The meeting began by gathering at the laboratory of Dr. Sherman. The group was led on a tour of the facility while being given a brief description of the research being performed. It was pointed out that the Sherman laboratory is using biochemistry, physiology, and molecular biology approaches to the study of cyanobacteria. Much of the groups efforts is devoted to the understanding of the regulation of the diurnal rhythms observed in Cyanothece sp. strain ATCC 51142, and their relationship to photosynthesis, nitrogen fixation, and growth. The trainees also visited the controlled-environment chambers and were shown various cultures of cyanobacteria maintained by the laboratory.
The group then moved to a conference room for some opening statements by Dr. Schneegurt and general discussion. The presentation by Dr. Schneegurt began with a survey of the CELSS-related facilities being developed at various NASA sites, including the BPC, HRTF, and South Pole Station. There was then a brief overview of the Stella simulation model under development at the NSCORT. Finally, there was a discussion of the ways in which the trainee meetings could be used to advance the efforts underway at NASA by focusing the group's multi-disciplinary expertise on unsolved problems of CELSS integration and simulation. Dr. Schneegurt gave several examples of problems which may be addressed including issues involved in sustainability and robustness, overall system design emphasizing issues of integration, and the unavailability of certain critical CELSS subsystem data.
There was a substantial amount of interest in some of the problems surveyed. And given more time on any particular issue, it was clear that significant discussions would ensue, with the possibility of identifying creative solutions. It was agreed that we would continue our general discussions at the next meeting, keeping the agenda unstructured at this time. The next trainee meeting will be held Monday, January 23, at 3:30 in the Hansen Life Sciences Building.
The trainees gathered in Hansen's conference room. There was a brief recap of last meeting's discussions. The floor was then left open for comments by the group. There were no fast-breaking stories from the labs to discuss. Eventually, there was some discussion of mission architectures. The basic question was whether during a mission to Mars the "CELSS-module" would be landed on the surface. It was pointed out that the engineering design of the vessel would need to be useful both with and without gravity. This imposes some design challenges. The vessel would also have to be sturdy enough for a landing and ascent. Then there is the problem of fuel. Landing and launching the CELSS may require more fuel than leaving the CELSS in orbit and then taking a shuttle craft to the surface for expeditions. There was also discussion about the use of CELSS for food production during transit. It was concluded that for a 3 year mission to Mars, with 9 month transits, it seems logical that CELSS technology should be used in transit, since this represents more than half of the mission. It was recognized that this greatly increases the size of the transit vehicle.
The discussion changed direction and some questions were raised about the South Pole CELSS project run out of NASA Ames. This led to some discussion of Biosphere II and the future of that facility. Peter Eckart's book on CELSS was passed around and the group was made aware of other resources and datasources on CELSS systems. During refreshments, there was some discussion about the subject of future meetings. The group seems to have some difficulty in seeing a clear path for future efforts. There are some who prefer a unstructured, almost "club-like" meetings. Others would prefer a more goal-oriented structured work group setting. These issues were not resolved and no agenda was set for the next meeting. Since the NSCORT will have a seminar this Monday no trainee meeting was planned for the week of January 30.
Although announcements were not sent out in advance of the trainee meeting, several interested trainees gathered at the Hansen Labs. One of the trainees had just been exploring the NSCORT HTTP site and there was a discussion about the NSCORT Web site and the protocol for access. It was suggested that the trainees explore the site on their own and give particular attention to documents that relate directly to their laboratories. A call for contributions to the site was made, and it was suggested that graphics or other technical information be supplied to the site curator for inclusion in the next update of the site.
The group then began the task of brainstorming ideas to be used as topics for future discussions. Several areas were identified, including the following: diet design and optimization, menu (meal) design, storage & packaging of foodstuffs (short-term), food quality assurance and testing, candidate crop selection, crop rotation (size, safety factors, redundancy), uses for glucose, medical issues, waste processors (and back-ups), waste reuse inventions, water recycling, gas exchange, and the broader issues of mass losses, failure modes (at subsystem level), sustainability, robustness, size/weight, and crew composition and psychology. It was decided that the order in which these issues will be discussed does not need to be defined now. The area of diets and menus was chosen as the first subject area for discussion, in part due to the composition of the group, but also since dietary needs are a strong driving force in overall CELSS design. It was suggested that the group bring data packages to the next meeting. In order to optimize a diet, it will necessary to define the dietary parameters and requirements of a crewmember and define "cost" factors for fulfilling these requirements with specific CELSS candidate crops. Cost factors may include values for productivity in terms of area, energy, volume and/or labor, and storage costs. The palatability of the proposed diets will also be considered. After some initial decisions, and with the compositional and nutritional data collected, it will be possible to compare various diets using the What's Best linear optimization program. It should be possible to set up a conference room with a PC and actually run the optimizations with the whole group at a future meeting.
It was further agreed that in order to avoid confusion about the scheduling of trainee meetings in the future, it should be assumed that there will be a trainee meeting on Mondays at 3:30 unless there is an NSCORT seminar or a University holiday. The next trainee meeting has been called for February 13, 1995 at 3:30 in the Hansen 3rd floor conference room.
