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The need for greater capacity in automotive transportation (in the midst of constrained resources) and the convergence of key technologies from multiple domains may eventually produce the emergence of a “swarm” concept of operations. The swarm, a collection of vehicles traveling at high speeds and in close proximity, will require management techniques to ensure safe, efficient, and reliable vehicle interactions. We propose a shared-autonomy approach in which the strengths of both human drivers and machines are employed in concert for this management. A fuzzy logic-based control implementation is combined with a genetic algorithm to select the shared-autonomy architecture and sensor capabilities that optimize swarm operations.

This paper describes work that has begun at Ames Research Center on development of a heat melt compactor that can be used on near term and future missions. The heat melt compactor can handle wastes with a significant plastic composition and minimize crew interaction. The current solid waste management system employed on the International Space Station (ISS) consists of compaction, storage, and disposal. Wastes such as plastic food packaging and trash are compacted manually and wrapped in duct taped “footballs” by the astronauts. Much of the waste is simply loaded into the empty Russian Progress spacecraft that is used to bring supplies to ISS. The progress spacecraft and its contents are intentionally burned up in the earth's atmosphere during reentry. This manual method of trash management on ISS is a wasteful use of crew time and does not transition well to far term missions.

In this paper, an aggregate system level modeling and analysis framework is proposed to facilitate the integration and design of advanced life support systems (ALSS). As in process design, the goal is to choose values for the degrees of freedom that achieve the best overall ALSS behavior without violating any system constraints. At the most fundamental level, this effort will identify the constraints and degrees of freedom associated with each subsystem and provide estimates of the system behavior and interactions involved in ALSS. This work is intended to be a starting point for developing insights into ALSS from a systems engineering point of view. At this level, simple aggregate static input/output mapping subsystem models from existing data and the NASA ALS BVAD document are used to debug the model and demonstrate feasibility.

In an effort to define and advance the new discipline of Space Architecture, the AIAA technical subcommittee on Aerospace Architecture organized a Space Architecture Workshop that took place during the World Space Congress 2002 in Houston, Texas. One of the results of this workshop is a “Mission Statement for Space Architecture” that addresses the following core issues in a concise manner: definition, motivation, utility, required knowledge, and related disciplines. The workshop also addressed the typology and principles of space architecture, as well as basic philosophical guidelines for practitioners of this discipline. The mission statement, which was unanimously adopted by the workshop participants, reads as follows ([1], [2], [3]): “Space Architecture is the theory and practice of designing and building inhabited environments in outer space, responding to the deep human drive to explore and occupy new places.

An important function of life support systems developed for a long duration human mission to Mars is the ability to recycle water and air. The Bio-Regenerative Environmental Air Treatment for Health (BREATHe) is part of a multicomponent life support system and will simultaneously treat wastewater and air. The BREATHe system will consist of packed bed biofilm reactors. Model waste streams will be used for experiments conducted during the design phase of the BREATHe system. This paper summarizes expected characteristics of water and air waste steams that would be generated by a crew of six during a human mission to Mars. In addition to waste air and water generation rates, the chemical composition of each waste stream is defined. Specifically, chemical constituents expected to be present in hygiene wastewater, dishwater, laundry water, atmospheric condensate, and cabin air are presented.

The Advanced Life Support Research and Technology Development Metric, or Metric, for Government Fiscal Year 2002 provides a measure of the equivalent system mass for a life support system using the “best” available advanced technologies compared to the equivalent system mass for a life support system using technologies from International Space Station. The present paper details the assumed life support system configurations and algorithm used to compute the Metric. Additionally, various peripheral issues of importance are mentioned.

Of the many competing technologies for resource recovery from solid wastes for long duration manned missions such as a lunar or Mars base, incineration technology is one of the most promising and certainly the most well developed in a terrestrial sense. Various factors are involved in the design of an optimum fluidized bed incinerator for inedible biomass. The factors include variability of moisture in the biomass, the ash content, and the amount of fuel nitrogen in the biomass. The crop mixture in the waste will vary; consequently the nature of the waste, the nitrogen content, and the biomass heating values will vary as well. Variation in feed will result in variation in the amount of contaminants such as nitrogen oxides that are produced in the combustion part of the incinerator. The incinerator must be robust enough to handle this variability. Research at NASA Ames Research Center using the fluidized bed incinerator has yielded valuable data on system parameters and variables.

Engineers at the Johnson Space Center (JSC) are using innovative strategies to design the TCS for the Bio-regenerative Planetary Life Support Systems Test Complex (BIO-Plex), a regenerative advanced life support system ground test bed. This paper provides a current description of the BIO-Plex TCS design, testing objectives, analyses, descriptions of the TCS test articles expected to be tested in the BIO-Plex, and forward work regarding TCS. The TCS has been divided into some subsystems identified as permanent “infrastructure” for the BIO-Plex and others that are “test articles” that may change from one test to the next. The infrastructure subsystems are the Heating, Ventilation and Air-Conditioning (HVAC), the Crew Chambers Internal Thermal Control Subsystem (CC ITCS), the Biomass Production Chamber Internal Thermal Control Subsystem (BPC ITCS), the Waste Heat Distribution Subsystem (WHDS) and the External Thermal Control Subsystem (ETCS).

This paper provides an overview of the IMMWPS Integrated Ground Test Program, completed at the NASA Johnson Space Center (JSC) during October and November 2001. The JSC Crew and Thermal Systems Division (CTSD) has developed the IMMWPS orbital flight experiment to test the feasibility of a microbe-based water purifier for use in zero-gravity conditions. The IMMWPS design utilizes a Microbial Processor Assembly (MPA) inoculated with facultative anaerobes to convert organic contaminants in wastewater to carbon dioxide and biomass. The primary purpose of the ground test program was to verify functional operations and procedures. A secondary objective was to provide initial ground data for later comparison to on-orbit performance. This paper provides a description of the overall test program, including the test article hardware and the test sequence performed to simulate the anticipated space flight test program. In addition, a summary of significant results from the testing is provided.

