Popular Videos | Expanded | NESC Academy Online

Model-Centric Engineering, Part 1: Introduction to Model-Based Systems Engineering

Presenter	Dr. Daniel Dvorak
Published	December 2013
Recorded	October 2012
Duration	01:00:47
Tags	#Intermediate, #Advanced, #Fundamental, #State of the Art, ~Model Based Systems Engineering

Discipline: Systems Engineering For examples of how NASA uses model-based systems engineering, use the "Systems Engineering Webcast Series" link.

Shock & Vibration: 01. Natural Frequencies, Part 1

Presenter	Tom Irvine
Published	February 2014
Recorded	February 2014
Duration	56:56
Tags	#Fundamental, ~Natural Frequencies, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

7 Habits of Highly Effective (NASA) Systems Engineers

Presenter	NASA
Published	September 2018
Recorded	September 2018
Duration	01:22:22
Tags	#Intermediate, #Advanced, #Fundamental, #State of the Art, .Lessons Learned, ~Applied Systems Engineering

Successful NASA projects are a complex balancing act of meeting scientific and technical requirements, while managing schedule, cost, and risk. In a Virtual Project Management Challenge (VPMC), we learned that highly effective program manager share key habits—habits that anyone can develop to improve their performance. In this follow up to that session, we turn our focus to systems engineers. Specifically, "What are the qualities of an effective systems engineer?" In addition to looking at the research, we asked our viewers. Hundreds of VPMC viewers responded, ranking the characteristics of effective systems engineers. In this session of the VPMC, we will present the top seven characteristics of effective systems engineers as identified by our viewer poll. For each characteristic, a NASA systems engineer will illustrate how they successfully applied that characteristic to their project work. In addition to describing the characteristic in action, each presenter will provide advice on how others might develop their project management competencies. Please note: presenters for this VPMC will appear via pre-recorded interviews, so there will not be a question and answer session.

Short Course on Lithium-ion Batteries: Fundamental Concepts, Battery Safety, and Modeling Techniques

Presenter	William Walker
Published	February 2019
Recorded	November 2018
Duration	02:18:28
Tags	#Fundamental, .Hardware

Originally aired December 4, 2018. Disciplines: Passive Thermal, Electrical Power This short course provides participants with an in-depth discussion on three aspects of lithium-ion (Li-ion) batteries. First an understanding of Li-ion battery fundamentals is provided through a brief discussion centered on the aerospace industry’s choice to use Li-ion batteries, general performance characteristics, electrochemical reaction basics, and the heat generated during nominal operation. Secondly, Li-ion battery safety is addressed with respect to thermal runaway and battery safety. Lastly, this course will lead the participants through the basic construction process of a thermal model of a Li-ion battery assembly that is capable of simulating nominal heating and thermal runaway heating. The overall goal of the course is to provide participants with an in-depth understanding of both the fundamental and thermal aspects of Li-ion batteries.

Common Thermal Modeling Mistakes, Part 1

Presenter	Ruth Amundsen
Published	October 2016
Recorded	September 2016
Duration	01:15:04
Tags	#Fundamental, .Analysis / Modeling and Simulation

Discipline: Passive Thermal This presentation was recorded at the Thermal & Fluids Analysis Workshop (TFAWS) on August 3rd, 2016. This course will cover the some of the common mistakes made in thermal modeling, and how to avoid them. Thermal Desktop will be used as a platform to demonstrate many of the common errors by both new analysts as well as experienced engineers in building a thermal model. Other non-software-associated errors will also be covered. Topics covered will include common errors in assumptions, materials, configurations, radiation, orbital analysis, and common faults in problem setup, analysis case runs and record-keeping. The course should help you as an engineer to watch for these common errors in the future, and help you avoid them.

Model-Centric Engineering, Part 2: Introduction to System Modeling

Presenter	Steve Jenkins
Published	March 2014
Recorded	April 2013
Duration	01:04:04
Tags	#Intermediate, #Advanced, #Fundamental, #State of the Art, ~Model Based Systems Engineering

Discipline: Systems Engineering For examples of how NASA uses model-based systems engineering, use the "Systems Engineering Webcast Series" link.

An Overview of Fastener Requirements in the new NASA-STD-5020

Presenter	Robert Wingate
Published	April 2013
Recorded	April 2013
Duration	01:13:10
Tags	#Intermediate, .Analysis / Modeling and Simulation, .Testing, .Hardware, ~Fastener, ~Locking Features

Discipline: Mechanical Systems NASA-STD-5020 “Requirements for Threaded Fastening Systems in Spaceflight Hardware” was created to provide an Agency-wide consensus standard to provide uniform requirements for design and analysis of threaded fastening systems in spaceflight hardware across all NASA programs and projects. The development of the standard resulted from a NESC assessment initiated in 2006 following several costly fastener issues on NASA projects and many recent debates over fastener design and analysis criteria. The new standard was also intended replace and improve upon NSTS 08307 “Criteria for Preloaded Joints,” which had become the de facto NASA standard for fastener analysis across multiple programs and projects even though it was a Space Shuttle Program standard and would be withdrawn at the conclusion of the program. This webcast will provide an overview of the contents of the new standard, including rationale for differences from NSTS 08307, and case studies to illustrate application of some of the concepts.

Fundamentals of Aircraft Engine Control

Presenter	Dr. Sanjay Garg
Published	November 2011
Recorded	October 2011
Duration	55:15
Tags	#Fundamental, .Design, ~Control Design, ~Control Systems

The fundamental control problem for turbomachinery based aircraft engines is to provide the right amount of fuel needed for the engine to produce a desired power (or thrust), based on the pilot's power request through a throttle (or a power lever), and maintain the engine power at the desired level in the presence of air flow disturbance and changes in flight conditions. In-flight engine thrust measurements are not possible. So some other measurable parameters which are good indicators of thrust, such as engine shaft rotational speed (N) or engine pressure ratio (EPR) are regulated by the engine control. An aircraft engine is designed to operate in a wide operating envelope in terms of altitude and speed variations. To a control engineer, these challenges are represented on a fuel flow (Wf) versus engine shaft speed (N) graph, or a fuel ratio unit (Wf/P3, where P3 is the compressor exit static pressure) versus speed graph. The control design challenge is then to be able to transition from one operating point to another while staying within the safe operational limits represented by the max. and min. fuel flow limits as well as the structural limits of the various engine components. The max. flow limit prevents the engine from over-temperature while the min. flow limit prevents the engine from flame-out. Other operational safety limits that are important are surge/stall avoidance and maximum shaft rotational speed. This lecture will cover the basic principles behind modeling the engine system for control design and how the various safety and operational limits are implemented in the engine control to provide safe and reliable operation over the flight envelope.

