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Environmental control and life support systems are usually associated with high demands for performance robustness and cost efficiency. However, considering the complexity of such systems, determining the balance between those two design factors is nontrivial for even the simplest space missions. Redundant design is considered as a design optimization dilemma since it usually means higher system reliability as well as system cost. Two coupled fundamental questions need to be answered. First, to achieve certain level of system reliability, what is the corresponding system cost? Secondly, given a budget to improve system reliability, what is the most efficient design for component or subsystem redundancy? The proposed analysis will continue from previous work performed on series systems by expanding the scope of the analysis and testing parallel systems. Namely, the online and offline redundancy designs for a Lunar Outpost Mission are under consideration.

A reconfigurable control system is an intelligent control system that detects faults within the system and adjusts its performance automatically to avoid mission failure, save lives, and reduce system maintenance costs. The concept was first successfully demonstrated by NASA between December 1989 and March 1990 on the F-15 flight control system (SRFCS), where software was integrated into the aircraft's digital flight control system to compensate for component loss by reconfiguring the remaining control loop. This was later adopted in the Boeing X-33. Other applications include modular robotics, reconfigurable computing structure, and reconfigurable helicopters. The motivation of this work is to test such control system designs for future long term space missions, more explicitly, the automation of life support systems.

High costs and extreme risks prevent the life testing of NASA hardware. These unavoidable limitations prevent the determination of sound reliability bounds for NASA hardware; thus the true risk assumed in future missions is unclear. A simulation infrastructure for determining these risks is developed in a configurable format here. Positive preliminary results in preparation for validation testing are reported. A stochastic filter simulates non-deterministic output from the various unit processes. A maintenance and repair module has been implemented with several levels of complexity. Two life testing approaches have been proposed for use in future model validation.

BioSim is a simulation tool which captures many basic life support functions in an integrated simulation. Conventional analyses can not efficiently consider all possible life support system configurations. Heuristic approaches are a possible alternative. In an effort to demonstrate efficacy, a validating experiment was designed to compare the configurational optima discovered by heuristic approaches and an analytical approach. Thus far, it is clear that a genetic algorithm finds reasonable optima, although an improved fitness function is required. Further, despite a tight analytical fit to data, optimization produces disparate results which will require further validation.

Thermophilic aerobic digestion was investigated as a potential waste treatment technology for biodegradable wastes generated in a long-term closed eco-system. The overall objectives of this research were to contribute to a regenerable closed-loop system for food production and water, air and waste treatment, while also minimizing the mass, volume, power, cooling and crewtime needs of the overall system. Biological treatment becomes more feasible due to resupply constraints with longer mission scenarios. The primary objectives of this research included the evaluation of the system, including effects of influent solids loadings, hydraulic retention time, oxygen transfer, and the influence of operational parameters such as pH, ORP, and temperature. Investigation into the effect of mechanical changes in the system on oxygen transfer was evaluated.

The On-line Project Information System (OPIS) is a LAMP-based (Linux, Apache, MySQL, PHP) system being developed at NASA Ames Research Center to improve Agency information transfer and data availability, largely for improvement of system analysis and engineering. The tool will enable users to investigate NASA technology development efforts, connect with experts, and access technology development data. OPIS is currently being developed for NASA's Exploration Life Support (ELS) Project. Within OPIS, NASA ELS Managers assign projects to Principal Investigators (PI), track responsible individuals and institutions, and designate reporting assignments. Each PI populates a “Project Page” with a project overview, team member information, files, citations, and images. PI's may also delegate on-line report viewing and editing privileges to specific team members. Users can browse or search for project and member information.

The Advanced Life Support (ALS) Project has accelerated an effort to develop an On-line Project Information System (OPIS) for research and technology development (R&TD) data centralization and sharing. This paper presents the OPIS development strategy and status. OPIS is being built as an application framework consisting of an underlying Linux/Apache/MySQL/PHP (LAMP) stack and supporting class libraries, which provide database abstraction and automatic code generation. This approach simplifies the development and maintenance process. The approach also allows for quick adaptation to serve multiple Programs/Projects, although initial deployment is for an ALS module. Data will be located on a secure server at NASA Ames Research Center (ARC). Initial functionality of OPIS will involve a Web-based solicitation of project and technology data, directly from ALS Principal Investigators (PIs) through data collection forms.

Resource recovery, including that of urine water extraction, is one of the most crucial aspects of long-term life support in interplanetary space travel. This paper will consequently examine an innovative approach to processing raw, undiluted urine based on low-temperature freezing. This strategy is uniquely different from NASA's current emphasis on either ‘integrated’ (co-treatment of mixed urine, grey, and condensate waters) or ‘high-temperature’ (i.e., VCD [vapor compression distillation] or VPCAR [vapor phase catalytic ammonia removal]) processing strategies, whereby this liquid freeze-thaw (LiFT) procedure would avoid both chemical and microbial cross-contamination concerns while at the same time securing highly desirable reductions in likely ESM levels.

The application of biological treatment to solid waste is very promising to facilitate recycling of water, carbon, and nutrients and to reduce the resupply needs of long-term crewed space missions. Degradation of biodegradable solid wastes generated during such a mission is under investigation as part of the NASA Center of Research and Training (NSCORT) at Purdue University. Processing in the solids thermophilic aerobic reactor (STAR) involves the use of high temperature micro-aerobic slurry conditions to degrade solid wastes, enabling the recycling of water, carbon, and nutrients for further downstream uses. Related research presently underway includes technical development and optimization of STAR operations as well as a complementary evaluation of post-STAR processing for gas-stream purification, water recovery by condensate purification, and residuals utilization for both mushroom growth media and nutritional support for fish growth.

