Space Systems Engineering Conference

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Now showing 1 - 10 of 36
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    Comparison of Return to Launch Site Options for a Reusable Booster Stage
    (Georgia Institute of Technology, 2005-11-10) Hellman, Barry Mark ; Georgia Institute of Technology. Space Systems Design Lab
    There is a major need in the U.S. Air Force to develop launch vehicles that can be used for Operational Responsive Spacelift and possibly be used for rapid global Strike. One strategy to achieve these mission goals is to develop a Reusable Military Launch System (RMLS) or a hybrid system which uses a reusable booster with expendable upper stages. In support of the development work of the Aerospace Systems Design Branch (ASC/ENMD) of the USAF Aeronautical Systems Center at Wright-Patterson AFB, this study looked at comparing three basic methods for Return to Launch Site (RTLS) for a reusable booster. These methods are glideback to launch site, flyback using an airbreathing turbofan, and boostback using the booster's main or secondary rocket engines. The booster carries the upper stage(s) on its back to the staging point. Currently, most RTLS vehicle studies either assume a glideback or flyback booster. Very little work outside of the Kistler K-1 has been done to look at boostback methods. The vehicle modeling was integrated into ModelCenter using the MDO method of Optimizer Based Decomposition to handle the branching trajectory problem that arises from the booster performing a RTLS maneuver. Each of the three vehicles was optimized to minimize dry weight and gross weight separately in order to get a better understanding if boostback can provide any advantages over the two more traditional RTLS methods.
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    Planetary Probe Entry, Descent, and Landing Systems: Technology Advancements, Cost, and Mass Evaluations with Application to Future Titan Exploration Missions
    (Georgia Institute of Technology, 2005-11-10) Ong, Chester ; Bieber, Ben S. ; Needham, Jennifer ; Huo, Bing ; Magee, Angela ; Montuori, Craig ; Ko, Chiwan ; Peterson, Craig ; Georgia Institute of Technology. Space Systems Design Lab
    Heritage is the double-edged sword in space systems engineering. Reliance on heritage can ensure redundant success but will diminish advancements in science and technology that are integral to the success of future missions. Current reliance on heritage flight hardware is due to the absolute cost ceilings and short development timetables. Since the pre-phase A design stage mandates that system engineers establish complex and crucial decisions governing the mission design, system engineers would greatly benefit from an apples-to-apples comparison of the mass and cost benefits from different technologies across a range of performance parameters. The Cost and Mass Evaluation of Technology (CoMET) removes the “hand-waving” arguments in EDL technology benefits, and identifies possible points of diminishing returns for the advancement of specific technologies. Ultimately, CoMET: EDL is a design-to-cost model that answers the following question: Would further technology development just be “polishing the cannonball?” EDL sub-systems include, but are not limited to, aeroshell and thermal protection entry systems; parachute systems; powered descent and landing systems; power systems; and in-situ exploration systems of aerobots. CoMET explores the technology trades between mass and cost in the collaborative engineering environment regarding key technology areas and launch vehicle considerations. To demonstrate CoMET’s potential in confronting future mission concepts that require new operational approaches and technology advancements, a planetary probe mission is designed around the exploration of Saturn’s moon, Titan. In January 14, 2005, the planetary probe Huygens befell Titan’s surface in search of life’s origins. On the Titan-Huygens probe, the limitations of communications relay geometry and battery power vastly restricted the operational time, scientific goals, and total returns of this mission. Without the improvement of battery efficiency or the evolution of nuclear power systems, state of the art technology will always restrict planetary scientists to short-duration missions and miniscule data sampling. Furthermore, to capitalize on each planet’s or moon’s unique environment, future probes will require innovative systems of in-situ exploration, such as blimps for mobility in dense atmospheres. This paper explores mass, cost, and technology trade-offs of an airship among several EDL technologies within general mission requirements of a mission to Titan.