Rationale for Selected MIL-STD-1540E Thermal Test Requirements

Presenter	John W Welch
Published	December 2012
Recorded	September 2012
Duration	37:34
Tags	#Intermediate, .Testing

Discipline: Passive Thermal

Shock & Vibration: 13. Power Spectral Density Function

Presenter	Tom Irvine
Published	November 2014
Recorded	October 2014
Duration	01:04:38
Tags	#Intermediate, ~Power Spectral Density, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Fundamentals of Launch Vehicle Flight Control System Design

Presenter	John Rakoczy
Published	May 2012
Recorded	May 2012
Duration	52:10
Tags	#Fundamental, .Design, ~Control Design, ~Flight Control Systems

This presentation is intended to be an introductory overview of launch vehicle guidance, navigation and control for ascent. We will look at the big picture of how these three disciplines are interconnected in a launch vehicle design, and we will look at the flow of the design process. We will see how GN&C design relies on and influences many project stakeholders. Then we will look at each of the three disciplines, individually. Some key issues and design implementations will be pointed out in each of the three disciplines. Recent experiences from Ares I design will be used to illustrate some of the concepts.

Structural Analysis Part 1

Presenter	Dr. Ivatury Raju
Published	July 2013
Recorded	February 2012
Duration	39:59
Tags	#Fundamental, .Analysis / Modeling and Simulation, .Lessons Learned, ~Structural Analysis, ~Stress Analysis, ~Boundary Conditions, ~Building Blocks Approach

Discipline - Structures

High Voltage Engineering Techniques for Space Applications: Part 1, Background Engineering Discussion

Presenter	Steve Battel
Published	July 2013
Recorded	June 2012
Duration	01:08:51
Tags	#Intermediate, ~Voltage System, ~Power Supply, ~Power System, ~Electric Field, .Design, .Materials, .Hardware

Discipline: Electrical Power Presented via Webcast on April 2-3, 2012

Fundamentals of Kalman Filtering and Estimation

Presenter	Chris D'Souza
Published	March 2013
Recorded	January 2013
Duration	59:16
Tags	#Fundamental, .Design, ~Navigation

Kalman Filtering and Least Squares Estimation have been at the heart of the GNC system design within the US Space Program since it's inception. Yet, there is a great deal of mystique surrounding the subject because it requires a modicum of familiarity with linear analysis, nonlinear analysis, optimization, and statistics. This goal of this seminar is to present a gentle introduction to Kalman Filtering and estimation to those who aren't familiar with the topic, or who have viewed it with fear and trepidation. Beginning with linear systems, the basic concepts will be introduced, and several examples will serve to flesh out the concepts. There will be an emphasis on practical implications and implementations of these concepts, with an eye toward helping develop intuition and demystifying the field.

Shock & Vibration: 06. Random Vibration

Presenter	Tom Irvine
Published	October 2014
Recorded	February 2014
Duration	56:22
Tags	#Intermediate, #Fundamental, ~Random Vibration, .Analysis / Modeling and Simulation, ~White Noise

Discipline: Loads & Dynamics

Shock & Vibration: 02. Natural Frequencies, Part 2

Presenter	Tom Irvine
Published	February 2014
Recorded	February 2014
Duration	50:54
Tags	#Intermediate, #Fundamental, ~Natural Frequencies, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Standard Check-Cases for Six-Degree-of-Freedom Flight Vehicle Simulations

Presenter	Daniel Murri
Published	June 2015
Recorded	April 2015
Duration	01:03:03
Tags	#Intermediate, .Analysis / Modeling and Simulation, .Environments, .Systems / Subsystems, .Other, ~Flight Mechanics

Discipline: Flight Mechanics Original Webcast Air Date: April 21, 2015 The rise of innovative unmanned aeronautical systems and the emergence of commercial space activities have resulted in a number of relatively new aerospace organizations that are designing innovative systems and solutions. These organizations use a variety of commercial off-the-shelf and in-house-developed simulation and analysis tools including 6-degree-of-freedom (6-DOF) flight simulation tools. The increased affordability of computing capability has made high-fidelity flight simulation practical for all participants. Verification of the tools’ equations-of-motion and environment models (e.g., atmosphere, gravitation, and geodesy) is desirable to assure accuracy of results. However, aside from simple textbook examples, minimal verification data exists in open literature for 6-DOF flight simulation problems. The NESC undertook an assessment that compared multiple solution trajectories to a set of verification check-cases that covered atmospheric and exo-atmospheric (i.e., orbital) flight. Each scenario consisted of redefined flight vehicles, initial conditions, and maneuvers. These scenarios were implemented and executed in a variety of analytical and real-time simulation tools. This tool-set included simulation tools in a variety of programming languages based on modified flat-Earth, round-Earth, and rotating oblate spheroidal Earth geodesy and gravitation models, and independently derived equations-of-motion and propagation techniques. The resulting simulated parameter trajectories were compared by over-plotting and difference-plotting to yield a family of solutions. In total, seven simulation tools were exercised. The check cases and the generated family of solutions are now available for download from the NESC Academy web-site for use in cross comparison with other simulation tools. This webast will give an overview of the check-cases, the comparison approach, the types of differences remaining in the comparison set, and an introduction to the contents of the “flightsim” website where the check case descriptions and generated results are stored.

Model-Centric Engineering, Part 3: Foundational Concepts for Building System Models

Presenter	Steve Jenkins
Published	April 2015
Recorded	September 2014
Duration	01:13:22
Tags	#Intermediate, #Advanced, #Fundamental, #State of the Art, ~Model Based Systems Engineering

Discipline: Systems Engineering For examples of how NASA uses model-based systems engineering, use the "Systems Engineering Webcast Series" link.

An Overview of Spacecraft Attitude Determination and Estimation

Presenter	John Crassidis
Published	January 2013
Recorded	July 2012
Duration	01:01:44
Tags	#Fundamental, .Design, ~Navigation, ~Spacecraft Attitude

This webcast will provide a general overview of attitude determination estimation. First, a review of attitude kinematics, in particular quaternions, is shown. Then, a solution to the point-by-point batch least squares problem, known as Wahba’s problem, is given. The attitude covariance is then derived and its relationship to maximum likelihood is shown. Next, an attitude Kalman filter-based estimator using attitude and gyro measurements coupled with quaternion kinematics is derived. Examples from practical scenarios and real missions are shown.

Fundamentals of Spacecraft Attitude Control

Presenter	Scott Starin
Published	July 2012
Recorded	June 2012
Duration	58:54
Tags	#Fundamental, .Design, ~Attitude Control, ~Control Design, ~Control Systems

Spacecraft attitude control systems are onboard systems that autonomously orient a spacecraft relative to a target reference frame. Spacecraft operate in a regime of very little disturbance torque as compared to atmospheric vehicles, and we therefore have greater expectations for their accuracy and stability. An understanding of the disturbance environments in various flight regimes is critical to design choices. Means of attitude stabilization run the gamut from passive to active methods and from spin-stabilized to zero-momentum three-axis stabilized systems. Control methods derive from the same body of control theory as other modern systems, with control bandwidths often in a range of much less than 1 Hz to avoid control-structure interaction. Attitude dynamics are inherently nonlinear but only occasionally require nonlinear control techniques, as the typically slow rate of attitude change usually allows linear design techniques to work well. Related topics that will be briefly addressed include attitude estimation techniques, attitude ground systems, and jitter (attitude motion outside the control bandwidth).