Solid Waste Management (SWM) systems of current and previous space flight missions have employed relatively uncomplicated methods of waste collection, storage and return to Earth. NASA's long-term objectives, however, will likely include human-rated missions that are longer in both duration and distance, with little to no opportunity for re-supply. Such missions will likely exert increased demands upon all sub-systems, particularly the SWM system. In order to provide guidance to SWM Research and Technology Development (R&TD) efforts and overall system development, the establishment of appropriate SWM system requirements is necessary. Because future long duration missions are not yet fully defined, thorough mission-specific requirements have not yet been drafted.

Long duration missions pose substantial new challenges for solid waste management in Advanced Life Support (ALS) systems. These possibly include storing large volumes of waste material in a safe manner, rendering wastes stable or sterilized for extended periods of time, and/or processing wastes for recovery of vital resources. This is further complicated because future missions remain ill-defined with respect to waste stream quantity, composition and generation schedule. Without definitive knowledge of this information, development of mission requirements is hampered. Additionally, even if waste streams were well characterized, other operational and processing needs require clarification (e.g. resource recovery requirements and planetary protection constraints). Therefore, the development of solid waste management (SWM) subsystem requirements for long duration space missions is an inherently uncertain, complex and iterative process.

In order to estimate the exposure to a crew in space, there are three essential steps to be performed: first, the ambient radiation environment at the vehicle must be characterized; second, the mass distribution properties of the vehicle, including the crewmembers themselves must be developed, and third a model of the interactions of space radiations with matter must be employed in order to characterize the radiation field at the dose point of interest. The Space Radiation Analysis Group (SRAG) at the NASA, Johnson Space Center carries the primary responsibility for the operational radiation protection support function associated with manned space flight. In order to provide support during the various planning, execution, and analysis/recording phase activities associated with a given mission, tools have been developed to allow rapid, repeatable calculations of exposure on orbit.

Three replicate aerobic-heterotrophic biotrickling filters were designed to promote the simultaneous biodegradation of graywater and a waste gas containing NH3, H2S and CO2. Upon visual observation of discolored solids, it was originally hypothesized that gas-phase CO2 concentrations were excessive, causing regions of anoxic zones to form within the biotrickling filters. Observed discolored (black) biofilm of this nature is typically assumed to be either lysed bacterial cells or anaerobic regions, implying alteration of operational conditions. Solid (biofilm) samples were collected in the presence and absence of gas-phase wastestream(s) to determine if the gas-phase contaminants were contributing to the solid-phase discoloration. Two sets of experiments (shaker flask and solids characterization) were conduced to determine the nature of the discolored solids. Results indicated that the discolored solids were neither anaerobic bacteria nor lysed cells.

Most of the gaseous contaminants generated inside ALS (Advanced Life Support) cabins can be degraded to some degree by microbial degradation in a biofilter. The entry of biofiltration techniques into ALS will most likely involve integration with existing physico-chemical methods. However, in this study, cabin air quality treated by only biofiltration was predicted using the one-box and biofiltration models. Based on BVAD (Baseline Values and Assumptions Document) and SMAC (Spacecraft Maximum Allowable Concentrations), ammonia and carbon monoxide will be the critical compounds for biofilter design and control. Experimentation is needed to identify the pertinent microbial parameters and removal efficiency of carbon monoxide and to validate the results of this preliminary investigation.

The Bioregenerative Air Treatment for Health system has been proposed for Advanced Life Support (ALS) planetary base applications. The system will be operated as a biotrickling filter to simultaneously treat graywater and waste gas. Preliminary experiments have focused on carbon removal from a graywater simulant. Six bench scale biotrickling filter reactors were constructed and monitored continuously. After a reactor startup phase of 40 days, the average total organic carbon (TOC) removal for reactors packed with Tri-packs® packing material was 62%. A second set of experiments was designed to evaluate TOC removal using different packing materials (Bee-cell and Biobale). It was hypothesized that the alternative packing materials would reduce the effects of channeling in the reactors, thus improving TOC removal. However, TOC removal did not significantly improve during the second set of experiments.

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.

Complete reuse of graywater will be essential during long duration human space missions. The highest loaded and most important component to remove from graywater is surfactant, the active ingredient in soaps and detergents. When considering a biological treatment system for processing of graywater, surfactant biodegradability becomes a very important consideration. Surfactants should be chosen that are degraded at a fast rate and yield inconsequential degradation byproducts. Experiments conducted for this research examined the biodegradation of the surfactants in Pert Plus for Kids, disodium cocoamphodiacetate (DSCADA) and sodium laureth-3 sulfate (SLES), using respirometry. Rates of CO2 production, or ultimate degradation, are reported. DSCADA was found to be toxic to bacteria when present at 270 ppm whereas no toxicity was observed during experiments with SLES.

Conventional suspension analysis of three-dimensional suspensions typically use two-dimensional analyses. This is done by projecting suspension components onto two-dimensional planes and then performing a two-dimensional analysis in each of these orthogonal planes or neglecting motions in one of the planes entirely. This requires multiple iterations because changes in one plane require a checking of their effects on motion in the other orthogonal planes. In doing so, much of the insight and accuracy gained from a three-dimensional analysis can be lost. A three-dimensional kinematic analysis approach is presented and applied to a dual A-Arm suspension system. All motions are considered instantaneously about a screw axis instead of a point as used by the usual two-dimensional modeling approach. The model predicts deflections of suspension components in response to the three-dimensional forces present at the contact patch.