2011 |
Whiting, James K Path Optimization Using Sub-Riemannian Manifolds with Applications to Astrodynamics PhD Thesis 2011. @phdthesis{Science2011, title = {Path Optimization Using Sub-Riemannian Manifolds with Applications to Astrodynamics}, author = {James K Whiting}, year = {2011}, date = {2011-01-01}, number = {2002}, abstract = {Differential geometry provides mechanisms for finding shortest paths in metric spaces. This work describes a procedure for creating a metric space from a path optimization problem description so that the formalism of differential geometry can be applied to find the optimal paths. Most path optimization problems will generate a sub-Riemannian manifold. This work describes an algorithm which approximates a sub-Riemannian manifold as a Riemannian manifold using a penalty metric so that Riemannian geodesic solvers can be used to find the solutions to the path optimization problem. This new method for solving path optimization problems shows promise to be faster than other methods, in part because it can easily run on parallel processing units. It also provides some geometrical insights into path optimization problems which could provide a new way to categorize path optimization problems. Some simple path optimization problems are described to provide an understandable example of how the method works and an application to astrodynamics is also given.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } Differential geometry provides mechanisms for finding shortest paths in metric spaces. This work describes a procedure for creating a metric space from a path optimization problem description so that the formalism of differential geometry can be applied to find the optimal paths. Most path optimization problems will generate a sub-Riemannian manifold. This work describes an algorithm which approximates a sub-Riemannian manifold as a Riemannian manifold using a penalty metric so that Riemannian geodesic solvers can be used to find the solutions to the path optimization problem. This new method for solving path optimization problems shows promise to be faster than other methods, in part because it can easily run on parallel processing units. It also provides some geometrical insights into path optimization problems which could provide a new way to categorize path optimization problems. Some simple path optimization problems are described to provide an understandable example of how the method works and an application to astrodynamics is also given. |
Sondecker, George Identification and Evolution of Quantities of Interest for a Stochastic Process View of Complex Space Systems Development PhD Thesis 2011. @phdthesis{sondeckerIdentificationEvolutionQuantities2011, title = {Identification and Evolution of Quantities of Interest for a Stochastic Process View of Complex Space Systems Development}, author = {George Sondecker}, year = {2011}, date = {2011-01-01}, number = {June}, abstract = {The underlying objective of a stochastic process design approach is to enable engineers and managers to guide the complex system development process by strategically identifying and reducing sources of uncertainty. These uncertainties are defined using quantities of interest that collectively describe the state of system development and evolve as the system matures. This thesis provides context for the contributions of quantities of interest to a stochastic process view of complex system development using three space hardware development projects. The CASTOR satellite provides the opportunity for retrospective identification of quantities of interest and their evolution through time. As a complement to CASTOR, the preliminary design of the REXIS x-ray spectrometer provides the foundation for applying stochastic process approaches during the early phases of space system development. Lastly, a spacecraft panel structural dynamics experiment is presented that illustrates analysis techniques commonly employed in stochastic process methods.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } The underlying objective of a stochastic process design approach is to enable engineers and managers to guide the complex system development process by strategically identifying and reducing sources of uncertainty. These uncertainties are defined using quantities of interest that collectively describe the state of system development and evolve as the system matures. This thesis provides context for the contributions of quantities of interest to a stochastic process view of complex system development using three space hardware development projects. The CASTOR satellite provides the opportunity for retrospective identification of quantities of interest and their evolution through time. As a complement to CASTOR, the preliminary design of the REXIS x-ray spectrometer provides the foundation for applying stochastic process approaches during the early phases of space system development. Lastly, a spacecraft panel structural dynamics experiment is presented that illustrates analysis techniques commonly employed in stochastic process methods. |
McLinko, Ryan Conceptual Phase Structural Design Tool for Microsatellites PhD Thesis 2011. BibTeX | Tags: @phdthesis{Unknown, title = {Conceptual Phase Structural Design Tool for Microsatellites}, author = {Ryan McLinko}, year = {2011}, date = {2011-01-01}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Jr, Daniel White B Technology Survey and Performance Scaling for the Design of High Power Nuclear Electric Power and Propulsion Systems PhD Thesis 2011. @phdthesis{whitejrTechnologySurveyPerformance2011, title = {Technology Survey and Performance Scaling for the Design of High Power Nuclear Electric Power and Propulsion Systems}, author = {Daniel B White Jr}, year = {2011}, date = {2011-01-01}, volume = {Aeronautic}, number = {May}, abstract = {High power nuclear electric propulsion systems have the capability to enable many next-generation space exploration applications. To date, use of electric primary propulsion in flight systems has been limited to low-power, solar electric missions. There is a need for a large-scale research and development effort to field systems capable of meeting the demands of future high-power electric propulsion missions, especially missions utilizing nuclear power plants to power electric propulsion systems. In formulating such an effort, it is first important to identify the likely requirements around which such a system might be designed. These requirements can be effectively cast in terms of required thruster lifetime, thrust, specific impulse, output power, and power plant specific power. Projected requirements can be derived based on the mass characteristics of space-borne nuclear power plants, and the optimized trajectories of spacecraft missions enabled by the use of megawatt-level nuclear electric power systems. Detailed mass modeling of space-based Rankine cycle nuclear power plants is conducted to evaluate the achievable specific power of these systems. Based on the figures for specific power so obtained, mission modeling is next conducted using the Mission Analysis Low-Thrust Optimization software package. Optimized thrust, specific impulse and lifetime figures are derived for several missions of interest. A survey of available electric propulsion thrusters is conducted and thruster configurations presenting the lowest developmental risks in migrating to high thruster output power are identified. Design evolutions are presented for three thrusters that would enhance or enable operation at the megawatt level. First, evaluation of projected lifetime for dual-stage gridded ion thrusters is conducted using the CEX2D simulation tool to evaluate the utility of multi-stage gridded ion engines in obtaining the required thruster lifetime for operation at high specific impulse. Next, to evaluate the utility of Hall thrusters operating at high propellant mass flow rate, a numerical thruster model is developed that incorporates the effects of the neutral fluid in predicting thruster performance. Using this code, numerical simulations are conducted to investigate the effects of variations in propellant mass flow rate, magnetic field topology, and thruster channel geometry on achievable performance. Finally, the effects of variations in the channel contour of magnetoplasmadynamic thrusters on performance and efficiency are evaluated using the MACH2 software package. Incremental variations in thruster channel contour are implemented, and the effects of these variations on the performance onset condition, and electrode current distributions are observed. Conclusions regarding the utility of each of these three design evolutions in developing thrusters for multi-megawatt electric propulsion systems are discussed. Contributions stemming from this research include, first, the establishment of an appropriate requirements space for the design of advanced highpower electric power and propulsion systems. This design space is comprised of projected requirements for power plant specific power, derived from power plant mass modeling, and thruster output power, specific impulse and lifetime derived from mission modeling. Additionally, this work provides evaluation, using state-of-the-art simulation suites, of several electric thruster design evolutions of potential utility in developing electric propulsion systems designed to operate at the megawatt level.