Systems Engineering & Model Based Systems Engineering Stakeholder State of the Discipline

Presenter	Jessica Knizhnik
Published	November 2020
Recorded	June 2020
Duration	01:02:54
Tags	#Intermediate, #Advanced, #Fundamental, #State of the Art, .Lessons Learned, ~Model Based Systems Engineering

Abstract: Join us as we discuss the results of a “comprehensive” study, conducted by the Systems Engineering TDT, in a special webinar. Find out where the SE discipline, in the aerospace industry, has opportunity for improvement and how cultural issues remain the number one challenge to MBSE implementation. We’ll also be discussing opportunities where NASA and its stakeholders can move forward together in SE innovation. Anyone interested in SE and its future, from systems engineers, MBSE practitioners, managers, and NASA partners are invited to attend. A full detailed report of study results that goes beyond the overview’s executive conclusions is also available. Both can be found at https://www.nasa.gov/nesc/articles/se-mbse-state-of-the-discipline Please join us in this informative discussion.

Shock & Vibration: 05. Sine Sweep Vibration

Presenter	Tom Irvine
Published	October 2014
Recorded	February 2014
Duration	45:36
Tags	#Intermediate, ~Natural Frequencies, .Analysis / Modeling and Simulation, ~Thrust Oscillation

Discipline: Loads & Dynamics

NASA Space Situational Awareness (SSA) Overview

Presenter	Lauri Kraft Newman
Published	July 2012
Recorded	June 2012
Duration	50:37
Tags	#Fundamental, .Environments

SSA is defined as "the requisite current and predictive knowledge of the space environment and the operational environment upon which space operations depend". SSA provides knowledge and understanding of threats posed to space systems by adversaries and the environment and is essential in developing and employing space asset protection measures. NASA is both a provider and consumer of SSA data. This talk will describe the Agency's role in SSA, with particular emphasis on the robotic conjunction assessment effort. SSA policy, procedures, interfaces, and goals will be discussed.

1. Overview and Introduction to Passive Thermal Control and Thermal Protection

Presenter	Steven L. Rickman
Published	December 2010
Recorded	November 2011
Duration	30:07
Tags	#Fundamental

Discipline: Passive Thermal Steve Rickman is the Technical Fellow for Passive Thermal discipline. In this overview he gives an introduction Passive Thermal Control and Thermal Protection. Keywords: Steve Rickman, Technical Fellow, Passive Thermal, Thermal Protection, Overview and Introduction to Passive Thermal Control and Thermal Protection, Discipline. Heat Transfer Conduction Convection Radiation Passive Thermal Control Thermal Protection Insulation Reusable Thermal Protection Ablative Thermal Protection Hot Structure

Lessons Learned on Past Manned Spaceflight Programs That Seem to Have Been Forgotten

Presenter	Bass Redd
Published	July 2011
Recorded	December 2011
Duration	52:04
Tags	#Fundamental, .Lessons Learned

Discipline: Aerosciences

Introduction to the International Space Station

Presenter	Dr. Donna Dempsey
Published	March 2017
Recorded	February 2017
Duration	57:02
Tags	#Fundamental, .Operations, ~ISS, ~ISS Modules, ~International Partners

Discipline: Human Factors Webcast Air Date: March 14, 2017 This presentation introduces the audience to the International Space Station (ISS) modules. Each of the modules is presented and the function or purpose of the module is briefly described. Time permitting, the presentation will end with a video sequence showing the assembly of the ISS and a separate video showing a tour of the interior of the ISS.

Shock & Vibration: 09. Fast Fourier Transform (FFT)

Presenter	Tom Irvine
Published	October 2014
Recorded	September 2014
Duration	01:10:02
Tags	#Intermediate, #Fundamental, ~Fourier Transform, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Shock & Vibration: 04. Sine Vibration

Presenter	Tom Irvine
Published	October 2014
Recorded	February 2014
Duration	59:02
Tags	#Intermediate, ~Response Acceleration, .Analysis / Modeling and Simulation, ~Pogo, ~Thrust Oscillation

Discipline: Loads & Dynamics

Shock & Vibration: 14. Power Spectral Density Data

Presenter	Tom Irvine
Published	February 2015
Recorded	December 2014
Duration	42:35
Tags	#Intermediate, ~Power Spectral Density, .Analysis / Modeling and Simulation, ~White Noise

Discipline: Loads & Dynamics

How To Make the Most of Your Human: Design Considerations for Single Pilot Operations

Presenter	Paul Schutte
Published	March 2016
Recorded	February 2016
Duration	59:45
Tags	#Intermediate, .Design, ~Automation, ~Allocation of Tasks, ~Human Capabilities, ~Human Limitations, ~Unanticipated Events, ~Fluid Automation

Webcast Air Date: 3/17/2016 Discipline: Human Factors There is no doubt that commercial aviation is one of the safest forms of long distance travel available today. The annual accident rate per million departures has, on average, continued to decrease over time and is now so close to zero that the results are perhaps driven more by chance than any trend in operational factors. Yet for those accidents that do occur, a majority of them are attributed to human error. Unfortunately, this has led to the belief that the flight crew is more of a liability than an asset when it comes to aviation safety. Indeed, many have used this statistic to call for fully automated aircraft; their logic being that if humans are the cause for a significant portion of the accidents, then removing the human from the flight deck will dramatically increase safety. Closer inspection reveals several flaws in this logic. First, while there is significant correlation between the increase in automation and the increase in safety, there does not appear to be much proof of causality. In the nineties as automation became more the norm, but CRM training and practices also became the norm during this period along with improved manufacturing and maintenance operations. Secondly, while human failures may have been the primary causes in accidents, in most cases, there is no evidence that automation would have fared any better. Finally, humans are also involved in other aspects of aviation – design, manufacture, programming, operation, and maintenance. These humans will continue to make errors, but without the pilot, there will be no one to catch these errors during the flight. The first part of this talk will describe how removing pilots will not eliminate human error and that the negative effects of human error might become more problematic and dangerous without pilots. The second part briefly describes how the primary role of the pilot on flight deck is not simply mission monitoring/management but is avoiding and compensating for the complex, unanticipated, and dangerous situations that arise. The third part argues that the current allocation of tasks and functions between the flight crew and automation can significantly hinder the pilot’s ability to perform their primary role. Finally, suggestions are provided for potentially better function allocation schemes, largely applicable to new flight deck designs, but that could also be implemented in current aircraft design.

Shock & Vibration: 07. Fourier Transform

Presenter	Tom Irvine
Published	September 2014
Recorded	September 2014
Duration	56:57
Tags	#Intermediate, #Fundamental, ~Fourier Transform, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

How to Get Started Using MBSE on a Project: The Basics of What, How and Who

Presenter	Trevor Grondin
Published	August 2020
Recorded	June 2020
Duration	57:49
Tags	#Intermediate, #Advanced, #Fundamental, #State of the Art, ~Model Based Systems Engineering

Model-based Systems Engineering is seeing a lot of attention lately. Many projects at NASA have started using MBSE on some portion of their SE work. The long list of proposed benefits for MBSE is impressive, but can MBSE be used throughout a project life-cycle? Should MBSE be an "all-or-nothing" decision when doing project planning? Answering these questions can be intimidating for individuals who are new to MBSE, or those that have only seen successes in small areas of the SE function, but are not able to visualize how to use MBSE across a whole project. This talk helps to define the process of starting Systems Engineering on any project, and how MBSE ties in to it. Through the lens of "modeling with a purpose", Trevor Grondin walks through how to examine the Systems Engineering role for a given project, and how to assess using MBSE to add value to the work being done. From sizing the scope of the work, assessing uses of MBSE, and identifying project constraints, to developing a modeling plan that support the Systems Engineering approach, this talk will help arm modelers and LSEs alike with the framework they need to start using MBSE on a project.

