Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Keyword
-
- Spacecraft (3)
- Artificial satellites--Attitude control systems (2)
- Reusable space vehicles (2)
- Space vehicles (2)
- Aerospace telemetry (1)
-
- Airships (1)
- Astronautics (1)
- Command and control systems (1)
- Control system (1)
- Electrons--Diffusion (1)
- Flexible (1)
- Flight control (1)
- Formations (1)
- Geostationary satellites (1)
- Gravity gradient booms (1)
- Launch vehicles (Astronautics) (1)
- Maneuvering (1)
- Modeling (1)
- Propellant (1)
- Radiation belts (1)
- Robust control (1)
- Simulation (1)
- Slew-maneuver (1)
- Sloshing (1)
- Space surveillance (1)
- Space vehicles--Atmospheric braking (1)
- Space vehicles--Atmospheric entry (1)
- Staging (Space flight) (1)
- Weight (Physics) (1)
- Publication
- Publication Type
Articles 1 - 25 of 25
Full-Text Articles in Space Vehicles
Arliss Come Back Competition - Summary, Robert J. Twiggs
Arliss Come Back Competition - Summary, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs on the "ARLISS Come Back Competition" from December 20, 2005.
Satellites In The Class Room, Robert J. Twiggs
Satellites In The Class Room, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs titled "Satellites in the Class Room" from December 2, 2005.
Contemporary-Classical Sequential Loop Design With Parameter Uncertainty, Donghyuk Jeong
Contemporary-Classical Sequential Loop Design With Parameter Uncertainty, Donghyuk Jeong
Mechanical & Aerospace Engineering Theses & Dissertations
Standard sequential loop closure design based on Evans root migration concepts is a well accepted, insightful and effective technique for meeting nominal performance objectives and traditional gain-phase stability margin requirements. Unfortunately, assessment of closed-loop variations resulting from parameter error is a post-process, implying an undesirable design-assess-redesign procedure is necessary if variations are found unacceptable. Further, the modem parameter uncertainty assessment framework is often inconsistent, both quantitatively and qualitatively, with the redesign task. Specifically, the parameter uncertainty assessment variables are not readily apparent in the sequential loop design framework, and these variables provide little guidance for the redesign strategy. Therefore, enhancing …
New Methodology For Robust Control System Design And Analysis For Single Parameter Uncertain Systems, Charles J. Player
New Methodology For Robust Control System Design And Analysis For Single Parameter Uncertain Systems, Charles J. Player
Mechanical & Aerospace Engineering Theses & Dissertations
Due to the conservative nature of the standard singular value robustness tests there is ambiguity in the results that they provide. The tests only establish a sufficient condition and therefore provide little insight to the stability robustness of a system that fails the test. However, for a single parameter uncertain system that is modeled using structured uncertainty, an Evans root locus can be derived that shows how system closed-loop poles change with the magnitude of the single parameter uncertainty. This technique provides clear stability robustness insight. Further, another Evans root locus can be derived that shows how system closed-loop zeros …
Hands-On, Go Do It Program, Robert J. Twiggs
Hands-On, Go Do It Program, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs titled "Hands-On, Go Do It Program" from September 14, 2005.
Privatization Of Space Ventures: Proposing A Proven Regulatory Theory For Future Extraterrestral Appropriation, Jonathan Thomas
Privatization Of Space Ventures: Proposing A Proven Regulatory Theory For Future Extraterrestral Appropriation, Jonathan Thomas
Brigham Young University International Law & Management Review
No abstract provided.
The University Cubesat Initiative: It's Global Acceptance, Some Present Projects And Speculation As To It's Future, Robert J. Twiggs
The University Cubesat Initiative: It's Global Acceptance, Some Present Projects And Speculation As To It's Future, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs titled "The University CubeSat Initiative: It's Global Acceptance, Some Present Projects and Speculation as to It's Future" from July 27, 2005.
Maneuvering Control Of A Spacecraft With Propellant Sloshing, Philip A. Savella
Maneuvering Control Of A Spacecraft With Propellant Sloshing, Philip A. Savella
Master's Theses - Daytona Beach
Propellant slosh has been a problem studied in spacecraft designs since the early days of large, liquid-fuel rockets. The conventional design solution involves physical structures inside the fuel tanks that limit propellant motion. Although effective, baffles and bladders add to spacecraft mass and structural complexity. In this research, the sloshing fuel mass is treated as an unactuated degree of freedom within a rigid body. Specifically, the propellant is modeled as a pendulum mass anchored at the center of a spherical tank. After obtaining the coupled equations of motion, several linear controllers are developed to achieve planar spacecraft pitch-maneuvers while suppressing …
Can A 10cm Cube Picosatellite Have Any Real Application In Space?, Robert J. Twiggs
Can A 10cm Cube Picosatellite Have Any Real Application In Space?, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs titled "Can a 10cm Cube Picosatellite Have Any Real Application in Space?" from May 13, 2005.
