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Dive into the research topics where Edgar Zapata is active.

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Featured researches published by Edgar Zapata.


45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit | 2009

Shuttle Shortfalls and Lessons Learned for the Sustainment of Human Space Exploration

Edgar Zapata; Daniel J. H. Levack; Russell E. Rhodes; John W. Robinson

Much debate and national soul searching has taken place over the value of the Space Shuttle which first flew in 1981 and which is currently scheduled to be retired in 2010. Originally developed post-Saturn Apollo to emphasize affordability and safety, the reusable Space Shuttle instead came to be perceived as economically unsustainable and lacking the technology maturity to assure safe, routine access to low earth orbit (LEO). After the loss of two crews, aboard Challenger and Columbia, followed by the decision to retire the system in 2010, it is critical that this three decades worth of human space flight experience be well understood. Understanding of the past is imperative to further those goals for which the Space Shuttle was a stepping-stone in the advancement of knowledge. There was significant reduction in life cycle costs between the Saturn Apollo and the Space Shuttle. However, the advancement in life cycle cost reduction from Saturn Apollo to the Space Shuttle fell far short of its goal. This paper will explore the reasons for this shortfall. Shortfalls and lessons learned can be categorized as related to design factors, at the architecture, element and sub-system levels, as well as to programmatic factors, in terms of goals, requirements, management and organization. Additionally, no review of the Space Shuttle program and attempt to take away key lessons would be complete without a strategic review. That is, how do national space goals drive future space transportation development strategies? The lessons of the Space Shuttle are invaluable in all respects ‐ technical, as in design, program-wise, as in organizational approach and goal setting, and strategically, within the context of the generational march toward an expanded human presence in space. Beyond lessons though (and the innumerable papers, anecdotes and opinions published on this topic) this paper traces tangible, achievable steps, derived from the Space Shuttle program experience, that must be a part of any 21 st century initiatives furthering a growing human presence beyond earth.


AIAA SPACE 2015 Conference and Exposition | 2015

Lunar COTS: An Economical and Sustainable Approach to Reaching Mars

Allison F. Zuniga; Daniel Rasky; Robert B. Pittman; Edgar Zapata; Roger A. Lepsch

The NASA COTS (Commercial Orbital Transportation Services) Program was a very successful program that developed and demonstrated cost-effective development and acquisition of commercial cargo transportation services to the International Space Station (ISS). The COTS acquisition strategy utilized a newer model than normally accepted in traditional procurement practices. This new model used Space Act Agreements where NASA entered into partnerships with industry to jointly share cost, development and operational risks to demonstrate new capabilities for mutual benefit. This model proved to be very beneficial to both NASA and its industry partners as NASA saved significantly in development and operational costs while industry partners successfully expanded their market share of the global launch transportation business. The authors, who contributed to the development of the COTS model, would like to extend this model to a lunar commercial services program that will push development of technologies and capabilities that will serve a Mars architecture and lead to an economical and sustainable pathway to transporting humans to Mars. Over the past few decades, several architectures for the Moon and Mars have been proposed and studied but ultimately halted or not even started due to the projected costs significantly exceeding NASAs budgets. Therefore a new strategy is needed that will fit within NASAs projected budgets and takes advantage of the US commercial industry along with its creative and entrepreneurial attributes. The authors propose a new COTS-like program to enter into partnerships with industry to demonstrate cost-effective, cis-lunar commercial services, such as lunar transportation, lunar ISRU operations, and cis-lunar propellant depots that can enable an economical and sustainable Mars architecture. Similar to the original COTS program, the goals of the proposed program, being notionally referred to as Lunar Commercial Orbital Transfer Services (LCOTS) program will be to: 1) reduce development and operational costs by sharing costs with industry; 2) create new markets in cis-lunar space to further reduce operational costs; and 3) enable NASA to develop an affordable and economical exploration Mars architecture. The paper will describe a plan for a proposed LCOTS program, its potential impact to an eventual Mars architecture and its many benefits to NASA, commercial space industry and the US economy.


winter simulation conference | 2000

Simulation based operational analysis of future space transportation systems

Alex J. Ruiz-Torres; Edgar Zapata

This paper presents an approach to the operational analysis of future space transportation systems. The approach combines knowledge from government and industry space operation and design experts, with system analysis methodologies to predict operational characteristics of a future space transportation system. The model proposed under this approach utilizes expert knowledge to predict the operational requirements of a vehicle concept, including the ground activities, flows, resources, and costs; all the components of the spaceport. The model incorporates simulation in order to include spaceport characteristics as alternative flows, processing variability, and other random events. This model will provide vehicle designers with useful understanding of the spaceport operations related to the investigated vehicle design. A stand-alone application is being developed where the model will be implemented and validated.


