Open Access. Powered by Scholars. Published by Universities.®

Aerospace Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

5,608 Full-Text Articles 6,991 Authors 2,171,447 Downloads 114 Institutions

All Articles in Aerospace Engineering

Faceted Search

5,608 full-text articles. Page 5 of 190.

Satellite Conjunction Assessment Risk Analysis For “Dilution Region” Events: Issues And Operational Approaches, Matthew D. Hejduk 2019 Astrorum Consulting LLC

Satellite Conjunction Assessment Risk Analysis For “Dilution Region” Events: Issues And Operational Approaches, Matthew D. Hejduk

Space Traffic Management Conference

An important activity within Space Traffic Management is the detection and prevention of possible on-orbit collisions between space objects. The principal parameter for assessing collision likelihood is the probability of collision, which is widely accepted among conjunction assessment practitioners; but it possesses a known deficiency in that it can produce a false sense of safety when the orbital position uncertainties for the conjuncting objects are high. The probability of collision is said to be “diluted” in such a situation and to understate the possible risk; certain approaches have been recommended by researchers to provide (largely conservative) risk estimates and remediation ...


End To End Satellite Servicing And Space Debris Management, Aman Chandra, Himangshu Kalita, Roberto Furfaro, Jekan Thanga 2019 Univ. of Arizona

End To End Satellite Servicing And Space Debris Management, Aman Chandra, Himangshu Kalita, Roberto Furfaro, Jekan Thanga

Space Traffic Management Conference

There is growing demand for satellite swarms and constellations for global positioning, remote sensing and relay communication in higher LEO orbits. This will result in many obsolete, damaged and abandoned satellites that will remain on-orbit beyond 25 years. These abandoned satellites and space debris maybe economically valuable orbital real-estate and resources that can be reused, repaired or upgraded for future use. Space traffic management is critical to repair damaged satellites, divert satellites into warehouse orbits and effectively deorbit satellites and space debris that are beyond repair and salvage. Current methods for on-orbit capture, servicing and repair require a large service ...


Lasers For Communication And Coordination Control Of Spacecraft Swarms, Himangshu Kalita, Leonard Dean Vance, Vishnu Reddy, Jekan Thanga 2019 University of Arizona

Lasers For Communication And Coordination Control Of Spacecraft Swarms, Himangshu Kalita, Leonard Dean Vance, Vishnu Reddy, Jekan Thanga

Space Traffic Management Conference

Swarms of small spacecraft offer whole new capabilities in Earth observation, global positioning and communications compared to a large monolithic spacecraft. These small spacecraft can provide bigger apertures that increase gain in communication antennas, increase area coverage or effective resolution of distributed cameras and enable persistent observation of ground or space targets. However, there remain important challenges in operating large number of spacecrafts at once. Current methods would require a large number of ground operators monitor and actively control these spacecraft which poses challenges in terms of coordination and control which prevents the technology from scaled up in cost-effective manner ...


Astria Ontology: Open, Standards-Based, Data-Aggregated Representation Of Space Objects, Jennie Wolfgang, Kathleen Krysher, Michael Slovenski, Unmil P. Karadkar, Shiva Iyer, Moriba K. Jah 2019 The University of Texas at Austin

Astria Ontology: Open, Standards-Based, Data-Aggregated Representation Of Space Objects, Jennie Wolfgang, Kathleen Krysher, Michael Slovenski, Unmil P. Karadkar, Shiva Iyer, Moriba K. Jah

Space Traffic Management Conference

The necessity for standards-based ontologies for long-term sustainability of space operations and safety of increasing space flights has been well-established [6, 7]. Current ontologies, such as DARPA’s OrbitOutlook [5], are not publicly available, complicating efforts for their broad adoption. Most sensor data is siloed in proprietary databases [2] and provided only to authorized users, further complicating efforts to create a holistic view of resident space objects (RSOs) in order to enhance space situational awareness (SSA).

The ASTRIA project is developing an open data model with the goal of aggregating data about RSOs, parts, space weather, and governing policies in ...