Shock & Vibration: 03. Natural Frequencies, Part 3

Presenter	Tom Irvine
Published	August 2014
Recorded	February 2014
Duration	55:33
Tags	#Intermediate, #Fundamental, ~Natural Frequencies, .Analysis / Modeling and Simulation, .Testing, ~Shaker Table

Discipline: Loads & Dynamics

Shock & Vibration: 47. PSD Special Topics

Presenter	Tom Irvine
Published	June 2015
Recorded	April 2015
Duration	55:43
Tags	#Intermediate, ~Power Spectral Density, ~Signal Analysis, ~Frequency Response, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Aerodynamic Performance Testing

Presenter	Fran Capone
Published	May 2017
Recorded	April 2017
Duration	42:31
Tags	#Intermediate, .Analysis / Modeling and Simulation

Discipline: Aerosciences Fran Capone, Bob Berrier and Larry Leavitt spent a majority of their NASA careers at the LaRC 16-Foot Transonic Tunnel conducting research in propulsion airframe integration (PAI). From WWII through its closure in 2004, the 16 Ft was at the center of PAI testing – practically every military vehicle was tested there. Fran, Bob and Larry have a tremendous amount of experience conducting PAI testing on a wide range of vehicles including DoD, commercial and space. Through the years, they developed several training modules for new employees on conducting wind tunnel tests with an emphasis on powered testing and PAI. They have graciously agreed to dust off some of those training presentations and share their knowledge with the NASA community.

Fundamentals of Aircraft Flight Control

Presenter	John Burken
Published	October 2012
Recorded	July 2012
Duration	59:37
Tags	#Fundamental, .Design, ~Control Design, ~Control Systems, ~Flight Control Systems

Discipline: Guidance, Navigation, and Control Webcast Air Date: 10/17/2012 Prerequisites: Understands Elementary Laplace Transforms (solutions to differential equations) Understands the root locus classical method. (the starting point of this class) This is a linear methods design class This 50 minute "short course" will hit the major control design issues and what to beware of in the "design process". In a linear design world the actuator rates and limits are ignored, along with time delays, and this can bring down an otherwise "good design method". This class will hopefully show you ways to design a robust control design method with some of the "real world" issues involved. The control method will be the Linear Quadratic Tracker design technique, applied to the X-38 vehicle with matlab scripts included. The scripts will be provided for self-study purposes in the appendix. Not covered: Software and hardware System redundancy Verification and validation testing Digital control design

Buckling, Shells, Knockdown Factors, and Validation Testing

Presenter	Dr. Mark Hilburger
Published	November 2012
Recorded	November 2012
Duration	01:46:14
Tags	#Advanced, .Analysis / Modeling and Simulation, .Testing, ~Structural Analysis, ~Stress Analysis, ~Failure Modes, ~Structural Response, ~Buckling, ~Digital Image Correlation

Discipline: Structures NASA’s Shell Buckling Knockdown Factor Project (SBKF), was established in the spring of 2007 by the NASA Engineering and Safety Center (NESC) in collaboration with NASA’s Constellation Program and Exploration Systems Mission Directorate. The SBKF project has the goal of developing improved (i.e., less-conservative, robust), shell buckling design factors (a.k.a. knockdown factors) and design and analysis technologies for launch vehicle (LV) structures. Preliminary design studies indicate that implementation of these new knockdown factors can enable significant reductions in mass and control mass-growth in these vehicles and can help mitigate some of the typical LV development and performance risks. In particular, the new design technologies are expected to reduce the reliance on testing, provide high-fidelity estimates of structural performance, reliability, robustness, and enable increased payload capability. The lecture will provide a brief summary of SBKF objectives and approach towards developing and validating these new technologies and provide a look towards the future of design, analysis and testing of the next generation of buckling-critical launch vehicle structures. In particular, a historical review of the current design recommendations for buckling-critical thin-walled cylindrical shell structures will be presented, and their limitations relative to the design of modern launch vehicle structures will be discussed. Next, the lecture will identify some key technologies that are enabling the development of updated design factors including advancements in computational tools for structural analysis, testing and measurement technologies, and manufacturing and materials, and suggest other areas of R&D investment. Finally, results from a recent (and exciting!) full-scale structural test of a 27.5-ft-diameter orthogrid-stiffened Space Shuttle External Tank barrel section, ETTA1, will be presented.

Shock & Vibration: 39. Rainflow Cycle Counting for Random Vibration Fatigue Analysis

Presenter	Tom Irvine
Published	June 2015
Recorded	April 2015
Duration	01:07:26
Tags	#Intermediate, ~Power Spectral Density, ~Random Vibration, ~Response Acceleration, ~Fatigue, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Introduction to On-Orbit Thermal Environments Part I

Presenter	Steven L. Rickman
Published	September 2011
Recorded	October 2011
Duration	15:34
Tags	#Fundamental, .Environments

Discipline: Passive Thermal Keywords: Thermal Radiation Orbit Solar Flux Albedo Planetary Flux OLR Beta Angle Charged Particle Heating Free Molecular Heating

Thermal Testing and Verification, Part 1 - Fundamentals of Thermal Testing

Presenter	David Gilmore
Published	December 2013
Recorded	July 2013
Duration	27:25
Tags	#Fundamental, .Testing

Discipline: Passive Thermal

Metal Fatigue Part 1

Presenter	Raymond Patin
Published	May 2013
Recorded	March 2013
Duration	01:44:37
Tags	#Fundamental, .Materials, ~Material Properties, ~Fracture Mechanics, ~Fracture Control, ~Structural Analysis, ~Crack Growth

Structural integrity is assured via static strength and service life (fracture control) requirements. The mitigation of catastrophic failures in metallic materials resulting from fatigue damage accumulation during the useful life of a structure is one of the primary functions of fracture control. This Webcast provides a cursory overview of metal fatigue which includes the basic elements of stress-life (S-N) fatigue, strain-life, and linear elastic fracture mechanics. Details regarding the micro and macro mechanics associated with metal fatigue crack nucleation, initiation, and propagation are also addressed.

Human Factors of Remotely Piloted Aircraft Systems: Lessons from Incident Reports

Presenter	Dr. Alan Hobbs
Published	September 2016
Recorded	September 2016
Duration	01:00:27
Tags	#Advanced, .Operations, ~Resillience, ~Remotely Piloted, ~Viigilance, ~Teleoperation, ~Tombstone Safety

Discipline: Human Factors Webcast Air Date: September 13, 2016 Before remotely piloted aircraft systems (RPAS) can operate routinely and safely in civilian airspace, we need to understand the unique human factors associated with these aircraft. Minor incidents are a potentially rich source of data, however, the RPAS sector has produced relatively few incident reports that describe events from the perspective of RPAS pilots. An exploratory study was conducted to examine the feasibility of collecting voluntary incident reports from RPAS pilots. Twenty-three experienced RPAS pilots volunteered to participate in focus groups in which they were invited to recall incidents that revealed a system flaw, or that highlighted a case where the human operator contributed to system resilience or mission success. Participants reported a total of 90 incidents. Some of the issues described in the reports have received significant attention in the literature, or are analogous to human factors of manned aircraft. In other cases, incidents involved human factors that have not yet been the subject of extensive study. Human factor issues included control station design considerations, vigilance during monotonous flights, transfer of control between control stations, the management of lost link procedures, and decision-making during emergencies. Although many of the reported incidents involved pilot errors, the participants also provided examples of the positive contribution that humans make to the operation of highly-automated systems.