AIAA SPACE 2016 | 2016

Kickstarting a New Era of Lunar Industrialization via Campaign of Lunar COTS Missions

Allison F. Zuniga; Edgar Zapata; Mark Turner; Daniel J. Rasky; Robert B. Pittman

To support the goals of expanding our human presence and current economic sphere beyond LEO, a new plan was constructed for NASA to enter into partnerships with industry to foster and incentivize a new era of lunar industrialization. For NASA to finally be successful in achieving sustainable human exploration missions beyond LEO, lessons learned from our space history have shown that it is essential for current program planning to include affordable and economic development goals as well as address top national priorities to obtain much needed public support. In the last 58 years of NASAs existence, only Apollos human exploration missions beyond LEO were successful since it was proclaimed to be a top national priority during the 1960s. However, the missions were not sustainable and ended abruptly in 1972 due to lack of funding and insufficient economic gain. Ever since Apollo, there have not been any human missions beyond LEO because none of the proposed program plans were economical or proclaimed a top national priority. The proposed plan outlines a new campaign of low-cost, commercial-enabled lunar COTS (Commercial Orbital Transfer Services) missions which is an update to the Lunar COTS plan previously described. The objectives of this new campaign of missions are to prospect for resources, determine the economic viability of extracting those resources and assess the value proposition of using these resources in future exploration architectures such as Mars. These missions would be accomplished in partnership with commercial industry using the wellproven COTS Program acquisition model. This model proved to be very beneficial to both NASA and its industry partners as NASA saved significantly in development and operational costs, as much as tenfold, while industry partners successfully expanded their market share and demonstrated substantial economic gain. Similar to COTS, the goals for this new initiative are 1) to develop and demonstrate cost-effective, cis-lunar commercial services, such as lunar transportation, lunar mining and lunar ISRU operations; 2) enable development of an affordable and economical exploration architecture for future missions to Mars and beyond; and 3) to incentivize the creation of new lunar markets through use of lunar resources for economic benefit to NASA, commercial industry and the international community. These cost-effective services would not only enable NASA to economically and sustainably achieve its human exploration missions to the Moon, Mars and beyond but it would also kickstart a new era of lunar industrialization. This paper will describe the goals, objectives and approach for implementing this new campaign of missions. It will also describe the potential benefits and progress that can be accomplished with these low-cost, Lunar COTS missions. Lastly, a preliminary economic analysis approach is proposed for understanding the cost and potential return on investment in the use of lunar resources to reach the goal of lunar industrialization and an expanded and sustainable human presence into cis-lunar space and beyond.


47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit | 2011

Pros, Cons, and Alternatives to Weight Based Cost Estimating

Claude R. Joyner; Jonathan R. Lauriem; Daniel J. H. Levack; Edgar Zapata

Summary/Conclusions During architecture studies and conceptual design studies, details of any new items to be traded arerarely known: Part counts, features of individual parts, the manufacturing processes to be used, and eventhe weight are not easily obtainable. WBS details are not available without large expenditures of effort.What is available are the major choices of parameters and the choices of how to produce and how toprocure. Consequently, development and production cost models that do not need weight nor details aboutthe hardware are especially useful for studies at these levels. An ideal model would include factors thatallow examination not only ofthe change in cost due to design choices, but also the change in cost due tochanges in approaches to manufacturing, testing, and oversight.RECM and LLEGO are examples of such models. RECM has been incorporated by NASA intoNAFCOM. It has also been successfully used by PWR for many contractual and internal efforts. LLEGOhas been used by KSC.


