3,753 research outputs found

    Advanced Manned Launch System (AMLS) study

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    To assure national leadership in space operations and exploration in the future, NASA must be able to provide cost effective and operationally efficient space transportation. Several NASA studies and the joint NASA/DoD Space Transportation Architecture Studies (STAS) have shown the need for a multi-vehicle space transportation system with designs driven by enhanced operations and low costs. NASA is currently studying an advanced manned launch system (AMLS) approach to transport crew and cargo to the Space Station Freedom. Several single and multiple stage systems from air-breathing to all-rocket concepts are being examined in a series of studies potential replacements for the Space Shuttle launch system in the 2000-2010 time frame. Rockwell International Corporation, under contract to the NASA Langley Research Center, has analyzed a two-stage all-rocket concept to determine whether this class of vehicles is appropriate for the AMLS function. The results of the pre-phase A study are discussed

    A framework for documenting and analyzing life-cycle costs using a simple network based representation

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    The introduction of high reliability systems combined with new ways of operating complex systems, particularly in aircraft design and operation has received much attention in recent years. Some systems are now being introduced into service, however, justifying such systems on a financial basis is difficult and may act to limit the rate of introduction on new products. Conventional life cycle costing based on a hierarchical cost breakdown structure is poor at recording and analysing the cost implications of introducing new technologies that have effects that span more than one phase in the life cycle. There is a risk that too much emphasis is put on ‘faith’ that a candidate technology will reduce cost because the cost analysis methods lack descriptive and analytical power. We describe an approach to representing the costs associated with introducing new technologies and evaluating their total cost. Our aim was to facilitate the comparison of different technological choices in new product development, with a particular interest in how the perceived benefits of enhanced reliability systems can be shown in a way that is inclusive, objective and easy to understand

    Space Generic Open Avionics Architecture (SGOAA) reference model technical guide

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    This report presents a full description of the Space Generic Open Avionics Architecture (SGOAA). The SGOAA consists of a generic system architecture for the entities in spacecraft avionics, a generic processing architecture, and a six class model of interfaces in a hardware/software system. The purpose of the SGOAA is to provide an umbrella set of requirements for applying the generic architecture interface model to the design of specific avionics hardware/software systems. The SGOAA defines a generic set of system interface points to facilitate identification of critical interfaces and establishes the requirements for applying appropriate low level detailed implementation standards to those interface points. The generic core avionics system and processing architecture models provided herein are robustly tailorable to specific system applications and provide a platform upon which the interface model is to be applied

    Feasibility study of an Integrated Program for Aerospace-vehicle Design (IPAD) system. Volume 2: Characterization of the IPAD system, phase 1, task 1

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    The aircraft design process is discussed along with the degree of participation of the various engineering disciplines considered in this feasibility study

    Determining Logistics Ground Support Manpower Requirements for a Reusable Military Launch Vehicle

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    Successful space-based technologies like satellite imagery and GPS have increased military demand for a rapid-response launch capability. AF Space Command\u27s Operationally Responsive Spacelift program was developed to ensure that the AF has the capability to launch a payload into orbit within hours of a tasking notification, and requires development of a new space launch vehicle. The Reusable Military Launch Vehicle (RMLV) is currently in the design phase. The AF Research Laboratory sponsored development of the MILEPOST simulation model in order to assess the turnaround time, and thus responsiveness, of various design alternatives. The focus of this thesis is to improve the fidelity of the MILEPOST model by assessing the logistics manpower required to support the modeled turnaround activities. The research determined the appropriate AF organizational structure and manpower requirements for RMLV ground support agencies based on the activities modeled in MILEPOST. This information will be incorporated into the model in future research efforts, resulting in the capability to evaluate RMLV design alternatives based on both turnaround time and workforce requirements

    Metrics Pilot Project for Military Avionics Sustainment: Experimental Design and Implementation Plan

