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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

Beyond The High Ground: A Taxonomy For Earth-Moon System Operations, Adam P. Wilmer, Robert A. Bettinger Jul 2022

Beyond The High Ground: A Taxonomy For Earth-Moon System Operations, Adam P. Wilmer, Robert A. Bettinger

Faculty Publications

Situational and space domain awareness in the space domain can no longer be confined to that which is found in geosynchronous orbit. International activities—commercial and military—and threats to the planet itself exist and are increasing across the entire Earth-Moon system. This reality requires a new taxonomy to accurately classify space domain awareness missions and better apply resources to and development of the same. This work presents such a taxonomy for the classification of space domain awareness regions.


A Decision Analysis Framework To Consider Space Congestion In Orbit Selection, Anthony J. Correale Mar 2022

A Decision Analysis Framework To Consider Space Congestion In Orbit Selection, Anthony J. Correale

Theses and Dissertations

Low Earth Orbit (LEO) is becoming more congested, which increases the risk to space missions. Decision makers will need to consider this increase in congestion as an increased risk within their mission engineering process. This thesis proposes a methodology to create and implement a value structure that quantitatively scores a range of orbits based on congestion factors of each orbit and how well each orbit meets mission requirements. This thesis demonstrates this methodology on a set of circular LEO orbits defined by altitude and inclination, and scores this illustrative scenario based on notional mission measures and expected number of encounters …


Evaluation Framework For Cislunar Space Domain Awareness (Sda) Systems, Simon R. Knister Mar 2020

Evaluation Framework For Cislunar Space Domain Awareness (Sda) Systems, Simon R. Knister

Theses and Dissertations

Modern space missions are increasingly transiting cislunar space, requiring expansion of existing Space Traffic Management (STM) functions. Legacy Space Domain Awareness (SDA) systems were not purpose-built to detect and track cislunar objects, which could require acquisition of a new system of systems. There are numerous parameters that could be varied for each system, as well as the type and location of systems across the architecture. This research attempts to solve this problem by applying a model-based systems engineering (MBSE) approach to assess the performance and financial burden of a given system of systems. Fitness metrics are developed based upon the …


Development Of Cislunar Space Logistics Networks For Satellite Constellation Support Using Event-Driven Generalized Multi-Commodity Network Flows, Alexander R. Collins Nov 2019

Development Of Cislunar Space Logistics Networks For Satellite Constellation Support Using Event-Driven Generalized Multi-Commodity Network Flows, Alexander R. Collins

Theses and Dissertations

As space becomes an increasingly congested domain, the risk of damage to satellite constellations is increasing. In response, there is an increasing need for capabilities for unmanned repair, refueling, and reconstitution (R3) of those constellations. Cislunar orbits offer a promising storage and low-cost transfer solution for on-orbit service vehicles and replacement satellites to leverage those capabilities. This research makes use of mixed-integer linear programming-based logistics models to determine the situations in which a cislunar mission architecture would offer a cost-effective alternative to Earth-based R3. The network models presented in this research make use of the latest developments in Event-Driven Generalized …


Case Study: Cooling Channels For Material Testing Applications Using Laser Powder Bed Fusion, Benjamin M. Doane, Ryan P. O'Hara, K. Liu, Carl R. Hartsfield Apr 2018

Case Study: Cooling Channels For Material Testing Applications Using Laser Powder Bed Fusion, Benjamin M. Doane, Ryan P. O'Hara, K. Liu, Carl R. Hartsfield

Faculty Publications

Additive Manufacturing continues to gain a reputation as a key technology that will have a major impact on all aspects of mechanical engineering. The United States Air Force’s (USAF) Air Force Institute of Technology (AFIT), based in Dayton, Ohio, has expanded its AM-focused education and R&D capabilities with the purchase of a Laser Powder Bed Fusion system from Germany’s Concept Laser.