Stanford Satellite & Polar Programs: Polar Technology Conference, Robert J. Twiggs
Stanford Satellite & Polar Programs: Polar Technology Conference, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs titled "Stanford Satellite & Polar Programs: Polar Technology Conference" from April 23, 2005.
Studying The Troposphere, Stratosphere And Ionosphere Of The Earth, Per Hoeg
Studying The Troposphere, Stratosphere And Ionosphere Of The Earth, Per Hoeg
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Per Hoeg titled "Studying the Troposphere, Stratosphere and Ionosphere of the Earth" from April 7, 2005.
A New Use For Cubesats Utilizing Low Data Rate Downlinks: Stec2005, Robert J. Twiggs
A New Use For Cubesats Utilizing Low Data Rate Downlinks: Stec2005, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs titled "A New Use for CubeSats Utilizing Low Data Rate Downlinks: STEC2005" from April 6, 2005.
Modeling And Slew-Maneuver Control Of A Flexible Spacecraft, Jeremy E. Eckhart
Modeling And Slew-Maneuver Control Of A Flexible Spacecraft, Jeremy E. Eckhart
Master's Theses - Daytona Beach
Slew-maneuver control problem is studied for a flexible spacecraft consisting of a rigid main body to which a long flexible appendage is attached. Nonlinear dynamical system models are developed using both distributed parameter modeling and discrete parameter modeling; these models are shown to be equivalent for appropriately chosen system parameters. Lyapunov-based nonlinear feedback controllers are designed for the control of rigid-body motion while suppressing the lowest frequency vibrational mode. In case of large-angle maneuvers, these nonlinear controllers are shown to outperform the linearization-based controllers including the filtered proportional-derivative (PD) controllers as well as the linear quadratic regulator (LQR) controllers. Finally, …
Use Of Picosatellites & Rovers For Space Science And Education, Robert J. Twiggs
Use Of Picosatellites & Rovers For Space Science And Education, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs titled "Use of Picosatellites & Rovers for Space Science and Education" from April 1, 2005.
Performance Study Of Staging Variable On Two-Stage-To-Orbit Reusable Launch Vehicles, James K. Nilsen
Performance Study Of Staging Variable On Two-Stage-To-Orbit Reusable Launch Vehicles, James K. Nilsen
Theses and Dissertations
The purpose of this research is to investigate the effects of staging variables on Two-Stage-To-Orbit reusable launch vehicles, specifically, the question of what measurable factors play important roles in staging performance. Three different configurations (Rocket-Rocket, Turbojet-Rocket and Turbine Based Combined Cycle-Rocket) were considered. The software, Program to Optimize Simulated Trajectories (POST), was used to analyze these configurations. Vehicle coasting time, staging dynamic pressure and staging Mach number were all varied to determine their influence on the final payload.
A Numerical Analysis For Passive Attitude Stabilization Using A Tethered Balloon On A Gravity Gradient Satellite, Ernest Matias Maramba
A Numerical Analysis For Passive Attitude Stabilization Using A Tethered Balloon On A Gravity Gradient Satellite, Ernest Matias Maramba
Theses and Dissertations
This research effort analyzes the fundamental dynamics governing a satellite with a gravity gradient boom and a tethered balloon. Satellites that use gravity gradient booms for passive attitude control are characterized by undamped pitch oscillations and no roll control. The tethered balloon acts as a high drag device that accounts for the most drag on the satellite system. By attaching a drag device, the system resists rolling movements while also damping oscillations. This could potentially be a cost effective method for increasing satellite stabilization. The goal of this research is to model the dynamics and determine the feasibility of a …
Timing Of Increasing Electron Counts From Geosynchronous Orbit To Low Earth Orbit, Kirk M. Olson
Timing Of Increasing Electron Counts From Geosynchronous Orbit To Low Earth Orbit, Kirk M. Olson
Theses and Dissertations
Under certain conditions, high energy electron fluxes can increase over short periods of time in the outer radiation belt and diffuse to low altitudes. Sudden increases of high energy electron densities at low altitudes can drastically damage unsuspecting low-earth-orbit satellites. The progression of electron flux increases from a geosynchronous orbit to low-earth orbit during an electron event is somewhat unknown. If the beginning of electron flux increases at low-earth-orbits could be anticipated, warnings could be issued to space system operators allowing time to take proper measures to protect and minimize satellite damage extending satellite lifetimes and space mission operations. The …
Attitude Model Of A Reaction Wheel/Fixed Thruster Based Satellite Using Telemetry Data, Jason E. Smith
Attitude Model Of A Reaction Wheel/Fixed Thruster Based Satellite Using Telemetry Data, Jason E. Smith
Theses and Dissertations
Attitude determination of satellites is normally the job of inertial instruments, such as gyroscopes, or through sensing instruments, such as star trackers or Global Positioning Satellites (GPS). Satellite health monitoring systems watch and determine if the satellite deviates from its normal operating attitude orientation. Knowing the orientation of a satellite is essential in being able to control it in order to complete the satellite's designated mission. While there are a multitude of ways to determine a satellite's orientation, very little research has been done on determining if the attitude of a satellite can be determined directly from telemetry data of …