As the result of the previous meeting, several interesting aspects were identified as potential subjects for future discussions. It was decided that the group would begin with a discussion of diets and menus. This discussion was led off by dividing the process of diet optimization into three categories: targets (human nutritional needs), composition of foodstuffs (or edible biomass), and costs (energy, weight, etc.). In order to design diets and get a quantitative measure of real costs for comparison, it will be necessary to first define the parameters which will be modeled in each of these categories. The initial discussion was on the nutritional needs of a human. What nutritional needs are important enough to be included in the diet model? The group first made a list of possible candidates, including: water, protein, essential amino acids, essential fatty acids, calories, vitamins, minerals, total fat intake, fiber, and antinutrients. We then began to discuss the relative merits of each of these for inclusion in the simulation. There was also some discussion about where we might locate literature values for these nutritional needs. For most dietary parameters it was suggested that RDA or FAO/WHO values are easily accessible. But, it was pointed out that human nutritional needs in microgravity may be somewhat different than RDA values.
No decisions were made as to the source(s) of data that may be appropriate, but the trainees associated with food or nutrition projects would be the best judges of the available data. These trainees were asked to begin the process of pulling together human nutritional requirements and compositional information about as many CELSS candidate crops as possible. The goal is to compile a database of this type of information for use with a linear optimization program. The What's Best program, first used at the Purdue NSCORT by the Nelson laboratory, is a spreadsheet-based linear optimization application for PC platforms. It would be desirable to amass the relevant data in such a spreadsheet for use in planning and comparing diets. An annotated database would also be a good source of information for other NSCORT and CELSS researchers. It was agreed that we would continue these discussion for the next several meetings, hopefully leading to an interactive demonstration of the database within the What's Best program. This would be an opportunity for the group to test various optimization strategies, to test the logic of the factors chosen for the model, and to compare and contrast various diets in a quantitative fashion. The next meeting of the trainees will be Monday, February 20, 1995, at 3:30 in Hansen.
The group continued its discussion of diet design and optimization. Drs. Park and Schneegurt had met earlier in the week to explore the What's Best linear optimization program. It was decided that the most efficient course of action centers around compiling compositional and nutritional information into the spread-sheet-based application. It was decided that this was best done by the food scientists and nutritionists themselves. There was a brief discussion about a trainee "special subgroup" to accomplish this task outside of the regular trainee meetings, and it was agreed that the trainee subgroup meetings will take place over the next few weeks.
Discussion then turned to the concept of costs. The food scientists and nutritionists should be able to gather the necessary compositional and human nutrition data, but the diet compositions will be optimized with the goal of minimizing costs, such as crop growth area and volume, growth chamber energy usage, waste processing energy, and manual labor. The best measure of costs would include all of these considerations, however, it is difficult to equate costs as disparate as electrical energy and crew labor. It was agreed that at the very least, energy costs for each crop should be fairly easy to estimate and would be a good parameter to use for optimization. It was suggested that the group continue to think about this problem, with the hope of an insight which would lead to a composite cost factor.
No trainee meeting will be held on Monday, February 27 due to the NSCORT seminar. The trainees will meet informally with the seminar speaker Peter Eckart for pizza in Watson's Crick (Lilly Hall) from 5-7 on the 27th. The trainees will also be invited to attend a reception for the speaker at the home of Dr. Sherman. It is likely that the next regular trainee meeting will be on Monday, March 6, 1995, at 3:30 in Hansen 326A.
On a glorious Spring day the trainees gathered out-of-doors for their discussions. Bonnie McClain, the NSCORT Outreach Administrator, opened the meeting. She presented some information about a fellowship program, a bit about the BLAST organizational meeting, and about an upcoming K-12 outreach gathering. The group went on to continue their discussions of CELSS diets and their costs. First there was an update on the progress of the What's Best diet simulation. Then a general discussion about costs and how to model these mathematically. It seemed that energy and area/volume costs were the easiest to describe, while labor and other costs were less tangible. The group then started to discuss plant growth chamber design. What is the most area/volume-efficient way to grow plants hydroponically? What is the best plan for maximizing growth area while minimizing access area (within reasonable limits)? The best design seemed to one in which the plants were grown in trays on either side of an accessway. The trays would be able to slide back and forth, thus creating accessways between the trays. In this way the trays could be any depth while maintaining good accessibility. The group decided to meet again on Monday, March 20, at 3:30 in Hansen 326A
This was an abbreviated meeting. The progress of the What's Best simulation was discussed. There was also some discussion of the NSCORT HTTP site and its renovation. Basically, the group is progressing but has not yet reached the next plateau for discussion. It was decided that there would not be a trainee meeting the week of March 27.
The group discussed the progress of the What's Best modeling effort. A meeting of the subgroup of trainees involved in that work was set up. Then followed an active discussion about the Hodges' Lab project on lignin reduction. Suggestions were made about how to follow and measure lignin in the transformants. There was also some discussion about what the consequences of lowered lignin content may have on plant morphology and vigor.
Finally, the group was made away of some recent CELSS-related literature, and told of Dr. Goldin's testimony before a Congressional Appropriations committee. The group was to meet on April 10, but that meeting will be pre-empted by an NSCORT seminar.