1

2008 TECHNICAL UPDATE

NASA ENGINEERING & SAFETY CENTER

National Aeronautics and Space Administration

www.nasa.gov
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It gives me a lot of pleasure to recognize the 5th anniversary of the 

establishment of the NASA Engineering and Safety Center. It also 

offers, for me, a valuable reminder that it is important always to be 

open to new ideas and new approaches to solving problems. When 

the NESC was established, I was more than a bit pessimistic that 

it could work, that it could provide value for the Agency over and 

above that offered by our various center engineering directorates. 

I was wrong. The synergy that has been achieved by the NESC and 

its cross-agency approach to solving difficult technical problems 

has been truly impressive. It is, in my mind, a useful model for 

future endeavors and a great example that it is actually possible for 

us to “be NASA”, to rise above some of the parochial geographic 

concerns which have plagued NASA for five decades. These days, 

when someone tells me that the NESC is looking at a particular 

issue, I am reassured, because I know that if a solution can be 

found, this group will find it.

– Dr. Michael D. Griffin, NASA Administrator
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Table of Contents

Stakeholder Messages ........................................................................................ 2

NESC Leadership ................................................................................................ 3

Overview: How the NESC Works .......................................................................... 4

NESC Academy: Learning from the Past ............................................................... 8

Technical Highlights

Collecting Flight Force Measurements to Improve Coupled Loads Analysis ... 11

Analysis of Constellation Program Mass Properties ....................................... 11

Prediction and Reduction of Ares SRB Thrust Oscillation ............................... 12

Review of the Launch Abort System Motor Qualification Plan ........................ 13

Ares I-X Upper Stage Simulator Project Independent Structural Review ....... 13

Max Launch Abort System Risk Mitigation Project ....................................... 14

Updating of Launch Vehicle Shell Buckling Knockdown Factors ................... 17

Composite Crew Module Pressure Vessel Pathfinder Development .............. 18

Improved Crew Seat Attenuation Designs for the Orion Crew Module ........... 20

Improving Orion Crew Impact Tolerance Modeling ....................................... 21

Hypervelocity Particle Impact Resistance of JWST Electrical Cables ............. 23

Risk Assessment of Kepler Reaction Wheel Premature Failure ..................... 24

RTAX Risk Mitigation Testing ....................................................................... 25

Entry, Descent, and Landing Data Repository and Analyses Task ................. 25

Development of DC/DC Converter Application Guidelines ............................. 26

HYTHIRM Validation and Calibration Testing Demonstration ......................... 27

NESC Data Mining and Trending Working Group (DMTWG) .......................... 27

Probabilistic Requirements Verification ........................................................ 28

Flight Battery Working Group Update ........................................................... 28

Investigation of ISS Solar Alpha Rotary Joint Issue ....................................... 29

Determination of EMU Space Suit Glove Damage Modes ............................. 29

Reproduction of ISS Solar Array Mast Shadowing ........................................ 30

Center Focus:

Ames Research Center ................................................................................ 33

Dryden Flight Research Center .................................................................... 34

Glenn Research Center ................................................................................ 35

Goddard Space Flight Center ....................................................................... 36

Jet Propulsion Laboratory ............................................................................ 37

Johnson Space Center ................................................................................ 38

Kennedy Space Center ................................................................................ 39

Langley Research Center ............................................................................. 40

Marshall Space Flight Center ....................................................................... 41

Stennis Space Center .................................................................................. 42

White Sands Test Facility ............................................................................ 43

Featured Technical Paper ............................................................................. 44-59

Biographies .................................................................................................. 61-64

NESC Alumni ..................................................................................................... 65

NESC Honor Awards ..................................................................................... 66-67

Recent NESC Publications .................................................................................. 68

Cover images clockwise from upper left - International Space Station solar array 

anomaly resolution, Composite Overwrapped Pressure Vessel testing, Orion 

Composite Crew Module construction pathfinder and Max Launch Abort System 

forward fairing wind tunnel testing.
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Stakeholder Messages

The NASA Engineering and Safety Center (NESC) is now 5 years old and more vibrant and 

influential than ever. It is time to reflect a bit on how the NESC has evolved to become the 

success it has; clearly it has achieved its primary goal to engage the best personnel in NASA 

and from the outside to address our most difficult problems. However, over the last 5 years 

it has become more; it serves to train our workforce through the NESC Academy, it provides 

the technical leaders through the NASA Technical Fellows who provide leadership for their 

discipline. The NESC provides common tools to remove misunderstanding, and develop new 

tools as it has with the Max Launch Abort System and the Composite Crew Module. By all 

measures of organizational success the NESC and its people have excelled — so we all look 

forward to the next 5 years as the NESC and NASA pioneer this ‘New Ocean.’

Christopher Scolese NASA Associate Administrator

The NESC has continued to serve the Agency over the past year as “the” technical organization of choice for our toughest engineering problems. They have developed over time an 

exceptional ability to expeditiously place the best people from both inside and outside of the 

Agency on the team. Of special importance to me this past year has been the discipline they 

have put into their technical reports. When an NESC assessment team reports their results, 

they take the time and effort to write them in a format that clearly states the problem, the 

scope and method of the assessment, and a clear English discussion of the results, findings 

and recommendations. And, they show the data. In an organization like NASA, this should 

not have been a big deal. But, over time, our hurry-up PowerPoint culture had led us to tolerate incomplete technical reporting almost as a standard. Old mishap lessons learned are 

replete with communications failures, so I applaud the NESC for reminding us all of the important contribution of clear communications to safety and technical excellence.

Bryan O’Connor NASA Chief Safety and Mission Assurance Officer

From its inception, the NESC’s core tenet has been to assemble the best possible technical 

expertise to apply to NASA’s toughest and most important problems. For tasks large and 

small, the NESC has demonstrated its agility and reach by quickly assembling the needed 

talent, whatever the source, and quickly bringing it to bear on a wide range of challenges. 

In the past year, the NESC has added to its strong record and continues to be the “go to” 

resource for NASA Programs and Projects. A few examples include expanding NASA’s 

technical experience with composites via the Composite Crew Module work for Constellation, 

increasing our depth of knowledge on the Reinforced Carbon-Carbon Orbiter wing leading 

edges, providing micrometeorite and orbital debris design input for the James Webb Space 

Telescope or characterizing solar array mass buckling behavior for the International Space 

Station. Perhaps the highest accolade is that it has become difficult to imagine what NASA 

would do if we did not have the NESC! On behalf of many, I offer my thanks and congratulations 

to the whole team for another year of excellent work.

Michael Ryschkewitsch NASA Chief Engineer
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NESC Leadership

his year marks NASA’s 50th anniversary and the 5th year that the NASA Engineering and Safety Center (NESC) has provided the Agency with the value-added independent assessments, testing and analyses it needs to address its highest-risk 

issues. The NESC’s operating model reaches across the Agency, industry, other 

government agencies and academia to create diverse technical teams, and this 

inclusive outreach continues to be our true strength. Our broad-based, multi-disciplinary 

teams have provided NASA with a unique resource, and we are pleased to feature members 

of these teams throughout this year’s Technical Update. 

The NESC has used the broad-based team approach on two major efforts this year that 

are increasing the Agency’s understanding and capabilities for designing and building future 

spacecraft. Both the Composite Crew Module and Max Launch Abort System teams are featured in this publication. In addition to the numerous activities on behalf of the Constellation 

Program, the NESC continued to actively engage in the Space Shuttle and International Space 

Station Programs – including the Shuttle launch pad flame trench damage and ISS solar array 

buckling anomaly resolutions. The NESC has also maintained a focus on the Agency’s critical 

science missions, such as Kepler and Phoenix. This publication will also feature the NESC’s 

efforts to advance the state of the disciplines for many of our NASA Technical Fellows.

Over the past five years, the NESC has demonstrated the value and power of broad-based, 

diverse teams. While our team members have changed, with many of our alumni going on to 

key leadership positions in the Agency, we have remained true to our core mission: providing NASA with a strong, independent resource to solve its toughest technical problems. We 

strive to remain current, relevant, and responsive to our customers and stakeholders. We 

have actively shared the lessons and results of our activities across the Agency through various avenues, including this publication. We are very proud to highlight our accomplishments 

and team members in this year’s Technical Update.

T

From left: Ralph Roe, Jr., Dawn Schaible, Tim Wilson, Kenneth Cameron, and Patricia Dunnington
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NESC Overview

How the NESC works

NASA’s mission is to pioneer the 

future in space exploration, scientific 

discovery and aeronautical research. 

Achieving this requires unique technologies 

that inevitably give rise to problems that 

require unique solutions. Imagine if the 

people working on those problems could 

easily call on the entire Agency — not just 

colleagues within their program or their Center 

— to help with the most difficult problems. 

They would have available a pool of 18,000 

talented people from across the country from 

which to draw. Take that proposition one 

step further – beyond the confines of NASA 

to the engineering and scientific community 

as a whole – and the pool of available talent 

would increase significantly.

Now further imagine a small organization 

within NASA, not reporting to any one 

Center or specific program, but a resource 

for the entire Agency. Fill this organization 

with the leading authorities in 13 different 

engineering disciplines. Give the authorities 

the resources to form standing teams of 

experts in their disciplines from across NASA, 

industry, academia, and the government. 

Add an engineering representative for each 

Center, and a group of engineers dedicated 

to leading multi-discipline teams in solving 

technical problems. Finally, solidify the 

organization with strong systems engineering 

and a resourceful business office. This 

organization exists. It is called the NASA 

Engineering and Safety Center (NESC).

The NESC Model

The NESC provides objective engineering 

and safety assessments of NASA’s high risk 

projects, following the principle that safety 

is achieved through engineering excellence. 

By searching out all of the resources 

available, the NESC creates successful 

broad-based teams by tapping into the best 

the Agency has to offer. Although based at 

the Langley Research Center, by design, the 

NESC maintains a decentralized framework 

with members located at all of the Centers 

including Headquarters. Then by reporting 

directly to the NASA Chief Engineer, the NESC 

maintains a separation from the mission 

directorates and their programs, and from 

Center leadership, to provide an alternate 

reporting path through which problems can 

be addressed. The NESC also works closely 

with the NASA Office of Safety and Mission 

Assurance and the NASA Safety Center.

The NESC is divided into the

following six offices:

1. NASA Technical Fellows

The NASA Technical Fellows are the Agency’s 

senior technical experts in 13 engineering 

disciplines (see inset). Each Technical Fellow 

leads a technical discipline team (TDT) made 

up of experts from across the country – both 

inside and outside of NASA. They provide 

a pool of discipline-specific expertise from 

which to draw when assessment teams are 

formed. 

NASA Technical Fellows act as stewards for 

their disciplines by sponsoring workshops, 

conferences, and discipline-advancing 

activities. They also work to maintain 

consistency in Agency-level standards and 

incorporate lessons-learned into NASA’s 

engineering processes. Periodically, each 

Technical Fellow will present a “state-of-thediscipline” to the Agency’s senior leadership 

to enhance awareness of specific concerns 

within the discipline. Some of these concerns 

are pursued with resources provided by the 

NESC — resources granted specifically for the 

purpose of proactively answering technical 

challenges faced by their disciplines that may 

impact NASA’s programs in the future.

2. NESC Chief Engineers

Each Center plus Headquarters has an NESC 

Chief Engineer (NCE). The NCEs provide insight into the programs that impact their own 

Centers. They also help coordinate the facilities and resources of each Center as required to support NESC assessments and 

activities. 

3. Systems Engineering Office (SEO)

The Systems Engineering Office provides 

system engineering and integration for 

assessments and other NESC activities. The 

SEO and the SEO-led Systems Engineering 

TDT provide technical expertise in systems 

Current NASA Technical 

Fellow Disciplines

• Aerosciences

• Avionics

• Flight Mechanics

• Guidance, Navigation

 and Control

• Human Factors

• Life Support/Active

 Thermal

• Loads and Dynamics

• Materials

• Mechanical Systems

• Nondestructive

 Evaluation

• Propulsion

• Software

• Structures

Future Technical

Fellow Disciplines

• Electrical Power

• Passive Thermal

• Space Environments

• Cryogenics

• Sensors/Instrumentation

• Systems Engineering

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NESC Overview

engineering processes such as systems 

analysis, statistics, data mining and trending, 

and requirements analysis. 

4. Principal Engineers Office (PEO)

The PEO is responsible for technical assessments carried out by the NESC. The Principal Engineers (PEs) and back-up PEs lead 

assessment teams – especially for those activities that require the participation of multiple disciplines – and provide guidance for 

assessments led by individuals from outside 

of the NESC. The PEs have the project management skills to complement the focused 

expertise of the NASA Technical Fellows.

5. Management and Technical

Support Office (MTSO)

The MTSO is the NESC’s business office. 

Because the NESC relies on support from 

many companies and agencies outside of 

NASA, an effective business office is essential to handle the budgetary and contracting 

challenges faced by the NESC and the technical aspects of setting up and maintaining 

partnerships. 

6. Office of the Director

In addition to the Director and his Deputy, 

the Office of the Director includes a Deputy 

Director for Advanced Projects and a Deputy 

Director for Safety. Also under the Director’s 

Office are the Chief Scientist and a representative from the astronaut corps detailed to 

the NESC as the NESC Chief Astronaut.

––––

NESC Review Board (NRB)

The NESC leadership team meets weekly as 

the NESC Review Board. All decisions made 

by the NESC are products of the NRB. Each 

member has equal footing and brings his or 

her background to the decision-making process. The success of the NRB results from 

its broad diversity and the outstanding technical competence of its members.

Broad-based Teams

The NESC builds networks of technical expertise with discipline specialists that are 

selected from all 10 NASA Centers. These 

broad-based teams work on NASA’s most 

critical issues, together with additional experts that have been recruited from industry, 

academia, and other government agencies. 

In the 5 years since its creation, the NESC 

has advanced the art of bringing such a diversity of individuals together to benefit the 

entire Agency, its Centers, its programs, its 

projects, and its people. 

Chief among these benefits are better-informed stakeholder decisions on technical 

issues in the near term, and better Agency 

decision-makers in the longer term. The 

Agency also benefits from innovative solutions that result from the diversity that the 

NESC intentionally builds into its teams. The 

Agency further benefits from the geographically-dispersed networks of expertise that 

endure long after the teams are disbanded. 