X-15 Flight 3-65-97 Accident Analysis: A Fresh Look at the Role of the MH-96 "Self-Adaptive" Flight Control System

Presenter	Jeb Orr
Published	July 2014
Recorded	April 2014
Duration	01:01:51
Tags	#Intermediate, .Design, .Testing, .Environments, ~Attitude Control, ~Flight Control Systems

Discipline: Guidance, Navigation and Control Presented via Webcast on May 28, 2014 Over its ten year lifespan and 199 flights, the X-15 program was remarkably successful in developing and operating the first manned hypersonic research platform. However, the program suffered a fatal accident in November 1967 when X-15-3, the only aircraft outfitted with advanced pilot displays, an adaptive flight control system, and an advanced reaction control system was lost after entering a spin at an altitude of 230,000 feet and a velocity near Mach 5. The pilot, USAF Maj. Michael J. Adams, was killed when the aircraft broke up at 62,000 feet near Cuddeback Lake, CA. In an effort to reduce risk to emerging aerospace vehicle concepts, a comprehensive analysis has been undertaken to fully understand the causes and evolution of the accident in light of fifty years of flight control and human factors experience. Attention is focused on both the technical as well as the programmatic and cultural factors that affected the outcome in this incredibly complex accident. New findings have emerged that change our understanding of the roles of the adaptive control system, the pilot, and ground control in the incident.

Shock & Vibration: 18. General Method for Calculating VRS

Presenter	Tom Irvine
Published	March 2015
Recorded	January 2015
Duration	01:05:12
Tags	#Intermediate, #Fundamental, ~Power Spectral Density, ~Signal Analysis, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Fundamentals of Planetary Tour Design

Presenter	Aron Wolf
Published	September 2015
Recorded	March 2015
Duration	01:01:02
Tags	#Fundamental, .Design, ~Mission Planning

Discipline: Loads & Dynamics Original Webcast Air Date: August 26th, 2015. The first robotic planetary missions (e.g. Mariners, Voyager) were flybys, with limited time in the vicinity of their targets for scientific observations. Following these were planetary orbiters, including missions to planets with multiple satellites (Galileo to Jupiter, Cassini to Saturn) for which the satellites were themselves targets of scientific investigation along with the planetary environment. Both Jupiter and Saturn have satellites that are large enough so that flybys of these satellites can be used to shape and “steer” the trajectory through the planetary system to wring the most science out of the limited amount of propellant (and money) available for the mission. This webcast will discuss the fundamentals of design of satellite tours and the twists and tricks that are used by designers using the satellites as trajectory design tools.

Electromagnetic Compatibility (EMC): Antennas - Lecture, Part 1

Presenter	Ken Javor
Published	September 2014
Recorded	June 2014
Duration	49:47
Tags	#Intermediate, ~Electromagnetic Waves, ~Magnetic Field, ~Electric Field, ~Measurement, ~Electromagnetic Interference, ~EMI, ~EMC, ~Current, ~Audio Frequency, ~Radio Frequency, ~RF, ~Time Domain, ~Potential, ~Fast Fourier Transform, ~FFT, ~EMI Receiver, ~Spectrum Analyzer, ~Biconical Antenna, ~Antenna, ~Resolution Bandwidth, ~RBW, ~Video Bandwidth, ~VBW, ~Display Range, ~Noise Level, ~Thermal Noise, ~1 DB Gain Compression, ~Peak Detector, ~Crest Factor, ~Average Level, ~Peak Level

Discipline: Avionics

Shock & Vibration: 16. Power Spectral Density Synthesis

Presenter	Tom Irvine
Published	February 2015
Recorded	December 2014
Duration	56:18
Tags	#Intermediate, ~Fourier Transform, ~Power Spectral Density, ~Signal Analysis, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Autonomous Deep Space Navigation

Presenter	Neil Dennehy
Published	October 2015
Recorded	March 2015
Duration	01:01:51
Tags	#Advanced, #State of the Art, .Design, ~Navigation

Discipline: Guidance, Navigation, & Control Webcast Air Date: 09/30/2015 For over 40 years, nations have sent spacecraft to visit other natural bodies in the Solar System, with mission profiles including high speed flybys, rendezvous and orbit, and landings. For the vast majority of these missions, navigation is performed on the ground using standard radiometric tracking data and, when required, onboard optical data (images taken by the spacecraft camera of nearby target bodies). This combination has worked well and resulted in remarkably accurate navigation over the years. Despite its success, one inherent drawback in ground-based navigation are the delays caused by the round-trip light-time and the time needed to process the data once it gets to the ground. As a result, the latest and best navigation information is not used to execute the current event with a resulting net loss of fuel, science data, or both. To overcome this limitation, an onboard autonomous navigation system, called AutoNav, was developed. Since GPS is not available in deep space, the system uses passive optical data and is thus entirely self-contained. This not only eliminates the light-time delay but also circumvents the human-related delays for performing the navigation functions, thus reducing the turnaround time to minutes, or even seconds, for reacting to late-breaking navigation information. This capability can enable certain classes of missions and greatly enhance science return on others. In this webcast, the details of AutoNav are presented, with a discussion of the basics of passive optical data and descriptions of the functions performed by AutoNav. Past uses of AutoNav on the Deep Space 1, Stardust, and Deep Impact missions are also shown, along with some thoughts about future directions.

Fundamentals of Image Processing for Terrain Relative Navigation (TRN)

Presenter	Andrew Johnson
Published	July 2014
Recorded	February 2013
Duration	01:12:02
Tags	#Fundamental, .Analysis / Modeling and Simulation, ~Relative Navigation

Discipline: Guidance, Navigation and Control (SLaMS Webcast Series) Presented via Webcast on April 23, 2014 Current robotic planetary landers do not identify landmarks for navigation or detect landing hazards for safe landing. Typically they just measure altitude and velocity and land in a relatively large landing ellipse that is free from hazards. Since the best science is usually located near terrain relief that exposes material from of different ages, this “blind” landing approach limits science return. For example, the Mars Science Laboratory Curiosity rover landed in with a landing ellipse tens of kilometers wide in a flat region of Gale crater. Curiosity is currently driving to Mount Sharp, which is the primary science destination. There are two complimentary technologies being developed to enable access to more extreme terrain during landing: Terrain Relative Navigation (TRN) for accurate position estimation and Hazard Detection for avoiding small, unknown hazards. During TRN the lander automatically recognizes landmarks and computes a map relative position, which can be used in two different ways. First, if there is enough fuel, the lander is guided to a pin-point landing (within 100m of the target). If the vehicle is limited on fuel, then the landing ellipse is populated with safe landing sites and the lander is guided to the safest reachable site. This multi-point safe landing strategy enables selection of landing ellipses with large distributed hazards. Both applications improve science return by placing the lander closer to terrain relief. This presentation will describe the image processing building blocks for development of a TRN system for planetary landing including: image warping, feature selection and image correlation. It will then describe the Lander Vision System (LVS) that integrates these components into a real-time image-based terrain relative navigation system and show results from a recent field test of the LVS. The presentation will conclude by showing how the same image processing techniques can be applied to lidar data to enable TRN under any lighting conditions.