Near Real Time Satellite Event Detection And Characterization With Remote Photoacoustic Signatures, Justin Spurbeck, Moriba K. Jah 2019 University of Texas at Austin

Near Real Time Satellite Event Detection And Characterization With Remote Photoacoustic Signatures, Justin Spurbeck, Moriba K. Jah

Space Traffic Management Conference

Active satellites frequently maneuver to mitigate conjunctions and maintain nominal mission orbits. With an ever-growing Resident Space Object (RSO) population, the need to detect and predict any changes in active RSO trajectories has become increasingly important. There is typically a lag on the order of hours to days from time of maneuver to unmodeled dynamic event detection depending on the magnitude of the delta-v. For uncooperative objects, this detection lag poses a threat to other satellites. Implementing an active photoacoustic signature change detection methodology to detect and predict unmodeled dynamic events would reduce the overall conjunction risk and provide a ...


Space Objects Classification And Characterization Via Deep Learning And Light Curves: Applications To Space Traffic Management, Roberto Furfaro, Richard Linares, Vishnu Reddy 2019 University of Arizona

Space Objects Classification And Characterization Via Deep Learning And Light Curves: Applications To Space Traffic Management, Roberto Furfaro, Richard Linares, Vishnu Reddy

Space Traffic Management Conference

Recent advancements in deep learning (e.g. Convolutional Neural Networks (CNN), Recurrent Neural networks (RNN)) have demonstrated impressive results in many practical and theoretical fields (e.g. speech recognition, computer vision, robotics). Whereas deep learning methods are becoming ubiquitous, they have been barely explored in SSA applications, in particular with regard to object characterization for Space Traffic Management (STM).

In this paper, we report the results obtained in designing and training a set of CNNs and RNNs for Space Object (SO) classification and characterization using light-curve measurements. More specifically, we provide a comparison between deep networks trained on both physically-based ...


Nanosat Tracking And Identification Techniques And Technologies, Mark A. Skinner 2019 Aerospace

Nanosat Tracking And Identification Techniques And Technologies, Mark A. Skinner

Space Traffic Management Conference

Nanosats (and CubeSats, ‘Smallsats’, etc.) are of order 10 cm in size, and are at or near the limits of what can be tracked and characterized, using existing space surveillance assets. Additionally, given the CubeSat form-factor, they are often launched in large numbers (scores), and can be virtually identical. Thus are they difficult to track and to identify.

We have identified a number of technologies that future nanosat missions could employ that would enhance the trackability and/or identification of their satellites when on-orbit. Some of these technologies require active illumination of the satellite with electromagnetic energy, either in the ...


Framework For Evaluating Traffic Management Services In Higher Airspace, Jennifer Gentry, Debra Moch-Mooney, Anuja Mahashabde 2019 MITRE

Framework For Evaluating Traffic Management Services In Higher Airspace, Jennifer Gentry, Debra Moch-Mooney, Anuja Mahashabde

Space Traffic Management Conference

Flying faster, farther, longer and higher has always captured the public’s imagination. Yet there is a vast realm of airspace that remains unexplored, save for a handful of scientific and national security missions. It is a realm rife with extremes, where flights can reach multi-Mach speeds or stay aloft for months as they slowly circumnavigate the globe. It is a realm that lies high above the clouds, at the edge of space.

Recent breakthroughs in technology, fueled by a globalized economy and society’s appetite for information, have set the stage for routine commercial operations in this new realm ...


Human-In-The-Loop Landing Flare Flight Test Simulation Of The Spaceliner Orbiter, Frank Morlang 2019 DLR German Aerospace Center

Human-In-The-Loop Landing Flare Flight Test Simulation Of The Spaceliner Orbiter, Frank Morlang

Space Traffic Management Conference

Against the background that all future air traffic participants are requested to act as System Wide Information Management (SWIM) communicating sub-systems by the future Single European Sky Air Traffic Management Research (SESAR) SWIM 'Intranet for ATM' concept, facing the challenge of integration of space traffic in the current Air Traffic Management (ATM) needs SWIM compliance of future commercial space transportation (CST) vehicles having “landing like an aircraft at an airport” characteristics. In order to evaluate future spacecraft cockpit procedures in a transition context from Aircraft Access to SWIM (AAtS) to Spacecraft Access to SWIM in a network wide airspace management ...