Finally, Agency programs and projects benefit as the NESC’s safety culture is spread 

across the enterprise. 

Partnerships

To take advantage of expertise available 

outside of NASA, the NESC has leveraged 

partnerships with other government agencies such as the National Transportation 

Safety Board, the Federal Aviation Administration, and the Department of Defense. The 

NESC has also enlisted the resources and 

personnel of national laboratories and independent research organizations like Sandia 

and Lawrence Livermore National Laboratories, Southwest Research Institute, Los Alamos National Laboratory, and the National 

Institute of Aerospace. Other participants 

for NESC activities are pulled from industry 

partners ranging from large aerospace companies such as Alliant Techsystems, Boeing, 

Lockheed Martin, and The Aerospace Corporation, down to smaller companies and individual consultants. 

Services for the Agency

The NESC’s primary vehicle for pursuing 

engineering issues is the assessment. Assessment teams are formed by pulling in 

technical experts from the TDTs and other 

sources to create a tiger team atmosphere 

that is focused on a specific technical issue. Requests for NESC assistance come 

from various sources: Associate Administrators, program/project managers, scientists 

and engineers, NASA contractors, and even 

the general public. The level of participation 

— Continued on following page

Members of the NRB (NESC 

Leadership Team)

• NESC Director

• NESC Deputy Director

• Chief Astronaut

• Chief Scientist

• Deputy Director for Safety

• Deputy Director for

 Advanced Projects

• MTSO Manager

• SEO Manager

• All Principal Engineers

• All NASA Technical Fellows

• All NESC Chief Engineers

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NESC Overview

40

35

30

25

20

15

10

5

0

2003 2004 2005 2006 2007 2008

4 4 54 54 46 46 57 57 56 56 5151

Yearly totals

Aeronautics

Science

Exploration

General

Space 

Operations

Accepted Requests

from the NESC in an assessment can range 

from the furnishing of expertise for consultation to a completely independent investigation with testing, modeling, and analysis. The 

results from every assessment are published 

in a final report that has been discussed and 

approved by the NRB. 

The diversity and technical excellence of the 

NESC also provides a centralized source from 

which specific expertise can be drawn for 

other Agency needs such as technical review 

boards, mishap investigations, and situations 

where real-time technical advice is required. 

The NESC also provides a framework for 

creating Agency-wide teams, with members 

brought in from around the Agency to participate in activities that extend beyond the 

NESC. Another important goal of the NESC 

is to educate. The NASA Technical Fellows 

share their insight and experience through the 

NESC Academy, in conferences and seminars, 

and by encouraging junior level engineers to 

participate in TDTs. In fact, all members of the 

TDTs (over 600-plus), by interacting with the 

leaders of their engineering disciplines, gain 

experience and knowledge to bring back to 

their home Centers and organizations.

In summary

As NASA celebrated its 50th anniversary in 

2008, the NESC observed its 5th. While the 

NESC as an organization has evolved over the 

past 5 years, the primary mission remains unchanged – to improve safety through engineering excellence. This Technical Update serves 

to highlight many of the activities that have 

succeeded by employing the NESC model, 

but the greater goal of the NESC is to foster 

the atmosphere of Agency-wide cooperation 

and set the example of the power of diversity 

to promote engineering excellence. Available 

to anyone searching for an independent engineering assessment, the NESC can be reached 

through any NESC Chief Engineer or by email 

at nesc@nasa.gov. More contact information 

and many NESC reports are available from the 

NESC website: www.nesc.nasa.gov.

Accepted Requests by Continued from previous page

Mission Directorate: 268 Total

Safety Mission

Assurance at Centers 4%

External to Agency 4%

NESC 28%

Engineering

& Scientific

Organization

38%

Source of Accepted Requests: 268 Total

Program Analysis &

Evaluation <1% 

Anonymous <1%

Office of Chief

Engineer 2%

Center

Management 3%

Office of Safety and

Mission Assurance 3%

Program

Management 16%

Industry 17%

Other U.S. Gov. 4%

Other 1%

University 4%

NASA 74%

2008 Technical Discipline Team Composition

All statistics as of Nov. 12, 2008
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NESC Overview

The NESC model: 

“I have witnessed the effectiveness of the NESC model, which brings together 

engineering talent from around the country to tackle difficult problems. While at times 

hard to manage, this inclusion of a diverse set of individuals with varied backgrounds 

and experiences, ultimately leads to better technical solutions.”

– Mike Hagopian, Chief Engineer for Engineering Directorate, GSFC

ATK

Upper shell of the Composite 

Crew Module (foreground) is being 

prepared for mating with the lower 

shell (background).

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10

NESC Academy

An important function of the NASA 

Technical Fellows Program is the

 NESC Academy that was established 

to capture, share, and preserve the lifetimes 

of experiences and knowledge of NASA 

scientists and engineers and to guide the 

next generation of the Agency’s technical 

staff in the art of technical problem solving. 

The key objective is to broaden NASA 

engineers’ experiences and technical skills 

through interaction with the NASA Technical 

Fellows and selected members of their TDTs. 

The ultimate goal is for each NASA Technical 

Fellow to have an opportunity to deliver their 

discipline-specific Academy course. Team 

work. Imagination. Flexibility. Innovation. 

All of these elements and many more have 

been integral to the creation and growth of 

the NASA Engineering and Safety Center 

(NESC) Academy, which celebrated its third 

year in operation in June 2008. To date, 

the Academy has developed and offered 

10 discipline courses in the classroom and 

has launched nine of them as online courses 

via the Academy website. Two courses, 

Propulsion and Human Factors, have been 

repeated. Courses have been provided to 368 

individuals from across the NASA Centers. 

This year the following courses

were offered:

Loads and Dynamics with NASA

Technical Fellow Dr. Curtis Larsen

and colleagues

The University of Houston at Clear Lake, Dec., 2007

Understanding loads and dynamics is critical 

to NASA’s mission, a mission that includes 

safe and reliable human and robotic space 

travel and air transportation systems. Loads 

and dynamics combines mathematics, 

physics, statistics, probability, structural and 

mechanical engineering, and systems theory 

into one field vital to the safety and success 

of every NASA mission. An emphasis of the 

course was that loads and dynamics problem 

mitigations were “trade-offs” for other areas 

(e.g., payload), so it is a balancing act requiring 

teamwork to make a mission successful. The 

Academy emphasized lessons learned from 

past experts.

Structures/Nondestructive Evaluation 

(NDE) with NASA Technical Fellows

Dr. Ivatury Raju and Dr. William Prosser 

and colleagues

National Institute of Aerospace, April, 2008

This course offered an overview of the 

collaboration between the two major 

disciplines. This was not a course that focused 

on equations, but rather took a broader view 

of concepts, processes and lessons learned. 

Course topics included: Failure Prediction 

in Structures and NDE, System Integration, 

Structural Modeling and Analysis, Structural 

Stability, Validation Testing and other related 

topics. Dr. Raju and Dr. Prosser collaborated 

with other experts to bring to life the real 

world issues faced during their extensive 

aerospace careers.

Innovative Engineering Design with

Dr. Charles Camarda and colleagues

Penn State University, July, 2008

Innovative Engineering Design differed from 

previous NESC Academy offerings in that 

the participants and instructors worked 

and played hard together in the creative 

environment of the Penn State Learning 

Factory. Design methodologies ranged 

from “skunk works” — like rapid prototype 

development — to current launch vehicle 

development programs, and focused on the 

conceptual design phase. Students learned 

techniques to leverage their creative thinking 

and to apply innovative, hands-on design 

methods in solving real vehicle design 

problems. Dr. Camarda mixed academia with 

faculty from Penn State, MIT, and Georgia 

Tech with aerospace experts to immerse 

the students in a “Space Boot Camp-like” 

experience.

Repeat courses offered this

year included:

Space Propulsion Systems with

Mr. George Hopson and colleagues

Tulane University, May, 2008

The encore delivery of Space Propulsion Systems was presented by George Hopson and 

Learning from the Past
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NESC Academy

colleague Len Worlund. Hopson’s four decades of contributions to America’s space 

program include work on Skylab, the Space 

Shuttle, and the International Space Station. In this two-day course, Mr. Hopson 

who worked with the renowned Werhner von 

Braun, shared stories from meetings with 

von Braun and gave his guidance and insight 

on: lessons learned, best practices, problem 

solving/resolution, Agency knowledge being 

lost, working at NASA, and latest trends.

Human Factors with NASA Technical 

Fellow Dr. Cynthia Null and colleagues

National Institute of Aerospace, June, 2008

Dr. Null’s expertise in human factors 

bridges academia and aerospace. This 

was an encore performance of the original 

classroom offering. The course content 

focused on the integration of human factors 

into NASA missions from conception through 

operations to include detailed case studies 

and problem-solving activities. Topics 

included: Developing in-space systems, 

Procedure development, Maintenance and 

manufacturing, Control center design and 

Ground operations.

The NESC Academy experience: 

“I’m a new engineer with NASA working with the crawler transporter. This course has been 

a great opportunity to hear the cumulative knowledge of all the teachers here, as well as 

a lot of the students sharing their knowledge base from their different projects.”

– Gordon Coffey, Kennedy Space Center, student at Academy Structures/NDE course

■ Active Thermal Control and Life Support 

Systems: NASA Technical Fellow Hank Rotter 

■ Space Propulsion Systems: George 

Hopson

■ Power and Avionics: Robert Kichak

■ Satellite Attitude Control Systems: NASA 

Technical Fellow Neil Dennehy

■ Human Factors: NASA Technical Fellow,

 Dr. Cynthia Null

■ Software as an Engineering Discipline: 

NASA Technical Fellow Michael Aguilar

■ Materials Durability – Understanding 

Damage Modes: NASA Technical Fellow

Dr. Robert Piascik

■ Loads and Dynamics: NASA Technical Fellow Dr. Curtis Larsen

■ Structures/Nondestructive Evaluation: 

NASA Technical Fellows Dr. Ivatury Raju and 

Dr. William Prosser

More information can be found at:

http://www.nescacademy.org

NESC Academy courses available 

online and the course leader

9
Technical Highlights

12

Finite element model (FEM) of the Orion 

Crew Module with FEM crash test 

dummies used to study crew seat design 

effectiveness against launch vibrations 

and landing impacts.
13

Technical Highlights

Problem: Traditionally, acceleration measurements are used to reconstruct flight loads in structures. 

The penalties of using only acceleration are the weak correlation of 

Coupled Loads Analysis (CLA) and 

conservative qualification testing. Thus, a need exists to utilize 

force measurements in the CLA 

process. Force measurements will 

greatly benefit all future missions 

and could assist the Orion Crew 

Module requirements and development process.

NESC Contribution: An NESC 

team is demonstrating the benefits of acquiring interface force measurements during flight. 

A simplified approach was used that involved mounting of 

strain gages on the trussed Payload Adaptor Fitting (PAF) 

of the Gamma-Ray Large Area Space Telescope (GLAST) 

spacecraft, now called the Fermi Telescope, in a way that 

forces and moments may be derived. The NESC is developing 

methodologies to predict interface 

forces based on these strain measurements that will be validated in 

ground testing. The PAF design 

used on this flight is the most suitable test article for resolving forces 

based on strain measurements.

Results: GLAST was successfully 

launched in June 11, 2008. Postflight data analysis is complete and 

flight coupled loads reconstruction 

underway. The next step consists 

of reconciling flight-based forces 

with flight reconstruction and/or 

nominal coupled loads results. The team will investigate 

the benefits of flight force measurements and the force prediction methodologies developed for use in ground testing 

to eliminate or substitute the use of strain gages in future 

launch vehicle flights.

Problem: The NASA Constellation Program (CxP) Chief Engineer requested an independent assessment to review and 

compare the current CxP mass 

and performance management 

implementation against industry 

practices.

NESC Contribution: The 

NESC investigated: standards 

terminology, mass and 

performance data capture and 

reporting, mass properties and 

margin management plans, 

mass margins, mass growth 

allowance (MGA), launch 

vehicle performance reserves, 

integrated performance 

margins, and sequential mass 

properties. The NESC team also reviewed the current 

project calculations and reporting of predicted mass, MGA 

and project management reserve, and identified methods to 

assess margins with respect to maturity and project phase. 

Results: Findings addressed details in terminology, data 

collection, accounting, reporting, 

adherence to standards, 

and the results of applying a 

method that assessed weight 

as a function of design maturity. 

Recommendations incorporated 

specifics for refining the CxP 

mass properties processes, 

thoroughly engaging the system 

designers in managing mass 

growth, and improved practices 

for tracking and measuring the 

mass growth risk. Results are 

being implemented to improve 

the overall accuracy of current 

mass properties and performance 

processes, ongoing analysis and 

reporting.

Lessons Learned: Programs 

and projects should recognize and incorporate the discipline 

of mass properties management early in the project life 

cycle. Implementation of mass properties management, 

requirements and practices should be based on industry 

standards, use of consistent terminology, data collection, 

margin measurement and reporting methodology. 

Exploration

Collecting Flight Force Measurements to Improve Coupled Loads Analysis

The number of parts on the Crew Exploration Vehicle, Orion, 

and other CxP components requires accurate knowledge of 

mass properties and its effects on the vehicle’s performance.

Analysis of Constellation Program Mass Properties

Lockheed 

Martin Corp.

Boeing employees Gerry Darter (left), Henry Fung (center), 

and Eric Thomas (right) install instrumentation on the GLAST 

PAF to collect flight force measurements.
Technical Highlights

14

Problem: The Ares I vehicle has a thrust oscillation 

frequency close to the vehicle’s second axial structural mode 

frequency. The NESC was asked to make an independent 

prediction of the thrust oscillation in the five segment 

Reusable Solid Rocket Motor (RSRMV) and to develop 

motor design change options for reducing or eliminating it.