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    This working paper outlines the design of an experiment, employing a pilot project, for identifying and validating new metrics for managing the US Air Force military avionics sustainment system. The paper also presents a plan for implementing the pilot project. The experimental design allows for the quantitifation of the effects of the new metrics, while controlling for the effects of other factors impacting the observed outcomes. Underlying the pilot project, and the proposed experimental design, are three main hypotheses derived from earlier research: (a) currently used metrics foster local optimization rather than system-wide optimization; (b) they do not allow measures of progress towards the achievement of system-wide goals and objectives, and, hence, do not allow visibility into the impact of depot maintenance on the warfighter; and (c) they are driving the “wrong behavior,” causing suboptimal decisions governing maintenance and repair priorities and practices and, as a result, undermining the efficiency and effectiveness of the sustainment system, despite the fact that the Air Force sustainment system has a dedicated and highly skilled workforce supporting the warfighter

    Systems design analysis applied to launch vehicle configuration

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    As emphasis shifts from optimum-performance aerospace systems to least lift-cycle costs, systems designs must seek, adapt, and innovate cost improvement techniques in design through operations. The systems design process of concept, definition, and design was assessed for the types and flow of total quality management techniques that may be applicable in a launch vehicle systems design analysis. Techniques discussed are task ordering, quality leverage, concurrent engineering, Pareto's principle, robustness, quality function deployment, criteria, and others. These cost oriented techniques are as applicable to aerospace systems design analysis as to any large commercial system

    Shuttle Ground Operations Efficiencies/Technologies (SGOE/T) study. Volume 2: Ground Operations evaluation

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    The Ground Operations Evaluation describes the breath and depth of the various study elements selected as a result of an operational analysis conducted during the early part of the study. Analysis techniques used for the evaluation are described in detail. Elements selected for further evaluation are identified; the results of the analysis documented; and a follow-on course of action recommended. The background and rationale for developing recommendations for the current Shuttle or for future programs is presented

    A Simulation-Based Analysis of the Impact of In-Sourcing a Major Process Element on the Coast Guard HH-601 Depot Maintenance Process

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    Leaders at the United States Coast Guard\u27s Aircraft Repair and Service Center (ARSC) in Elizabeth City, North Carolina recently formalized their planning and analysis functions by adding a dedicated branch to their command structure. The Planning and Analysis Branch intends to apply computer modeling and simulation to study the impact of process changes to the various Programmed Depot Maintenance (PDM) lines. This research considers the applicability of this type of modeling and simulation, using ARENA to study the current HH-6OJ PDM process. The contribution of this research is a methodology specific to ARSC needs, an analysis of methodology based on a discrete event simulation model of PDM lines, and a specific case study demonstrating the methodologies. The response variable of interest is average PDM process time as a function of either in-sourcing or out-sourcing labor for a major process step. The research includes development and evaluation of a macro-level process model using ARENA 5.0

    Identification and Reduction of Bottlenecks Concerning MICAP Re-Supply of F-16 Weapons System Avionics Line Replaceable Units

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    This thesis evaluates selected F-16 avionics Line Replaceable Units (LRUs) transiting the logistics pipeline in order to examine the existence of bottlenecks and explore potential solutions within the current Department of Defense (DoD) logistics reparable pipeline. A previous study reported that a reduction in the overall pipeline resupply time of at least one day equates to a savings of approximately $25.45 million (Hill et al, 1990:iii). Bottlenecks cause movement delays to the entities moving through the logistics reparable pipeline. The pipeline segments are: AO (requisition), AE (item availability), AS (shipment status), and D6 (receipt). The bottlenecks of concern are those that occur when normally allowed transit times are exceeded. The transit times are set forth by supply and transportation priorities in the Uniformed Materiel Movement and Issue Priority System (UMMIPS). This study focuses on five specific NMCS avionics Line Replaceable Units (LRU) which are also two level maintenance (2LM) parts for the F-16 weapons system. The data, retrieved from the Enhanced Transportation Automated Data System (ETADS), consists of 682 Air Force shipments from the period 1 July through 31 September 1996. The overall performance of the shipments was poor with approximately 83 percent failing to meet the authorized UMMIPS standard. The segment with the most bottlenecks is the AS (shipping status) segment. Of the 63 shipments evaluated (accompanied with shipping documents), 49 contained bottlenecks within the AS segment
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