Fundamentals of Vision Based Navigation

Presenter	Dr. John Christian
Published	February 2014
Recorded	February 2013
Duration	01:04:17
Tags	#Fundamental, .Design, ~Navigation, ~Relative Navigation

This webcast will introduce participants to the fundamental ideas behind spacecraft optical navigation. We will begin by discussing camera projection and how pixel coordinates in an image may be related to line-of-sight directions. With this in mind, we will explore some common optical navigation measurement techniques including centroiding, star-limb measurements, and landmark tracking. These techniques have found widespread use in exploration missions to the Moon, other planets, comets, and asteroids. Beyond this, optical navigation methods may also be used for relative navigation in support of rendezvous, proximity operations, and docking (RPOD) activities. We will briefly discuss some techniques used for these applications, such as Natural Feature Image Recognition (NFIR) algorithms.

Common Thermal Modeling Mistakes, Part 2

Presenter	Ruth Amundsen
Published	October 2016
Recorded	September 2016
Duration	58:19
Tags	#Fundamental, .Analysis / Modeling and Simulation

Discipline: Passive Thermal This presentation was recorded at the Thermal & Fluids Analysis Workshop (TFAWS) on August 3rd, 2016. This course will cover the some of the common mistakes made in thermal modeling, and how to avoid them. Thermal Desktop will be used as a platform to demonstrate many of the common errors by both new analysts as well as experienced engineers in building a thermal model. Other non-software-associated errors will also be covered. Topics covered will include common errors in assumptions, materials, configurations, radiation, orbital analysis, and common faults in problem setup, analysis case runs and record-keeping. The course should help you as an engineer to watch for these common errors in the future, and help you avoid them.

Ball Bearings 101

Presenter	Alan Leveille
Published	July 2014
Recorded	April 2014
Duration	55:04
Tags	~Mechanical Systems

Discipline: Mechanical Systems (SLaMS Webcast Series) Presented via Webcast on April 23, 2014 The subject of ball bearings is presented. The goal is to provide a very basic explanation of ball bearings to those who may need to use bearings but are not familiar with the subject matter.

Fundamentals of Electromagnetic Compatibility, Part 1 - Introduction

Presenter	John McCloskey
Published	April 2015
Recorded	December 2014
Duration	25:13
Tags	~Noise Source, #Fundamental, ~Electromagnetic Compatibility, ~Electromagnetic Interference, ~EMI, ~EMC, ~Crosstalk, ~Coupling Mechanism, ~Culprit, ~Victim, ~Electromagnetic Energy, ~Conducted Coupling, ~Radiated Coupling

Discipline: Avionics

High Voltage Engineering Techniques for Space Applications: Part 4, High Voltage Insulators and Electrical Field Control Methods

Presenter	Eric Hertzberg
Published	August 2013
Recorded	June 2012
Duration	01:36:51
Tags	~Voltage System, ~Power Supply, ~Power System, ~Thermal Analysis, #State of the Art, .Design, .Materials, .Hardware, .Systems / Subsystems

Discipline: Electrical Power Presented via Webcast on April 2-3, 2012

Shock & Vibration: 15. SDOF Response to PSD Base Input

Presenter	Tom Irvine
Published	February 2015
Recorded	December 2014
Duration	47:06
Tags	#Intermediate, #Fundamental, ~Power Spectral Density, ~Signal Analysis, ~Random Vibration, .Analysis / Modeling and Simulation, ~White Noise

Discipline: Loads & Dynamics

Fundamentals of Electromagnetic Compatibility, Part 2 - Building Blocks

Presenter	John McCloskey
Published	May 2015
Recorded	December 2014
Duration	01:24:09
Tags	~Capacitive Coupling, ~Magnetic Field, ~Electric Field, #Fundamental, ~Electromagnetic Compatibility, ~Electromagnetic Interference, ~EMI, ~EMC, ~Current, ~Potential, ~Hertzian Dipole, ~Magnetic Loop, ~Magnetic Dipole, ~Inductance, ~Permittivity, ~Permeability, ~Maxwell's Equations, ~Capacitance, ~Inductive Coupling, ~Wave Propagation, ~Wave Equations, ~Decibels, ~dB, ~Differential Mode, ~DM, ~Common Mode, ~CM, ~Electric Dipole

Discipline: Avionics

Fundamentals of Spacecraft Control-Structure Interaction

Presenter	Dr. Davin Swanson
Published	March 2017
Recorded	January 2017
Duration	01:03:51
Tags	#Fundamental, .Analysis / Modeling and Simulation, ~Attitude Control, ~Control Design, ~Control Systems

Discipline: Guidance, Navigation & Control Webcast Air Date: March 15, 2017 Flexibility and nonlinearities in a spacecraft or launch vehicle’s structure can interact with control loops, potentially impacting pointing performance or creating instabilities or limit cycles. These effects can cause mission degradation or even loss of vehicle. In order to successfully assess the interplay between controls and structures, a cross-discipline design and analysis process must be established and followed throughout the development phase of a program. This presentation provides an introduction to the fundamentals of control-structure interaction, providing an overview of the design process, some examples and rules of thumb, and references for further study. Topics addressed include structural model accuracy and validation, structural damping, model reduction, model uncertainty, and common control design and analysis techniques.

Shock & Vibration: 26. Response to Classical Pulse Excitation

Presenter	Tom Irvine
Published	March 2015
Recorded	March 2015
Duration	57:06
Tags	#Intermediate, #Fundamental, ~Shock Response Spectrum, ~Response Acceleration, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Shock & Vibration: 10. Waterfall FFT

Presenter	Tom Irvine
Published	October 2014
Recorded	September 2014
Duration	36:51
Tags	#Fundamental, ~Fourier Transform, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Introduction to Numerical Methods in Heat Transfer, Part 1

Presenter	Steven L. Rickman
Published	July 2013
Recorded	May 2013
Duration	20:26
Tags	#Fundamental, .Analysis / Modeling and Simulation

Discipline: Passive Thermal Keywords: Thermal Radiation Numerical Methods Heat Equation Heat Transfer Finite Difference Euler-Lagrange Equation Variational Formulation Finite Element

Generalized Fluid System Simulation Program (GFSSP) Training Course 01: Course Introduction

Presenter	Dr. Alok Majumdar
Published	August 2016
Recorded	May 2016
Duration	47:47
Tags	#Advanced, .Analysis / Modeling and Simulation

Discipline: Propulsion

Fundamentals of Libration Point Mission Design

Presenter	Dr. Kathleen Howell
Published	November 2016
Recorded	October 2016
Duration	58:36
Tags	#Fundamental, .Design, ~Mission Planning

Discipline: Guidance, Navigation & Control Webcast Air Date: October 19, 2016 The vicinity near the Earth-Moon libration points has recently emerged as a potential location to support future crewed and robotic missions as part of a resilient and evolving space infrastructure. Beyond cislunar space, successful missions to the vicinity of the Sun-Earth/Moon libration points have also been accomplished and other Sun-planet and planet-moon options are being explored. Such mission scenarios offer unprecedented opportunities but involve complex and competing requirements. The mathematical foundations and dynamical structures in this multi-body environment are exploited for trajectory design in planning missions of this type and a new generation of strategies and analysis tools are evolving to enable the practical implementation of the complex new concepts. In particular, the existence of periodic orbits throughout a libration point region serves as a framework and the connections between various families allows movement throughout the region. This webcast will include a discussion of the astrodynamics basics to design such trajectories and some techniques to leverage the dynamical structures.