NESC Contribution: The NESC team included personnel 

from JSC, MSFC, LaRC, Gloyer-Taylor Laboratories LLC 

(GTL), ATK, and Jacobs Engineering Group. GTL provided 

access to key expertise at Penn State University, the 

California Institute of Technology, and at the University of 

Tennessee Space Institute. Additionally, GTL provided 

expertise with their Universal Combustion Device StabilityTM

(UCDS) system that predicts and identifies the specific design 

sources of propulsion system instabilities. Using the UCDS 

simulation, the team identified and cataloged the design 

features that cause thrust oscillation and their individual 

contribution to the overall oscillation amplitude. Design 

options for eliminating and/or reducing the contribution of 

individual design features were developed and analytically 

evaluated using UCDS. The best options were provided 

to the NASA Constellation Program-chartered Thrust 

Oscillation Focus Team and the Ares project.

Results: Independent confirmation of the predicted RSRMV 

thrust oscillation frequency and amplitude characteristic 

was achieved. The specific contribution of individual design 

features was quantified for the first time. This provides 

very valuable information to address the thrust oscillation 

phenomena. Variability seen in thrust oscillations can 

be accounted for by inhibitor protrusion height and edge 

shape variability. With measured control of the regression 

rate of the inhibitors, particularly in the aft of the motor, 

substantial reduction in oscillation amplitudes could be 

achieved. Specific suggested design improvements will be 

experimentally assessed by the Ares project. Introduction 

of the most successful modifications will be evaluated as a 

potential upgrade in the future.

Lessons Learned: Aerodynamic streamlining principles 

apply within a rocket combustion chamber in the same 

manner that they apply in external aerodynamics. By 

applying aerodynamic streamlining principles inside rocket 

combustion chambers, the dynamic stability of the motor 

can be substantially improved.

Exploration

Steve Skelley, a propulsion engineer of the MSFC’s Fluid Dynamics Branch, studies the assembly of the solid rocket motor airflow test rig. The rig internally replicates the wetted surfaces of the RSRM at specific times in the burn. The proposed design modifications for reducing the thrust oscillations 

will be tested in this rig to verify their effectiveness.

Prediction and Reduction of Ares SRB Thrust Oscillation

Data from the shuttle RSRM ground test at Promontory, Utah was used 

to validate thrust oscillation models.
15

Technical Highlights

Problem: The Launch Abort System (LAS) system for 

Orion includes three new design solid rocket motors (SRM). 

The supplier team has baselined a qualification program for 

the three SRMs (Abort Motor, Attitude Control Motor, and 

Jettison Motor) while the government propulsion engineering 

team proposed a larger, more comprehensive set of 

qualification tests. To implement the larger qualification 

test matrix would significantly impact the baselined LAS 

qualification program. The LAS Project 

Office asked the NESC to conduct an 

independent assessment and provide a 

recommendation as to what is required 

to qualify the three LAS SRMs. 

NESC Contribution: The NESC 

formed an independent review team 

of experienced engineers, including 

industry experts, consultants, and 

retired NASA personnel to conduct 

this assessment. Both the supplier 

and Government LAS teams provided 

data for their approaches to LAS 

SRM qualification and their rationale 

showing the logic for their approaches 

to qualify the motors for human space 

flight application. 

Results: The NESC team conditionally 

agreed that the qualification plan as proposed by the motor 

suppliers for LAS can provide adequate demonstration that 

the motor designs are robust and have sufficient margins. 

A list of 10 conditions was supplied as part of the report. 

Included in these conditions was that all design and 

performance requirements must be verified as a part of the 

formal qualification program by a combination of tests and 

analyses, and that design and manufacturing processes 

should be mature at the beginning of 

full scale qualification motor testing. 

It was also noted that effective, clear, 

and timely communication must occur 

between the motor suppliers and the 

government engineering team.

A minority view was expressed on the 

NESC team that the baselined motor 

qualification plans are not acceptable 

and that it is improbable that there 

will be sufficient data necessary to 

establish that the motors meet all the 

key requirements at the end of the 

proposed qualification program. One 

of the premises of this perspective 

is that the LAS motor’s design 

departs significantly from previous 

configurations.

Problem: The NESC was requested to perform an 

independent review of structural design calculations 

and modeling of the Ares I-X Upper Stage Simulator 

(USS) and report any recommendations associated with 

the design methodology or structural 

integrity, including any need for additional 

mechanical testing.

NESC Contribution: The NESC team 

consisted of the NASA Technical Fellow for 

Loads and Dynamics, the NASA Technical 

Fellow for Structures, and experts 

from MSFC, ATA Engineering, Quartus 

Engineering, and Applied Structural 

Dynamics. 

Results:The NESC team found that the USS 

Project stress analyses were conservative 

and robust, followed industry accepted 

methods, and provided high margins of 

safety via the structural design. Finite 

Element Model (FEM) development was generally good, 

utilizing industry accepted methods. Concerns with the 

use of linear triangular elements were mitigated due to high 

margins of safety provided by the structural design. Some 

minor issues were identified and addressed 

by the USS Project. Adequate capability 

of the segment-to-segment bolted joints 

was demonstrated by test and analysis, 

with adequate “as-designed” margins of 

safety. Final “as-built margins” following 

flange machining to reduce gapping were 

not available for review. Existing design 

and analysis for other structure and joints 

was found adequate for proposing use of 

“no-test” factors of safety.

Lesson Learned: Consistent application 

of FEM best practice techniques within an 

organization can be improved by training, 

mentoring, and internal peer review. 

Ares I-X Upper Stage Simulator Project Independent Structural Review

Exploration

Review of the Launch Abort System Motor Qualification Plan

The NASA and Orion industry team conducted 

a successful test firing of the LAS abort motor.

Ares I-X illustration
Technical Highlights

16

Problem: The launch abort system (LAS) for the Orion crew 

exploration vehicle will provide a means of automatically 

separating the crew module from the launch vehicle in 

the case of emergency while on the launch pad through 

ascent to orbit. As a risk mitigation effort for the technical 

development of the Orion launch abort system, the then 

Associate Administrator for the Exploration Systems Mission 

Directorate requested the NESC design, build, and test an 

alternative concept independent of the 

project development.

NESC Contribution: The Max Launch 

Abort System (MLAS), named after 

Maxime (Max) Faget, a Mercury-era 

pioneer, will be theoretically capable 

of extracting the CEV from the launch 

vehicle at any time from crew ingress 

at the launch pad through staging 

and successful ignition of the second 

or upper stage of the Crew Launch 

Vehicle (CLV). The MLAS Flight Test 

will culminate with at least one fullscale unmanned pad abort test to 

demonstrate the viability of this alternate concept. In order 

to be timely and relevant to the Constellation Program, the 

NESC was challenged to complete this first flight test in 

parallel with the Orion LAS Pad Abort Test 1.

The MLAS flight test vehicle is designed to lift the crew 

module (CM) simulator from the launch pad to an altitude 

high enough and with enough distance downrange to allow 

the CM to execute a nominal landing. The MLAS pad abort 

flight test will demonstrate a passively controlled coast 

phase, reorientation and extraction of a CM simulator from 

the fairing. The test will also include a landing parachute

demonstration of an alternative landing system configuration 

for CM recovery.

The MLAS team is comprised of over 150 engineers, 

researchers and analysts from across the Agency and 

industry. NESC has partnered with the Wallops Flight Facility 

for the pad abort test to leverage both their launch range and 

sounding rocket development expertise. To minimize the 

development and manufacturing time, 

the MLAS team is employing existing 

technology and off-the-shelf hardware 

to the greatest extent possible. The 

full-scale composite fairing is being 

manufactured by Northrop Grumman 

Ship Systems in Gulfport, Mississippi. 

The four MK-70 solid rocket motors are 

surplus US Navy motors obtained from 

the Wallops sounding rocket inventory. 

The MLAS team has also capitalized on 

an opportunity to share lessons-learned 

and pass on corporate knowledge by 

bringing Apollo-era veterans as mentors 

and advisors together with junior engineers with 5-10 years 

of experience. The mentors have provided the MLAS 

team with first-hand knowledge acquired while building a 

human-rated spacecraft. The junior engineers, referred to 

as Resident Engineers based on the concept of medical 

residencies, are getting hands-on experience with the entire 

design, build and test life cycle. The multi-generational 

nature of the team has been rewarding and enriching for 

all involved and is helping to meet the goal of expanding 

NASA’s experience base in fast turnaround design and 

development projects.

Max Launch Abort System Risk Mitigation Project

Apollo and Shuttle veteran T.K. Mattingly and Karrie Trauth, Northrop

Grumman, discuss large scale composite structure fabrication.

Resident Engineer Geminesse Dorsey prepares an eight percent scale 

model of the MLAS fairing for wind tunnel testing at the Calspan facility.

NGC Calspan

As a resident engineer, meeting 

and working with people from the 

entire NASA Agency has been an 

interesting learning experience. 

The One NASA concept is alive 

and well on the MLAS Team!

—Terrian Nowden, MLAS

Resident Engineer, GRC

Exploration
17

Technical Highlights

The full scale Orion Crew Module simulator being 

prepared for mass properties measurements.

Technicians

prepare the 

forward fairing 

nose ring for 

installation.

One quarter of the composite forward 

fairing being lifted in the Wallops

Payload Processing Facility.

Technicians install an 

inert separation joint 

in the bottom of the 

Coast Skirt.

MLAS major

structural

components

CM Simulator

Boost Skirt

Coast Skirt

Forward Fairing

Photos and graphic/NASA

15

Exploration
Technical Highlights

18

On Multi-Center Teams:

My membership on the Materials TDT has provided me the opportunity to work with many 

people at the space flight Centers... Often the space flight Centers don’t understand the 

value of research Centers until our unique capabilities solve their real problems.

– Brian Jensen, Senior Researcher for Advanced Materials, LaRC, Materials TDT

Wind tunnel testing of the Orion 

Crew Module separating from 

the MLAS forward fairing.

Univ. of Washington

16
19

Technical Highlights

Problem: The NESC Shell Buckling Knockdown Factor 

Project (SBKF) was established in March 2007 to develop 

and validate new analysis-based shell buckling design 

factors (a.k.a. knockdown factors) for Ares I and Ares 

V metallic and composite launch vehicle structures. 

Improved, i.e., less-conservative, knockdown factors will 

enable significant weight savings in these vehicles and will 

help mitigate some of NASA’s 

launch vehicle development and 

performance risks.

NESC Contribution:The NESC 

has supported a significant 

portion of the SBKF Project, 

including funding for the design 

and fabrication of a large-scale 

test facility and the first series 

of large-scale buckling test 

articles, programmatic and 

technical support, peer reviews, 

and advocacy. In addition, the 

NESC has helped coordinate 

activities between LaRC and 

MSFC, the two primary centers 

involved in this project, and 

has enabled an efficient working relationship between the 

Centers.

Results: In FY08, the SBKF project designed and 

fabricated a new test facility to test 8-ft-diameter cylindrical 

shell structures subjected to combined axial compression 

and bending. Two 8-ft-diameter, 2195 Aluminum-Lithium 

(Al-Li) orthogrid cylinder test articles have also been 

designed and fabricated. The 

first test article was successfully 

tested in November 2008 

and the second article will be 

tested in January 2009. Subcomponent tests of 2195 Al-Li 

orthogrid stiffened panels are 

being conducted at LaRC to 

investigate local skin pocket 

buckling and stiffener crippling 

behavior. This test data is being 

used to assess the current 

design approaches for these 

structural details and validate 

new high-fidelity numerical 

simulations of common Areslike structural details.

Exploration

Updating of Launch Vehicle Shell Buckling Knockdown Factors

New Shell Buckling Test Facility at MSFC used for testing 8-ft-diameter cylinders subjected to combined compression, bending and internal pressure.

Dr. Mark Hilburger (left) and Dr. Robert Thornburgh (right), structures engineers from LaRC, monitor test data during the shell 

buckling test at MSFC.
Technical Highlights

20

ATK

Problem: In 2006, the NESC studied the feasibility of 

a (primary structure) composite crew module for the 

Constellation Program Crew Exploration Vehicle. The 

overall finding indicated a composite crew module was 

feasible, but a detailed design would be necessary to 

quantify technical characteristics, particularly in the areas 

of mass and manufacturability. Subsequently the NASA 

Administrator, Associate Administrator for the Exploration 

Systems Mission Directorate, and the Constellation Program 

Manager chartered the NESC to design, build, and test a 

composite crew module structural test article with the goal 

of developing a network of Agency engineers with handson experience using structural composites on complex 

habitable spacecraft design. The NESC Composite Crew 

Module (CCM) Project was chartered in January of 2007, 

with a goal of delivering a full-scale test article for structural 

testing 18 months after project initiation. 

NESC Contribution: Led by the NESC, the project 

team is a partnership between NASA and industry, which 

includes design, manufacturing, and tooling expertise. 

Partners include civil servants from ARC, DFRC, GRC, 

GSFC, JSC, JPL, KSC, LaRC, MSFC, the Air Force 

Research Laboratories, and contractors from Alcore, Alliant 

Techsystems, Bally Ribbon Mills, Collier Corporation, 

Genesis Engineering, Janicki Industries, Lockheed Martin, 

and Northrop Grumman.

The composite crew module team operates in a virtual 

environment, electronically connecting participants across 

the country. During the design phase, the team constrained 

the design to match interfaces with the then current Orion 

crew module including the internal packaging constraints 

that utilize a backbone for securing internal components. 

The team evaluated design solutions and focused on a 

design that utilizes aluminum honeycomb sandwich and 

solid polymer matrix laminate material systems. One 

unique feature of the composite crew module design was 

the structural integration of the packaging backbone with 

the floor and pressure shell walls. This provides a load 

path that accommodates load sharing with the heatshield, 

especially for water landing load cases. Another unique 

feature of the composite design is the use of lobes between 

the webs of the backbone. This feature puts the floor into a 

membrane type loading resulting in a lower mass solution. 

Connecting the floor to the backbone and placing lobes 

into the floor resulted in mass savings of approximately 150 

pounds to the overall primary structure design.

(Foreground) The lower shell cured inner skin on the lower shell cure tool. (Background) Aluminum honeycomb core on the upper pressure shell following 

the core tack cycle at the ATK factory in Iuka, MS. 