Operationally Responsive Space (Ors): An Architecture And Enterprise Model For Adaptive Integration, Test And Logistics, Jeff A. Alexander, Martha Charles-Vickers, Talbot L. Smith, Michael L. Vickers Jun 2008

Operationally Responsive Space (Ors): An Architecture And Enterprise Model For Adaptive Integration, Test And Logistics, Jeff A. Alexander, Martha Charles-Vickers, Talbot L. Smith, Michael L. Vickers

Theses and Dissertations

The capability to rapidly deploy tactical satellites to meet a Joint Force Commander's immediate battlespace requirements is a well-documented joint capability need. Key U.S. strategic documentation cites the need for the capability to maintain persistent surveillance or an "unblinking eye" over battlespace and to rapidly reconstitute critical space capabilities to preserve situational awareness. The warfighter requires a tactical space-based deployment capability which employs a request to launch and operational deployment window of 90 to 120 days. This master's thesis executed two (2) major areas of work: apply, and reinforce the Operationally Responsive Space (ORS) mission tasks using the Joint Capabilities …


Prioritizing Satellite Payload Selection Via Optimization, Benjamin S. Kallemyn Mar 2007

Prioritizing Satellite Payload Selection Via Optimization, Benjamin S. Kallemyn

Theses and Dissertations

This thesis develops optimization models for prioritizing payloads for inclusion on satellite buses with volume, power, weight and budget constraints. The first model considers a single satellite launch for which the budget is uncertain and constellation requirements are not considered. Subsequently, we include constellation requirements and provide a more enhanced model. Both single-launch models provide a prioritized list of payloads to include on the launch before the budget is realized. The single-launch models are subsequently extended to a sequence of multiple launches in two cases, both of which incorporate an explicit dependence on the constellation composition at each launch epoch. …


Discrete Event Simulation Model Of The Ground Maintenance Operations Cycle Of A Reusable Launch Vehicle, John T. Pope Iii Mar 2006

Discrete Event Simulation Model Of The Ground Maintenance Operations Cycle Of A Reusable Launch Vehicle, John T. Pope Iii

Theses and Dissertations

The Air Force uses a family of expendable launch vehicles to meet its spacelift needs. Unfortunately, this method is not responsive: months of preparation are typically required and launch costs are high. Consequently, the Air Force seeks a reusable military launch vehicle that can be launched inexpensively and quickly regenerated between flights. Air Force Research Laboratory personnel desire a tool to help evaluate candidate designs and perform tradeoff studies necessary to acquire a launch vehicle that will achieve Air Force goals. The objective of this research was first to develop a conceptual model of maintenance operations needed to regenerate a …


A Discrete Event Simulation Model For Evaluating Air Force Reusable Military Launch Vehicle Prelaunch Operations, Adam T. Stiegelmeier Mar 2006

A Discrete Event Simulation Model For Evaluating Air Force Reusable Military Launch Vehicle Prelaunch Operations, Adam T. Stiegelmeier

Theses and Dissertations

As the control and exploitation of space becomes more important to the United States military, a responsive spacelift capability will become essential. Responsive spacelift could be defined as the ability to launch a vehicle within hours or days from the time a launch order is given, instead of the weeks or months it takes currently. As the Air Force contemplates moving toward a reusable military launch vehicle (RMLV) capability, it faces key design and ground processing decisions that will affect the vehicle regeneration timeline. This thesis develops a computer simulation model that mimics RMLV prelaunch operations-those activities that take place …


Optimizing Mean Mission Duration For Multiple-Payload Satellites, John A. Flory Mar 2006

Optimizing Mean Mission Duration For Multiple-Payload Satellites, John A. Flory

Theses and Dissertations

This thesis addresses the problem of optimally selecting and specifying satellite payloads for inclusion on a satellite bus to be launched into a constellation. The objective is to select and specify payloads so that the total lifetime utility of the constellation is maximized. The satellite bus is limited by finite power, weight, volume, and cost constraints. This problem is modeled as a classical knapsack problem in one and multiple dimensions, and dynamic programming and binary integer programming formulations are provided to solve the problem. Due to the computational complexity of the problem, the solution techniques include exact methods as well …


Analysis Of Online-Delaunay Navigation For Time Sensitive Targeting, David Chow Mar 2005

