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Engineers designing life support systems for NASA's next Lunar Landers face unique challenges. As with any vehicle that enables human spaceflight, the needs of the crew drive most of the lander requirements. The lander is also a key element of the architecture NASA will implement in the Constellation program. Many requirements, constraints, or optimization goals will be driven by interfaces with other projects, like the Crew Exploration Vehicle, the Lunar Surface Systems, and the Extravehicular Activity project. Other challenges in the life support system will be driven by the unique location of the vehicle in the environments encountered throughout the mission. This paper examines several topics that may be major design drivers for the lunar lander life support system. There are several functional requirements for the lander that may be different from previous vehicles or programs and recent experience.

Applied research and technology development (R&TD) is often characterized by uncertainty, risk, and significant delays before tangible returns are obtained. Given the increased awareness of limitations in resources, effective R&TD today needs a method for up-front assessment of competing technologies to help guide technology investment decisions. Such an assessment approach must account for uncertainties in system performance parameters, mission requirements and architectures, and internal and external events influencing a development program. The methodology known as decision analysis has the potential to address these issues. It was evaluated by performing a case study assessment of alternative carbon dioxide removal technologies for NASA's proposed First Lunar Outpost program. An approach was developed that accounts for the uncertainties in each technology's cost and performance parameters as well as programmatic uncertainties such as mission architecture.

Plants can be grown in space to support human life, providing food, and regenerating water and air. Various groups have demonstrated that plants can support human life on the ground, and that plants can grow in space. One would suppose that plants are also able to support human life in space, though obviously it would be a good idea to demonstrate that ability before committing to a mission requiring bioregeneration. However, plant growth in space requires that we provide the necessary conditions for growth, and this might require not only providing water and fertilizer as we do in terrestrial agriculture, but also a controlled environment and lighting. This would make crops much more costly than we are accustomed to on Earth, where the majority of crops are grown outside and where natural sunlight is generally adequate. On the other hand, providing food, air, and water in space by any other means is also costly.

The paper describes some of the features of a reference manual to be issued by the European Space Agency that will form part of a set of standards covering the subjects of environmental control, life support, habitability and human factors. The Manual contains information on the general requirements of life support and habitability and the missions that will drive its associated technologies. It is formatted as a series of individual data sheets that can be updated regularly and which are designed to accommodate inputs from other organisations and individuals. It also includes details of promising experimental work and theoretical concepts, as well as historical reviews that will help to guide the selection of technologies and the design of new systems. The paper presents examples from the Manual which highlight aspects of a systems approach to life support.

Studies for manned logistic spacecraft have provided much information and preliminary design data. This paper presents the results of an evaluation that led to the selection of environmental control, life support, and auxiliary power subsystems for a winged lifting body spacecraft. The vehicle was designed to be usable for a variety of missions such as space laboratory logistics and resupply, rescue, and reconnaissance-surveillance.

This paper considers the design of safety systems as they might be applied to a manned habitat operating in space. Areas reviewed include the delineation, monitoring and suppression of hazards as well as the design of control systems. Examples of methods that could be used to suppress hazards are presented, including schematics for a shut-down hierarchy and a fire and hazardous gas control system.

In this paper we consider sample size selection for life tests when the product life follows the two parameter Weibull distribution. Two situations are considered: 1) an acceptance test where the purpose is to determine whether the product under test meets specified or historical life objectives and 2) a routine endurance test where the purpose is to determine a parameter’s value within a sufficiently small interval of uncertainty just to add to a growing body of knowledge and serve as an item of information in future as yet unformulated decision making processes.

Given the constraints of the current launchers, manned exploration beyond LEO implies long time missions, a high mass of metabolic consumables and consequently regenerative life support technologies developments. To validate their efficiency, as well as their reliability, these technologies need to be tested in the most analog conditions (i.e. isolation, limited spare part, …). A large number of these conditions are met in the new permanent French-Italian settlement called Concordia, currently being built in the Antarctic continent. Over the last 15 years, ESA developed regenerative life support technologies. Two of these technologies: a Grey Water Treatment Unit and a Black Water Treatment Unit are currently assembled at the size of 15 to 70 persons to fulfill the Concordia crew needs The first technology is a multi step filtration system and will recycle the shower, washing machine, dish washer and cleaning water.

The lead-acid couple is potentially capable of fulfilling the battery requirement for high performance electric delivery vehicles in the one tonne payload category. Development of such a battery, combining high energy density and good cycle life, involves extensive and painstaking testing. During the course of the Lucas development programme test methods and procedures have been evolved to ensure that the battery array with its supporting equipment is capable of fully performing the tasks required of it in such an application. Much of the experience gained is applicable to any electrochemical couple being developed for electric vehicle use.

This paper presents life test data of two controlled pump assemblies continuously running since September 1993. The tests, running on FLUOROCARBON CCIF2 - CCIF2, are still in progress (Current date May 1997). One pump operates at the design point, the other one at 3 different RPM's. Reliability considerations lead to a novel, sensorless, brushless DC motor of very high reliability. Given is an outline of the extensive environmental test compaign and Micro-G tests, with results. Pump performance data taken prior and after the environmental tests, performances after 1 and 3 years of continuous operation are given and compared. Up to now, after 3 years of operation no pump degradation can be detected. A pre-runner of the above pumps, featuring the same bearing design is continuously running since November 1990 with no observable degradation.

One of the key selling criteria of brake linings is their related cost per life time. Individual wear rates must match a required service interval which in most cases is part of the warranty a vehicle is sold with. OEMs, brake manufacturers as well as friction material suppliers are therefore conducting in-depth investigations on the wear behaviour of brake systems and their friction pair. These consider various parameters influencing pad and rotor life expectancy as part of the pre selection process before running final fleet trials for confirmation. Thus, selecting the right test procedures and parameters for the determination of wear rates is key in enabling a confident life time prediction. As of today, a multitude of wear test procedures are used in the automotive industry, each of them related to the specific experience of the respective OEM or BM.