Composite Crew Module Pressure Vessel Pathfinder Development

Exploration
21

Technical Highlights

Janicki Industries

The design is constructed in two major components: an 

upper and lower pressure shell. The two halves are joined 

in a process external to the autoclave to enable subsystem 

packaging of large or complex subsystems. The initial 

and preliminary design concepts were reviewed by an 

independent review panel in March and June 2007. The 

team conducted building block testing of critical design 

and technology areas, which were used to validate critical 

assumptions and design allowables for the final design. The 

detailed design was reviewed and approved in December 

2007 by an independent review panel. Full-scale fabrication 

of the upper and lower pressure shells began in February 

2008, and post-cure assembly operations 

started in late May. The project plan is 

to statically test the combined upper and 

lower shell assembly to verify that the 

analysis models predict the response of 

the structure under load, and then repeat 

the static tests with internal pressure up to 

30 psi. Testing is scheduled to occur at 

LaRC in March 2009.

Results: In September 2008, the Orion 

project was asked to evaluate the 

implications of adapting a composite crew 

module in the baseline Orion design. A 

tiger team was formed between Orion and 

the NESC composite crew module team 

to evaluate opportunities and challenges. 

At this stage of the overall Orion vehicle 

design, the composite crew module does 

not appear to offer significant mass or unit 

cost savings because of the complex nature 

of its design. It also posed a significant threat to the Orion 

schedule because of the manufacturing changes required 

by composite versus metallic materials. However, because 

of the advantages of the split clam shell design found on 

the composite crew module, Orion is considering adopting 

this approach for their aluminum-lithium configuration.

Lessons Learned: Design lessons show that nonautoclave splices allow concurrent fabrication, assembly, 

and integration of major structural components and 

subsystems, and provide a lower cost cure tooling option. 

Through the use of complex shapes enabled by composites 

a membrane lobed floor integrated with 

backbone subsystem packaging feature 

offers a weight savings. A honeycomb 

core, combined with mature secondary 

attachment technology, provides flexibility 

and robustness in secondary attachment 

locations. As loads and environments 

change with program maturation, inner 

mold line tooling offers the opportunity to 

optimize or change design through tailoring 

of layups or core density. Composite 

solutions offer opportunity for lower piecepart numbers resulting in a lower drawing 

count which helps minimize overall life 

cycle costs. Also, a minimal number of 

tools are required to manufacture the 

primary structure. Thermal and dynamic 

property differences from aluminum are 

under investigation; however, preliminary 

estimates do not indicate that composites 

create system level issues. 

(Far Left) Dr. Dan Polis 

(on floor), CCM Materials lead, GSFC, and Mike 

Kirsch, NESC (on ladder), installing pre-preg 

carbon fiber fabric ply on 

the inner mold line skin.

Illustrations of the Apollo 

and CCM pressure vessels.

Apollo

CCM

Exploration

(Left) A tool proof of the 

upper pressure shell is 

extracted at the tooling 

vendor, Janicki Industries 

in Sedro-Woolley, WA. 

The tool proof was created to validate that the 

tool draft angle was sufficient to extract the part.
Technical Highlights

22

Problem: The Orion Project 

requested alternate seat attenuation 

designs to be developed and 

analyzed for the Crew Module (CM) 

with primary emphasis to provide 

improved crew survivability for 

nominal water and Contingency 

Land Landing (CLL). The NESC 

was later asked to evaluate crew 

seat design options to reduce 

the effects of the Ares thrust 

oscillations problem and its effect 

on landing loads.

NESC Contributions: The assessment team consisted of designers 

and analysts from multiple NASA 

centers including GSFC, JSC, JPL 

and LaRC, contractors, academia, 

NASCAR seat design experts and 

engineers from the Apollo era with 

design and test experience on its landing systems. Prior to 

developing alternate concepts, assessment members had 

the opportunity to evaluate the seat attenuation systems in 

the Apollo XVII Command Module, and in mockups of the 

Soyuz and Orion CM.

Results: The Orion baseline crew seats are located on a 

rigid pallet, which is suspended in the volume of the CM by 

load attenuating struts. The struts attenuate the loads to 

the crew when the pallet is accelerated in response to an 

external force applied to the CM. An Orion landing (water or 

land) orients the CM such that the reclined crew impacts the 

earth’s surface “feet first”, resulting in a major force vector 

along the axis of the crew’s spine. Analysis performed 

by NESC members assisting with finite element modeling 

of Orion occupant injuries found 

that improving the lateral restraint 

of the crew as well as holding the 

crew tighter in a conformal seat 

reduced injury risk. An NESC seat 

design expert developed and tested 

mockups of improved harnessing 

techniques to achieve these results. 

The team focused detailed design 

and analysis effort on investigating 

the effectiveness of incorporating an 

isolation system between the seat 

pallet and the CEV pressure vessel 

structure. Two concepts emerged. 

The first tilted the crew pallet during 

landing to provide a greater stroking 

distance to absorb more energy 

in the spine axis direction. The 

second concept focused on 

providing isolation at the strutpallet interface. The NESC team 

developed simplified dynamic 

response models and utilized the 

Orion baseline seat attenuation 

models to examine a range of 

pallet isolation properties for 

crew landing attenuation. This 

led to a request from the Orion 

Project to examine mitigating 

the effects of Thrust Oscillation 

(TO) from the Ares stage 1 

solid rocket booster on the 

crew using isolation concepts. 

Coupled loads models for 

launch and landing models were 

used to examine the optimal TO 

isolation frequency that would minimize crew loads during 

all phases of the Orion flight. Hardware design concepts 

for implementation of this feature have been generated and 

specific recommendations for the baseline seat system such 

as the shoulder harness attach point were also developed. 

Isolation system models showed reduction in the impact 

acceleration forces experienced by the seat occupant in 

all three axes for most load cases over the Orion baseline 

design by reducing the dynamic amplification portion of the 

load for crew response in the axis along the crew spine.

The NESC team is planning to evaluate smart materials and 

active systems to improve the strut performance over the 

baseline. Results from the TO study confirmed the optimal 

crew isolation frequency of 4.5Hz and revealed a potential 

problem with a rocking mode of 

the crew seat should isolation 

be implemented at that location. 

The team also examined pallet 

isolation and found that approach 

to be more appealing from a 

load mitigation perspective. 

Isolating in series with the 

pallet struts has a lower effect 

on crew landing loads than 

seat isolation and a higher 

probability of successful 

implementation. The NESC 

team continues to evaluate 

updated load cases and refine 

the hardware design concept.

Resultant 

velocity

vector

Improved Crew Seat Attenuation Designs for the Orion Crew Module

NESC team member Pete Rossoni performs a fit check in 

an Orion seat mock-up at JSC.

Exploration

The NESC worked to improve impact attenuation in the 

Z-axis (along the spine) of Orion crew members.
23

Technical Highlights

Problem: Reliable injury predictive tools and injury criteria 

are required for protecting Orion crew members during 

water and land landings. While conventional tools used in 

the aerospace community typically lead to safe designs, 

they may be overly conservative — resulting in additional 

complexity and increased system mass. Alternate 

approaches, such as those used in the automotive industry, 

may provide more fidelity; however, their application to 

Orion requires modification and study.

NESC Contribution: The NESC is supporting the Orion 

Project’s investigation in the use of crash test dummies for 

assessing injury risk for the Orion crew. The study objective 

is to better predict loads on the crew during water and land 

landings. Results from finite element math models and 

physical sled tests with the dummies are being compared 

to the whole body injury models commonly referred to as 

the Brinkley criteria, which have been typically used for 

aerospace applications. The crash dummy models allow 

for assessing the occupant restraint systems, cushion 

materials, side constraints, flailing of limbs, and detailed 

seat/occupant interactions to minimize landing injuries to 

the crew whereas the whole body models do not provide 

this level of detailed assessment. This information will 

be used to understand trends in occupant protection and 

to define acceptable injury criteria associated with seat 

restraint and attenuation systems. An accurate crew injury 

tolerance model would allow any changes to the Orion 

structure, seat attenuation system and landing conditions 

to be examined for its safety effects on the crew.

Results: While this work is ongoing, results thus far indicate 

the crash test dummies used in conjunction with the 

Brinkley criteria provide a useful set of tools for predicting 

and eliminating potential crew injuries. The finite element 

math models developed in support of this task have also 

been used to evaluate proposed designs by the NESC team 

investigating alternate landing attenuation and isolation 

systems.

Improving Orion Crew Impact Tolerance Modeling

Finite Element Hybrid III crash test dummy models 

represent the Orion crew members. Dr. Charles 

Lawrence, GRC, (right) developed this integrated model 

of the Orion crew module and seat attenuation system.

Exploration
Technical Highlights

24

MLAS team members lower the 

Crew Module Simulator into a mass 

properties measurement fixture.

Developing professional relationships: 

...by working with people outside your normal sphere of influence, you meet individuals 

who are able to challenge you and who help bring out the best in you... and vice versa. A 

mutually beneficial relationship develops, the projects become more exciting, and the quality 

of work is superbly better than the sum of what the individuals could have produced.”

– Dawn Phillips, MSFC, Structures TDT 22
25

Technical Highlights

Problem: The James Webb Space Telescope (JWST) 

uses a series of fine gauge wires and cables to interconnect 

the cryogenically operated (35K) optics and detectors to 

the warmer (~300K) electronics of the Integrated Science 

Module (ISIM). It was proposed that these cables, which 

are exposed to direct meteoroid flux in the Earth-Moon L2 

environment, can be damaged by the meteoroids. 

NESC Contribution: The NESC conducted an independent 

study of the cryogenic cable harnesses vulnerability and 

shielding requirements for the ISIM. Hypervelocity impact 

(HVI) tests were conducted that provided data on particle 

size/energy at the failure threshold for the ISIM’s exposed 

cables, and evaluated shielding options to protect the ISIM 

cable harnesses from meteoroid impact damage.

Results: The harness exposure, spacecraft orbit, and 

meteoroid environment as well as harness impact testing 

results were combined to predict the probability of ISIM 

mission success. This mission success prediction was then 

compared to the mission success requirement to define the 

necessary meteoroid shielding. The historical approach to 

meteoroid protection was also reviewed. One unexpected 

result found during testing was a large deviation between 

damage predictions and test results. Damage was 

estimated from the extrapolation of an analytical damage 

equation — valid for aluminum shields — to shields of 

different metals and compared with the test results. The 

extrapolated damage equation predicted better 

shield performance than the tests showed. The 

effects of cryogenic temperature were assessed 

on harness damage tolerance. The results 

showed that ambient temperature impact 

testing was adequate because less damage 

was seen at cryogenic temperatures. To cool 

the test articles in the vacuum chamber of the 

test range, an enclosure was built to insulate 

against convection, conduction, and radiation. 

A pressure system delivered cryogenic gas 

to the enclosure. One result was that the 

conductors within the ribbon cable assembly 

(silver-colored spheres in the cross-section 

above) apparently moved during impact, and 

thereby sustained less damage than had been 

expected for these types of impacts which did 

not fully penetrate or pass through the harness. 

HVI testing was also performed to study the 

contamination potential from micrometeoroid 

impact on the Aft Optics Assembly (AOA) 

light enclosures from debris generated by 

penetrations through the enclosures.

Hypervelocity Particle Impact Resistance of JWST Electrical Cables

Dennis Garcia, WSTF (right) uses a mirror to view inside the JWST cryogenic box to verify 

impact on target. Paul Mirabal, WSTF (left) verifies projectile integrity post test on the 

high speed imaging system.

WSTF

Optical cross-section at 30X of ribbon cable harness after High Velocity Impact testing. Harness was impacted by a 0.20mm diameter Sodium-LimeGlass projectile at 6.92 km/s at 0 ̊ impact angle. The impact in left image was at a cryogenic temperature and indicates damage of lesser depth but 

includes cracks marked by red circles compared to room temperature impact on right.

77K cryogenic temperature Room temperature

Science
Technical Highlights

26

Problem: One of the Reaction Wheel Assemblies (RWA) 

that is used to provide attitude control authority and stability 

on the Thermosphere, Ionosphere, Mesosphere Energetics 

and Dynamics (TIMED) spacecraft, failed in February, 2007 

after five years of continuous operation on orbit. Four 

RWAs of similar design have failed after two and a half years 

operation on two other spacecraft. The RWAs on the Kepler 

spacecraft, due to launch in early 2009, are identical to the 

TIMED RWAs. Based on the 

results of a Jet Propulsion 

Laboratory (JPL) failure 

investigation, the Kepler 

Project directed that design 

changes and corrective 

measures be implemented 

in the RWAs. Because the 

modifications were limited to 

minimize the overall impact to 

the Kepler mission, the NESC 

was asked to assess the risk to 

success of the Kepler mission 

from a RWA failure, given the 

history of flight failures and 

the limited modifications 

being implemented.

NESC Contribution:A multidiscipline, multi-Center team 

was formed by the NESC 

that included mechanism 

and tribology experts from 

GSFC, JPL and LaRC as 

well as Industry consultants. 

The assessment of RWA 

anomalies and associated 

risk to the Kepler project was 

broken into two parts. The 

first was an evaluation of 

the mechanism design and 

its ability to meet project life 

requirements. The second 

was an evaluation of the 

wheel usage.

To evaluate the mechanism 

design, the NESC team 

performed analyses and tests 

and also used data that was 

available from other NASA 

tiger teams involved with this 

issue. A Ball Speed Variation 

analysis was performed on 

the RWA bearings to assess 

the effects of misalignment. The team also evaluated the 

change in bearing lubricant film thickness as a function of 

rotational speed and operational temperature. The results 

of these tests and analyses fed into the short term and long 

term recommendations for the unit.

The NESC team also reviewed operational strategies for 

use of the Attitude Control System (ACS) with the Kepler 

Chief Engineer and the lead ACS engineer at the prime 

contractor. The strategies 

would maximize RWA life by 

minimizing the total number 

of RWA revolutions. Several 

operational recommendations 

previously not considered by 

the project resulted from these 

discussions and analyses.

Results: The direct results 

of this assessment warranted 

both in process and post 

assembly inspections and 

tests to reduce project risk. 

Ultimately, it was determined 

that the robustness of the 

ACS system (due to RWA 

redundancy) results in a low 

level of risk to meeting the 

project’s minimum mission 

objectives. The NESC team’s 

contributions provided the 

Kepler Project Management 

the data required for their 

overall mission performance 

assessments and on orbit 

operational suggestions 

should an anomaly occur with 

two RWA units. 