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } High power nuclear electric propulsion systems have the capability to enable many next-generation space exploration applications. To date, use of electric primary propulsion in flight systems has been limited to low-power, solar electric missions. There is a need for a large-scale research and development effort to field systems capable of meeting the demands of future high-power electric propulsion missions, especially missions utilizing nuclear power plants to power electric propulsion systems. In formulating such an effort, it is first important to identify the likely requirements around which such a system might be designed. These requirements can be effectively cast in terms of required thruster lifetime, thrust, specific impulse, output power, and power plant specific power. Projected requirements can be derived based on the mass characteristics of space-borne nuclear power plants, and the optimized trajectories of spacecraft missions enabled by the use of megawatt-level nuclear electric power systems. Detailed mass modeling of space-based Rankine cycle nuclear power plants is conducted to evaluate the achievable specific power of these systems. Based on the figures for specific power so obtained, mission modeling is next conducted using the Mission Analysis Low-Thrust Optimization software package. Optimized thrust, specific impulse and lifetime figures are derived for several missions of interest. A survey of available electric propulsion thrusters is conducted and thruster configurations presenting the lowest developmental risks in migrating to high thruster output power are identified. Design evolutions are presented for three thrusters that would enhance or enable operation at the megawatt level. First, evaluation of projected lifetime for dual-stage gridded ion thrusters is conducted using the CEX2D simulation tool to evaluate the utility of multi-stage gridded ion engines in obtaining the required thruster lifetime for operation at high specific impulse. Next, to evaluate the utility of Hall thrusters operating at high propellant mass flow rate, a numerical thruster model is developed that incorporates the effects of the neutral fluid in predicting thruster performance. Using this code, numerical simulations are conducted to investigate the effects of variations in propellant mass flow rate, magnetic field topology, and thruster channel geometry on achievable performance. Finally, the effects of variations in the channel contour of magnetoplasmadynamic thrusters on performance and efficiency are evaluated using the MACH2 software package. Incremental variations in thruster channel contour are implemented, and the effects of these variations on the performance onset condition, and electrode current distributions are observed. Conclusions regarding the utility of each of these three design evolutions in developing thrusters for multi-megawatt electric propulsion systems are discussed. Contributions stemming from this research include, first, the establishment of an appropriate requirements space for the design of advanced highpower electric power and propulsion systems. This design space is comprised of projected requirements for power plant specific power, derived from power plant mass modeling, and thruster output power, specific impulse and lifetime derived from mission modeling. Additionally, this work provides evaluation, using state-of-the-art simulation suites, of several electric thruster design evolutions of potential utility in developing electric propulsion systems designed to operate at the megawatt level. |
Yue, Howard K 2011. @phdthesis{yuePROPULSIVELOGISTICALFEASIBILTY2011, title = {PROPULSIVE AND LOGISTICAL FEASIBILTY OF ALTERNATIVE FUTURE HUMAN- ROBOTIC MARS EXPLORATION ARCHITECTURES}, author = {Howard K Yue}, doi = {10.16194/j.cnki.31-1059/g4.2011.07.016}, year = {2011}, date = {2011-01-01}, volume = {64}, number = {June}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Saenz-Otero, Alvar; Katz, Jacob; Mwijuka, Alvin T The Zero Robotics SPHERES Challenge 2010 Inproceedings Aerospace Conference, 2011 IEEE, pp. 1–13, IEEE 2011. BibTeX | Tags: @inproceedings{saenz2011zero, title = {The Zero Robotics SPHERES Challenge 2010}, author = {Alvar Saenz-Otero and Jacob Katz and Alvin T Mwijuka}, year = {2011}, date = {2011-01-01}, booktitle = {Aerospace Conference, 2011 IEEE}, pages = {1--13}, organization = {IEEE}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Tweddle, BE; McClellan, J; Vulikh, G; Francis, J; Miller, D Relative Vision Based Navigation and Control for the Mars Sample Return Mission: Capturing the Orbiting Sample Miscellaneous 2011. BibTeX | Tags: @misc{tweddle2011relative, title = {Relative Vision Based Navigation and Control for the Mars Sample Return Mission: Capturing the Orbiting Sample}, author = {BE Tweddle and J McClellan and G Vulikh and J Francis and D Miller}, year = {2011}, date = {2011-01-01}, publisher = {May}, keywords = {}, pubstate = {published}, tppubtype = {misc} } |
Katz, Jacob G; Saenz-Otero, Alvar; Miller, David W Development and demonstration of an autonomous collision avoidance algorithm aboard the ISS Inproceedings Aerospace Conference, 2011 IEEE, pp. 1–6, IEEE 2011. BibTeX | Tags: @inproceedings{katz2011development, title = {Development and demonstration of an autonomous collision avoidance algorithm aboard the ISS}, author = {Jacob G Katz and Alvar Saenz-Otero and David W Miller}, year = {2011}, date = {2011-01-01}, booktitle = {Aerospace Conference, 2011 IEEE}, pages = {1--6}, organization = {IEEE}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Pong, Christopher Masaru; Saenz-Otero, Alvar; Miller, David W Autonomous thruster failure recovery on underactuated spacecraft using model predictive control Journal Article 2011. BibTeX | Tags: @article{pong2011autonomous, title = {Autonomous thruster failure recovery on underactuated spacecraft using model predictive control}, author = {Christopher Masaru Pong and Alvar Saenz-Otero and David W Miller}, year = {2011}, date = {2011-01-01}, publisher = {Univelt, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Courtney, Daniel 2011, ISSN: 1098-6596. Abstract | Links | BibTeX | Tags: icle @phdthesis{courtneyIonicLiquidIon2011, title = {Ionic Liquid Ion Source Emitter Arrays Fabricated on Bulk Porous Substrates for Spacecraft Propulsion}, author = {Daniel Courtney}, doi = {10.1017/CBO9781107415324.004}, issn = {1098-6596}, year = {2011}, date = {2011-01-01}, volume = {1}, number = {June}, abstract = {onic Liquid Ion Sources (ILIS) are a subset of electrospray capable of producing bipolar beams of pure ions from ionic liquids. Ionic liquids are room temperature molten salts, characterized by negligible vapor pressures, relative high conductivities and surface ten- sions lower than water. Compared with the colloid form of electrospray, renowned for its applications to spectroscopy, ILIS yield highly monoenergetic beams composed entirely of ions. In this respect they are similar to Liquid Metal Ions Sources, but o er the ability to emit both positive and negative ions from a benign propellant that remains in the liquid state over a wide range of temperatures. When applied to spacecraft propulsion these sources are very power e cient and yield high speci c impulses. Furthermore, the low ow rates and negligible vapor pressures of ionic liquids allow for passive feeding systems which can remain exposed to the vacuum of space. This con guration would remove the need for pressurized propellant tanks or valves, both of which are di cult to miniaturize for small satellites. However; the thrust produced from each emitter is very low, less than 0.1 N . As a result, compact arrays of active ILIS have been sought since their discovery. If arrays of modest packing density ( 5 emitters/mm 2 ) could be achieved, ILIS as thrusters would o er a scalable form of propulsion capable of providing useful thrust levels to small satellites with performance comparable to established, but di cult to miniaturize, plasma based ion engines. This research has sought a technique for creating arrays of ILIS from bulk porous sub- strates as part of an overall process for microfabricating complete thrusters. The thesis includes a survey of potential fabrication methods considering both suitability for form- ing arrays of ILIS and the ability to integrate each technique within a thruster packaging process. Electrochemical etching is highly selective and can proceed at rates which are