!!!!!!!!!!!!!%!!! !!!!!!!!!!!!!!!!800! !!!!!!!!!!!!!!!!!!!%!!!
University of Colorado and Colorado State University
Page 13 of 16
A . T echnology E valuation
To compare how well this BLSS concept performs, a detailed mass analysis was done for three different possible
mission concepts. The first mission concept assumed the largest mass where everything was brought up for the crew
with no recycling. This is generally an unreasonable and improbable mission, but it provides a maximum value for
comparing not to exceed mass values. The second mission used the latest advanced physic-chemical (P/C) technologies
currently used on the ISS for maximizing consumable reuse. The last concept is the BLSS coupled with the advanced
P/C system. The mass estimate for the hybrid system assumes the ECLSS is the same as that of the advanced P/C
system, but with the addition of a BLSS. The expectation is that the BLSS would be an experimental system testing the
technology and performance, so it is not considered a critical system for life support. Table 7 shows the mass
comparisons between the three Mars habitat concepts.
Figure 8 shows a graphical representation of the
breakeven point considering only the edible food
Habitat!Mass!in!
generated from the BLSS overcoming the mass
LEO!
differences between a hybrid habitat and a
physiochemical habitat on both the surface and in
LEO. Burn and structure costs for resupply were
calculated based on the proposed mission architecture.
It should be noted that because both systems house
fully functional ECLSS this graph only compares the
produced edible biomass and does not take in to
account the additional benefits of a BLSS including
Habitat!Mass!on!
but not limited to CO2 scrubbing, O2 production, waste
Mars!
management, antioxidant production, psychological
benefits,
methane production, and water reclamation.
F igure 8. E dible mass resupply breakeven point.
B. T echnology M aturation Plan
The fully-integrated BLSS concept has not been built or tested before for spaceflight, but each of the components has
some prototype if not actual spaceflight precedent. The approach for developing a Technology Maturation Plan (TMP)
was to first identify each component of the system and determine its current TRL. Then a timeline was developed to
determine the steps involved in maturing each technology until the system is fully integrated and ready to fly. The
mission to Mars would be the first
T able 8. T echnology Readiness L evel for the different B LSS components.
experimental test of the BLSS in a longduration space mission. At the time of
flight, the system would be considered
TRL 7, where it is defined as a system
prototype demonstration in a space
environment. 22 if catastrophic failure of
BLSS all the systems are still usable.
The three components to the BLSS are
the Plant Garden System, the Biodigestor,
and the Bio-Wick. The most mature of
these technologies is the garden system as
plants have been grown in pots for
millennia 23 and are considered old
technology. But it is important to note the
robotic gardening component still needs
further design and development before it
can be considered ready for flight. Anaerobic biodigestors have been commercially implemented and utilized since the
1940s,24 but have never flown in space. Maturation of this technology would be required to account for the partial
gravity of Mars, but also if it is used in transit.
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 14 of 16
The Watson Wick system has only been around the past few decades and is not yet used at the industrial level. The
Bio-Wick uses the same concepts, but is less-developed for space flight applications. To improve the reliability and
robustness of these living systems, there must be a stringent test and validation protocol enforced, similar to any other
hardware system that needs to be flight rated. The figure below indicates the steps required to advance the Bio-Wick
system up the TRL scale. The cost for each of these processes were determined using analogy based estimating whereby
the required complexity of each step is assessed and paralleled to analogous technology maturation costs. 25
Implementing an integrated bioregenerative life support system will bring humanity one step closer to expanding their
presence in space.
F igure 9. T echnology development plan estimates.
V I I I.
E ducation and O utreach
The number of students in this nation interested in pursuing science, technology, engineering, or math (STEM)
degrees is in decline. Often, lack of exposure to possible ca
cited as a major reason for the waning interest. 26
gathering for Girls in Exploring STEM (GESTEM) careers workshop. The event was held on April 5th 2013 at the
Denver Convention Center. There were over 500 girls in attendance from the ages of 12 to 15 years old. The objective
of the event was to expose the girls to different types of engineering and science careers so they have a better idea of
what type of skills and work they might be interested in pursuing.
The BLSS team held an activity that challenged the girls to
create a robot for depositing seeds into a pot of soil located in the
middle of their table. The girls were provided with a bag of arts
and crafts supplies including things like dowels, plastic spoons,
rubber bands, and sheets of paper. As part of the design process,
they were asked to discuss and draw their ideas before building
anything. Then once they designed their robot, they moved on to
the construction phase. The girls came up with incredibly creative
designs and several succeeded in accomplishing the mission and
in some cases had additional capabilities to not just plant the
seed, but dig a hole and bury it. The important metric of the day
was their level of enjoyment and excitement at their
accomplishments. For the team, it was an unforgettable
experience to share this excitement for engineering.