Risk Assessment of Kepler Reaction Wheel Premature Failure

Science

(Left) Kepler spacecraft showing the 

location of two of the four Reaction 

Wheel Assemblies. A reaction wheel 

is shown (above).
27

Technical Highlights

Problem: NASA and the Entry, Descent, and Landing 

(EDL) community lack a common repository of EDL data 

from previous Earth and planetary flight missions to aid in 

the design of future EDL systems. Recent missions to Mars 

will provide a wealth of information, however, much of the 

older data has been lost or is at risk of being unusable due 

to poor storage conditions. Some examples are: Viking EDL 

data and Viking design data (parachute tests); Planetary 

Atmosphere Entry Tests (from Wallops and Ames); Pioneer 

Venus (EDL); Galileo (ED); Magellan (aero-braking data); 

Project Fire (Apollo design and test data for re-entry); and 

Shuttle EDL test data.

NESC Contribution: The NESC EDL Repository team is 

focusing on two aspects: (1) to locate, collect, and digitize 

NASA technical and engineering EDL material, and (2) 

to develop a secure, web-based repository (EDL-R). It 

is password-protected and requires user-authorization 

for sensitive documents. EDL-R has browse and search 

capabilities, email notification of new material, and will 

follow a strict Submit, Review, and Release life cycle.

Results: Beta testing of EDL-R was completed in February 

2008. Since then selected users from NASA and academia 

have used it to archive material. In addition to continued data 

addition, the remaining work includes documentation (user 

guide, curator guide, etc.), and the implementation of some 

features such as Browse-by-Mission, Virus Check, etc. It is 

anticipated that the full system will be fielded in FY 09, and 

transferred to a NASA-selected Center for continued growth 

and maintenance.

Problem: Multiple projects across the Agency strongly 

desire to use the latest RTAX-S series Field Programmable 

Gate Arrays (FPGAs). These parts offer significant 

advantages over the use of the previous version RTSX-S 

or –SU regarding maintenance of signal integrity, capacity, 

capability, speed, and electrostatic discharge (ESD) 

tolerance. Reported user failures in the previous generation 

of FPGAs (RTSX-S) precipitated concerns late in the 

hardware design cycle for several NASA projects, causing 

significant cost impacts and higher mission risks. These 

concerns were not a result of the part performing in a clear 

failure mode condition, but rather a result of user application 

issues combined with unknown limitations of the original –S 

part with regard to marginal programmed antifuses. It is 

desired to avoid a similar late discovery of issues for the 

latest RTAX-S FPGAs.

NESC Contribution: The NESC is conducting a test 

of 80 units (2 lots) of RTAX250S and 80 units (2 lots) of 

RTAX2000S programmed with an algorithm designed to 

emulate expected space flight applications. The test will 

subject the parts to the voltage specification limit and to 

the temperature specification limit conditions. The selected 

representative space flight designs include multiple copies 

of a Military Specification 1553 Remote Terminal interface, 

an 8-bit micro-processor (PIC 16F84), an error detection and 

correction algorithm, a memory controller, and a Universal 

Asynchronous Receiver/Transmitter.

Results: The test was started in the second quarter of 

Calendar Year 2008 and is expected to be finished in the 

first quarter of Calendar Year 2009. The parts have passed 

the 1000 hour point of a planned 6000 hour test. Preliminary 

results have indicated no major issue at this time. 

RTAX Risk Mitigation Testing

Illustration of Mars Exploration Rover entry.

General

Entry, Descent, and Landing Data Repository and Analyses Task

RTAX250S FPGA and RTAX2000S FPGA Test Plan. 

Detailed 

analysis on 

anomalies

Programming Initial testing 

on ATE

Life testing

ATE = Automatic

Test Equipment

Report 

progress

Time, voltage,

and temperature 

profiles

Repeat each 

1000 hours for 

6000 hours total ATE tests on 

all parts
Technical Highlights

28

Problem: Hybridized DC/DC 

converters are ubiquitous in flight 

hardware designs, forming an 

important bridge between the 

spacecraft power bus and localized 

users of power within instruments and 

other electronic subsystems. These 

parts are actually complex microsystems containing the same types 

of elements that one would expect to 

see on a printed circuit board except 

all within a 12 inch2 package. For 

many years they have been found 

to inconsistently meet performance 

and quality requirements and to fail 

catastrophically in flight hardware. 

The complexity and cost of these parts 

can have a severe impact on program 

schedule and budget when a failure 

occurs or can be mission-ending if 

the failure occurs in flight. Hybrid DC/

DC converter flight failures have been 

demonstrated or have been suspected 

on several projects including GRACE, 

Hubble Space Telescope, and the 

International Space Station. In addition, 

numerous flight projects, both manned 

and unmanned, have had severe prelaunch cost and schedule impacts due 

to hybrid DC/DC converter quality and 

application issues. It is well established 

within NASA that there is difficulty with 

converter specifications and how that 

data can be interpreted and used.

NESC Contribution: The NASA 

Engineering and Safety Center 

(NESC) funded the development of 

a guidelines document to capture 

the knowledge that projects seem to 

constantly re-learn about DC/DC converters, particularly 

converters of hybrid microelectronics technology. Testing 

of several types of DC/DC converters was conducted to 

develop a standard set of test approaches and procedures 

for flight projects to use. This testing explored the operation 

of DC/DC converters at different conditions (thermal, power 

levels, etc.) to show where problems typically can be 

expected. The vendors were consulted regarding datasheet 

improvements that provide additional types of information 

important to projects. Standard tests, test procedures, 

sample datasheets, etc. were developed and are included in 

the guidelines document.

The guidelines document also 

covers a broad spectrum of general 

information including applications 

overview, mission environments, 

performance requirements, design 

practices, test methods, hybrid 

packaging and elements, quality 

levels, vendor-contract-related 

topics, and handling and installation 

precautions. The guidelines 

document also contains appendices 

on DC/DC converter usage by 

project and failure history in NASA 

hardware, a DC/DC converter 

specification template, boilerplates 

for contract documents, and a 

checklist for implementing this 

guidelines document for a flight 

project. These can be used by 

projects to get a jump start on their 

planned usage of DC/DC converters 

while eliminating many of the 

typical problems that are often 

encountered.

Results: The document provides 

a practical set of guidelines 

for characterization, selection, 

purchase, and application of 

hybridized DC/DC converters in 

NASA flight hardware to prevent or 

mitigate failures and risks in the field. 

The document describes practices 

that should be integrated into the 

following local processes: electrical 

system design and validation, 

electrical circuit design, thermal 

and packaging design, device 

characterization and evaluation, 

device qualification, device 

selection, and device procurement and acceptance testing. 

The recommendations and guidelines directly address a 

history of problems NASA has encountered with this device 

type. The document is meant to be used as a guideline; it 

is not mandatory and is not intended to be invoked as a 

requirements document by NASA Centers. Several current 

projects have already started using this information.

Lessons Learned: A NASA website has been developed 

to track the usage of converters as well as any failures. 

These data will be used to ensure the lessons-learned are 

communicated across NASA Centers, as well as being 

added to the Lessons Learned Information System (LLIS).

Development of DC/DC Converter Application Guidelines

General

Test images of a typical hybrid DC/DC converter: (top to bottom) cover removed, X-ray, 

thermal under load, and electron microscope 

at 24 MHz. 
29

Technical Highlights

Problem: Predicting aeroheating of complex surfaces 

during hypersonic entry into an atmosphere is complex, 

driven by uncertainties in both boundary layer transition 

(BLT) onset and subsequent turbulent heating. The 

inability to accurately predict these phenomena with 

numerical turbulence models can impose unnecessarily 

large thermal protection system margins that translate 

to reduced payload capability and degraded mission 

performance. Global temperature infrared (IR) images with 

adequate spatial resolution and dynamic range could nonintrusively complement thermocouple data by providing 

spatially continuous surface temperatures at targeted Mach 

numbers.

NESC Contribution: The HYpersonic AeroTHermodynamic InfraRed Measurements (HYTHIRM) team, established by the NESC, undertook a field deployment to perform radiometric calibration and validation of the nation’s 

existing suite of land-based and airborne IR imaging assets 

and tools for remote thermographic imaging. The test subject was a Shuttle tile array heated to surface temperatures 

typical of a Shuttle re-entry. The Sandia National Laboratory’s National Solar Thermal Test Facility in Albuquerque, 

NM, was used to aim an intense solar beam at a 4 ft x 4 ft 

panel of 64 Shuttle LI-900 ceramic tiles located on top of 

a 200-ft high tower (right). Thermocouples installed on the 

array and an IR imager located in close proximity to the test 

target provided actual surface temperature conditions. 

Results: The HYTHIRM systems were successfully 

calibrated and analysis of the imagery was used to evaluate 

the performance of the IR imaging assets. The team 

demonstrated the viability of obtaining surface temperature 

measurements of hypersonic flight vehicles, and more 

specifically, to reliably acquire, track and return surface 

temperatures of the Orbiter during entry aero-heating and 

provide flight BLT thermography data. These data could 

be utilized for calibration and validation of empirical and 

theoretical aero-heating tools.

Problem: The NESC is leading an Agency level Data 

Mining and Trending Working Group whose purpose is to 

assist in the formulation and implementation of a capability 

to strengthen trending of NASA programs and projects, and 

to ensure appropriate visibility of data mining and trending. 

Through workshops, monthly meetings, and training, the 

NESC has developed working relationships with data 

mining and statistical experts within academia, industry, 

and other government agencies. The NESC’s collaboration 

with other organizations has enabled cross pollination of 

ideas, particularly regarding methodology and lessons 

learned.

NESC Contribution: The DMTWG is assisting NASA 

organizations in strengthening trending activities for the 

Agency’s programs and projects. This is being accomplished 

in part by developing a data mining toolbox including tools 

such as the commercial data mining software, SAS. The 

team is also aiding the development and implementation 

of linguistic data mining approach meant to ameliorate 

terminology inconsistencies in problem reporting, under 

joint development by the JSC Engineering Directorate and 

the University of Central Florida. This group provides a 

forum to enhance communications across the Agency in 

the areas of data mining, trending, and statistics by sharing 

ideas, methods, technologies, processes, tools, and 

lessons learned.

NESC Data Mining and Trending Working Group (DMTWG) 

USA

General

HYTHIRM Validation and Calibration Testing Demonstration

Top

Bottom

East West

Cast Glance aircraft IR image of the Shuttle tile array heated by the solar 

collectors. (Inset) Image of non-uniform, top-to-bottom, heating of Shuttle 

tiles with temperatures ranging from 2000 °F to 500 °F.

Delmar Foster, Senior Analyst for United Space Alliance, performs data 

mining using SAS Enterprise and Text Miner software. 
Technical Highlights

30

Problem: Batteries are used in virtually every space 

mission and the differences in the application, duration, 

and operations result in the use of a large array of batteries 

and, therefore, battery issues. In the past there has been 

no coordinated NASA-wide approach to the common 

issues. The large array of issues include: exceeding the 

recommended wet life prior to launch, recognizing cell 

degradation signatures, and understanding the features 

and limitations. 

NESC Contribution: In 2006 the NESC chartered the 

NASA Aerospace Battery Working Group to carry out a 

series of tasks based on Agency-wide issues related to 

aerospace batteries. Studies were performed, issues were 

discussed, and test programs were executed in the 

generation of a series of recommendations and guidelines to 

reduce risk associated with various aspects of implementing 

battery technology in the aerospace industry. Over the 

past year, the working group, comprised of representatives 

from NASA Centers including GRC, JSC, GSFC, MSFC and 

JPL addressed (among others) the following technology 

areas: Recommendations for Binding Procurements of 

Battery Systems; Wet Life of Nickel-Hydrogen (Ni-H2) 

Batteries; Generic Safety, Handling and Qualification 

Recommendations and Guidelines for Lithium-Ion (LiIon) Batteries; Generation of a Guidelines Document that 

addresses Safety and Handling and Qualification of Li-Ion 

Batteries.

Results: The working group published a report 

entitled “Generic Safety, Handling and Qualification 

Recommendations and Guidelines for Lithium-Ion (LiIon) Batteries.” The document provides a summary of 

aerospace Li-Ion battery performance, guidance for the 

selection, design, operation and qualification of Li-Ion 

batteries, and specific guidance related to the use of pouch 

cells, commercial 18650 cells in high capacity, high voltage 

series/parallel strings, and recommendations for defining 

safe operational conditions for Li-Ion batteries.

Problem: Probabilistic requirements — those which 

include quantifiable uncertainty — occur in significant 

numbers in Constellation Program (CxP) requirements 

documents. Verification has sometimes been confusing or 

difficult for requirements owners and verifiers. A team was 

commissioned by the Constellation Chief Engineers Forum 

(CxCEF) to provide guidance for generating verifications with 

probability and confidence for both Monte Carlo analysis 

and all other applicable areas.

NESC Contribution: The NESC provided expertise to the 

CxCEF team in statistics and probabilistic risk assessment 

(PRA) from several NASA Centers and academia through 

its Systems Engineering Technical Discipline Team’s NESC 

Engineering Statistics Team (NEST).

Results: A pair of broadly-applicable templates modeling 

verification statements applicable to both probabilistic 

Safety, Reliability and Quality Assurance (PRA-type) and 

engineering performance requirements. The templates 

include: a “six-step” best-practice process for ensuring 

that verification is truly achieved; a tutorial glossary aimed 

at standardizing terms and explaining statistical concepts 

in engineering language; and a method for predicting the 

number of simulation trials necessary to prove verification of 

engineering performance requirements to the required risk 

level. For the NESC team, post delivery follow-up has been 

proven vital. Team members continue to supply consulting 

services to CxP users on applying the recommendations. In 

return, the team is learning how its recommendations could 

be extended to other programs.

Flight Battery Working Group Update 

Probabilistic Requirements Verification

Dr. K. Preston White (Left), University of Virginia, a key member of the 

probabilistic requirements verification team.

Li-Ion 

spacesuit 

pouch 

cell.

General
31

Technical Highlights

Problem: As a result of high current, auto-tracking of the 

starboard Solar Alpha Rotary Joint (SARJ) was halted in 

2007. The SARJ is a circular component that allows the 

truss to rotate to keep the solar arrays pointed at the sun. 