limited by mass transport conditions. In this thesis we show how this etching regime can be exploited to smoothly remove material from the surface of a bulk porous metal substrate without damaging the internal pore structure. Dry lm photoresists have been identi ed as a suitable alternative to spin on techniques for porous materials and have been applied within an electrochemical etching process. A two step process for forming arrays of ILIS has been motivated using numerical sim- ulations of the etching process to predict emitter pro les and investigate the impacts of non-uniform etching conditions. These concepts have been applied experimentally using a custom built, automated, etching station capable of repeatedly producing arrays of 480 emit- ters spaced 500 m apart on a 1 x 1 cm porous nickel substrate pre-mounted, and aligned, 3 within a silicon thruster package. The emitters are typically 165 m tall with rounded tips suitable for operation as ILIS. Pulsed voltage conditions were found to signi cantly enhance wafer level uniformity enabling fabrication of functional emitters within a few hundred m of the substrate boundary. The structures have been smoothed and rounded, making them suitable for use as ILIS, during a secondary etch process using electrolytes doped with nickel chloride to suppress transient e ects. These doped solutions enabled a few m of material to be removed selectively from the porous surface while maintaining smooth features. These arrays have been mounted and aligned with electrostatic grids to demonstrate their emission capabilities. Propellant has been fed to the emitters by capillarity within the porous bulk and then extracted at potentials as low as 850 V . Beam currents exceeding several 100 A at both positive and negative polarities have been measured using both EMI- Im and EMI-BF 4 ionic liquid propellant. Two complete devices were tested yielding large beam currents and very high transmission fractions ( 88-100 %) from both attempts. We estimate that these devices can supply 10's of N of thrust at modest operating potentials, 1.5 kV , with a speci c impulse of roughly 2000-3000 s . When completely packaged, the thrusters measure 1.2 x 1.2 x 0.2 cm , weigh less than 1 g and require less than 0.65 W of operating power. These characteristics would be ideal for a small satellites where volume, mass and power are all at a premium, while the thrust levels would be su cient to enable a variety of orbit variation and attitude control maneuvers. For example, applied to a CubeSat, this type of thruster system, including PPU, would occupy roughly 10 % of the spacecraft volume and mass while enabling de-orbiting from an 800 km altitude in roughly 100 days, compared with many years when left to decay naturally.}, keywords = {icle}, pubstate = {published}, tppubtype = {phdthesis} } onic Liquid Ion Sources (ILIS) are a subset of electrospray capable of producing bipolar beams of pure ions from ionic liquids. Ionic liquids are room temperature molten salts, characterized by negligible vapor pressures, relative high conductivities and surface ten- sions lower than water. Compared with the colloid form of electrospray, renowned for its applications to spectroscopy, ILIS yield highly monoenergetic beams composed entirely of ions. In this respect they are similar to Liquid Metal Ions Sources, but o er the ability to emit both positive and negative ions from a benign propellant that remains in the liquid state over a wide range of temperatures. When applied to spacecraft propulsion these sources are very power e cient and yield high speci c impulses. Furthermore, the low ow rates and negligible vapor pressures of ionic liquids allow for passive feeding systems which can remain exposed to the vacuum of space. This con guration would remove the need for pressurized propellant tanks or valves, both of which are di cult to miniaturize for small satellites. However; the thrust produced from each emitter is very low, less than 0.1 N . As a result, compact arrays of active ILIS have been sought since their discovery. If arrays of modest packing density ( 5 emitters/mm 2 ) could be achieved, ILIS as thrusters would o er a scalable form of propulsion capable of providing useful thrust levels to small satellites with performance comparable to established, but di cult to miniaturize, plasma based ion engines. This research has sought a technique for creating arrays of ILIS from bulk porous sub- strates as part of an overall process for microfabricating complete thrusters. The thesis includes a survey of potential fabrication methods considering both suitability for form- ing arrays of ILIS and the ability to integrate each technique within a thruster packaging process. Electrochemical etching is highly selective and can proceed at rates which are limited by mass transport conditions. In this thesis we show how this etching regime can be exploited to smoothly remove material from the surface of a bulk porous metal substrate without damaging the internal pore structure. Dry lm photoresists have been identi ed as a suitable alternative to spin on techniques for porous materials and have been applied within an electrochemical etching process. A two step process for forming arrays of ILIS has been motivated using numerical sim- ulations of the etching process to predict emitter pro les and investigate the impacts of non-uniform etching conditions. These concepts have been applied experimentally using a custom built, automated, etching station capable of repeatedly producing arrays of 480 emit- ters spaced 500 m apart on a 1 x 1 cm porous nickel substrate pre-mounted, and aligned, 3 within a silicon thruster package. The emitters are typically 165 m tall with rounded tips suitable for operation as ILIS. Pulsed voltage conditions were found to signi cantly enhance wafer level uniformity enabling fabrication of functional emitters within a few hundred m of the substrate boundary. The structures have been smoothed and rounded, making them suitable for use as ILIS, during a secondary etch process using electrolytes doped with nickel chloride to suppress transient e ects. These doped solutions enabled a few m of material to be removed selectively from the porous surface while maintaining smooth features. These arrays have been mounted and aligned with electrostatic grids to demonstrate their emission capabilities. Propellant has been fed to the emitters by capillarity within the porous bulk and then extracted at potentials as low as 850 V . Beam currents exceeding several 100 A at both positive and negative polarities have been measured using both EMI- Im and EMI-BF 4 ionic liquid propellant. Two complete devices were tested yielding large beam currents and very high transmission fractions ( 88-100 %) from both attempts. We estimate that these devices can supply 10's of N of thrust at modest operating potentials, 1.5 kV , with a speci c impulse of roughly 2000-3000 s . When completely packaged, the thrusters measure 1.2 x 1.2 x 0.2 cm , weigh less than 1 g and require less than 0.65 W of operating power. These characteristics would be ideal for a small satellites where volume, mass and power are all at a premium, while the thrust levels would be su cient to enable a variety of orbit variation and attitude control maneuvers. For example, applied to a CubeSat, this type of thruster system, including PPU, would occupy roughly 10 % of the spacecraft volume and mass while enabling de-orbiting from an 800 km altitude in roughly 100 days, compared with many years when left to decay naturally. |
Crowell, Corey Whitcomb Development and Analysis of a Small Satellite Attitude Determination and Control System Testbed PhD Thesis 2011, ISBN: 7000102004. Abstract | Links | BibTeX | Tags: @phdthesis{crowellDevelopmentAnalysisSmall2011, title = {Development and Analysis of a Small Satellite Attitude Determination and Control System Testbed}, author = {Corey Whitcomb Crowell}, doi = {http://hdl.handle.net/1721.1/67177}, isbn = {7000102004}, year = {2011}, date = {2011-01-01}, number = {June}, abstract = {Attitude Determination and Control Systems (ADCS) are critical to the operation of satel- lites that require attitude knowledge and/or attitude control to achieve mission success. Furthermore, ADCS systems only operate as designed in the reduced friction, micro-gravity environment of space. Simulating these characteristics of space in a laboratory environment in order to test individual ADCS components and integrated ADCS systems is an important but challenging step in verifying and validating a satellite's ADCS design. The purpose of this thesis is to design and develop an ADCS testbed capable of sim- ulating the reduced fiction, micro-gravity environment of space within the Massachusetts Institute of Technology's Space Systems Laboratory. The ADCS testbed is based on a table- top style, three degree of freedom, rotational air bearing, which uses four reaction wheels for attitude control and a series of sensors for attitude determination. The testbed includes all the equipment necessary to allow for closed loop testing of individual ADCS components and integrated ADCS systems in the simulated inertial environment of space. In addition to the physical ADCS testbed, a MATLAB Simulink based model of the ADCS testbed is developed to predict the performance of hardware components and software algorithms before the components and algorithms are integrated into the ADCS testbed. The final objective of this thesis is to validate the operation of the ADCS testbed and simulation to prepare the tool for use by satellite design teams.