F igure 10 . M iddle school girls testing out their
robotic planter.
I X.
Acknowledgements
The team would like to thank the following people for their work and dedication to helping with this project: Elise
Kolwaski for helping with the outreach program, Dr. David Klaus for his expertise and insight, and Joe Tanner for his
input regarding his experiences as an astronaut.
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 15 of 16
Wor ks Cited
1
Poynter, J. and Bearden, D. E. (1997). Biosphere 2: A closed bioregenerative life support system, an analog for long duration space
missions. In Goto et. al (Eds), Plant Production in Closed Ecosystems (pp. 263-277). Netherland: Kluwer Academic Publishers.
2
Barta, D. J. and Henninger, D. L. (1994). Regenerative Life Support Systems Why Do We Need Them? Adv. Space Res. Vol. 14,
(11) 403-410.
3
BVAD Advanced Life Support Baseline Values and Assumptions Document, Anthony J. Hanford, Ph.D., Editor Lockheed Martin
Space Operations Houston, Texas 77058
4
World Health Organization 2004- F ruits and Vegetables for Health. Workshop Report.
5
http://www.spaceref.com/iss/ops/SSP50481.nonrec.cargo.plan.pdf
6
Serio, M. A., Kroo, E. Bassilakis, R., Wojtowicz, M. A., and Suuberg, E. M. (2001). A Prototype Pyrolyzer for Solid Waste
Resource Recovery in Space. Society of Automotive Engineers, Inc.
7
National Research Council (1998).Report of the Workshop on Biology-based Technology to Enhance Human Well-being and
Function in Extended Space Exploration. Washington D. C.: National Academy Press.
8
US Dept. of Agriculture, National Nutrient Database for Standard Reference. http://ndb.nal.usda.gov/ndb/foods/
9
for a controlled
-CR Publication 166324.
10
http://www.srh.noaa.gov/jetstream/downloads/hydro2010.pdf
11
www.oasisdesign.net
12
Strayer, R.F., B.W. Finger, and M.P. Alazraki. 1997. Stability and reliability of biological reactors. SAE Technical Paper Series
972549.
13
Tare, V., and Yadav, K.D. (2009). Fate of Physico-Chemical Parameters During Decomposition of Human Feces. Global Journal
of Environmental Research. 3(1): 18-21, 2009. http://idosi.org/gjer/gjer3%281%2909/3.pdf
14
Kirsten A. Hirneisen, Manan Sharma, and Kalmia E. Kniel. Foodborne Pathogens and Disease. May 2012, 9(5): 396-405.
doi:10.1089/fpd.2011.1044.
15
http://research.eeescience.utoledo.edu/lees/papers_pdf/Dragoni_2005_AFM.pdf
16
http://naldc.nal.usda.gov/download/16240/PDF
17
Hounslow E. 2011- Designing the Ideal Compact Anaerobic Digester for Middle Class S ri Lanka Project Report, University of
Sheffield.
18
Weiland, Pete
-860.
19
http://www.scientificamerican.com/article.cfm?id=new-menu-item-on-space-st
20
Larson, Wiley J., and Linda K. Pranke. Human Spaceflight: Mission Analysis and Design. (HSMAD) New York: McGraw-Hill,
2000.
21
Vasile, M., Summerer, L., & De Pascale, P. (2005). Design of Earth Mars transfer trajectories using evolutionary-branching
technique. Acta Astronautica, 56(8), 705-720.
22
http://www.hq.nasa.gov/office/codeq/trl/trl.pdf
23
Aker, S. and Moramarco, D. (1995) House Plants. History of Houseplants. Maryland Institute for Agriculture and Natural
Resources. . http://www.gardening.cornell.edu/education/mgprogram/mgmanual/15houseplants.pdf
24
Abbasi,T.,
Springer Briefs in Environmental Science, Vol. 2.
25
Wertz, J.R., Wiley, J.L., Space Mission Analysis and Design. Space Technology Libray: Microcosm Press. 3rd Edition, 2007.
16
http://www.asla.org/2009studentawards/462.html.
26
National Science Board. (2010). Preparing the Next Generation of Stem Innovators: Identifying and Developing our Nation's
Human Capital. Arlington, VA: National Science Foundation.
NASA RAS C-AL 2013
University of Colorado and Colorado State University
Page 16 of 16
Appendix A
Crew Menu
Crop Yields and Growth Area
System Mass Overview
Crew Nutrient Break Down
Crew Nutrient Break Down Cont.
Crew Nutrient Break Down Cont.
Crew Nutrient Break Down Cont.
Crew Nutrient Break Down Cont.
Crew Nutrient Break Down Cont.