Shock & Vibration: 30. SRS Synthesis - Wavelets

Presenter	Tom Irvine
Published	May 2015
Recorded	March 2015
Duration	43:56
Tags	#Intermediate, ~Shock Response Spectrum, ~Response Acceleration, ~Frequency Response, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Glove 101

Presenter	Amy Ross
Published	August 2015
Recorded	July 2015
Duration	01:03:03
Tags	None

Discipline: Environmental Control/Life Support This presentation addressed the question “What is a spacesuit glove?” – a highly specialized mobility system. It is an excellent basic tutorial on the design considerations of a spacesuit glove and the many facets of developing a glove that provides good mobility and thermal protection.

Introduction to On-Orbit Thermal Environments Part II

Presenter	Steven L. Rickman
Published	September 2011
Recorded	October 2011
Duration	24:31
Tags	#Fundamental, .Environments

Discipline: Passive Thermal Keywords: Thermal Radiation Orbit Solar Flux Albedo Planetary Flux OLR Beta Angle Charged Particle Heating Free Molecular Heating

Exploring Human Performance Contributions to Safety in Commercial Aviation

Presenter	Dr. Jon Holbrook
Published	November 2019
Recorded	February 2019
Duration	36:37
Tags	#Intermediate, .Other, ~Research Study, ~Safety II, ~Decision Making, ~Safety Management, ~Human Operators, ~Pilot Interventions, ~Contingency Table, ~Human Intervention and Outcome, ~Safety I, ~Hollnagel, ~Work As Done, ~Work As Imagined, ~Future Operations, ~Protective Safety, ~Productive Safety, ~Resilience, ~Study Methods, ~FOOQA, ~Pilot And Traffic Controller Interviews, ~Strategies, ~Machine Learning (DT-MIL Algorithm), ~High Speed Exceedance Example, ~Recommendations

Instructions: - Add this to your calendar using the "Add to Calendar" link for a convenient 15-minute reminder. - Slides are available to download in the "Links." - Please submit questions as they arise rather than waiting until the end. - Enjoy! Abstract: Data-driven decisions about safety management and design of safety-critical systems are limited by the available data, which influence, and are influenced by, how decision makers characterize problems and identify solutions. In the commercial aviation domain, data are systematically collected and analyzed on the failures and errors that result in infrequent incidents and accidents, but in the absence of data on behaviors that result in routine successful outcomes, safety management and system design decisions are based on a small sample of non-representative safety data. As a case in point, analysis of aviation accident data suggests that human error is implicated in up to 80% of accidents, which has been used to justify future visions for aviation in which the roles of human operators are greatly diminished or eliminated in the interest of creating a safer aviation system. However, failure to fully consider the human contributions to successful system performance in civil aviation represents a significant and largely unrecognized risk. Without understanding how humans contribute to safety, any estimate of predicted safety of autonomous machine capabilities is incomplete and inherently suspect.

Introduction to On-Orbit Thermal Environments Part III

Presenter	Steven L. Rickman
Published	September 2011
Recorded	October 2011
Duration	27:34
Tags	#Fundamental, .Environments

Discipline: Passive Thermal Keywords: Thermal Radiation Orbit Solar Flux Albedo Planetary Flux OLR Beta Angle Charged Particle Heating Free Molecular Heating

Shock & Vibration: 17. SDOF Response to Base Input in the Frequency Domain

Presenter	Tom Irvine
Published	March 2015
Recorded	January 2015
Duration	01:05:29
Tags	#Intermediate, #Fundamental, ~Power Spectral Density, ~Signal Analysis, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Fundamentals of Adaptive Control

Presenter	Irene Gregory
Published	November 2012
Recorded	July 2012
Duration	01:03:13
Tags	#Fundamental, .Design, ~Control Theory

Prerequisites: • Basic knowledge of concepts of linear vs. nonlinear systems and their stability. • Conversant with the concepts of uncertainty, model based design (i.e. performance specification within state-space system context), robust optimal control. The field of adaptive control is as diverse as the potential applications. There are a myriad of methodologies but only some are appropriate for application to flight control. This short lecture will touch on history of adaptive control in flight, present on overview of methods that have been employed in flight over the past 10 years with illustrative examples, and discuss advantages and limitations of the methodologies. Furthermore, a recent flight test example will be presented briefly. In conclusion, current open problems and future directions will be discussed.

A Unified Approach to Modal Reduction Methods

Presenter	Dr. Arya Majed
Published	June 2015
Recorded	January 2015
Duration	01:49:48
Tags	#Intermediate, ~Coupled Loads Analysis, ~Equation of Motion, ~Model Reduction, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics Original Webcast Air Date: April 22, 2015 A survey of the papers on modal reduction methods exhibits a variety of mathematical techniques and procedures utilized by the developers of each method. For example, Hurty and Craig/Bampton utilized a Rayleigh-Ritz procedure to derive their fixed-boundary methods. MacNeal used electrical circuits analogies for his free-boundary method. Rubin improved MacNeal's method with a non-Rayleigh-Ritz procedure involving a power series expansion. Craig/Chang and Benfield/Hruda offered modal reduction methods which require special modal synthesis procedures. Hintz utilized an adhoc technique with some features of other techniques to derive a mixed-boundary method. The end result of this has been confusion and uncertainty on the part of engineers with the consequence of often opting for the simplest of the methods, Craig/Bampton for all applications. In addition, some methods, such as Hintz mixed-boundary, have gone largely unrecognized due to the complex language/procedures of the paper. Another unfortunate consequence has been some methods being utilized beyond their mathematical limitations, and when not performing, unfairly eliminated as faulty. Part 1 of this two part series on modal synthesis methods presents a unified mathematical approach to the derivation of the modal reduction methods. The presenter provides a single mathematical tool capable of deriving all methods of modal reduction including the more involved mixed-boundary methods. With this, the user gains an immediate level of comfort with all approaches including the more exotic methods. In addition, with the ability to now derive the method, the assumptions, approximations, application and pitfalls of each method automatically become more clear. Another objective of this presentation is to enable the engineers to develop their own NASTRAN/DMAP or other computer programs for implementing any of the modal reduction methods. A quick preview of Part 2: The Part 2 presentation is concerned with the modal synthesis methods themselves. Again, an attempt is made to unify this important subject as much as possible. In addition to modal synthesis methods, methods for recovery of dynamic response including modal acceleration, residual flexibility, and residual vectors are considered. Part 2 also includes special topics including generalized Guyan, Improved Reduced System (IRS), and System Equivalent Reduction Expansion Process (SEREP) utilized in the development of test analytical models (TAMs).