The knowledge of mechanical behaviour of material is vital for durability prediction and attending initial project requirements. Through the experimental evaluations is possible to measure this behaviour and use it as input in numerical simulations. Temperature changes considerably static and dynamic mechanical properties of materials, particularly in elastomers. This study was motivated to predict the durability under several working temperatures of center bearings rubber cushion of driveshafts that needs to achieve prespecified stiffness and durability parameters. Standardized specimens were tested in fatigue for experimental investigation of the rubber compound. Durability tests were performed in the final product sample and compared with tests performed in standardized specimens. It was concluded that this approach produces accurate results for fatigue predictions and provided useful equations for practical design applications and reducing product validation time.

Theoretical estimates are made of life time of Ceramic Turbocharger Rotor (CTR) for suitable mechanical design and suitable material selection. Life time of CTR is predicted taking into account the stress-temperature distribution in CTR, required failure probability, volume effect of strength and material properties. Three fatigue failure modes which are slow crack growth, oxidation, and creep failure are considered. The stress-temperature distribution in CTR in operation is estimated by means of Finite Element Method numerical analysis. The probabilistic design map is proposed as a function of turbine inlet temperature and tip speed.

The implementation of an aircraft gas turbine engine conceptual design procedure currently being developed under Air Force (AFWAL) sponsorship will result in improved aircraft gas turbine designs with which to proceed to preliminary design. Although gas turbine engine performance and weight sensitivities to changes in life are generally not large (due to the logarithmic relationship of life to stress), past conceptual efforts have not quantified these trades. This is primarily due to the complexity of existing life prediction techniques and the associated detailed design information required by these techniques. A methodology is being developed which will quantify these life/performance trades cost effectively, on a relative basis, via computerized design procedures. Critical to the methodology is an accurate detailed engine utilization definition, which was not known in past efforts.

The survival of humanity in the upcoming decades will depend on the sustainability of the consumed products. There is a global effort to develop solutions to reduce environmental and energy impacts with the production of these products. This paper presents a careful analysis of automotive recycling and the role of aluminum in the life cycle of these vehicles. It is known that the number of vehicles is getting close to 1 billion units while the number of end-of-life vehicles (ELVs) has also been increasing dramatically throughout the entire planet. The average car has between 30 to 150 kg of aluminum, there is an increasing trend in this amount in exchange of a reduced final weight of the vehicle. Aluminum can be recycled repeatedly without losing its physical-chemical properties. There are two ways of obtaining the metal; one is by the direct extraction of natural resources through the mining of bauxite and the second through its recycling.

The objective of this study is to develop a design decision support tool that incorporates life cycle costing including the environmental effects of a system. A life cycle costing that incorporates the effects of the environment is essential to support the design decisions required during today''s product or system developments. Since the international environmental standards (ISO 14000 Series) were issued in the early 1990s, the leading companies in the automotive industry have been developing integrated assessment methodologies. These methodologies attempt to integrate cost, quality, environment and other related areas into the total life cycle assessment of a system. Therefore, it is important to develop a tool that integrates all information concerning the product in the early stages of development. It is also appropriate to support the decision-making in selecting the best design alternatives.

In the vein of the paper we presented at the last SAE Congress (SAE 970538), the evolution of the exothermic process of combustion (an event referred to popularly as ‘heat release’) in an engine is considered from the point of view of the utilization of fuel. Its consumption in the course of this process is expressed in a functional form, akin to that engendered for mathematical description of life. There are a number of such functions recorded in the literature and their salient features are revealed. Of particular relevance to fuel utilization in engines is a reverse form of the Vibe function (known in the English engine literature as the ‘Wiebe function’), which we call the fuel life function. Its parameters can be derived from numerical modeling of combustion in engines or from reduction of indicator diagram data.

This paper presents an overview on an Air Force initiative aimed at increasing the performance and reliability of aircraft batteries. A major thrust of the initiative is the elimination of flight line battery maintenance shops. Cost savings, increased mission capability and battle readiness are the pay-offs that will be realized from this effort. Current maintenance requirements for vented nickel-cadmium (Ni-Cd) batteries used in most U.S. military aircraft are unacceptable. This paper addresses other available technology options, decisions made to date and benefits that will result from this effort to increase the performance and reliability of aircraft batteries.

This study is a life-cycle assessment (LCA) comparing two types of a powertrain structural component: one made of diecast primary aluminum and another hypothetical part made of semi-solid injection molded primary magnesium (Thixomolded®). The LCA provides an indication of the potential environmental burdens throughout the life-cycles of both parts, ranging from raw material acquisition to product end-of-life. Preliminary results show high sensitivity to selection of primary vs. secondary metals, and to the SF6 emission factor used in the model. Opportunities exist for reducing energy consumption using secondary instead of primary metals for both parts, although the use of such is influenced by market supply and demand

Life-cycle cost analysis can provide a solid basis to support improvements in how fleet managers use their vehicles and in how manufactures design them. The challenge to it be an established practice rests on getting quality data provided by fleet operators and on the understanding that the data is significantly influenced by both the operational environment and the quality of management (operations and maintenance). In 2012, a benchmark study was conducted using the public transportation system of Salvador, Bahia, Brazil. Twelve companies participated in the study. Although the primary purpose of the study was to assess the differences in the competitiveness among the twelve companies, the data collected provide a database that was very consistent in providing critical analysis of vehicle maintainability by generating life-cycle cost analysis. The study proved to be an important tool to link vehicle design to the operational and maintenance management of company fleets.