This paper presents a system-level design and initial equivalent systems mass (ESM) analysis for a solid-phase thermophilic aerobic reactor (STAR) system prototype that is designed for a Mars surface mission. STAR is a biological solid waste treatment system that reduces solid waste, neutralizes pathogens, and produces a stabilized product amenable to nutrient reuse and water recovery in a closed life support system. The STAR system is designed for long-duration space missions or long-term remote planetary operations. A system-level design analysis for sizing a STAR process and the subsequent ESM based sensitivity analysis based on a 600-day Mars surface mission with a 6-person crew will be presented. Preliminary ESM sensitivity analysis identified that improving system energy conservation efficiency should be the focus of future research once the fundamental STAR process development has matured.

Solids thermophilic aerobic reactor (STAR) processing of biodegradable solid waste residuals uses high temperature conditions to reduce waste volume, inactivate pathogens, and render products that may enter the recycle system by providing plant substrate, fish food, and mushroom growth medium. The STAR process recovers and enables the reuse of nutrients, water, and carbon. During the time of this study, STAR was operated at a 3% solids loading rate, with an 11-day retention time at a temperature range of 50-55°C. This document presents the following details: a the evolution to date of the STAR reactor b review of reactor operation and analytical methods c a synopsis of the performance results and related discussion, and d a synopsis of future goals relative to this project's associated research roadmap.

An ongoing effort is underway at NASA Ames Research Center (ARC) to develop an On-line Project Information System (OPIS) for the Advanced Life Support (ALS) Program. The objective of this three-year project is to develop, test, revise and deploy OPIS to enhance the quality of decision-making metrics and attainment of Program goals through improved knowledge sharing. OPIS will centrally locate detailed project information solicited from investigators on an annual basis and make it readily accessible by the ALS Community via a Web-accessible interface. The data will be stored in an object-oriented relational database (created in MySQL®) located on a secure server at NASA ARC. OPIS will simultaneously serve several functions, including being an research and technology development (R&TD) status information hub that can potentially serve as the primary annual reporting mechanism for ALS-funded projects.

The ALS Metric is the predominant tool for predicting the cost of ALS systems. Metric goals for the ALS Program are daunting, requiring a threefold increase in the ALS Metric by 2010. Compounding the problem is the slow rate new ALS technologies reach the maturity required for consideration in the ALS Metric and the slow rate at which new configurations are developed. This limits the search space and potentially gives the impression of a stalled research and development program. Without significant increases in the state of the art of ALS technology, the ALS goals involving the Metric may remain elusive. A paper previously presented at his meeting entitled, “Managing to the metric: An approach to optimizing life support costs.” A conclusion of that paper was that the largest contributors to the ALS Metric should be targeted by ALS researchers and management for maximum metric reductions.

The handling of uncertain data is demonstrated on an empirical grading function used for the assessment of tomato quality. The grading function studied here is designed to measure the departure of the properties of a tomato or a population of tomatoes from an assumed optimal tomato. Uncertain data are considered using the Taylor Series expansion of the grading function, a function of random variables, which provides the ability to determine the variability of the outcome of the function. Once this variability is quantified, confidence intervals are determined and considered. The degree of confidence in a result has a wide array of ramifications, ranging from providing valuable decision support to assisting in guidance of research activity.

BIO-Plex is a ground-based test bed currently under development by NASA for testing technologies and practices that may be utilized in future long-term life support missions. All aspects of such an Advanced Life Support (ALS) System must be considered to confidently construct a reliable system, which will not only allow the crew to survive in harsh environments, but allow the crew time to perform meaningful research. Effective handling of solid wastes is a critical aspect of the system, especially when recovery of resources contained in the waste is required. This is particularly important for ALS Systems configurations that include a Biomass Production Chamber. In these cases, significant amounts of inedible biomass waste may be produced, which can ultimately serve as a repository of necessary resources for sustaining life, notably carbon, water, and plant nutrients. Numerous biological and physicochemical solid waste processing options have been considered.

Metric analysis of research activity and technology development has become one of the deciding factors in whether or not the research of potential technologies receives the needed funding or a technology is incorporated into a system. It is difficult to accurately predict the configuration of an ALS system that will transport humans to the surface of Mars and support surface exploration. Determining which ALS research activities will support this effort is a very discretionary process, and there simply is not enough information to accurately make these types of decisions. Requirements change as research develops, and it is very difficult to create a metric that can accurately assess a potential or ongoing research project. The SSM team of the NJ-NSCORT has developed an internet platform to perform the assessment of potential technologies for the purpose of the development of an ALS system. The platform is called IFA and it has completed validation with current NJ-NSCORT projects.

Accurate, flexible, and dynamic mathematical computer modeling tools are required for the development and parametric evaluation of the various possible Advanced Life Support Systems (ALSS) configurations. Such models are expected to take a top-level approach to maximize modularity, flexibility in development, and user/developer friendliness. Two approaches are taken for modeling the WPRR component of an ALSS: an object oriented approach coded in Java and a SIMULINK model. Each model exhibits distinct properties for the interchange of technologies, startup requirements, and hardware/software requirements, but are anticipated to provide successful ALSS models.

As ALS goals branch out to extended missions to the moon and Mars, concurrent science and engineering projects take center stage in the development of new ALS technology. It is necessary to optimize the interdisciplinary research activities in order to ensure ALS research goals are met in a timely manner, and to guarantee the reliability of future long term missions. The SSM team of the NJ-NSCORT has developed an internet software platform capable of performing a systems level analysis of the ALS research activity. The information produced by the analysis can assist ALS researchers in the streamlining of research activity.