Best Practices for Fatigue Risk Management in Non-traditional Shiftwork

Presenter	Dr. Erin Flynn-Evans
Published	July 2016
Recorded	June 2016
Duration	58:56
Tags	#Intermediate, .Lessons Learned, ~Caffeine, ~Strategies For Managing Fatigue, ~Astronauts, ~Extended Duty Workshifts, ~Airline Pilots, ~Gemini Missions, ~Physiological Limits To Performance, ~Assessment, ~Mitigations, ~Circadian Pacemaker, ~Shift Schedule Planning, ~ Circadian Nadir, ~Resetting By Light, ~Strategies To Manage Circadian Desynchrony, ~Acute Sleep Loss, ~Real World Example (Phoenix Mars Lander New Horizons Iss, Short Haul Aviation, Solar Impulse), ~Sleep Deprivation, ~Countermeasures, ~Self-Assessment, ~Chronic Sleep Loss, ~Sleep Inertia, ~Screening, ~Actiwatch

Discipline: Human Factors Webcast Air Date: July 12, 2016 Fatigue risk management programs provide effective tools to mitigate fatigue among shift workers. Although such programs are effective for typical shiftwork scenarios, where individuals of equal skill level can be divided into shifts to cover 24 hour operations, traditional programs are not sufficient for managing sleep loss among individuals with unique skill sets, in occupations where non-traditional schedules are required. Such operations are prevalent at NASA and in other high stress occupations, including among airline pilots, military personnel, and expeditioners. These types of operations require fatigue risk management programs tailored to the specific requirements of the mission. Without appropriately tailored fatigue risk management, such operations can lead to an elevated risk of operational failure, disintegration of teamwork, and increased risk of accidents and incidents. In order to design schedules for such operations, schedule planners must evaluate the impact of a given operation on circadian misalignment, acute sleep loss, chronic sleep loss and sleep inertia. In addition, individual-level factors such as morningness-eveningness preference and sleep disorders should be considered. After the impact of each of these factors has been identified, scheduling teams can design schedules that meet operational requirements, while also minimizing fatigue.

Shock & Vibration: 28. Pyrotechnic Shock Response, Part 1

Presenter	Tom Irvine
Published	May 2015
Recorded	March 2015
Duration	01:00:42
Tags	#Intermediate, ~Natural Frequencies, ~Shock Response Spectrum, ~Response Acceleration, ~Circuit Boards, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Aircraft System Identification

Presenter	Dr. Gene Morelli
Published	April 2011
Recorded	October 2011
Duration	32:07
Tags	#Intermediate, .Analysis / Modeling and Simulation, .Design, .Systems / Subsystems, .Other, ~Flight Mechanics, ~Trajectories

Discipline: Flight Mechanics Keywords: Aircraft System Identification, SIDPAC, Flight Mechanics, NASA Langley Research Center

The Evolution of Guidance, Navigation, and Control in Mars Entry, Descent, and Landing

Presenter	Miguel San Martin
Published	May 2013
Recorded	February 2013
Duration	01:04:45
Tags	#Fundamental, .Design, .Lessons Learned, .Systems / Subsystems, ~Flight Control Systems

From Viking in the 70's to MSL/Curiosity in the present, Guidance, Navigation, and Control for Mars Entry, Descent, and Landing (EDL), has varied dramatically in form and function, as it had to adapt to different types of landing architectures in response to ever changing mission requirements. This presentation will describe the history of EDL GN&C as represented by its functional and performance requirements, and the architectures and implementations needed to satisfy them, starting with the unguided Viking legged-landers, continuing with the Mars Exploration Rover airbag-landers, and concluding with Curiosity's fully guided Entry and SkyCrane-lander.

Sandwich Structures Failure Modes and Their Prevention

Presenter	Dr. Ronald Krueger
Published	October 2016
Recorded	September 2016
Duration	01:13:14
Tags	#Intermediate, .Analysis / Modeling and Simulation, .Materials, ~Fracture Mechanics, ~Failure Models

Discipline: Structures Webcast Air Date: September 28, 2016 Typical damage modes in light honeycomb sandwich structures include face sheet/core disbonding and core fracture, both of which can pose a threat to the structural integrity of a component. These damage modes are of particular interest to aviation certification authorities since several in-service occurrences, such as rudder structural failure and other control surface malfunctions, have been attributed to face sheet/core disbonding. Extensive studies have shown that face sheet/core disbonding and core fracture can lead to damage propagation caused by internal pressure changes in the core. In order to identify, describe and address the phenomenon associated with facesheet/core disbonding, a reliable means of characterizing facesheet/core disbonding must be developed. In addition to the characterization tests, analysis tools are required, to help assess the likelihood of a structure exhibiting critical disbonding. These analysis tools need to be verified and validated. In this webcast, sandwich structures are introduced and their failure modes are discussed. Actual in-service occurrences are presented and a road map to standardization for facesheet/core disbonding in sandwich composite components is described. An overview is given on the development of test methods that yield a critical strain energy release rate associated with disbonding, with a focus on mode-I dominated loading conditions. Further, an analysis approach is discussed to compute energy release rates along an arbitrarily shaped disbond front. Finally, a brief summary of observations is presented and recommendations for improvements are provided.

PLSS 101

Presenter	Gretchen Thomas
Published	April 2015
Recorded	January 2015
Duration	55:58
Tags	#Intermediate, .Lessons Learned, ~Space Suits

Discipline: Environmental Control/Life Support This presentation reviewed basic interfaces and considerations necessary for prototype suit hardware integration from an advanced spacesuit engineer perspective during the early design and test phases. The discussion included such topics such as the human interface, suit pass-throughs, keep-out zones, hardware form factors, subjective feedback from suit tests, and electricity in the suit.

Shock & Vibration: 12. Sample Rate, Nyquist Frequency & Aliasing

Presenter	Tom Irvine
Published	November 2014
Recorded	October 2014
Duration	37:15
Tags	#Fundamental, ~Signal Analysis, .Analysis / Modeling and Simulation

Discipline: Loads & Dynamics

Space Radiation Environments

Presenter	Dr. Steven Koontz
Published	February 2018
Recorded	August 2017
Duration	01:31:56
Tags	#Advanced, .Design, .Environments

Disciplines: Environmental Control/Life Support, Space Environments US Spacesuit Knowledge Capture - Recorded June 29, 2017 The spaceflight ionizing radiation (IR) environment is dominated by very high-kinetic energy-charged particles with relatively smaller contributions from X-rays and gamma rays. The Earth’s surface IR environment is not dominated by the natural radioisotope decay processes. Dr. Steven Koontz’s lecture will provide a solid foundation in the basic engineering physics of space radiation environments, beginning with the space radiation environment on the International Space Station and moving outward through the Van Allen belts to cislunar space. The benefits and limitations of radiation shielding materials will also be summarized.

Creating a World Class Safety Culture, Part I: Lessons Learned from Launch Vehicle Failures

Presenter	Stan Graves
Published	February 2021
Recorded	January 2021
Duration	01:58:02
Tags	#Intermediate, #Advanced, #Fundamental, #State of the Art, .Lessons Learned, ~Applied Systems Engineering