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    Design and Systems Engineering of AFRL's Demonstration and Sciences Experiment
    (Georgia Institute of Technology, 2005-11-10) Cohen, Dan ; Spanjers, Gregory ; Winter, James ; Ginet, Gregory ; Dichter, Bronislaw ; Adler, Aaron ; Tolliver, Martin ; Guarnieri, Jason ; Air Force Research Laboratory (Wright-Patterson Air Force Base, Ohio). Space Vehicles Directorate ; Georgia Institute of Technology. Space Systems Design Lab
    The Air Force Research Laboratory (AFRL) Space Vehicles Directorate has developed the Demonstration and Science Experiments (DSX) mission to research technologies needed to significantly advance Department of Defense (DoD) capability to operate spacecraft in the harsh radiation environment of medium-earth orbits (MEO). The ability to operate effectively in the MEO environment significantly increases the DoD’s capability to field space systems that provide persistent global targeting-grade space surveillance, high-speed satellite-based communication, lower-cost GPS navigation, and protection from space weather on a responsive satellite platform. The three DSX experiments areas are: 1. Wave Particle Interaction Experiment (WPIx): Researching the physics of very-low-frequency (VLF) transmissions in the magnetosphere and characterizing the feasibility of natural and manmade VLF waves to reduce space radiation; 2. Space Weather Experiment (SWx): Characterizing and modeling the space radiation environment in MEO, an orbital regime attractive for future DoD and commercial missions; 3. Space Environmental Effects (SFx): Researching and characterizing the space weather effects on spacecraft electronics and materials. DSX uses a modular design that allows for launch either as a primary satellite on a conventional launcher, such as a Minotaur, or as a secondary payload on a larger rocket, such as the Evolved Expendable Launch Vehicle (EELV). An overview of the DSX spacecraft design, requirements, systems engineering approach, bus subsystems, payload designs, and experiments will be described.
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    Using Systems Engineering to Develop Responsive Logistics for Future Space Missions
    (Georgia Institute of Technology, 2005-11-09) Bennett, Gisele ; O'Neill, Gary S. ; Georgia Institute of Technology. Space Systems Design Lab ; Georgia Tech Research Institute. Logistics and Maintenance Applied Research Center ; Georgia Tech Research Institute
    The goal of establishing a long term manned presence on the Moon and eventual exploration of Mars brings the practice of logistics to a whole new level. We describe an approach to logistics as a 'system of systems' that integrates logistic system development with vehicle design and mission planning, and provides the basis for a data management architecture that can provide Health Monitoring for the entire logistic system using data from enterprise systems and other resources.
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    Aerobraking Cost/Risk Decisions
    (Georgia Institute of Technology, 2005-11-10) Spencer, David A. ; Tolson, Robert ; Jet Propulsion Laboratory (U.S.) ; National Institute of Aerospace ; Georgia Institute of Technology. Space Systems Design Lab
    Three missions have successfully used aerobraking to reduce the spacecraft orbit period and achieve the desired orbit geometry. A fourth, Mars Reconnaissance Orbiter, will employ aerobraking following its orbit insertion in March, 2006. The propellant mass reductions enabled by the aerobraking technique allow the use of smaller launch systems, which translate to significant savings in launch costs for flight projects. However, there is a significant increase in mission risk associated with the use of aerobraking. Flying a spacecraft through a planetary atmosphere hundreds of times during months of aroundthe- clock operations places the spacecraft in harm’s way, and is extraordinarily demanding on the flight team. There is a cost/risk trade that must be evaluated when a project is choosing between a mission baseline that includes aerobraking, or selecting a larger launch vehicle to enable purely propulsive orbit insertion. This paper provides a brief history of past and future aerobraking missions, describes the aerobraking technique, summarizes the costs associated with aerobraking, and concludes with a suggested methodology for evaluating the cost/risk trade when selecting the aerobraking approach.
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    The Apollo Lunar Orbit Rendezvous Architecture Decision Revisited
    (Georgia Institute of Technology, 2005-11-09) Reeves, David M. ; Scher, Michael D. ; Wilhite, Alan W. ; Stanley, Douglas O. ; Georgia Institute of Technology. Space Systems Design Lab ; University of Maryland (College Park, Md.)
    The 1962 Apollo architecture mode decision process was revisited with modern analysis and systems engineer tools to determine driving selection criteria and technology/operational mode design decisions that may be used for NASA’s current Space Exploration program. Results of the study agreed with the Apollo selection of the Lunar Orbit Rendezvous mode based on the technology maturity and politics in 1962. Using today’s greater emphasis on human safety and improvements in technology and design maturity, a slight edge may be given to the direct lunar mode over lunar orbit rendezvous. Also, the NOVA direct mode and Earth orbit rendezvous mode are not competitive based any selection criteria. Finally, reliability and development, operations, and production costs are major drivers in today’s decision process.
