An Approach for Optimizing the On-Orbit Servicing Architecture for the Space-Based Radar Constellation

Satellite systems, once operational, are essentially a consumable item with no capacity to maintain, repair, or upgrade them while on-orbit. In order to avoid having to replace costly space assets, the Defense Advanced Research Projects Agency (DARPA) and Air Force Space Command (AFSPC) are looking to developing programs to provide an on-orbit servicing capability for future satellite systems under development, such as the Space-Based Radar (SBR) system. DARPA and AFSPC are studying on-orbit servicing using the Orbital Express platform as part of an Analysis of Alternatives for the SBR program. Like their satellite clients, on-orbit servicing assets are expected to be resource intensive, and so proper management of these space logistics assets is essential. This research provides a flexible planning tool to determine the optimal on-orbit servicing architecture for a given client satellite constellation and applies it to the proposed SBR constellation. The model uses a generalized network structure with side constraints to efficiently solve this large combinatorial optimization problem. The optimal number and type of servicing vehicles to use is found, along with the associated most efficient routing to meet client satellite demand for two commodities within multiple time windows

A multiobjective, multidisciplinary design optimization methodology for the conceptual design of distributed satellite systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2002.Includes bibliographical references (p. 427-438).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.A multiobjective, multidisciplinary design optimization methodology for mathematically modeling the distributed satellite system (DSS) conceptual design problem as an optimization problem has been developed to advance the state-of-the-art in complex distributed satellite network design. An increasing number of space missions are utilizing DSS architectures in which multiple satellites work in a coordinated fashion to improve system performance, cost, and survivability. The trade space for distributed satellite systems can be enormous - too large to enumerate, analyze, and compare all possible architectures. The seven-step methodology enables an efficient search of the trade space for the best families of architectures, and explores architectures that might not otherwise be considered during the conceptual design phase, the phase of a DSS program in which the majority of lifecycle cost gets locked in. Four classes of multidisciplinary design optimization (MDO) techniques are investigated - Taguchi, heuristic, gradient, and univariate methods. The heuristic simulated annealing (SA) algorithm found the best DSS architectures with the greatest consistency due to its ability to escape local optima within a nonconvex trade space. Accordingly, this SA algorithm forms the core single objective MDO algorithm in the methodology. The DSS conceptual design problem scope is then broadened by expanding from single objective to multiobjective optimization problems, and two variant multiobjective SA algorithms are developed.(cont.) The utility in knowing the global Pareto boundary of a DSS trade space is presented, and several methods are explored for approximating the true global Pareto boundary with only a limited knowledge of the full DSS trade space. Finally, methods for improving the performance of the SA algorithm are tested, and it was found that the 2-DOF variant of the SA algorithm is most effective at both single objective and multiobjective searches of a DSS trade space. The versatility of the methodology is demonstrated through its application to the conceptual design of three separate distributed satellite systems - the civil NASA Origins Terrestrial Planet Finder mission, the military TechSat 21 GMTI space-based radar mission, and the commercial broadband satellite communications mission. In each case, the methodology identifies more cost-effective system architectures than those previously considered for the single objective optimization problem, and a Pareto optimal set of architectures for the multiobjective optimization problem. In this manner, the methodology serves as a powerful, versatile systems engineering tool for the conceptual design of distributed satellite systems.by Cyrus D. Jilla.Ph.D

A Methodology for the Optimization of Disaggregated Space System Conceptual Designs

Optimal design techniques have proven to be an effective systems engineering tool. Using systems architecture as the foundation, this research explores the use of mixed variable optimization models for synthesizing and evaluating disaggregated space system concepts. Model-based conceptual design techniques are used to identify and assess system architectures based upon estimated system cost, performance trades, and cost risk. The Disaggregated Integral System Concept Optimization (DISCO) methodology is introduced, and then applied to representative space-based missions. Several results are obtained that indicate significant cost effectiveness gains from the optimization of multi-orbit and multi-function/multi-orbit disaggregated space systems. The general methodology has broad applicability for model-based conceptual design (MBCD) of many system types, but is particularly useful for dynamic disaggregated space systems

Increased confidence in concept design through trade space exploration and multiobjective optimization

