Search Results

The following abstract is that provided to first year undergraduate students as part of the recruitment effort for 1st Year Seminar Courses at the University of Guelph. When humankind begins the colonization of the moon or Mars, we will be bringing along more of Earth than one might think. A number of space and government agencies around the world, including researchers at the Controlled Environment Systems Research Facility, University of Guelph, are involved in the design and engineering of self-contained ecosystems based on Earthly biological processes. These processes can be harnessed, with complementary physical and chemical technologies to support human life (food production, air revitalization, psychology) in the hostile conditions of space.

For a planetary base, a reliable life support system including food and water supply, gas generation and waste management is a condition sine qua non. While for a short-term period the life support system may be an open loop, i.e. water, gases and food provided from the Earth, for long-term missions the system has to become more and more regenerative. Advanced life support systems with biological regenerative processes have been studied for many years and the processes within the different compartments are rather complete and known to a certain extent. The knowledge of the associated interfaces, the management of the input and output phases: liquid, solid, gas, between compartments, has been limited. Nowadays, it is well accepted that the management of these phases induces generic problems like capture, separation, transfer, mixing, and buffering. A first ESA study on these subjects started mid 2003.

The process of integrating a Higher Plant Chamber (HPC) in the MELiSSA Pilot Plant demands reliable data on crop photosynthetic responses to varying light intensity. Such data allow for the development of dynamic photosynthetic models which, in turn, are used in the control of the HPC. A number of full canopy research trials have been conducted using sealed environment chambers with beet (Beta vulgaris cv. Detroit Medium Red) and lettuce (Lactuca sativa L. cv. Grand Rapids) as candidate crops. In this study, data were collected at the full canopy scale using a differential-compensating CO2 analysis system and at the leaf scale using a LI-6400 leaf gas exchange system in an attempt to derive parameter estimates for a leaf and canopy photosynthesis model. Results indicate that a rectangular hyperbola model was suitable in defining the leaf and the linear phase of full canopy Net Carbon Exchange Rate (NCER) response to light.

Mars is likely the best candidate for future planetary exploration however the Martian atmosphere is at a pressure of ~0.6 kPa. This extremely low pressure demands that plant growth structures be isolated from the ambient environment. While it is clear that it is desirable to predict the contributions that plants will make to bioregenerative life support systems at reduced atmospheric pressures, research has been limited. This study examines carbon exchange and evapotranspiration in order to establish a baseline that will aid in the development of an atmospheric composition that allows for reduced pressure plant growth without compromising the plant production yields required for human life support.

The concept for Tomatosphere originated in late 1999 and the project held its first formal meeting on February 7, 2000. The project was formally activated when 200,000 Heinz tomato seeds went into space on November 30, 2000, with Canadian astronaut, Dr. Marc Garneau. The seeds were part of an experiment designed to test the effects of short- term space travel on seed germination and interaction with new techniques designed to enhance germination rates. An equal number of seeds stayed behind on Earth and the two lots, space-flown and Earth-bound, were further sub-divided into two treatments using new Infra Red and Red light technology developed at the University of Guelph. The resulting four treatments were packaged and sent to almost 2700 classrooms across Canada, along with posters and a teacher's guide matched to the Pan-Canadian Protocol for Collaboration on School Curriculum, a framework of Science Learning Outcomes developed by the Council of Ministers of Education, Canada.

Future space exploration will require advanced life support (ALS) systems capable of in situ resource recycling. Hypobaric, bioregenerative life support systems have been proposed to address this requirement. The need to explore the limits of plant tolerance to hypobaric conditions is clear, however, research has been limited due to the difficulties and costs associated with this field. The Controlled Environment Systems Research Facility (CESRF), at the University of Guelph, Canada, has been designed to address the issues surrounding plant production under reduced pressure conditions. The measurement of plant physiological responses to hypobaric conditions is the subject of this study. Measurements of whole plant water relations, in terms of transpiration and plant water potential, are the ultimate goal.

Carbon monoxide is a major indoor contaminant responsible for over 1000 deaths a year in North America. Sealed environments such as buildings are particularly at risk for this contaminant. Studies in the 1970's and 80's determined that green plants are capable of fixing carbon monoxide through both the light and dark reactions of photosynthesis. Common bacteria oxidize carbon monoxide, utilizing the enzyme carbon monoxide dehydrogenase. Therefore, controlling carbon monoxide levels through botanical and microbial systems may have merit. Preliminary studies have indicated that moss based systems remove significant amounts of the contaminant from a recirculating air stream.

Initiated in March 1989, the MELISSA (Micro-Ecological Life Support Alternative) has been conceived as a micro-organisms and higher plants based ecosystem intended as a tool to gain understanding of the behaviour of artificial ecosystems, and for the development of the technology for a future biological life support system for long term manned space missions, e.g. a lunar base or a mission to Mars. The collaboration was established through a Memorandum of Understanding and is managed by ESA/ESTEC. It involves several independent organisations: IBP Orsay (F), University of Ghent (B), University of Clermont Ferrand (F), VITO Mol (B), ADERSA (F), University “Autonoma” of Barcelona (E), University of Guelph (CND). It is co-funded by ESA, the MELISSA partners, the Spanish (CIRIT and CICYT) and Canadian (CRESTech) authorities. The driving element of MELISSA is the recovering of edible biomass from waste (faeces, urea), carbon dioxide and minerals.

A number of curve fitting methods were evaluated for their applicability in modeling plant canopy photosynthetic dynamics. Non-Parametric and Non-Linear models were applied to long term dynamics in photosynthesis and response surfaces relating photosynthesis to crop age and light intensity. All models performed well, but computational details in the non-linear least squares algorithm made the simpler, non-parametric model forms more attractive. Applications of these modeling techniques are addressed in the context biomass production research and in the assessment of air revitalization capacity for bioregenerative life support. These techniques are especially useful in the modeling of crops exhibiting complicated growth profiles.