Weight Analysis Of Two-Stage-To-Orbit Reusable Launch Vehicles For Military Applications, Richard A. Caldwell
Weight Analysis Of Two-Stage-To-Orbit Reusable Launch Vehicles For Military Applications, Richard A. Caldwell
Theses and Dissertations
In response to Department of Defense (DoD) requirements for responsive and low-cost space access, this design study provides an objective empty weight analysis of potential reusable launch vehicle (RLV) configurations. Each two-stage-to-orbit (TSTO) RLV has a fixed payload requirement of 20,000 lbf to low Earth orbit. The propulsion systems considered in this study include pure rocket, pure turbine, rocket-based-combined-cycle (RBCC), and turbine-based-combined-cycle (TBCC). The hydrocarbon dual-mode scramjet (DMSJ) engines used in the RBCC and TBCC propulsion systems represent possible applications of the current research being performed in the U.S. Air Force HyTech program. Two sensitivity analyses were then performed on …
Technical Feasibility Of Loitering Lighter-Than-Air-Near-Space Maneuvering Vehicles, Eric R. Moomey
Technical Feasibility Of Loitering Lighter-Than-Air-Near-Space Maneuvering Vehicles, Eric R. Moomey
Theses and Dissertations
The near-space region of earth's atmosphere above 20 kilometers altitude is greatly underutilized. Lighter-than-air maneuvering vehicles, or airships, using the principle of buoyancy can take advantage of this region to become potential platforms for precision navigation, environmental monitoring, communication relays, missile warning, surveillance, and weapon delivery. These vehicles purportedly provide persistent coverage over large areas of the earth's surface at substantially lower costs than orbiting satellites. This study investigated the technical requirements to loiter an operational payload within this high altitude region using a lighter-than-air maneuvering platform. A parametric analysis was conducted to identify the critical technologies needed to achieve …
Investigation Of Aerobraking To Return The Space Maneuver Vehicle To Low Earth Orbit From Geotransfer Orbit, Benjamin M. Berlin
Investigation Of Aerobraking To Return The Space Maneuver Vehicle To Low Earth Orbit From Geotransfer Orbit, Benjamin M. Berlin
Theses and Dissertations
This study investigated the use of ballistic and Double-Dip'' aerobraking reentry to return the Space Maneuver Vehicle (SMV) from geotransfer orbit in no more than two atmosphere passes. Lift and drag accelerations were applied to the two-body problem when either of their magnitudes exceeded 1/1000 g. Lift and drag coefficients, along with the SMV model, were taken from Investigation of Atmospheric Reentry for the Space Maneuver Vehicle by Captain McNabb, AFIT/GA/ENY/04-M03. Target perigees were formulated using the two-body problem. The orbit from each target perigee was numerically integrated around a planar earth model using a fourth order Runge-Kutta method. Ballistic …
Katysat: Kids Aren’T Too Young For Satellites, Robert J. Twiggs, Ben Yuan
Katysat: Kids Aren’T Too Young For Satellites, Robert J. Twiggs, Ben Yuan
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs and Bob Yuan titled "Katysat: Kids Aren’t Too Young for Satellites" from February 8, 2005.
An Existing Global Heptane Mechanism Augmented With Diffusive Transport, Michael R. Foster, Howard Pearlman
An Existing Global Heptane Mechanism Augmented With Diffusive Transport, Michael R. Foster, Howard Pearlman
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
The couplings between diffusive transport and the temperature and species concentration distributions associated with low and intermediate temperature heptane oxidation are explored using an existing four-step heptane mechanism, tuned for elevated pressures. The energy and species concentration equations are augmented with diffusive fluxes for heat and species and solved numerically in a one-dimensional domain. The ignition delay times are also tabulated and compared with the zero-dimensional data reported in the literature.
Control System Design And Simulation Of Spacecraft Formations, Daniel Dyer
Control System Design And Simulation Of Spacecraft Formations, Daniel Dyer
Master's Theses - Daytona Beach
The objective of this thesis is to analyze an effective control scheme for a formation of spacecraft, implement that control, and provide a 3-D simulation. The thesis first summarizes the progress made in formation flight control schemes and then provides a theoretical framework for the control system design. Using established control design techniques, feedback laws are constructed to control both rotational and translational motion of a group of spacecraft. Computer simulations are carried out using Matlab to generate the ephemeris and attitude data, which are exported to Satellite Tool Kit (STK) to create animations. The process by which Matlab is …
The Katysat Project: Kids Aren’T Too Young (For Satellites), Benjamin Yuan
The Katysat Project: Kids Aren’T Too Young (For Satellites), Benjamin Yuan
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Benjamin Yuan titled "The KatySat Project: Kids Aren’t Too Young (for satellites)" from April 14, 2005.