International Journal of Quality & Reliability Management | 2010

A reliability, maintainability, and safety model to support the assessment of space vehicles

Alex J. Ruiz-Torres; Jianmei Zhang; Edgar Zapata; Arunkumar Pennathur; Russell E. Rhodes; Carey M. McCleskey; Marcella L. Cowen

Purpose – The focus of this paper is on reliability and availability design goals. It aims to provide top‐level estimates of the safety and maintainability of future spacecraft systems.Design/methodology/approach – The developed design tool uses basic reliability principles to estimate the probability of a safe mission and the need for repairs/replacement during ground processing, before launch and start of mission, based on the characteristics of the vehicles main systems: the number of subsystems, the mean time to repair, and the per subsystem average reliability.Findings – A simple reliability, maintainability and safety model is developed to support the top‐level design process of future space transportation vehicles. It also describes how the developed design tool uses various sensitivity analysis functions to improve design decisions.Originality/value – The goal of the developed tool is to provide engineers/vehicle developers during the early stages of design with a tool that demonstrates the effec...


45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit | 2009

Concepts for Life Cycle Cost Control Required to Achieve Space Transportation Affordability and Sustainability

Russel E. Rhodes; Edgar Zapata; Daniel J. H. Levack; John W. Robinson; Benjamin B. Donahue

Cost control must be implemented through the establishment of requirements and controlled continually by managing to these requirements. Cost control of the non-recurring side of life cycle cost has traditionally been implemented in both commercial and government programs. The government uses the budget process to implement this control. The commercial approach is to use a similar process of allocating the non-recurring cost to major elements of the program. This type of control generally manages through a work breakdown structure (WBS) by defining the major elements of the program. If the cost control is to be applied across the entire program life cycle cost (LCC), the approach must be addressed very differently. A functional breakdown structure (FBS) is defined and recommended. Use of a FBS provides the visibifity to allow the choice of an integrated solution reducing the cost of providing many different elements of like function. The different functional solutions that drive the hardware logistics, quantity of documentation, operational labor, reliability and maintainability balance, and total integration of the entire system from DDT&E through the life of the program must be fully defined, compared, and final decisions made among these competing solutions. The major drivers of recurring cost have been identified and are presented and discussed. The LCC requirements must be established and flowed down to provide control of LCC. This LCC control will require a structured rigid process similar to the one traditionally used to control weight/performance for space transportation systems throughout the entire program. It has been demonstrated over the last 30 years that without a firm requirement and methodically structured cost control, it is unlikely that affordable and sustainable space transportation system LCC will be achieved.


Knowledge Based Systems | 2006

Knowledge based representation and operations assessment of space transportation system architectures

Alex J. Ruiz-Torres; Edgar Zapata; Kazuo Nakatani; Marcella L. Cowen

Achieving the goals of safe and cost effective space transportation systems requires the development of new methods and tools that allow leap-frog improvements in the conceptualization, design, development, production, and operation of these systems. This paper reports on a modeling methodology aimed at the knowledge based representation and operational assessment of space transportation systems to be used during early stages of design with the objective of improved design via estimation of their ground operations and performance. The model uses knowledge based logic and equations combined with a process database to determine the appropriate ground processes and their duration, allowing the estimation of operational measures of performance such as labor, cycle time, and flight rate.


Space technology and applications international forum (STAIF - 97) | 1997

A quality function deployment method applied to highly reusable space transportation

Edgar Zapata

This paper will describe a Quality Function Deployment (QFD) currently in work the goal of which is to add definition and insight to the development of long term Highly Reusable Space Transportation (HRST). The objective here is twofold. First, to describe the process, the actual QFD experience as applies to the HRST study. Second, to describe the preliminary results of this process, in particular the assessment of possible directions for future pursuit such as promising candidate technologies or approaches that may finally open the space frontier. The iterative and synergistic nature of QFD provides opportunities in the process for the discovery of what is key in so far as it is useful, what is not, and what is merely true. Key observations on the QFD process will be presented. The importance of a customer definition as well as the similarity of the process of developing a technology portfolio to product development will be shown. Also, the relation of identified cost and operating drivers to future spac...


AIAA SPACE 2015 Conference and Exposition | 2015

Small Habitat Commonality Reduces Human Mars Mission Costs

Brand N. Griffin; Robert Howard; Scott Howe; Roger A. Lepsch; John Martin; Natalie Mary; Carey M. McCleskey; Philip Nerren; Michelle Rucker; Edgar Zapata; Tara Polsgrove

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Robert Howard

Walter Reed National Military Medical Center

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Arunkumar Pennathur

University of Texas at El Paso

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Assem Kaylani

University of Central Florida

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Jianmei Zhang

University of Texas at El Paso

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