Inspection of the starboard SARJ revealed severe damage 

to the outer steel race with large quantities of magnetized 

debris present on both the race ring and trundle bearing 

assembly (TBA). The NESC was asked to support the 

International Space Station (ISS) Program anomaly root 

cause investigation team.

NESC Contribution: NESC Mechanical Systems 

Technical Discipline Team (TDT) members and gear and 

tribology experts from GRC, GSFC and MSFC reviewed 

SARJ build records, consulted on lubrication solutions, and 

provided testing of root causes. NESC members inspected 

the SARJ static test article and TBA returned from orbit, 

supported vacuum roller traction rig testing at GRC, and 

block on ring testing at MSFC.

Results: The NESC’s efforts provided the necessary data 

to exonerate potential root causes such as incorrectly 

installed TBA rollers and led to the discovery that gold 

plating adhesion was an issue on several TBAs during the 

initial build. Further investigation revealed that the gold 

adhesion issue might be a distinguishing characteristic 

between the current nominal operations of the ISS port SARJ 

versus the anomalous starboard SARJ. The team validated 

their hypotheses with laboratory testing which resulted in 

physical proof of the low friction benefit of gold surfaces. 

The ISS Program anomaly investigation team has adopted 

this as a very likely contributor to the SARJ anomaly and the 

NESC team continues to support them with the corrective 

action for short and long-term operations.

Lessons Learned: The report for this assessment is not 

yet complete and lessons learned are still in process.

Determination of EMU Space Suit Glove Damage Modes

Problem: The number of Extravehicular 

Mobility Unit (EMU) gloves damaged during 

extravehicular activities has increased. The 

NESC is assisting a JSC Materials and 

Processes team to identify glove damage 

modes.

NESC Contribution: The NESC assembled 

materials experts from LaRC, GRC, JSC, 

the US Army and SRI International. The 

team (a) reviewed EMU glove materials, 

manufacturing processes and testing, (b) 

examined ten damaged EMU gloves using a 

unique NASA scanning electron microscope 

facility with enhanced capabilities, and (c) conducted 

laboratory tests to duplicate observed microscopic damage 

modes where different off-nominal surfaces were used to 

replicate glove damage.

Results: Three damage modes were identified, which 

are likely the result of glove contact with 

off-nominal surfaces. The first damage 

mode noted was a linear separation of 

VectranTM fabric most likely produced by 

a press-and-draw motion of the glove over 

a relatively sharp surface severing multiple 

yarns along a single path and resulting in a 

linear shaped hole. At each fabric weave, 

a higher region or crown of yarn is exposed 

to rubbing contact with surfaces. The 

second damage mode, crown abrasion, 

is a common fabric damage mode and is 

characterized by severed frayed fiber ends 

located on each side of the crown and flattened fibers at the 

center of the crown. Finally, a snag-and-pull damage mode 

was noted. The loose VectranTM fabric weave is snagged by 

contact with an off-nominal surface protrusion. A portion of 

the snagged yarn is damaged (severed) as the fabric is pulled 

away from the surface.

Close-up of damage in the thumb 

region on right EMU glove.

Investigation of ISS Solar Alpha Rotary Joint Issue

Space Operations

Magnetized debris seen on the SARJ trundle bearing assembly. Twelve 

trundle bearing assemblies are equally spaced around the circumference 

of the SARJ and provide precision support and alignment during rotation 

of the SARJ.
Technical Highlights

32

Problem: Partial shadowing of the 108-foot-long support 

masts on the International Space Station (ISS) solar arrays 

can occur. This induces differential heating between the 

sunlit and the shadowed portions of the mast structure. The 

resulting thermal strains are predicted to buckle the mast in 

as little as 30 minutes. The condition was not considered 

in the original design of the mast. The 30 minute maximum 

exposure time has added complexity to controlling the solar 

arrays to avoid failure and raised concerns if attitude control 

were lost for any considerable period of time. ISS program 

management requested the NESC conduct an independent 

assessment of the thermal and structural analyses predicting 

the failure and its time to effect.

NESC Contribution: The NESC conducted an initial 

assessment of the analyses and did not find any modeling or 

analysis assumptions or techniques that could be improved 

to gain more margin and lengthen the time to mast buckling. 

However, it was observed that this partial shadowing thermal 

condition was not tested in the mast’s original development 

or qualification process. As a result the NESC is conducting 

a ground test program to provide the best possible thermal 

and structural response data for correlation of the mast 

models. The NESC contracted with the mast manufacturer 

to design and fabricate a special instrumented mast test 

section that was exposed to a simulated space vacuum 

and solar environment in the JPL’s 25-foot diameter Space 

Simulator facility. The mast was tested in October 2008. 

Results: Preliminary test data are being examined. Final 

test data will be correlated into thermal and structural models 

of the solar array masts. Predictions of the mast buckling 

failure load under the partial shadowing condition will be 

updated. The NESC will work with the ISS Structures and 

Mechanisms team to recommend appropriate constraints 

for on-orbit operations.

Reproduction of ISS Solar Array Mast Shadowing

(Above) On orbit, the solar array mast extends, retracts, and 

provides structural support for the solar array panels. 

(Left) Mathew Stegman (left) from JPL, Justin Templeton 

(center), and Dr. Kenny Elliott (on ladder) from LaRC set up 

the ISS solar array mast in JPL’s 25-foot-diameter Space 

Simulator Facility. The mast was subjected to the extreme 

temperatures of space to investigate the conditions that 

cause mast buckling.

Solving the Agency’s toughest problems: 

The NESC model of assembling a team of discipline experts from different NASA centers 

and companies enables solutions to problems otherwise not solvable.

— Don Shockey, Director SRI International Center for Fracture Physics, Materials TDT

NASA and its extended family in Government, Industry and Academia represent the most 

powerful engineering resource in the world.

— Paul M. Munafo, Chief Engineer, Teledyne Brown Engineering, Materials TDT

Space Operations

30
Port side truss segments showing 

solar array components.
Center Focus

Computer image of Vehicle

Assembly Building fire scenario. 
35

Center Focus

During 2008, Ames Research Center (ARC) continued to 

provide a wide variety of expertise to NESC activities. 

Over 50 ARC civil servants and contractors provided 

support to the NESC’s Technical Discipline Teams and 

technical assessments. ARC provided experts in disciplines 

ranging from human factors, data mining, and computational 

modeling to composites, aeroacoustics, and nondestructive 

evaluation testing. The NASA Technical Fellow for human 

factors, Dr. Cynthia Null, is resident at ARC.

Exploration Systems 

Composite Crew Module (CCM): ARC personnel are a key 

part of the NESC’s CCM team, leading the design of the 

lower primary structure. The innovative design, in which the 

floor beams carry pressure load instead of the traditional 

ring frame and dome, has yielded a 100 lbs. mass savings. 

A variation of the load sharing backbone has been adopted 

by the Orion Project. An additional 50 lbs. mass savings was 

realized by shaping the shell into lobes which was easily 

accomplished with composites. ARC personnel performed 

analysis of test components and assisted in the composite 

fabrication at ATK Iuka. Most of the 

lower structure is bonded with 

woven preform technology 

developed by Lockheed 

Martin. A new structural 

element was needed 

at two intersections 

along the main beams, 

but existing preform 

technology was not 

mature. Titanium 

fittings were designed 

as back-ups while 

composite preforms 

could be developed. 

Fittings were fabricated and 

shipped to ATK Iuka for assembly 

into test specimens. Pi preform shear strength tests will be 

performed at Ames in late 2008.

Vehicle Assembly Building (VAB) Analysis: To support 

upcoming space exploration missions, modeling and 

simulation experts are providing a computational framework 

for simulating elements of the ground operations of future 

launch vehicles at KSC. Part of this NESC-sponsored effort 

is determining whether the VAB at KSC, used for the Space 

Shuttle, is properly equipped to safely handle the storage 

of significantly more fuel required for the Agency’s nextgeneration Ares I and Ares V vehicles. ARC experts are 

developing the capability to employ high fidelity CFD tools 

(OVERFLOW and Cart3D) to predict the effects of various 

fire scenarios in the VAB. The modeling will help determine 

the probability of the solid rocket boosters in any of the other 

three bays igniting, then identify the maximum possible heat 

flux generated in the worst-case scenario and the resulting 

effects on nearby structures at KSC. 

Max Launch Abort System (MLAS): The USM3D flow 

solver is generating MLAS aerodynamic data that cannot be 

readily generated experimentally. ARC engineers improved 

USM3D, focusing on increased performance and support 

for larger problem sizes. As a result, run time has been 

reduced by 5 times, and memory requirements have been 

reduced by 2 times. Simulations that took a week now take 

a day. ARC engineers are also incorporating visualization 

capabilities into the USM3D code that will allow the user to 

view the progress of computations on their desktop.

USM3D flow solution of the MLAS at a subsonic flight condition.

Results from the OVERFLOW simulation tool show instantaneous particle 

traces colored by temperature in a VAB fire scenario.

Lower section of the 12-

foot CCM Pressure Vessel

Ames Research Center

Dr. Tina Panontin

NESC’s Chief

Engineer at ARC

SEE ALSO: CCM, Page 18
36

Center Focus

Dryden Flight Research Center

Dr. James Stewart

NESC’s Chief

Engineer at DFRC

Dryden Flight Research Center (DFRC) engineers have 

contributed to the NESC’s multi-discipline teams in 

addressing the Agency’s toughest problems. This year DFRC 

scientists and engineers supported NESC assessments 

in the areas of Composite Crew Module Structural tests, 

Hypersonic Thermodynamic Infrared Measurements 

(HYTHIRM), and have supported Max Launch Abort System 

(MLAS) project and Space Shuttle.

Exploration Systems

Composite Crew Module (CCM) Structural Testing: 

DFRC is supporting the structural testing on the NESC’s 

CCM team with fiber optic sensing and measurement 

technology. DFRC engineers are using NASA-developed 

fiber optic sensor technology to monitor the structural 

strains in approximately 300 locations along four optical 

fibers mounted on the CCM. Each fiber is approximately the 

diameter of a human hair and can be placed in geometrically 

complex regions where conventional sensors can not be 

installed. Such areas include the regions in a highly loaded 

bolted joint, between L-brackets and a composite substrate. 

The fiber optic system, which has recently been flown on 

the Ikhana Unmanned Aerial Vehicle, can monitor strains at 

record rates that surpass commercially available systems. 

The CCM team supported testing of this technology at 

LaRC, with the support of the DFRC engineers. 

Max Launch Abort System (MLAS): DFRC is supporting 

MLAS launch operations at the Wallops Flight Facility by 

providing flight termination receiver /decoder equipment for 

use as a command uplink to the MLAS flight test vehicle.

Space Operations

DFRC senior engineers participated in a wide range of 

activities pertaining to NESC loads and dynamics work. 

One major area of activity was related to the Broadband 

Aeroacoustic Stator Simulator (BASS) Project which evolved 

to support the root-cause determination of the Space Shuttle 

Main Engine flowliner cracking due to acoustic resonance. 

DFRC engineers were involved in modifications of the BASS 

software code to facilitate implementation of coupling of 

wall motion and unsteady loading in the flowliner.

General

Hypersonic Thermodynamic Infrared Measurements 

(HYTHIRM): DFRC supported the NESC sponsored 

HYTHIRM project with Dryden’s Mobile Aerial Tracking and 

Imaging System (MATRIS). The objective of HYTHIRM was 

to bring high resolution infrared imaging assets to support 

the Space Shuttle boundary layer transition experiment. 

On STS-119, a special tile with local roughness will be 

placed on the port wing of the orbiter windward surface to 

induce boundary layer transition at higher Mach numbers.

The earlier transition will result in additional heating that 

will be measured on the Orbiter by discreet thermocouples. 

The IR assets will add global thermal imaging to the discreet 

measurements. This data will be used to improve prediction 

methods of aeroheating and boundary layer transition at 

hypersonic conditions. The improved predictions will aid 

in future thermal protection system design and damage 

assessments. In preparation for the Shuttle tests this year 

the MATRIS and other HYTHIRM assets participated in a 

calibration test at the Sandia National Labs Solar Tower 

that was sponsored by the NESC. Engineers from PVP 

Advanced EO Systems Inc. Tustin, CA, built the MATRIS 

system and supported the calibration test which was the 

first field test of MATRIS. 

Allen Parker, Dr. Lance Richards (Group Lead) and Anthony Piazza of the 

Advanced Structures and Measurement Technology Group check the fiber 

optics measurement system at DFRC before the CCM test at LaRC.

Mobile Aerial Tracking and Imaging System (MATRIS) set up to support the 

HYTHIRM calibration test at Sandia National Laboratory’s Solar Tower.

SEE ALSO: MLAS, Page 14; HYTHIRM, Page 27
Glenn Research Center (GRC) contributed to a broad 

range of assessments and discipline advancing studies 

for the NESC. GRC draws upon Engineering, Research 

and Technology, Safety & Mission Assurance and Facilities 

organizations to provide the unique skill sets and facilities 

required to successfully complete special tests, and 

evaluations in support of NESC assessments.

Exploration Systems

Orion Occupant Protection: GRC is currently supporting 

work on Orion Crew Module (CM) occupant protection 

systems. The primary objective of the effort is to develop 

spacecraft design alternatives and injury criteria that ensure 

the CM design provides minimal risk to the crew during 

nominal and contingency landings. This work includes crew 

protection systems such as the crew seat pallet attenuation, 

seat designs and development of tools to predict injuries 

and injury criteria.

Space Operation

International Space Station Solar Alpha Rotary Joint 

(SARJ): GRC personnel performed a forensic failure analysis 

and supporting tests to investigate failure mechanisms and 

anomaly resolution for the SARJ. Roller manufacturing 

specifications and tolerances, combined with key trundle 

design features, including sensitivity to the effects of 

sliding friction coefficient and limited compliance, were 

investigated to develop failure scenarios for the SARJ. A 

review of the manufacturing records, discussions with the 

suppliers, and in-house testing revealed that adhesion of 

gold, has a solid lubricant film is critical to extending the life 

and performance of the rolling elements.

Additional GRC Space Operations support included 

providing expertise in plasma sources, plasma diagnostics, 

and simulation of space plasma conditions for investigations 

into charging models used to determine safe operations for 

the Extravehicular Mobility Unit and safe operations with 

the International Space Station plasma contactor unit.