Crew Nutrient Break Down Cont.
!""#$%&'()(
(
!"#$%&'(')*+,&%'-,".'/%&01'2*34'
(
(
!"#$%&'5'-6-'60$47,'/%&01'2*34'
(
(
!"#$%&'()*+,-+'.#/(0#"1(((((((((((((((((((((((((((((((((((((((
(
!"#$%&'()%*+,(------------------------------------------------------------------------------(
(
.*&/0'1(23456#",(----------------------------------------------------------------------------(
!
!
!
"#$%&$'(!#"!&)%(#"#$%&$'(!*+,-+./0!
276'"*&'(8(9"5''%:(;%<#"'(=>?(<#5:'6@(
)#'*0-------------(
A"*0(;%<#"'(8(!"%6%:'*'5#:(=B?(<#5:'6@(
)#'*0-------------(
CD!A(*:3(!*"'5&5<*'#"1(CE<0#"*'5#:(=F(<#5:'6@(
)#'*0-------------(
.#"/+(!*"'5&5<*'5#:(G"5'%"5*(=F(<#5:'6@( (
)#'*0-------------(
(
(
(
276'"*&'(8(9"5''%:(G"5'%"5*(
G#+<05*:&%(*:3(&#+<"%J%:654%('"%*'+%:'(#K(L?MB(;2HGN2O(
)J%+%6(*:3("%6%*"&J(#7$%&'54%6(*6(6'*'%3(5:('J%(;2HGN2O(G*00(
="%K%"%:&%(G#+<05*:&%(P*'"5E@(
Q::#4*'54%R(/:5S/%(*:3D#"(61:%"T56'5&(*34*:&%3(&#:&%<'6(*:3(
*<<05&*'5#:('#(%:J*:&%('J%(%E<0#"*'5#:(+5665#:R(*"&J5'%&'/"%6R(
&*<*7505'5%6R(#"('%&J:#0#T5%6(
)%&J:5&*0D6&5%:'5K5&(%4*0/*'5#:(*:3("*'5#:*0(#K(+5665#:(&#:&%<'(
H16'%+6(2:*01656(#K("%S/5"%+%:'6R(5:&0/35:T(53%:'5K5&*'5#:(#K(
&J*00%:T%6(*:3(566/%6(5:&0/35:T()%&J:5&*0(;%*35:%66(O%4%0=6@(#K(
+5665#:N%:*705:T('%&J:#0#T5%6(
23%S/*'%01(*33"%66%3(J/+*:(J%*0'J(&"5'%"5*(=566/%6(*:3(
6#0/'5#:6@(
C453%:&%(#K(&"%3570%(*:3(5+<0%+%:'*70%(<"#$%&'(<0*:(
;%*056'5&(*66%66+%:'(#K(<"#$%&'(&#6'D6&J%3/0%(
A"*0(G"5'%"5*(
A"*0(<"%6%:'*'5#:(&#:656'%:&%(U5'J(9"5''%:(;%<#"'(
V/*05'1(#K(<"%6%:'*'5#:(=5:&0/35:T(6'10%@(
!"%6%:&%(#K('%*+U#"W(*:3(5:'%T"*'5#:(
V/*05'1(#K("%6<#:6%('#(S/%6'5#:6(
CD!A(*:3(!C(G"5'%"5*(
C3/&*'5#:(*:3(!/705&(A/'"%*&J(*&'545'5%6=CD!A@(8(!*"'5&5<*'#"1(
CE<0#"*'5#:(*&'545'5%6((=XNMLR(&*+</6R(&#++/:5'1R(</705&(
%:T*T%+%:'@(
.#"/+(!*"'5&5<*'5#:(
!*"'5&5<*'5#:R(*''%:3*:&%R(8(%:T*T%+%:'((*'(*00(.#"/+(*&'545'5%6(
=5:&0/35:T(!#6'%"(H%665#:@(
!#5:'(
H&*0%(
2&'/*0(
!#5:'6(
M?(
(
(
MF(
(
(
M?(
(
(
M?(
(
(
F(
(
(
F(
(
(
F(
!#5:'(
H&*0%(
F(
MF(
F(
F(
!#5:'(
H&*0%(
(
2&'/*0(
!#5:'6(
(
(
(
(
2&'/*0(
!#5:'6(
(
F(
(
!#5:'(
H&*0%(
2&'/*0(
!#5:'6(
F(
(
G#++%:'6DI#'%6(
G#++%:'6DI#'%6(
(
(
(
(
G#++%:'6DI#'%6(
(
G#++%:'6DI#'%6(
(
(
(
!
"#$%&''''''''''''''''''''''''''''''''''''''''''''''!!!!()*+,!-.)/&!'''''''''''''!