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2008.Includes bibliographical references (p. 134-143).The growing size, complexity and demands of engineering systems requires paying greater attention to the initial design of the system concept. To improve the process by which concept design is carried out, this thesis develops an Engineering Framework for Concept Development. The Engineering Framework is applicable to a diverse range of concept design problems. It helps guide the otherwise haphazard process of the early stages of design to provide confidence that the chosen concept is superior to a large set of alternatives. Accompanying the Engineering Framework is a collection of tools which aid the designer in analyzing different options. Two tools in particular are demonstrated for their mutually beneficial characteristics: 1) Object-Process Network is used to explore the full space of options, revealing the relationships among design decisions and system performance, and 2) a particle.swarm optimization algorithm is implemented to efficiently search through the design space. The use of such an optimization algorithm becomes especially advantageous when higher fidelity models are included in the analysis because it is able to quickly identify the most favorable families of designs. The complementary approaches of exploring the entire trade space and then efficiently searching for the best groups of designs are shown to provide valuable insights in concept design problems. Two case study examples are presented as applications of the Engineering Framework and design tools. The first is an air-launched sounding rocket propulsion system design. The second is the design of a responsive disaster monitoring system. In each case, the use of the Engineering Framework and concept design tools give the designer increased confidence that quality concept designs have been identified.by Ryan Glenn Odegard.S.M

Abstracts to Be Presented at the 2015 Supercomputing Conference

Compilation of Abstracts to be presented at the 2015 Supercomputing Conferenc

Aeronautics and space report of the President, 1980 activities

The year's achievements in the areas of communication, Earth resources, environment, space sciences, transportation, and space energy are summarized and current and planned activities in these areas at the various departments and agencies of the Federal Government are summarized. Tables show U.S. and world spacecraft records, spacecraft launchings for 1980, and scientific payload anf probes launched 1975-1980. Budget data are included

Multidisciplinary Design Optimization for Space Applications

Multidisciplinary Design Optimization (MDO) has been increasingly studied in aerospace engineering with the main purpose of reducing monetary and schedule costs. The traditional design approach of optimizing each discipline separately and manually iterating to achieve good solutions is substituted by exploiting the interactions between the disciplines and concurrently optimizing every subsystem. The target of the research was the development of a flexible software suite capable of concurrently optimizing the design of a rocket propellant launch vehicle for multiple objectives. The possibility of combining the advantages of global and local searches have been exploited in both the MDO architecture and in the selected and self developed optimization methodologies. Those have been compared according to computational efficiency and performance criteria. Results have been critically analyzed to identify the most suitable optimization approach for the targeted MDO problem

Reconfigurable satellite constellations for geo-spatially adaptive Earth observation missions

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 145-151).Continuously increasing demand for Earth observation in atmospheric research, disaster monitoring, and intelligence, surveillance and reconnaissance (ISR) has been met by responsive architectures such as unmanned aerial systems (UAS) or artificial satellites. Space-based architectures can provide non-dominated design solutions on the utility-cost curve compared to alternate architectures through the use of two approaches: (1) reducing satellite manufacturing and launch costs and (2) introducing reconfigurability to the satellite constellations. Reconfigurable constellations (ReCons) enable fast responses to access targets of interest while providing global monitoring capability from space. The wide-area coverage and fast responses provided ReCon can complement high-resolution imagery provided by UAS. A newly proposed ReCon framework improves the model fidelity of previous approaches by utilizing Satellite Tool Kit (STK) simulations and Earth observation mission databases. This thesis investigates the design and optimization of ReCon in low Earth orbits. A multidisciplinary simulation model is developed, to which optimization techniques are applied for both single-objective and multi-objective problems. In addition to the optimized baseline ReCon design, its variants are also considered as case studies. Future work will potentially co-optimize ReCon and UAS-like systems.by Sung Wook Paek.S.M

Research and Technology 1996

This report selectively summarizes the NASA Lewis Research Center's research and technology accomplishments for fiscal year 1996. It comprises 116 short articles submitted by the staff scientists and engineers. The report is organized into six major sections: Aeronautics, Aerospace Technology, Space Flight Systems, Engineering & Computational Support, Lewis Research Academy, and Technology Transfer. The diversity of topics attests to the breadth of research and technology being pursued and to the skill mix of the staff that makes it possible. This report is not intended to be a comprehensive summary of all research and technology work done over the past fiscal year