General

GRC personnel have leadership positions within two 

Agency-level working groups sponsored by the NESC. The 

Composite Pressure Vessel Working Group (CPVWG) has 

advanced understanding of aging effects for Orbiter Kevlar/

Epoxy Composite Overwrapped Pressure Vessels (COPVs). 

This work supports a collaborative effort with the Orbiter 

Project to perform a long-term stress rupture test with the 

benefit of contributing to applications of COPVs for the 

Constellation Program. GRC personnel also participated in 

the Flight Battery Working Group and developed guidelines 

that addressed safety, handling and qualification of Li-Ion 

batteries for crewed and robotic applications. 

Technical Discipline Team

GRC support to the NESC Technical Discipline Teams 

included Structures and Nondestructive Evaluation for 

composite materials in spacecraft structures. Trades 

focused on safety factors and material allowable values 

in critical structures. Probabilistic structural simulations 

were used as methods to quantify risk for highly stochastic 

conditions in loadings and materials. GRC personnel, 

experienced in these methods for high-temperature 

composites in aircraft propulsion systems, were able to 

apply this method to spacecraft component reliability.

37

Center Focus

Bryan Smith

NESC’s Chief Glenn Research Center Engineer at GRC

Bryan Smith (left) NESC Chief Engineer at GRC and NESC CCM Project 

Manager Michael Kirsch (right) discuss pull test results for critical composite interface joints used in the CCM Project.

Tim Krantz (left) and Chris Dellacorte (right) of the Tribology & Mechanical 

Components Branch, review test results of gold solid lubricant film 

adhesion for the SARJ anomaly investigation.

SEE ALSO: Orion Modeling, Page 21; SARJ, Page 29
38

Center Focus

Goddard Space Flight Center

The Goddard Space Flight Center (GSFC) continued its 

wide-ranging support to the NESC with over 140 resident 

and matrixed specialists involved in 56 tasks. GSFC provides 

expertise in Electronic, Electrical, and Electromechanical 

(EEE) parts, spacecraft electronics, guidance, navigation and 

control (GNC), materials, mechanical and power components 

and systems, reliability, software, and systems engineering. 

The Center benefited from participating in NESC activities 

as many had NASA- and industry-wide importance. Four 

NASA Technical Fellows reside at 

Goddard: Michael Aguilar, Software, 

Mitchell Davis, Avionics, Neil 

Dennehy, GNC, and Joe Pellicciotti, 

Mechanical Systems.

Exploration Systems 

The Center supported many 

Constellation Program (CxP) 

tasks for the NESC. Several 

addressed prominent design and 

system architecture issues: Ares 

aeroacoustic loads during launch, 

vehicle seat attenuation designs 

for assuring crew safety and 

survivability, the reliability of the GNC 

System, and the Program’s Safety, 

Reliability and Quality Assurance 

implementation. GSFC’s 

sister facility, the Wallops 

Flight Facility (WFF), provided 

considerable support to the 

Max Launch Abort System 

(MLAS) Project.

Space Operations

Key expertise for NESC 

Space Shuttle Program (SSP) 

support included substantive 

contributions identifying and 

resolving External Tank Engine 

Cut-Off Sensor reliability 

issues, Fuel Cell Pump Motor 

risks, Rudder/Speed Brake 

operational risks from chipped 

actuator gear teeth, and Solid 

Rocket Booster electronic 

component fatigue failures. 

Center engineers identified 

solar array “steering” joint 

degradation mechanisms – 

needed for supplying power 

to the Station, and tested 

TeflonTM wire integrity against 

embrittlement in the space radiation environment for the 

International Space Station.

Science

NESC science mission assessment support included an 

instrumented payload adaptor ring for the Fermi Gammaray Space Telescope’s to better understand coupled loads 

during launch, pre-launch risk assessments for the Dawn, 

Fermi, and Phoenix missions, mishap investigations for a 

spacecraft processing accident 

and telescope motor anomaly, and 

space laser transmitter EEE parts 

radiation testing. An extensive 

effort evaluated electrical cable 

vulnerability to hypervelocity particle 

impacts for the James Webb Space 

Telescope.

General

NESC discipline advancing 

tasks address potential NASAwide problems before they 

create significant impacts. The 

Center provided key support to 

discipline advancing assessments 

for Field Programmable GateArray reliability, DC-to-DC 

Converter failures, threaded 

fasteners for aerospace uses, 

a NASA/industry cooperative 

space battery program, and 

demonstrated high-speed 

optical data transfer using 

SpaceWire.

NESC Awards

Dr. Michael J. Dube (Discipline 

Deputy – Mechanical Systems) 

received the prestigious NESC 

Director’s Award for technical 

excellence for supporting 

and resolving numerous 

Agency-wide anomalies. Jim 

Lanzi, WFF Flight Mechanics 

Engineer, received an 

Engineering Excellence Award 

for his MLAS flight test vehicle 

work. A Group Achievement 

Award for the SSP Engine 

Cut-Off System Investigation 

Team was accepted by Dr. 

Henning Leidecker. 

Steven S. Scott

NESC’s Chief

Engineer at GSFC

Magnified image of multi-conductor wire damage from a 

0.65 mm particle collision at 7 km/sec. 

Natalie Panek, NASA Intern, setting up a transformer for wire fatigue 

testing with mentor, Dr. Henning Leidecker. 

SEE ALSO: MLAS, page 14; HYTHIRM, page 27
39

Center Focus

I

n 2008, the Jet Propulsion 

Laboratory (JPL) participated in 

numerous NESC assessments for 

the Science, Exploration Systems 

and Space Operations Mission 

Directorates. 

Space Operations

The JPL 25-foot Space Simulator 

is being used to create conditions 

that could cause buckling of the 

International Space Station solar 

array masts. Tests were completed 

in October and data analysis is 

underway.

Science

A Reaction Wheel Assembly (RWA) 

on the Thermosphere Ionosphere 

Mesosphere Energetics and 

Dynamics (TIMED) spacecraft 

was autonomously shut down by 

the spacecraft’s fault detection 

software after failing a torque 

check. Two other satellites 

currently are using these wheels 

in the operations phase and 

several future missions including 

the upcoming Kepler Project are 

in the implementation phase and 

planning to use these wheels, all 

from the same manufacturer.

JPL’s Office of the Chief Engineer 

formed a team to investigate the 

anomalies, evaluate the risk to 

current and future missions, and 

if possible give recommendations 

to mitigate the risk. Based on the 

results, the Kepler Project decided 

to mitigate the risk by reworking 

the RWAs instead of incorporating 

new design changes. The JPL 

Chief Engineer and Kepler Project 

requested an independent review 

by the NESC to validate the risk posture and plans for the 

RWA usage for Kepler. In response, the NESC formed an 

independent team that provided six specific recommendations 

for the Kepler mission and long-term recommendations 

for the future missions. These recommendations enabled 

the risks to the Kepler Project to be evaluated. The NESC 

assessment and its recommendations will also be valuable 

to future NASA and industry 

missions to assess project risks 

and develop mitigation plans 

when using RWAs from this 

manufacturer.

General

JPL is supporting the NESC-led 

Composite Pressure Vessel (CPV) 

and Flight Battery working groups. 

JPL is providing the leadership 

and is the host for the COPV 

Working Group to study the longterm safety of COPVs. In support 

of the Flight Battery Working 

Group, Glenn Research Center is 

using JPL battery experts and test 

facilities.

The NESC Robotics Technical 

Discipline Team (TDT), led by 

JPL, is working several tasks to 

advance robotic exploration. 

The Direct Current (DC/DC) 

Converters task has completed 

a comprehensive guidelines 

document for developers of 

power systems as well as test 

methodologies to be used. The 

guidelines directly address a 

history of problems NASA has 

encountered with this device type. 

A practical set of guidelines is given 

for characterization, selection, 

purchase, and application of 

hybridized DC/DC converters in 

NASA flight hardware to prevent 

or mitigate future failures and 

risks in the field. Several current 

projects have already started 

using this information and have 

been pleased with the results.

The Entry, Descent and Landing 

(EDL) task developed a database 

that is capturing at-risk EDL data 

to benefit future spacecraft designs. EDL experts from 

GSFC, JPL, JSC, and LaRC are populating the database. 

The Wireless Avionics task has developed a set of longterm requirements, developed an architectural approach 

and developed a preliminary prototype to prove out the 

concepts. ARC, GSFC, JPL and JSC avionics engineers are 

working this task cooperatively.

R. Lloyd Keith

NESC’s Chief

Jet Propulsion Laboratory Engineer at JPL

Tom Trippany, JPL, is shown adjusting parameters for the DC/

DC converter testing.

SEE ALSO: ISS mast shadowing, Page 30; Kepler RWA, Page 24; EDL repository, Page 25; DC/DC converter, Page 26

The JPL 25-foot Space Simulator, with ISS solar array mast 

installed, provides the vacuum and thermal conditions found 

in space. 
40

Center Focus

Johnson Space Center

NESC personnel at Johnson Space Center (JSC) continued 

to support the safe and successful execution of Space 

Shuttle Program (SSP) and International Space Station (ISS) 

missions and the development of the next generation of 

human-tended spacecraft for the Constellation Program. 

NESC personnel provided 

technical insight into 

NASA’s human spaceflight 

programs by serving as 

non-voting members on 

major technical boards and 

panels. They also provided 

JSC managers with periodic 

status briefings regarding 

NESC activities related to 

their programs/projects. 

They provided real-time 

mission support by serving 

as a member of the SSP and 

ISS Mission Management 

Teams. In addition to the 

NESC Chief Engineer, the 

NASA Technical Fellows 

for Loads and Dynamics 

and Life Support/Active 

Thermal and a member of 

the Systems Engineering 

Office are resident at JSC 

as are the NESC Deputy 

Directors for Safety and 

Advanced Projects. 

Exploration Systems

In recognition of the importance of independent assessment 

of design and development efforts for the next generation 

of human-tended spacecraft, the NESC is engaged at all 

levels of the Constellation Program. Numerous independent 

assessments of issues affecting the Constellation Program 

and Project elements were conducted during 2008. An 

independent team, led by the NASA Technical Fellow for 

Mechanical Systems, developed alternate seat and seat 

attenuation designs for Orion to reduce the potential for crew 

injuries. NESC personnel provided peer reviews of the Orion 

and Ares aerodynamic and aerothermodynamic database, 

models, and methodologies. They also assessed external 

pressure field predictions of Orion and Ares aeroacoustics 

and the predicted micrometeoroid environments for 

Constellation elements. NESC experts analyzed the loads 

and dynamics of the Orion/ARES vehicle stack and were 

involved extensively in improving the capability to model 

human response to accelerations to determine the potential 

risk of crew injury during landing scenarios.

Space Operations

In support of the Space Shuttle Program and Orbiter Project 

Office an interdisciplinary team of experts in structures, 

NDE, materials, mechanical systems, loads and dynamics, 

aerosciences and flight mechanics assisted with the 

root cause investigation 

and testing protocols 

for the anomalous local 

degradation of silicone 

carbide coating integrity 

on the Reinforced CarbonCarbon wing leading edges 

of the Orbiter. Other Space 

Shuttle issues that the 

NESC assessed or assisted 

with included: a buckling 

issue with the Orbiter 

radiator retract flexhoses, 

water-hammer effects in 

the orbiter Coolant Loop, 

atmospheric circulation 

issues on the Orbiter, and 

damage that occurred to

the KSC Pad 39A flame 

trench walls during launch 

of STS-124. 

The NESC conducted 

several independent 

assessments of issues 

affecting the ISS and its 

operations including thermal 

and structural analysis 

to support investigations 

into buckling issues associated with solar array mast 

longeron shadowing, damage modes and potential on-orbit 

remediation options for the Solar Alpha Rotary Joint, and 

failure investigation efforts for an incident in which a SelfContained Oxygen Generation System (SCOG) exploded 

on a Royal Navy submarine. The ISS uses both US and 

Russian SCOGs. Testing conducted at White Sands Test 

Facility reproduced the physical effects of the explosion 

and assisted in root cause identification of the failure and a 

redesign to prevent reoccurrence. 

NESC Awards

Kenneth L. Hodges received the NESC Engineering Excellence 

Award for the design, development, and implementation 

of state-of-the-art non-destructive techniques for the 

composite crew module project. Dr. John C. Graf received 

the NESC Director’s Award for the investigation of the Self 

Contained Oxygen Generator explosion on a British Royal 

Navy submarine.

Dr. Nancy J. Currie

NESC’s Chief

Engineer at JSC

SEE ALSO: Orion seat attenuation, Page 20

One major component of the International Space Station (ISS) remains to be 

installed. S6 contains the fourth and final set of solar arrays and batteries. 
41

Center Focus

The NESC is involved in multiple activities and projects at 

the Kennedy Space Center (KSC). Likewise, KSC continues to provide excellent support and expertise to a wide variety of NESC assessments and testing across the Agency. 

More than 30 KSC civil servants and contractors of various 

disciplines were active in NESC assessments and studies 

this year. Also, 25 NASA personnel at KSC are members of 

the NESC’s Technical Discipline Teams (TDTs). These discipline expert teams are the primary workforce the NESC calls 

upon when performing assessments and studies.

Exploration Systems

KSC engineers and researchers are working with the NESC 

on the Max Launch Abort System (MLAS). The MLAS project is focused on alternate launch abort techniques as risk 

mitigation for Constellation’s Orion Project. A unique aspect of the MLAS project is the Resident Engineer program. 

Engineers that are relatively early in their career are being 

paired up with NASA Technical Fellows and Apollo design 

engineers to get “hands-on” experience in designing, developing, building, and launching a full scale launch abort 

system. KSC has two engineers assigned to this project.

KSC researchers were also involved in the NESC MLAS 

Project. Personnel from KSC’s Electrostatics and Surface 

Physics Laboratory characterized the electrostatic buildup characteristics of the fairing material being used in the 

MLAS concept. In addition, a KSC engineer is on the design 

team of the NESC Composite Crew Module Project, developing expertise and techniques for potential composite use 

on crewed space vehicles. 

Space Operations 

NESC personnel were engaged in assessments at KSC for 

the Space Shuttle, including the main engine cut-off sensor 

anomaly root cause investigation and subsequent design 

changes, Nondestructive Evaluation techniques in support 

of the crawler track shoe cracks and casting flaws, and the 

launch pad flame trench brick wall integrity.