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    Tactical Satellite 3: Requirements Development for Responsive Space Missions
    (Georgia Institute of Technology, 2005-11-10) Straight, Stanley D. ; Davis, Thomas M. ; Air Force Research Laboratory (Wright-Patterson Air Force Base, Ohio). Space Vehicles Directorate ; Georgia Institute of Technology. Space Systems Design Lab
    The Department of Defense is embarking on a broad initiative to make its space programs more responsive. There are many different views of responsive space, but common tenets include no cost and schedule growth within space programs, and space capabilities delivered directly to the operational and tactical warfighter within a theater of war. The Tactical Satellite 3 (TacSat-3) mission success criteria are unique integration of program management objectives of cost and schedule and technical objectives. TacSat-3 will demonstrate a Hyperspectral Imaging capability direct to the tactical warfighter within 10 minutes of a collection opportunity. Central to providing this capability direct to the warfighter is fielding it in a responsive manner. Responsiveness demands a program structure and system design where cost and schedule are primary over mission performance to some minimum level. To be successful, the TacSat-3 program has developed requirements and mission success criteria which intimately link the cost and schedule to all aspects of requirements. The fundamental basis is the development of mission success criteria which are measurable, but allow for sufficient flexibility to meet aggressive cost and schedule constraints. Several examples of requirements trades are given.
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    EyasSAT: a Revolution in Teaching and Learning Space Systems Engineering
    (Georgia Institute of Technology, 2005-11-09) Sellers, Jerry J. ; Bishop, Carlee A. ; Gossner, Jesse R. ; White, James J. ; Clark, John B. ; Barnhart, David J. ; Georgia Institute of Technology. Space Systems Design Lab
    EyasSAT (patent pending) has transformed the spacecraft systems engineering teaching and learning experience. This new development is a fully functional nanosatellite project that is built up, tested, and “flown” in the classroom. EyasSAT has been used in various space education programs involving high school, undergraduate, and professional students. The overall concept and results from two years of experience are presented.
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    Systems Engineering Principles Applied to Basic Research and Development
    (Georgia Institute of Technology, 2005-11-10) Anderson, Norman C. ; Nolte, William ; Air Force Research Laboratory (Wright-Patterson Air Force Base, Ohio) ; Georgia Institute of Technology. Space Systems Design Lab
    Systems engineering principles and processes have grown out of the need to effectively manage complex programs, many of them for the acquisition of operational military systems. These multi-billion dollar programs truly benefit from the application of structured systems engineering principles, and the supporting processes have been finetuned to maximize their benefit in a requirements driven environment. Research and development efforts, on the other-hand, have typically avoided application of structured processes, primarily due to a perception that such structure inhibits the creative processes that are so crucial to the discovery and development of new technologies. This paper proposes that systems engineering principles and creative discovery are not mutually exclusive environments, and that, in fact, appropriately tailored systems engineering processes can enable and enhance scientific discovery. An example of this concept will be presented for the principles of risk management, including application to basic research, applied research and development, and technology demonstrations.
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    Space Systems Engineering Professional Development and Certification
    (Georgia Institute of Technology, 2005-11-09) Fisher, Gerard H. ; Aerospace Corporation ; Georgia Institute of Technology. Space Systems Design Lab
    In the mid-1990s, the Federal Government pursued "Acquisition Reform," which resulted in significantly reduced government technical oversight of contractors. This caused less technical personnel to be hired in the government program offices for the last ten years. Recent investigations of space problems have recognized the need to revitalize the systems engineering workforce within the government program offices. Two years ago, the National Reconnaissance Office (NRO) embarked on the development of a professional development and certification program for space systems engineering. The NRO workforce is heterogeneous; it is comprised of military and civilian members of all DoD services as well as several intelligence community agencies. Our objective was to develop a program that maximized the synergy with parent-agency programs and avoided any redundant training requirements. A three-level certification program was established that required technical education, systems engineering experience, and systems engineering training. The training selected is a combination of existing NRO courses, offthe- shelf academic courses, commercial training classes, and newly developed classes. After the first year, over 375 employees have attended at least one training class and we are certifying systems engineers at the rate of 10-12 per month. The success of this program has led to potential expansion into other areas of the government.