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } Attitude Determination and Control Systems (ADCS) are critical to the operation of satel- lites that require attitude knowledge and/or attitude control to achieve mission success. Furthermore, ADCS systems only operate as designed in the reduced friction, micro-gravity environment of space. Simulating these characteristics of space in a laboratory environment in order to test individual ADCS components and integrated ADCS systems is an important but challenging step in verifying and validating a satellite's ADCS design. The purpose of this thesis is to design and develop an ADCS testbed capable of sim- ulating the reduced fiction, micro-gravity environment of space within the Massachusetts Institute of Technology's Space Systems Laboratory. The ADCS testbed is based on a table- top style, three degree of freedom, rotational air bearing, which uses four reaction wheels for attitude control and a series of sensors for attitude determination. The testbed includes all the equipment necessary to allow for closed loop testing of individual ADCS components and integrated ADCS systems in the simulated inertial environment of space. In addition to the physical ADCS testbed, a MATLAB Simulink based model of the ADCS testbed is developed to predict the performance of hardware components and software algorithms before the components and algorithms are integrated into the ADCS testbed. The final objective of this thesis is to validate the operation of the ADCS testbed and simulation to prepare the tool for use by satellite design teams. |
Do, Sydney An Airbag-Based Crew Impact Attenuation System for the Orion Crew Exploration Vehicle PhD Thesis 2011. BibTeX | Tags: @phdthesis{doAirbagBasedCrewImpact2011, title = {An Airbag-Based Crew Impact Attenuation System for the Orion Crew Exploration Vehicle}, author = {Sydney Do}, year = {2011}, date = {2011-01-01}, number = {February}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Fragniere, Benjamin Advanced Staged Control Design for Stellar Interferometry with Experimental Results on SPHERES PhD Thesis 2011. @phdthesis{fragniereAdvancedStagedControl2011, title = {Advanced Staged Control Design for Stellar Interferometry with Experimental Results on SPHERES}, author = {Benjamin Fragniere}, doi = {10.16194/j.cnki.31-1059/g4.2011.07.016}, year = {2011}, date = {2011-01-01}, volume = {64}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Garcia, Carmen Guerra High Voltage Repetitive Pulsed Nanosecond Dis- Charges as a Selective Source of Reactive Species PhD Thesis 2011. BibTeX | Tags: @phdthesis{garciaHighVoltageRepetitive2011, title = {High Voltage Repetitive Pulsed Nanosecond Dis- Charges as a Selective Source of Reactive Species}, author = {Carmen Guerra Garcia}, year = {2011}, date = {2011-01-01}, number = {May}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Gomez, Pablo Diaz Electrospray Emitters For Diffusion Vacuum Pumps PhD Thesis 2011. BibTeX | Tags: @phdthesis{gomezElectrosprayEmittersDiffusion2011, title = {Electrospray Emitters For Diffusion Vacuum Pumps}, author = {Pablo Diaz Gomez}, year = {2011}, date = {2011-01-01}, number = {June}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Han, Christopher J Development of Modular Real-Time Software for the TALARIS Lunar Hopper Testbed PhD Thesis 2011. BibTeX | Tags: @phdthesis{hanDevelopmentModularRealTime2011, title = {Development of Modular Real-Time Software for the TALARIS Lunar Hopper Testbed}, author = {Christopher J Han}, year = {2011}, date = {2011-01-01}, number = {June}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Pong, Christopher Masaru; Saenz-Otero, Alvar; Miller, David W Autonomous thruster failure recovery on underactuated spacecraft using model predictive control Journal Article 2011. BibTeX | Tags: @article{pong2011autonomousb, title = {Autonomous thruster failure recovery on underactuated spacecraft using model predictive control}, author = {Christopher Masaru Pong and Alvar Saenz-Otero and David W Miller}, year = {2011}, date = {2011-01-01}, publisher = {Univelt, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Katz, Jacob G; Saenz-Otero, Alvar; Miller, David W Development and demonstration of an autonomous collision avoidance algorithm aboard the ISS Inproceedings Aerospace Conference, 2011 IEEE, pp. 1–6, IEEE 2011. BibTeX | Tags: @inproceedings{katz2011developmentb, title = {Development and demonstration of an autonomous collision avoidance algorithm aboard the ISS}, author = {Jacob G Katz and Alvar Saenz-Otero and David W Miller}, year = {2011}, date = {2011-01-01}, booktitle = {Aerospace Conference, 2011 IEEE}, pages = {1--6}, organization = {IEEE}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Pong, Christopher Masaru; Smith, Matthew William; Knutson, Matthew W; Lim, Sungyung; Miller, David W; Seager, Sara; Villasenor, Jesus Noel Samonte; Murphy, Shawn D One-arcsecond line-of-sight pointing control on exoplanetsat, a three-unit CubeSat Journal Article 2011. BibTeX | Tags: @article{pong2011one, title = {One-arcsecond line-of-sight pointing control on exoplanetsat, a three-unit CubeSat}, author = {Christopher Masaru Pong and Matthew William Smith and Matthew W Knutson and Sungyung Lim and David W Miller and Sara Seager and Jesus Noel Samonte Villasenor and Shawn D Murphy}, year = {2011}, date = {2011-01-01}, publisher = {Univelt, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Tweddle, BE; McClellan, J; Vulikh, G; Francis, J; Miller, D Relative Vision Based Navigation and Control for the Mars Sample Return Mission: Capturing the Orbiting Sample Miscellaneous 2011. BibTeX | Tags: @misc{tweddle2011relativeb, title = {Relative Vision Based Navigation and Control for the Mars Sample Return Mission: Capturing the Orbiting Sample}, author = {BE Tweddle and J McClellan and G Vulikh and J Francis and D Miller}, year = {2011}, date = {2011-01-01}, publisher = {May}, keywords = {}, pubstate = {published}, tppubtype = {misc} } |
Smith, Matthew; Seager, Sara; Pong, Christopher; Knutson, Matthew; Miller, David; Henderson, Timothy; Lim, Sungyung; Brady, Tye; Matranga, Michael; Murphy, Shawn The ExoplanetSat mission to detect transiting exoplanets with a cubesat space telescope Journal Article 2011. BibTeX | Tags: @article{smith2011exoplanetsat, title = {The ExoplanetSat mission to detect transiting exoplanets with a cubesat space telescope}, author = {Matthew Smith and Sara Seager and Christopher Pong and Matthew Knutson and David Miller and Timothy Henderson and Sungyung Lim and Tye Brady and Michael Matranga and Shawn Murphy}, year = {2011}, date = {2011-01-01}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Saenz-Otero, Alvar; Katz, Jacob; Mwijuka, Alvin T The Zero Robotics SPHERES Challenge 2010 Inproceedings Aerospace Conference, 2011 IEEE, pp. 1–13, IEEE 2011. BibTeX | Tags: @inproceedings{saenz2011zerob, title = {The Zero Robotics SPHERES Challenge 2010}, author = {Alvar Saenz-Otero and Jacob Katz and Alvin T Mwijuka}, year = {2011}, date = {2011-01-01}, booktitle = {Aerospace Conference, 2011 IEEE}, pages = {1--13}, organization = {IEEE}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
2010 |
Ramirez-Riberos, Jaime L; Pavone, Marco; Frazzoli, Emilio; Miller, David W Distributed control of spacecraft formations via cyclic pursuit: Theory and experiments Journal Article Journal of guidance, control, and dynamics, 33 (5), pp. 1655–1669, 2010. BibTeX | Tags: @article{ramirez2010distributedb, title = {Distributed control of spacecraft formations via cyclic pursuit: Theory and experiments}, author = {Jaime L Ramirez-Riberos and Marco Pavone and Emilio Frazzoli and David W Miller}, year = {2010}, date = {2010-01-01}, journal = {Journal of guidance, control, and dynamics}, volume = {33}, number = {5}, pages = {1655--1669}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Mohan, Swati Quantitative Selection and Design of Model Generation Architectures for On-Orbit Autonomous Assembly PhD Thesis 2010. BibTeX | Tags: @phdthesis{Mohan2010a, title = {Quantitative Selection and Design of Model Generation Architectures for On-Orbit Autonomous Assembly}, author = {Swati Mohan}, year = {2010}, date = {2010-01-01}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Pong, Christopher Masaru Autonomous Thruster Failure Recovery for Underactuated Spacecraft PhD Thesis 2010. @phdthesis{Pong2010, title = {Autonomous Thruster Failure Recovery for Underactuated Spacecraft}, author = {Christopher Masaru Pong}, year = {2010}, date = {2010-01-01}, keywords = {★}, pubstate = {published}, tppubtype = {phdthesis} } |
