{"539361":{"#nid":"539361","#data":{"type":"event","title":"PhD Defense by Michael J. Steffens","body":[{"value":"\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EPh.D. Thesis Defense\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003EBy\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003EMichael J. Steffens\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u0026nbsp;(Advisor: Prof. Dimitri Mavris)\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E1:00 PM, Thursday, June 2, 2016\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cem\u003EWeber Space Science and Technology Building (SST-II)\u003C\/em\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cem\u003ECollaborative Visualization Environment (CoVE)\u003C\/em\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003ETrajectory-Based Launch Vehicle Performance Analysis for \u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EDesign-Space Exploration in Conceptual Design\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EABSTRACT:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ETrajectory optimization is an important part of launch vehicle conceptual design.\u0026nbsp; It provides the link between a proposed vehicle and its performance.\u0026nbsp; Launch vehicle performance analysis is used to quantify how much payload a vehicle can put into the desired orbit and to compare vehicles against each other and against requirements.\u0026nbsp; This is especially important in early phases of design, where a large design space of vehicles may be considered and must be pared down to a few candidate vehicles.\u0026nbsp; Current methods for trajectory optimization do not allow for extensive design space exploration.\u0026nbsp; The methods involve numerical analysis, are computationally expensive, and require trajectory experts in the loop.\u0026nbsp; A simplified performance analysis, like the rocket equation, is much better suited to the types of studies desired in conceptual design, where thousands of vehicles can be considered and compared.\u0026nbsp; Unfortunately, the rocket equation does not take into account trajectory losses and therefore does not provide an accurate measure of performance.\u0026nbsp; The lack of a fast and accurate method to evaluate launch vehicle performance represents a gap in the current capability that will be addressed in this thesis.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EThe goal of this research is to formulate and implement a performance analysis method that is closed-form and takes into account the trajectory losses considered in a numerical trajectory analysis method. \u0026nbsp;Achieving this goal will result in a capability that enables rapid and accurate performance evaluation of launch vehicles.\u0026nbsp; In conceptual design, this can be used in the context of multi-disciplinary optimization, technology trade studies, probabilistic assessments, and Monte Carlo analysis for launch vehicles.\u0026nbsp; \u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EIn this thesis, the process is implemented for the Delta IV Heavy with an example design space.\u0026nbsp; The resulting surrogate model is able to accurately estimate the performance of a launch vehicle in the design space of interest virtually instantaneously.\u0026nbsp; This method is flexible and can be applied to any launch vehicle and any design space of interest.\u0026nbsp; The performance analysis capability that results from implementing the method proposed in this thesis meets the research objective of enabling rapid and accurate launch vehicle performance analysis in conceptual design.\u0026nbsp; This provides a way of estimating the performance for thousands of vehicles in the design space considered where previously only a few were considered. \u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EProf. Dimitri Mavris (Advisor)\u003C\/p\u003E\u003Cp\u003EProf. Daniel Schrage\u003C\/p\u003E\u003Cp\u003EProf. Marcus Holzinger\u003C\/p\u003E\u003Cp\u003EDr. Brad St. Germain\u003C\/p\u003E\u003Cp\u003EMr. Mark Rogers\u003C\/p\u003E\u003Cp\u003E \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Trajectory-Based Launch Vehicle Performance Analysis for Design-Space Exploration in Conceptual Design"}],"uid":"27707","created_gmt":"2016-05-24 10:22:39","changed_gmt":"2016-10-08 02:17:55","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2016-06-02T14:00:00-04:00","event_time_end":"2016-06-02T16:00:00-04:00","event_time_end_last":"2016-06-02T16:00:00-04:00","gmt_time_start":"2016-06-02 18:00:00","gmt_time_end":"2016-06-02 20:00:00","gmt_time_end_last":"2016-06-02 20:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}