A Statistical Approach For Commercial Space Vehicle Integration Into The National Airspace System, Christopher Hays, Daniel Chu, Pedro Llanos 2019 Embry-Riddle Aeronautical University

A Statistical Approach For Commercial Space Vehicle Integration Into The National Airspace System, Christopher Hays, Daniel Chu, Pedro Llanos

Space Traffic Management Conference

This paper explores commercial space vehicle (CSV) suborbital flight trajectories in the temporal and spatial domains for CSV integration into the National Airspace System. The research data was collected via the Suborbital Space Flight Simulator (SSFS) housed in the College of Aviation at Embry-Riddle Aeronautical University - Daytona Beach campus, and analyzed using an original MATLAB data analytics tool. This study primarily focuses on statistical trends observed in previously simulated flights supported by three Project PoSSUM (Polar Suborbital Science in the Upper Mesosphere) campaigns comprised of 34 flights and 19 control flights, and to identify relevant milestones in the CSV flight ...


Enhancing Suborbital Science Through Better Understanding Of Wind Effects, Pedro Llanos, Diane Howard 2019 Embry-Riddle Aeronautical University - Daytona Beach

Enhancing Suborbital Science Through Better Understanding Of Wind Effects, Pedro Llanos, Diane Howard

Space Traffic Management Conference

This paper highlights the importance of understanding some key factors, such as winds effects, trajectory and vehicle parameters variations in order to streamline the space vehicle operations and enhance science in the upper mesosphere at about 85 km. Understanding these effects is crucial to refine current space operations and establish more robust procedures. These procedures will involve training new space operators to conduct and coordinate space operations in class E above FL600 airspace within the Air Traffic Organization (ATO).

Space vehicles such as Space Ship Two can spend up to 6 minutes in class E airspace above FL600 after launch ...


Sure Abstract - Spring 2019: Biomimetic Metamaterial Scales Enhancing Thermal Coatings’ Mechanical Properties For Turbine Blades, Ryan Horton 2019 University of Central Florida

Sure Abstract - Spring 2019: Biomimetic Metamaterial Scales Enhancing Thermal Coatings’ Mechanical Properties For Turbine Blades, Ryan Horton

Ryan Horton

No abstract provided.


Naturacel Cream United Kingdom - Skin Care Beauty Cream Buy Online Store?, NaturaCel Cream 2019 University of California, San Francisco

Naturacel Cream United Kingdom - Skin Care Beauty Cream Buy Online Store?, Naturacel Cream

NaturaCel Cream

NaturaCel Cream United KingdomOn the off chance that you've been on the chase for new healthy skin items, we realize that you've most likely observed huge amounts of new items. All things considered, the present new item is NaturaCel Cream United Kingdom. On the off chance that you've officially known about this item, we presume you may as of now be on the temporary fad for this item. NaturaCel Cream United KingdomBe that as it may, on the off chance that not, at that point today we're planning to give you somewhat more data ...


A Higher-Order Method Implemented In An Unstructured Panel Code To Model Linearized Supersonic Flows, Jake Daniel Davis 2019 Cal Poly-San Luis Obispo

A Higher-Order Method Implemented In An Unstructured Panel Code To Model Linearized Supersonic Flows, Jake Daniel Davis

Master's Theses and Project Reports

Since their conception in the 1960s, panel codes have remained a critical tool in the design and development of air vehicles. With continued advancement in computational technologies, today's codes are able to solve flow fields around arbitrary bodies more quickly and with higher fidelity than those that preceded them. Panel codes prove most useful during the conceptual design phase of an air vehicle, allowing engineers to iterate designs, and generate full solutions of the flow field around a vehicle in a matter of seconds to minutes instead of hours to days using traditional CFD methods. There have been relatively ...


Slip Of Shuffle Screw Dislocations Through Tilt Grain Boundaries In Silicon, Hao Chen, Valery Levitas, Liming Xiong 2019 Iowa State University

Slip Of Shuffle Screw Dislocations Through Tilt Grain Boundaries In Silicon, Hao Chen, Valery Levitas, Liming Xiong

Aerospace Engineering Publications

In this paper, molecular dynamics (MD) simulations of the interaction between tilt grain boundaries (GBs) and a shuffle screw dislocation in silicon are performed. Results show that dislocations transmit into the neighboring grain for all GBs in silicon. For Σ3, Σ9 and Σ19 GBs, when a dislocation interacts with a heptagon site, it transmits the GB directly. In contrast, when interacting with a pentagon site, it first cross slips to a plane on the heptagon site and then transmits the GB. The energy barrier is also quantified using the climbing image nudged elastic band (CINEB) method. Results show that Σ3 ...