Propulsion, Electrospray Molecular Dynamics Modeling of Ionic Liquids in Electrospray Propulsion PhD Thesis 2010. @phdthesis{propulsionMolecularDynamicsModeling2010, title = {Molecular Dynamics Modeling of Ionic Liquids in Electrospray Propulsion}, author = {Electrospray Propulsion}, year = {2010}, date = {2010-01-01}, number = {June}, abstract = {Micro-propulsion has been studied for many years due to its applications in small-tomedium sized spacecraft for precise satellite attitude control. Electrospray thrusters are promising thrusters built upon the state of the art in micro-technology and with flexible performance in terms of their high efficiency and high specific impulse. One challenge is to investigate in detail the mechanism for ion emission to complement experimental results and understand better how emission occurs in the micro to nano scale. Thus, atomistic modeling is used to understand properties of emitted charged particles which determine how the thrusters perform. As a preliminary study of ion emission from Taylor cones, ion evaporation from 3 - 5 nm droplets was observed in molecular dynamics (MD) simulations to validate the atomistic modeling and to investigate activation energies. Ion emission was examined in terms of internal and external electric fields and the activation energies of each case were obtained using Schottky's model and direct energy calculation to compare with experimental values. Ion emission was mainly observed with electric field strengths between 1.2 -2.0 V/nm and the emitted species include both solvated and non-solvated ions. Propulsive properties from Taylor cones are examined using results from the analysis of electric current from ion emission. In addition to an observation of ion emission from liquid droplets, numerical simulations for interactions between a solid plate and liquid droplets were conducted with MD simulation. It was concluded that another selection of force field needs to be considered to pursue further details, such as electrochemical effects.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } Micro-propulsion has been studied for many years due to its applications in small-tomedium sized spacecraft for precise satellite attitude control. Electrospray thrusters are promising thrusters built upon the state of the art in micro-technology and with flexible performance in terms of their high efficiency and high specific impulse. One challenge is to investigate in detail the mechanism for ion emission to complement experimental results and understand better how emission occurs in the micro to nano scale. Thus, atomistic modeling is used to understand properties of emitted charged particles which determine how the thrusters perform. As a preliminary study of ion emission from Taylor cones, ion evaporation from 3 - 5 nm droplets was observed in molecular dynamics (MD) simulations to validate the atomistic modeling and to investigate activation energies. Ion emission was examined in terms of internal and external electric fields and the activation energies of each case were obtained using Schottky's model and direct energy calculation to compare with experimental values. Ion emission was mainly observed with electric field strengths between 1.2 -2.0 V/nm and the emitted species include both solvated and non-solvated ions. Propulsive properties from Taylor cones are examined using results from the analysis of electric current from ion emission. In addition to an observation of ion emission from liquid droplets, numerical simulations for interactions between a solid plate and liquid droplets were conducted with MD simulation. It was concluded that another selection of force field needs to be considered to pursue further details, such as electrochemical effects. |
Riberos, Jaime Ramirez L New Decentralized Algorithms for Spacecraft Formation Control Based on a Cyclic Approach PhD Thesis 2010. @phdthesis{riberosNewDecentralizedAlgorithms2010, title = {New Decentralized Algorithms for Spacecraft Formation Control Based on a Cyclic Approach}, author = {Jaime Ramirez L Riberos}, year = {2010}, date = {2010-01-01}, number = {June}, abstract = {When considering the formation control problem for large number of spacecraft, the advantages of implementing control approaches with a centralized coordination mechanism can be outpaced by the risks associated with having a primary vital control unit. Additionally, in formations with a large number of spacecraft, a centralized approach implies an inherent difficulty in gathering and broadcasting information from/to the overall system. Therefore, there is a need to explore efficient decentralized control approaches. In this thesis a new approach to spacecraft formation control is formulated by exploring and enhancing the recent results on the theory of convergence to geometric patterns and exploring the analysis of this approach using the tools of contracting theory. First, an extensive analysis of the cyclic pursuit dynamics leads to developing control laws useful for spacecraft formation flight which, as opposed to the most common approaches in the literature, do not track fixed relative trajectories and therefore, reduce the global coordination requirements. The proposed approach leads to local control laws that verify global emergent behaviors specified as convergence to a particular manifold. A generalized analysis of such control approach by using tools of partial contraction theory is performed, producing important convergence results. By applying and extending results from the theory of partially contracting systems, an approach to deriving sufficient conditions for convergence is formulated. Its use is demonstrated by analyzing several examples and obtaining global convergence results for nonlinear, time varying and more complex interconnected distributed controllers. Experimental results of the implementation of these algorithms were obtained using the SPHERES testbed on board the International Space Station, validating many of the important properties of this decentralized control approach. They are believed to be the first implementation of decen- tralized formation flight in space. To complement the results we also consider a short analysis of the advantages of decentralized versus centralized approach by comparing the optimal performance and the effects of complexity and robustness for different architectures and address the issues of implementing decentralized algorithms in a inherently coupled system like the Electromagnetic Formation Flight. i s Ramtextasciiacute i rez Riberos}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } When considering the formation control problem for large number of spacecraft, the advantages of implementing control approaches with a centralized coordination mechanism can be outpaced by the risks associated with having a primary vital control unit. Additionally, in formations with a large number of spacecraft, a centralized approach implies an inherent difficulty in gathering and broadcasting information from/to the overall system. Therefore, there is a need to explore efficient decentralized control approaches. In this thesis a new approach to spacecraft formation control is formulated by exploring and enhancing the recent results on the theory of convergence to geometric patterns and exploring the analysis of this approach using the tools of contracting theory. First, an extensive analysis of the cyclic pursuit dynamics leads to developing control laws useful for spacecraft formation flight which, as opposed to the most common approaches in the literature, do not track fixed relative trajectories and therefore, reduce the global coordination requirements. The proposed approach leads to local control laws that verify global emergent behaviors specified as convergence to a particular manifold. A generalized analysis of such control approach by using tools of partial contraction theory is performed, producing important convergence results. By applying and extending results from the theory of partially contracting systems, an approach to deriving sufficient conditions for convergence is formulated. Its use is demonstrated by analyzing several examples and obtaining global convergence results for nonlinear, time varying and more complex interconnected distributed controllers. Experimental results of the implementation of these algorithms were obtained using the SPHERES testbed on board the International Space Station, validating many of the important properties of this decentralized control approach. They are believed to be the first implementation of decen- tralized formation flight in space. To complement the results we also consider a short analysis of the advantages of decentralized versus centralized approach by comparing the optimal performance and the effects of complexity and robustness for different architectures and address the issues of implementing decentralized algorithms in a inherently coupled system like the Electromagnetic Formation Flight. i s Ramtextasciiacute i rez Riberos |
