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Full-Text Articles in Physical Sciences and Mathematics
Wind Climatology: A Study Of Trends On Rodgers' Dry Lakebed, Dana Coppernoll-Houston
Wind Climatology: A Study Of Trends On Rodgers' Dry Lakebed, Dana Coppernoll-Houston
STAR Program Research Presentations
A number of smaller projects at the Armstrong Flight Research Center fly on or close to the ground and are subject to ground-level winds. Many of these are new prototype models, such as PRANDTL-D (Preliminary Research Aerodynamic Design to Lower Drag). Waiting for the right conditions on a day of variable winds can sometimes mean that teams fail to complete testing. A strategic analysis of wind behavior at a locations where winds can vary greatly due to terrain could lend insight into the best times to test for near-ground aircraft. The purpose of this project was to data mine historical …
Metals Additive Manufacturing Powder Aging Characterization, Thomas Russell Lovejoy, Nicholas Karl Muetterties, David Takeo Otsu
Metals Additive Manufacturing Powder Aging Characterization, Thomas Russell Lovejoy, Nicholas Karl Muetterties, David Takeo Otsu
Mechanical Engineering
The metallic additive manufacturing process known as selective laser melting requires highly spherical, normally distributed powder with diameters in the range of 10 to 50 microns. Previous observations have shown a degradation in powder quality over time, resulting in unwanted characteristics in the final printed parts. 21-6-9 stainless steel powder was used to fabricate test parts, with leftover powder recycled back into the machine. Powder samples and test specimens were characterized to observe changes across build cycles. Few changes were observed in the physical and mechanical properties of the specimens, however, there were indications of chemical changes across cycles. Potential …
Directed Energy Missions For Planetary Defense, Philip Lubin, Gary Hughes, Mike Eskenazi, Kelly Kosmo, Isabella Johansson, Janelle Griswold, Mark Pryor, Hugh O'Neill, Peter Meinhold, Johnathan Suen, Jordan Riley, Qicheng Zhang, Kevin Walsh, Carl Melis, Miikka Kangas, Caio Motta, Travis Brashears
Directed Energy Missions For Planetary Defense, Philip Lubin, Gary Hughes, Mike Eskenazi, Kelly Kosmo, Isabella Johansson, Janelle Griswold, Mark Pryor, Hugh O'Neill, Peter Meinhold, Johnathan Suen, Jordan Riley, Qicheng Zhang, Kevin Walsh, Carl Melis, Miikka Kangas, Caio Motta, Travis Brashears
Statistics
Directed energy for planetary defense is now a viable option and is superior in many ways to other proposed technologies, being able to defend the Earth against all known threats. This paper presents basic ideas behind a directed energy planetary defense system that utilizes laser ablation of an asteroid to impart a deflecting force on the target. A conceptual philosophy called DE-STAR, which stands for Directed Energy System for Targeting of Asteroids and exploration, is an orbiting stand-off system, which has been described in other papers. This paper describes a smaller, stand-on system known as DE-STARLITE as a reduced-scale version …
A Fast High-Precision Six-Degree-Of-Freedom Relative Position Sensor, Gary B. Hughes, Van P. Macasaet, Janelle Griswold, Claudia A. Sison, Philip Lubin, Peter Meinhold, Johnathan Suen, Travis Brashears, Qicheng Zhang, Jonathan Madajian
A Fast High-Precision Six-Degree-Of-Freedom Relative Position Sensor, Gary B. Hughes, Van P. Macasaet, Janelle Griswold, Claudia A. Sison, Philip Lubin, Peter Meinhold, Johnathan Suen, Travis Brashears, Qicheng Zhang, Jonathan Madajian
Statistics
Lasers are commonly used in high-precision measurement and profiling systems. Some laser measurement systems are based on interferometry principles, and others are based on active triangulation, depending on requirements of the application. This paper describes an active triangulation laser measurement system for a specific application wherein the relative position of two fixed, rigid mechanical components is to be measured dynamically with high precision in six degrees of freedom (DOF). Potential applications include optical systems with feedback to control for mechanical vibration, such as target acquisition devices with multiple focal planes. The method uses an array of several laser emitters mounted …
Orbital Simulations On Deflecting Near Earth Objects By Directed Energy, Qicheng Zhang, Kevin J. Walsh, Carl Melis, Gary Hughes, Philip M. Lubin
Orbital Simulations On Deflecting Near Earth Objects By Directed Energy, Qicheng Zhang, Kevin J. Walsh, Carl Melis, Gary Hughes, Philip M. Lubin
Statistics
Laser ablation of a near-Earth object (NEO) on a collision course with Earth produces a cloud of ejecta that exerts a thrust on the NEO, deflecting it from its original trajectory. Ablation may be performed from afar by illuminating an Earth-targeting asteroid or comet with a stand-off "DE-STAR" system consisting of a large phased-array laser in Earth orbit. Alternatively, a much smaller stand-on "DE-STARLITE" system may travel alongside the target, slowly deflecting it from nearby over a long period. This paper presents orbital simulations comparing the effectiveness of both systems across a range of laser and NEO parameters. Simulated parameters …
Orbital Simulations On Deflecting Near-Earth Objects By Directed Energy, Qicheng Zhang, Kevin J. Walsh, Carl Melis, Gary B. Hughes, Philip M. Lubin
Orbital Simulations On Deflecting Near-Earth Objects By Directed Energy, Qicheng Zhang, Kevin J. Walsh, Carl Melis, Gary B. Hughes, Philip M. Lubin
Statistics
Laser ablation of a Near Earth Object (NEO) on a collision course with Earth produces a cloud of ejecta which exerts a thrust on the NEO, deflecting it from its original trajectory. Ablation may be performed from afar by illuminating an Earth-targeting asteroid or comet with a stand-off “DE-STAR” system consisting of a large phased-array laser in Earth orbit. Alternatively, a much smaller stand-on “DE-STARLITE” system may travel alongside the target, slowly deflecting it from nearby over a long period. This paper presents orbital simulations comparing the effectiveness of both systems across a range of laser and NEO parameters. Simulated …
Analysis Of The Precipitation Detection Algorithm For The Geonor T-200b Precipitation Gauge To Improve Accuracy, Megan Lerman, Robert K. Goodrich
Analysis Of The Precipitation Detection Algorithm For The Geonor T-200b Precipitation Gauge To Improve Accuracy, Megan Lerman, Robert K. Goodrich
STAR Program Research Presentations
In an effort to improve the precipitation detection algorithm for the Geonor All Weather Precipitation Gauge, an automated truth algorithm has been created to detect errors in the original algorithm. The original algorithm detects precipitation in real time and uses the rate of precipitation to indicate an event. The automated truth does not detect in real time, and focuses on precipitation accumulation to indicate an event. Since the automated truth is delayed, it is able to consider the data collected before and after the point it is analyzing. The automated truth is already more accurate than the original algorithm but …