Analysis Of Online-Delaunay Navigation For Time Sensitive Targeting, David Chow

Theses and Dissertations

Given the drawbacks of leaving time-sensitive targeting (TST) strictly to humans, there is value to the investigation of alternative approaches to TST operations that employ autonomous systems. This paper accomplishes five things. First, it proposes a short-hop abbreviated routing paradigm (SHARP) - based on Delaunay triangulations (DT), ad-hoc communication, and autonomous control - for recognizing and engaging TSTs that, in theory, will improve upon persistence, the volume of influence, autonomy, range, and situational awareness. Second, it analyzes the minimum timeframe need by a strike (weapons enabled) aircraft to navigate to the location of a TST under SHARP. Third, it shows …


An Approach For Optimizing The On-Orbit Servicing Architecture For The Space-Based Radar Constellation, Michael L. Mcconnell Mar 2005

An Approach For Optimizing The On-Orbit Servicing Architecture For The Space-Based Radar Constellation, Michael L. Mcconnell

Theses and Dissertations

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 …


An Object Oriented Simulation Of The C-17 Wingtip Vortices In The Airdrop Environment, Hans J. Petry Mar 1997

An Object Oriented Simulation Of The C-17 Wingtip Vortices In The Airdrop Environment, Hans J. Petry

Theses and Dissertations

This thesis effort focuses on the development of an object-oriented simulation of C-17 personnel airdrop operations and provides a tool for risk assessment of jumper and wingtip vortex interaction. Using the initial modeling efforts of the Wright Laboratory, this model expands those efforts to include random aircraft, wind and jumper movement within the simulation using MODSIM III as its language. Once the model was built, verified, and calibrated, it helped perform a preliminary analysis of jumper risk with varying element spacing and no crosswind. The results of the simulation provided 15 data points with which linear and logistic regression provided …


International Space Station Traffic Modeling And Simulation, Jillene B. Rylaarsdam Mar 1996

International Space Station Traffic Modeling And Simulation, Jillene B. Rylaarsdam

Theses and Dissertations

In an effort to provide NASA with an alternative perspective and some insights to the operational planning of the International Space Station (ISS), this research developed a simulation environment for the ISS and devised a method to evaluate various altitude strategies. The simulation environment allowed us to incorporate the natural random behaviors which affect the lifetime of objects in low earth orbit. We created prototype models of the operational planning process to analyze current altitude strategy approaches and acquire new strategies from insights observed. In addition, by extrapolating random future solar activity values from the interpolation of historical data, we …


A Multi-Attribute-Utility-Theory Model That Minimizes Interview-Data Requirements: A Consolidation Of Space Launch Decisions, Raymond W. Staats Dec 1994

A Multi-Attribute-Utility-Theory Model That Minimizes Interview-Data Requirements: A Consolidation Of Space Launch Decisions, Raymond W. Staats

Theses and Dissertations

This research uses multi-attribute utility theory (MAUT) to define a mathematical representation of a decision maker's utility associated with a satellite system. While developing the survey instrument, we focused on making it simpler to administer, primarily by eliminating the use of lottery questions. These simplifications enabled us to shorten our interview with the decision maker to under two hours for a rather complex model.


A Decision Support Model For Establishing A Plastics Recycling Program, Deven M. Dalcher Dec 1994

A Decision Support Model For Establishing A Plastics Recycling Program, Deven M. Dalcher

Theses and Dissertations

This research focuses on the development of a decision support model for the establishment of a plastics recycling program. The decision support model focuses on identifying the end-product uses and material specifications first. Once the end-product specifications have been identified, the recycling program can be designed. The model will provide solid waste managers an effective decision-making tool to evaluate the economic feasibility of establishing a plastics recycling program.


Automating Satellite Range Scheduling, S. Michael Schalck Dec 1993

Automating Satellite Range Scheduling, S. Michael Schalck

Theses and Dissertations

The objective of this study was to develop a computer based satellite range scheduling SRS algorithm to create a 24 hour satellite support schedule. The algorithms goal was to schedule as many satellite support requests as possible. An iterative heuristic approach was used to schedule satellite support requests in three successive sub problems. The first sub problem involves scheduling low altitude satellite support requests using a mixed integer programming approach. The next two sub problems each involve scheduling 12 hour blocks of medium and high altitude satellite support requests, again using a mixed integer programming approach. Fourteen 24 hour schedules …