Richmond, John Anger Adaptive Thermal Modeling Architecture For Small Satellite PhD Thesis 2010. @phdthesis{richmondAdaptiveThermalModeling2010, title = {Adaptive Thermal Modeling Architecture For Small Satellite}, author = {John Anger Richmond}, year = {2010}, date = {2010-01-01}, number = {May}, abstract = {The United States Air Force and commercial aerospace industry recognize the importance of moving towards smaller, better, and cheaper spacecraft to support the nation's increasing dependence on space-based technologies. Whether large or small, all spacecraft will require the same basic bus systems and environmental protection, simply scaled to fit the mission. The varying thermal environment in space is particularly important to spacecraft design and operation because of its affect on hardware performance and survivability. The Adaptive Thermal Modeling Architecture (ATMA) discussed in this thesis is meant to bridge the gap between the commercially available thermal modeling tools used for larger, more expensive satellites, and the low-fidelity algorithms and techniques used for simple first order analysis. The ATMA consists of the MATLAB based Adaptive Thermal Modeling Tool (ATMT) and its user's manual, as well as the process by which an inexperienced engineer can quickly and accurately perform on-orbit thermal trades studies for a range of space applications. The ATMA tools and techniques have been validated with an industry standard thermal modeling program (Thermal Desktop) and correlated to thermal test data taken from MIT's CASTOR nanosatellite. The concepts derived and evaluated within ATMA can be extended to a variety of aerospace modeling applications. The ATMT program and modeling architec- ture are currently being utilized by members of MIT's Space Engineering Academy (SEA) and undergraduate satellite team as well as the U.S. Air Force Academy's FalconSAT-6 program.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } The United States Air Force and commercial aerospace industry recognize the importance of moving towards smaller, better, and cheaper spacecraft to support the nation's increasing dependence on space-based technologies. Whether large or small, all spacecraft will require the same basic bus systems and environmental protection, simply scaled to fit the mission. The varying thermal environment in space is particularly important to spacecraft design and operation because of its affect on hardware performance and survivability. The Adaptive Thermal Modeling Architecture (ATMA) discussed in this thesis is meant to bridge the gap between the commercially available thermal modeling tools used for larger, more expensive satellites, and the low-fidelity algorithms and techniques used for simple first order analysis. The ATMA consists of the MATLAB based Adaptive Thermal Modeling Tool (ATMT) and its user's manual, as well as the process by which an inexperienced engineer can quickly and accurately perform on-orbit thermal trades studies for a range of space applications. The ATMA tools and techniques have been validated with an industry standard thermal modeling program (Thermal Desktop) and correlated to thermal test data taken from MIT's CASTOR nanosatellite. The concepts derived and evaluated within ATMA can be extended to a variety of aerospace modeling applications. The ATMT program and modeling architec- ture are currently being utilized by members of MIT's Space Engineering Academy (SEA) and undergraduate satellite team as well as the U.S. Air Force Academy's FalconSAT-6 program. |
Robinson, Joseph B An Integrated Evolutionary Model Approach to Small Satellite Engineering PhD Thesis 2010. BibTeX | Tags: @phdthesis{robinsonIntegratedEvolutionaryModel2010, title = {An Integrated Evolutionary Model Approach to Small Satellite Engineering}, author = {Joseph B Robinson}, year = {2010}, date = {2010-01-01}, number = {May}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Smith, Matthew W Minimizing Actuator-Induced Errors in Active Space Telescope Mirrors PhD Thesis 2010, ISSN: 0277786X. @phdthesis{smithMinimizingActuatorinducedErrors2010, title = {Minimizing Actuator-Induced Errors in Active Space Telescope Mirrors}, author = {Matthew W Smith}, doi = {10.1117/12.855947}, issn = {0277786X}, year = {2010}, date = {2010-01-01}, volume = {7731}, number = {September}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Tartler, Brett Construction and Performance of an Inverted Pendulum Thrust Balance PhD Thesis 2010. BibTeX | Tags: @phdthesis{tartlerConstructionPerformanceInverted2010, title = {Construction and Performance of an Inverted Pendulum Thrust Balance}, author = {Brett Tartler}, year = {2010}, date = {2010-01-01}, number = {May}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Tsay, Michael Meng-tsuan Two-Dimensional Numerical Modeling of Radio-Frequency Ion PhD Thesis 2010. BibTeX | Tags: @phdthesis{tsayTwoDimensionalNumericalModeling2010, title = {Two-Dimensional Numerical Modeling of Radio-Frequency Ion}, author = {Michael Meng-tsuan Tsay}, year = {2010}, date = {2010-01-01}, number = {August}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Ramirez-Riberos, Jaime L; Pavone, Marco; Frazzoli, Emilio; Miller, David W Distributed control of spacecraft formations via cyclic pursuit: Theory and experiments Journal Article Journal of guidance, control, and dynamics, 33 (5), pp. 1655–1669, 2010. BibTeX | Tags: @article{ramirez2010distributed, title = {Distributed control of spacecraft formations via cyclic pursuit: Theory and experiments}, author = {Jaime L Ramirez-Riberos and Marco Pavone and Emilio Frazzoli and David W Miller}, year = {2010}, date = {2010-01-01}, journal = {Journal of guidance, control, and dynamics}, volume = {33}, number = {5}, pages = {1655--1669}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Miller, David W ZERO-Robotics: a Student Competition Aboard the International Space Station Inproceedings Next-Generation Suborbital Researchers Conference, pp. 61–62, 2010. BibTeX | Tags: @inproceedings{miller2010zero, title = {ZERO-Robotics: a Student Competition Aboard the International Space Station}, author = {David W Miller}, year = {2010}, date = {2010-01-01}, booktitle = {Next-Generation Suborbital Researchers Conference}, volume = {1534}, pages = {61--62}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Katz, Jacob; Mohan, Swati; Miller, David On-orbit assembly of flexible space structures with SWARM Incollection AIAA Infotech@ Aerospace 2010, pp. 3524, 2010. BibTeX | Tags: @incollection{katz2010orbit, title = {On-orbit assembly of flexible space structures with SWARM}, author = {Jacob Katz and Swati Mohan and David Miller}, year = {2010}, date = {2010-01-01}, booktitle = {AIAA Infotech@ Aerospace 2010}, pages = {3524}, keywords = {}, pubstate = {published}, tppubtype = {incollection} } |
Bailey, James Zachary A Trade Space Model for Robotic Lunar Exploration PhD Thesis 2010, ISSN: 1098-6596. Abstract | Links | BibTeX | Tags: @phdthesis{baileyTradeSpaceModel2010, title = {A Trade Space Model for Robotic Lunar Exploration}, author = {James Zachary Bailey}, doi = {10.1017/CBO9781107415324.004}, issn = {1098-6596}, year = {2010}, date = {2010-01-01}, volume = {53}, number = {9}, abstract = {Predicting the binding mode of flexible polypeptides to proteins is an important task that falls outside the domain of applicability of most small molecule and protein-protein docking tools. Here, we test the small molecule flexible ligand docking program Glide on a set of 19 non-$alpha$-helical peptides and systematically improve pose prediction accuracy by enhancing Glide sampling for flexible polypeptides. In addition, scoring of the poses was improved by post-processing with physics-based implicit solvent MM- GBSA calculations. Using the best RMSD among the top 10 scoring poses as a metric, the success rate (RMSD $łeq$ 2.0 AA for the interface backbone atoms) increased from 21% with default Glide SP settings to 58% with the enhanced peptide sampling and scoring protocol in the case of redocking to the native protein structure. This approaches the accuracy of the recently developed Rosetta FlexPepDock method (63% success for these 19 peptides) while being over 100 times faster. Cross-docking was performed for a subset of cases where an unbound receptor structure was available, and in that case, 40% of peptides were docked successfully. We analyze the results and find that the optimized polypeptide protocol is most accurate for extended peptides of limited size and number of formal charges, defining a domain of applicability for this approach.