Environmental Performance Analysis Of Solid Freedom Fabrication Processes, Yanchun Luo, Zhiming Ji, Ming-Chuan Leu, R. J. Caudill 2019 Missouri University of Science and Technology

Environmental Performance Analysis Of Solid Freedom Fabrication Processes, Yanchun Luo, Zhiming Ji, Ming-Chuan Leu, R. J. Caudill

Ming C. Leu

This paper presents a method for analyzing the environmental performance of solid freeform fabrication (SFF) processes. In this method, each process is divided into life phases. Environmental effects of every process phase are then analyzed and evaluated based on the environmental and resource management data. These effects are combined to obtain the environmental performance of the process. The analysis of the environmental performance of SFF processes considers the characteristics of SFF technology, includes material, energy consumption, processes wastes, and disposal. Case studies for three typical SFF processes: stereolithography (SL); selective laser sintering (SLS); and fused deposition modeling (FDM) are presented ...


Characteristics And Optimal Design Of Variable Airgap Linear Force Motors, Ming-Chuan Leu, E. V. Scorza, D. L. Bartel 2019 Missouri University of Science and Technology

Characteristics And Optimal Design Of Variable Airgap Linear Force Motors, Ming-Chuan Leu, E. V. Scorza, D. L. Bartel

Ming C. Leu

An analytical model for predicting the characteristics of variable airgap linear force motors is developed. the model takes into account magnetic losses including the leakage and fringing effects and the reluctance existing at the contacts between permanent magnets and pole pieces. the model is validated by comparing its predicted characteristics with the results obtained from experiments and a finite element program. with the use of the modelled characteristics, computer programs based on the method of constrained steepest descent with state equations are developed for automating and optimising the design of linear force motors. Numerical studies are made for both minimisation ...


Cell Mapping Based Fuzzy Control Of Car Parking, Tea-Quin Kim, Ming-Chuan Leu 2019 Missouri University of Science and Technology

Cell Mapping Based Fuzzy Control Of Car Parking, Tea-Quin Kim, Ming-Chuan Leu

Ming C. Leu

This paper describes the development of a near-optimal fuzzy controller for maneuvering a car in a parking lot. To generate the rules of the fuzzy controller, a cell mapping method is utilized to systematically generate near-optimal trajectories for all possible initial states in the parking lot. Based on the input-output relations of these trajectories, which represent the states and controls of the corresponding cells, a set of fuzzy rules are generated automatically. In order to result in a small number of fuzzy rules from the large amount of numerical information generated by cell mapping, grouping of trajectories is proposed and ...


An Internet Based Intelligent Argumentation System For Collaborative Engineering Design, Xiaoqing Frank Liu, Samir Raorane, Man Zheng, Ming-Chuan Leu 2019 Missouri University of Science and Technology

An Internet Based Intelligent Argumentation System For Collaborative Engineering Design, Xiaoqing Frank Liu, Samir Raorane, Man Zheng, Ming-Chuan Leu

Ming C. Leu

Modern product design is a very complicated process which involves groups of designers, manufacturers, suppliers, and customer representatives. Conflicts are unavoidable in collaboration among multiple stakeholders, who have different objectives, requirements, and priorities. Unfortunately, current web-based collaborative engineering design systems do not support collaborative conflict resolution. In this paper, we will develop an intelligent computational argumentation model to enable management of a large scale argumentation network, and resolution of conflicts based on argumentation from many participants. A web-based intelligent argumentation tool is developed as a part of a web-based collaborative engineering design system based on the above model to resolve ...


Amplitude Modulated Droplet Formation In High Precision Solder Droplet Printing, Qingbin Liu, M. Orme, Ming-Chuan Leu 2019 Missouri University of Science and Technology

Amplitude Modulated Droplet Formation In High Precision Solder Droplet Printing, Qingbin Liu, M. Orme, Ming-Chuan Leu

Ming C. Leu

There are many methods used at present to apply solder to wafers, ceramics, laminate and flex circuit boards, and other substrates. Among these, high-precision solder droplet printing technology, which is noncontact, data driven, flexible and environmentally friendly, is a key enabling technology. This technology selectively deposits solder droplets only where required, and therefore needs no mask or secondary resist removal, uses materials more efficiently and creates less waste than other methods. Currently, continuous droplet formation from capillary streams is mainly achieved by application of the well-known Rayleigh instability in which a sinusoidal disturbance is applied to the stream, resulting in ...


Digital Commons powered by bepress