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } Predicting the binding mode of flexible polypeptides to proteins is an important task that falls outside the domain of applicability of most small molecule and protein-protein docking tools. Here, we test the small molecule flexible ligand docking program Glide on a set of 19 non-$alpha$-helical peptides and systematically improve pose prediction accuracy by enhancing Glide sampling for flexible polypeptides. In addition, scoring of the poses was improved by post-processing with physics-based implicit solvent MM- GBSA calculations. Using the best RMSD among the top 10 scoring poses as a metric, the success rate (RMSD $łeq$ 2.0 AA for the interface backbone atoms) increased from 21% with default Glide SP settings to 58% with the enhanced peptide sampling and scoring protocol in the case of redocking to the native protein structure. This approaches the accuracy of the recently developed Rosetta FlexPepDock method (63% success for these 19 peptides) while being over 100 times faster. Cross-docking was performed for a subset of cases where an unbound receptor structure was available, and in that case, 40% of peptides were docked successfully. We analyze the results and find that the optimized polypeptide protocol is most accurate for extended peptides of limited size and number of formal charges, defining a domain of applicability for this approach. |
Burke, Caley A Nutation in the Spinning SPHERES Spacecraft and Fluid Slosh PhD Thesis 2010. @phdthesis{burkeNutationSpinningSPHERES2010, title = {Nutation in the Spinning SPHERES Spacecraft and Fluid Slosh}, author = {Caley A Burke}, year = {2010}, date = {2010-01-01}, number = {June}, abstract = {Spacecraft today are often spin-stabilized during a portion their launch or mission. Though the basics of spin stabilization are well understood, there remains uncertainty in predicting the likelihood of rapid nutation growth due to onboard liquids. Solely analytical methods of prediction are mainly unsuccessful and physical tests to gather slosh data have only been done for a few specific spacecraft. Data from past spacecraft is subject to a number complex physical factors and anomalies during the launch or mission.}, keywords = {★}, pubstate = {published}, tppubtype = {phdthesis} } Spacecraft today are often spin-stabilized during a portion their launch or mission. Though the basics of spin stabilization are well understood, there remains uncertainty in predicting the likelihood of rapid nutation growth due to onboard liquids. Solely analytical methods of prediction are mainly unsuccessful and physical tests to gather slosh data have only been done for a few specific spacecraft. Data from past spacecraft is subject to a number complex physical factors and anomalies during the launch or mission. |
Cohan, Lucy E Integrated Modeling and Design of Lightweight, Active Mirrors for Launch Survival and On-Orbit Performance PhD Thesis 2010. Abstract | BibTeX | Tags: Integrated Modeling @phdthesis{cohanIntegratedModelingDesign2010, title = {Integrated Modeling and Design of Lightweight, Active Mirrors for Launch Survival and On-Orbit Performance}, author = {Lucy E Cohan}, year = {2010}, date = {2010-01-01}, number = {June}, abstract = {Lightweight, active mirrors are an enabling technology for large aperture, space-based optical systems. These mirrors have the potential to improve the optical resolution and sensitivity beyond what is currently possible. However, as with all technology development programs, there are remaining issues to be solved before such mirrors can be used in operational systems. As of yet, no efforts have been made to explore the design space or optimize the design of lightweight mirrors across operational environments and constraints. The extremely harsh launch environment is of particular concern because launch survival constraints could dictate aspects of the mirror design. Additionally, on-orbit optical performance, in terms of high spatial frequency wavefront error and low spatial frequency correctability, are extremely important aspects of mirror design. Due to the lack of heritage systems, the best designs for lightweight, active mirrors are not immediately apparent. Therefore, an integrated modeling methodology for technology development programs is developed. This framework uses model-based design and evolutionary models to guide the technology development program. This methodology is applied to the lightweight, active mirror systems of interest. The mirrors are modeled and analyzed in two distinct environments: on-orbit and during launch. The on-orbit model and analysis are presented, as well as the designs with the best optical performance, which tend to have many ribs and actuators. Additionally, a dynamic state-space model of the launch environment is developed. The designs that are most likely to survive launch have few ribs and actuators, directly in conflict with the best on-orbit designs. Launch load alleviation techniques, including techniques making use of the existing embedded actuators, are also implemented to increase the probability of launch survival. Finally, a fully integrated trade space analysis of designs is shown, along with families of designs that perform well with respect to different mission objectives. The integrated modeling approach allows for the seamless combination of the two analyses, as well as a way in which to determine the best performing designs. By using this approach, the model can be updated to include any new insights and to 3 reflect the current}, keywords = {Integrated Modeling}, pubstate = {published}, tppubtype = {phdthesis} } Lightweight, active mirrors are an enabling technology for large aperture, space-based optical systems. These mirrors have the potential to improve the optical resolution and sensitivity beyond what is currently possible. However, as with all technology development programs, there are remaining issues to be solved before such mirrors can be used in operational systems. As of yet, no efforts have been made to explore the design space or optimize the design of lightweight mirrors across operational environments and constraints. The extremely harsh launch environment is of particular concern because launch survival constraints could dictate aspects of the mirror design. Additionally, on-orbit optical performance, in terms of high spatial frequency wavefront error and low spatial frequency correctability, are extremely important aspects of mirror design. Due to the lack of heritage systems, the best designs for lightweight, active mirrors are not immediately apparent. Therefore, an integrated modeling methodology for technology development programs is developed. This framework uses model-based design and evolutionary models to guide the technology development program. This methodology is applied to the lightweight, active mirror systems of interest. The mirrors are modeled and analyzed in two distinct environments: on-orbit and during launch. The on-orbit model and analysis are presented, as well as the designs with the best optical performance, which tend to have many ribs and actuators. Additionally, a dynamic state-space model of the launch environment is developed. The designs that are most likely to survive launch have few ribs and actuators, directly in conflict with the best on-orbit designs. Launch load alleviation techniques, including techniques making use of the existing embedded actuators, are also implemented to increase the probability of launch survival. Finally, a fully integrated trade space analysis of designs is shown, along with families of designs that perform well with respect to different mission objectives. The integrated modeling approach allows for the seamless combination of the two analyses, as well as a way in which to determine the best performing designs. By using this approach, the model can be updated to include any new insights and to 3 reflect the current |
Field, John M Acquisition and Control of a Precision Formation Flying Mission PhD Thesis 2010. @phdthesis{fieldAcquisitionControlPrecision2010, title = {Acquisition and Control of a Precision Formation Flying Mission}, author = {John M Field}, year = {2010}, date = {2010-01-01}, number = {June}, abstract = {Using formation flying spacecraft as space-based interferometers will provide images of unprecedented resolution. Missions such as Stellar Imager plan to use multiple spacecraft in a formation instead of a typical monolithic space telescope, achieving a resolution up to 0.1 milliarcseconds. In order to assemble into a formation, these satellites must first locate each other using limited field-of-view sensors. Once the satellites are in a formation, the path length of the light going to the combiner satellite must be controlled to nanometer levels to produce an image of high quality. One solution to control to such precision is to use staged control methods, utilizingmultiple actuators with overlapping strokes and bandwidths. This thesis first provides an algorithm for three satellites to initialize into a for- mation using relative measurements and limited field-of-view sensors. The satellites perform a search to locate each other, accurately point their transmitters at each other, and move into an equilateral triangle formation. This thesis also provides the framework for developing a staged pointing and phasing testbed using the Synchronized Position Hold Engage Reorient Experimental Satellites (SPHERES) as the coarse stage. The pointing actuation is provided by a fast steering mirror and a linear stage, and the phasing actuation is provided by an optical delay line consisting of a voice coil mirror and a piezo mirror.}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } Using formation flying spacecraft as space-based interferometers will provide images of unprecedented resolution. Missions such as Stellar Imager plan to use multiple spacecraft in a formation instead of a typical monolithic space telescope, achieving a resolution up to 0.1 milliarcseconds. In order to assemble into a formation, these satellites must first locate each other using limited field-of-view sensors. Once the satellites are in a formation, the path length of the light going to the combiner satellite must be controlled to nanometer levels to produce an image of high quality. One solution to control to such precision is to use staged control methods, utilizingmultiple actuators with overlapping strokes and bandwidths. This thesis first provides an algorithm for three satellites to initialize into a for- mation using relative measurements and limited field-of-view sensors. The satellites perform a search to locate each other, accurately point their transmitters at each other, and move into an equilateral triangle formation. This thesis also provides the framework for developing a staged pointing and phasing testbed using the Synchronized Position Hold Engage Reorient Experimental Satellites (SPHERES) as the coarse stage. The pointing actuation is provided by a fast steering mirror and a linear stage, and the phasing actuation is provided by an optical delay line consisting of a voice coil mirror and a piezo mirror. |
Grindle, Abraham T A Technical, Financial, and Policy Analysis of the RAMSES RFID Inventory Management System for NASA's International Space Station: Prospects for SBIR/STTR Technology Infusion PhD Thesis 2010. BibTeX | Tags: @phdthesis{Grindle2010, title = {A Technical, Financial, and Policy Analysis of the RAMSES RFID Inventory Management System for NASA's International Space Station: Prospects for SBIR/STTR Technology Infusion}, author = {Abraham T Grindle}, year = {2010}, date = {2010-01-01}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Pong, Christopher M; Lim, Sungyung; Smith, Matthew W; Miller, David W; ~n, Jesus Villase S; Seager, Sara Achieving high-precision pointing on ExoplanetSat: initial feasibility analysis Inproceedings Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave, pp. 77311V, International Society for Optics and Photonics 2010. BibTeX | Tags: @inproceedings{pong2010achieving, title = {Achieving high-precision pointing on ExoplanetSat: initial feasibility analysis}, author = {Christopher M Pong and Sungyung Lim and Matthew W Smith and David W Miller and Jesus S Villase{~n}or and Sara Seager}, year = {2010}, date = {2010-01-01}, booktitle = {Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave}, volume = {7731}, pages = {77311V}, organization = {International Society for Optics and Photonics}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Pong, Christopher M; Lim, Sungyung; Smith, Matthew W; Miller, David W; ~n, Jesus Villase S; Seager, Sara Achieving high-precision pointing on ExoplanetSat: initial feasibility analysis Inproceedings Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave, pp. 77311V, International Society for Optics and Photonics 2010. BibTeX | Tags: @inproceedings{pong2010achievingb, title = {Achieving high-precision pointing on ExoplanetSat: initial feasibility analysis}, author = {Christopher M Pong and Sungyung Lim and Matthew W Smith and David W Miller and Jesus S Villase{~n}or and Sara Seager}, year = {2010}, date = {2010-01-01}, booktitle = {Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave}, volume = {7731}, pages = {77311V}, organization = {International Society for Optics and Photonics}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Smith, Matthew W; Seager, Sara; Pong, Christopher M; ~n, Jesus Villase S; Ricker, George R; Miller, David W; Knapp, Mary E; Farmer, Grant T; Jensen-Clem, Rebecca ExoplanetSat: detecting transiting exoplanets using a low-cost CubeSat platform Inproceedings Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave, pp. 773127, International Society for Optics and Photonics 2010. BibTeX | Tags: @inproceedings{smith2010exoplanetsat, title = {ExoplanetSat: detecting transiting exoplanets using a low-cost CubeSat platform}, author = {Matthew W Smith and Sara Seager and Christopher M Pong and Jesus S Villase{~n}or and George R Ricker and David W Miller and Mary E Knapp and Grant T Farmer and Rebecca Jensen-Clem}, year = {2010}, date = {2010-01-01}, booktitle = {Space Telescopes and Instrumentation 2010: Optical, Infrared, and Millimeter Wave}, volume = {7731}, pages = {773127}, organization = {International Society for Optics and Photonics}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Katz, Jacob; Mohan, Swati; Miller, David On-orbit assembly of flexible space structures with SWARM Incollection AIAA Infotech@ Aerospace 2010, pp. 3524, 2010. BibTeX | Tags: @incollection{katz2010orbitb, title = {On-orbit assembly of flexible space structures with SWARM}, author = {Jacob Katz and Swati Mohan and David Miller}, year = {2010}, date = {2010-01-01}, booktitle = {AIAA Infotech@ Aerospace 2010}, pages = {3524}, keywords = {}, pubstate = {published}, tppubtype = {incollection} } |
Miller, David W ZERO-Robotics: a Student Competition Aboard the International Space Station Inproceedings Next-Generation Suborbital Researchers Conference, pp. 61–62, 2010. BibTeX | Tags: @inproceedings{miller2010zerob, title = {ZERO-Robotics: a Student Competition Aboard the International Space Station}, author = {David W Miller}, year = {2010}, date = {2010-01-01}, booktitle = {Next-Generation Suborbital Researchers Conference}, volume = {1534}, pages = {61--62}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
2009 |
Mandy, Christophe Ph Trajectory Design and Control for Formation Flying Spaceborne Interferometers By PhD Thesis 2009. BibTeX | Tags: @phdthesis{mandyTrajectoryDesignControl2009, title = {Trajectory Design and Control for Formation Flying Spaceborne Interferometers By}, author = {Christophe Ph Mandy}, year = {2009}, date = {2009-01-01}, number = {2006}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Takiguchi, Yu Emission of Whistler Waves from an Ionospheric Tether PhD Thesis 2009. BibTeX | Tags: @phdthesis{Takiguchi, title = {Emission of Whistler Waves from an Ionospheric Tether}, author = {Yu Takiguchi}, year = {2009}, date = {2009-01-01}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } |
Zorzos, Anthony Nicholas The Use of Ionic Liquid Ion Source in FIB Applications PhD Thesis 2009. @phdthesis{zorzosUseIonicLiquid2009, title = {The Use of Ionic Liquid Ion Source in FIB Applications}, author = {Anthony Nicholas Zorzos}, year = {2009}, date = {2009-01-01}, volume = {2}, number = {5}, abstract = {نتم}, keywords = {نتم}, pubstate = {published}, tppubtype = {phdthesis} } نتم |
McCamish, Shawn B; Romano, Marcello; Nolet, Simon; Edwards, Christine M; Miller, David W Flight testing of multiple-spacecraft control on SPHERES during close-proximity operations Journal Article Journal of Spacecraft and Rockets, 46 (6), pp. 1202–1213, 2009. BibTeX | Tags: @article{mccamish2009flight, title = {Flight testing of multiple-spacecraft control on SPHERES during close-proximity operations}, author = {Shawn B McCamish and Marcello Romano and Simon Nolet and Christine M Edwards and David W Miller}, year = {2009}, date = {2009-01-01}, journal = {Journal of Spacecraft and Rockets}, volume = {46}, number = {6}, pages = {1202--1213}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
McCamish, Shawn B; Romano, Marcello; Nolet, Simon; Edwards, Christine M; Miller, David W Flight testing of multiple-spacecraft control on SPHERES during close-proximity operations Journal Article Journal of Spacecraft and Rockets, 46 (6), pp. 1202–1213, 2009. BibTeX | Tags: @article{mccamish2009flightb, title = {Flight testing of multiple-spacecraft control on SPHERES during close-proximity operations}, author = {Shawn B McCamish and Marcello Romano and Simon Nolet and Christine M Edwards and David W Miller}, year = {2009}, date = {2009-01-01}, journal = {Journal of Spacecraft and Rockets}, volume = {46}, number = {6}, pages = {1202--1213}, keywords = {}, pubstate = {published}, tppubtype = {article} } |