Likewise, the NESC supported the International Space Station (ISS) in several assessments by bringing Agency experts 

together to review program issues. In particular, Dr. Chris 

Iannello of KSC augmented the NESC Avionics TDT with 

his understanding of electrical power in assessing the ISS 

Russian BOK3 computer shutdown, the Shuttle/ISS power 

transfer system startup transients, and the ISS Solar Array 

Wing Lessons Learned Team. In addition, the NESC is partnering with KSC to assess safe operating distances around 

the Shuttle Vehicle Assembly Building (VAB) associated with 

an anticipated increase in the amount of solid propellant 

segment processing for the Ares I and Ares V boosters. The 

NESC is modeling the ignition characteristics of the propellant and motor segments within the VAB. KSC researchers continued support for the NESC on enhanced insulation 

materials, including Aerogel, for potential use on the Shuttle 

ET inter-tank flange.

Science

The NESC is actively working with KSC’s Launch Services 

Program on a Flight Force Measurement project to use 

flight measured strain data to resolve the actual flight forces at spacecraft interfaces. The system was flown on the 

GLAST mission.

Stephen A. Minute

NESC’s Chief

Engineer at KSC

Dr. Carlos Calle (left), Dr. Michael Hogue, (center), and Dr. Charles Buhler 

(right) with KSC’s Electrostatics and Surface Physics Laboratory take 

electrostatic measurements from a sample of MLAS fairing material.

Kennedy Space Center

SEE ALSO: MLAS, Page 14; CCM, Page 18

KSC’s Samantha Manning (center) and Sarah Quach (right) are getting 

real-time, hands-on design experience with NASA’s Technical Fellow for 

Avionics Mitch Davis (left) at a MLAS design review as part of the MLAS 

Resident Engineer program.
42

Center Focus

Langley Research Center (LaRC) continued to support 

the NESC mission to address the Agency’s high risk 

programs and projects. Langley is the home Center for the 

NESC Director’s Office. The NASA Technical Fellows for 

Materials — Dr. Robert Piascik, Nondestructive Evaluation 

(NDE) — Dr. William Prosser, Structures — Dr. Ivatury Raju, 

Aerosciences — Dr. David Schuster and Flight Mechanics 

— Mr. Daniel Murri are also resident at LaRC. 

Space Operations

LaRC supported the NESC investigation of the Orbiter 

Reinforced Carbon-Carbon (RCC) Silicon Carbide (SiC) 

coating liberation discovered in the Orbiter’s thermal 

protection system. The RCC, located along the wing 

leading edge and nose cap, protects the Orbiter from 

damaging plasma during re-entry. LaRC carbon-carbon 

composite material experts are conducting tests to develop 

an understanding of the damage phenomenon and assist 

in developing solutions. RCC specimens were exposed to 

simulated re-entry profiles using Langley’s Multi-parameter 

Mission Simulation Facility. The specimens are used to 

develop new mechanical tests that will determine the loss 

of adhesion strength of the protective SiC coating to the 

RCC substrate and to characterize selected mechanical 

properties of RCC.

Exploration Systems

LaRC experts in structures, materials, and nondestructive 

evaluation (NDE) made significant contributions to the NESC 

Shell Buckling Knockdown Factor (SBKF) assessment. SBKF 

was initiated with the goal of developing and validating new 

analysis-based shell buckling knockdown factors that date 

from the 1930s to the 1960s for relevant Ares V type metallic 

and composite shell structures. The first set of two 8-ftdiameter, orthogrid barrel test articles for validation testing 

were designed and fabricated by the Langley-led team. 

LaRC has also made major contributions to NESC 

independent technical assessments such as the critical 

initial flaw size (CIFS) of defects in welds in the Ares I-X 

Upper Stage Simulator (USS). The USS is an inert stage that 

simulates the upper stages of the Ares I launch vehicle. The 

Langley Fatigue and Fracture Laboratory and Environmental 

Fatigue Laboratory were used during the test to characterize 

the steel that is used in the USS. Tests were conducted 

on welds and fatigue crack growth rate tests were also 

conducted.

General

LaRC provided technical leadership in the NESC sponsored 

development and release of a NASA technical standard for 

models and simulations and also led the NESC sponsored 

HYpersonic THermodynamic InfraRed Measurements 

(HYTHIRM) assessment team. HYTHIRM is developing 

sensing methods and tools that will be used for thermographic 

imaging of aero-heating on the Orbiter during entry. The 

goal is to provide data that could be used for calibration and 

validation of empirical and theoretical aero-heating tools for 

future Agency missions.

NESC Awards

This year, Langley personnel received four group awards 

and four individual awards. Recipients of the NESC Group 

Achievement Award were the 8% MLAS Model Team, the 

Ice Mitigation Approaches for Space Shuttle External Tank 

Team, the NESC Ares I-X USS Critical Initial Flaw Size 

Analysis Team, and the Langley Mission Support Team. 

Dr. Kenny Elliott received the NESC Director’s Award and 

James Beaty, Dr. David Dawicke, Dr. Norman Knight, and 

Erik Tyler received NESC Engineering Excellence Awards.

Wallace Vaughn (left) and Craig Ohlhorst (right) examine an RCC test coupon after a high temperature mission simulation cycle in LaRC’s Multiparameter Mission Simulation Facility.

Clayton P. Turner

NESC’s Chief

Engineer at LaRC

Dr. David Dawicke and Greg Shanks conduct fracture tests on welded A516 

Steel for critical initial flaw sizes (CIFS) in USS segments for Ares I-X 

Langley Research Center

SEE ALSO: MLAS, Page 14; Shell buckling, Page 17; HYTHIRM, Page 27
43

Center Focus

Marshall Space Flight Center (MSFC) engineers have 

been supporting NESC efforts across a broad range 

of activities during 2008. Following the retirement of George 

Hopson, the NASA Office of the Chief Engineer named 

Roberto Garcia (resident at MSFC) as the NASA Technical 

Fellow for Propulsion.

Exploration Systems

The NESC is involved in Ares and Orion work at MSFC 

and has participated in several assessments and 

project reviews. The Shell Buckling Knockdown Factor 

assessment was initiated by the NESC in 2007 with the 

goal of developing and validating new analysis-based shell 

buckling knockdown factors for relevant Ares V type metallic 

and composite shell structures including Aluminum-Lithium 

orthogrid and composite sandwich constructions. MSFC 

and LaRC engineers are working together to develop and 

implement new high-fidelity structural testing methods and 

measurement techniques. Manufacturing and validation 

testing activities at MSFC will support the test and analysisbased knockdown factor development and validation.

Shell barrels manufactured at MSFC passed all required postfabrication nondestructive evaluation and were instrumented 

for testing. Structural testing began in November 2008 in 

a new large-scale test facility designed, fabricated and 

assembled at MSFC. The shells are subjected to combined 

axial compression, bending and internal pressure. 

MSFC engineers are continuing their activities in the NESC 

Composite Crew Module work, in which a multi-center team 

developed an Agency-wide expertise in design, analysis, 

manufacture, and testing of such a large composite 

structure. Fabrication of all building block test elements 

and process scouting tests are continuing at MSFC with the 

completion of a full-scale upper pressure shell manufacturing 

demonstration article in Iuka, MS.

Space Operations

MSFC personnel participated in NESC assessments of flight 

and operations hardware for the Space Shuttle Program 

and the International Space Station (ISS) Program. NESC 

personnel at MSFC continued to participate in Space Shuttle 

propulsion reviews including pre-flight readiness reviews.

MSFC engineers made key contributions to the ISS Solar 

Alpha Rotary Joint (SARJ) assessment. A trundle bearing 

assembly that had been removed from the SARJ on orbit 

was sent to MSFC for evaluation. This work included 

tribological evaluation of bearing failures, precision 

dimensional and surface metrology on program critical 

hardware, fundamental friction and wear testing, advanced 

materials analysis, and loading a special grease gun as 

a potential EVA repair tool. All 17 spare trundle bearing 

assemblies in the ISS inventory, and the 12 assemblies from 

the SARJ structural test article were sent to MSFC for the 

same detailed tribological examination.

General

MSFC engineers continued to participate in the NESCsponsored Composite Pressure Vessel (CPVWG) Working 

Group. The CPVWG working group is the Agency’s technical 

group responsible for reviewing and developing composite 

pressure vessel technologies related to human and robotic 

space missions.

Dr. Charles F. Schafer

NESC’s Chief

Engineer at MSFC

(Below) Lewis “Chip” Moore examines a trundle bearing

assembly prior to performing profile measurements.

Marshall Space Flight Center

Orthogrid panel segment welded into a barrel section in the Vertical Weld Tool for the 

Shell Buckling Knockdown Factor work.

SEE ALSO: MLAS, Page 14 Shell buckling, Page 17; CCM, Page 18; SARJ, Page 29
44

Center Focus

Stennis Space Center (SSC) engineers supported NESC 

assessments by using the unique capabilities and 

facilities available at SSC.

Exploration Systems

A-3 Test Stand: SSC is testing the J-2X engine that will be 

used in the second stages of Ares I and Ares V. The A-3 

test stand will be used to test the J-2X at simulated altitude 

conditions, including a high altitude start test capability 

to provide flight duration tests of 500 seconds. With 

personnel from SSC, the NESC supported an independent 

assessment of the baselined cost and schedule estimate 

for the A-3 test stand. The NESC also formed a team that 

included SSC engineers to assess the thermal and dynamic 

loads that could be generated by the facility. Critical to the 

A-3’s performance is a diffuser that incorporates the first 

and second-stage steam ejectors required to simulate 

high altitude. SSC had initiated the Subscale Diffuser Test 

(SDT) program, which is a 1/17 scale of the A-3 diffuser, to 

provide design validation for A-3. The NESC team used 

the SDT to verify and validate the modeling tools used to 

predict facility response, facility-induced environments (farfield acoustics, heat flux, etc.), and operational conditions. 

Predictions using Computational Fluid Dynamics analysis of 

the SDT diffuser flow path were performed. The predictions 

compared well to experimental data obtained during the SDT 

program. Computational heat transfer and aero-acoustics 

analyses were also performed to provide feedback to the 

project team in their evaluation of thermal and acoustic 

management strategies.

Integrated System Health Management (ISHM): The 

NESC also took proactive measures to adapt an ISHM 

capability developed at SSC to the SDT program. ISHM 

capabilities can provide several benefits including detection 

of anomalies, diagnosis of root causes, determination of 

effects and prediction of future anomalies. An anticipated 

benefit of the ISHM capability is its scalability to support the 

full scale diffuser on A-3. The SDT ISHM pilot capability was 

then replicated to support the Chemical Steam Generator 

(CSG) testing. The CSGs provide the steam required to 

operate the Subscale Diffuser.

Max Launch Abort System (MLAS): SSC engineers 

participated on the NESC MLAS team to assist in predicting 

thermal and dynamic loading of the solid rocket abort 

motors. They collected and analyzed heat flux data from 

a representative solid rocket motor (MK70) during ground 

testing at Indian Head, Maryland. SSC also supported 

MSFC with overpressure measurements during a sounding 

rocket launch at Wallops Island, Virginia, to predict the 

thermal and acoustic loads on the MLAS flight test vehicle. 

SSC personnel provided an analysis of the thermal radiative 

effects from the MK70s on structural and other critical 

components during the MLAS boost phase.

Space Operations Engine Cutoff Sensor 

(ECO): In response to an NESC call for 

support, the SSC Data Acquisition Team 

devised a technical solution that allowed 

the processing, formatting and displaying 

of critical test data taken from the STS-122 

External Tank ECO Sensors. This was the 

first complete and successful processing 

of the data captured in a very large file, 

with format issues. Furthermore, the SSC 

team assisted the NASA Technical Fellow 

for Avionics and the senor test team by 

processing specific areas of interest to 

facilitate the isolation of the ECO sensor 

problem.

NESC Awards

The SSC Data Acquisition Team received 

an NESC Group Achievement Award for 

their efforts in support of the Space Shuttle 

Program. Their outstanding technical 

abilities and dedicated service supported 

timely decision-making by the technical 

and management teams and ultimately the 

successful launch of STS-122.

Michael D. Smiles

NESC’s Chief

Engineer at SSC

Artist conception of the A-3 test stand at Stennis Space 

Center. (Inset) The J-2X subscale diffuser elbow at the E-3 

test stand at Stennis Space Center.

Diffuser

Diffuser 

elbow

Test cell

Stennis Space Center

SEE ALSO: MLAS, Page 14
45

Center Focus

White Sands Test Facility (WSTF) scientists and 

engineers have assisted the NESC in addressing 

important issues in NASA programs and projects. This year, 

testing and analysis centered on hypervelocity impacts, 

chemical oxygen generators, Composite Overwrapped 

Pressure Vessels (COPVs), technology requirements for the 

High Pressure Oxygen Generator Assemblies, pyrovalve 

failures, and a proposed method for treating hydrazine and 

monomethylhydrazine.

Space Operations

A chemical oxygen generator explosion aboard a UK Royal 

Navy (RN) submarine resulted in crew fatalities and extensive 

damage. Since similar chemical oxygen generators provide 

backup oxygen on the International Space Station (ISS), the 

NESC sponsored a cooperative agreement for scientists and 

engineers from NASA and RN to work together to conduct a 

root cause analysis, chemical modeling, laboratory analysis, 

and field testing that resulted in a series of full-scale tests at 

WSTF. The findings have increased fundamental knowledge 

of the mechanisms of chemical oxygen production and have 

led to operational changes and improved safety onboard RN 

submarines. 

A project focusing on research and development of the 

technology required for a High Pressure Oxygen Generator 

Assembly (HPOGA) was started this year. The HPOGA 

is a high differential pressure water electrolysis cell stack 

that uses water to produce oxygen gas at up to 3000 psi 

without the need for a mechanical compressor. The oxygen 

tanks on the ISS are currently resupplied with high pressure 

gaseous oxygen by using space shuttle oxygen. When the 

Space Shuttle is retired the HPOGA is being explored as one 

option to meet ISS oxygen needs. Personnel from WSTF, 

Hamilton Sundstrand, and JSC are performing testing on 

HPOGA simulators.

WSTF supported an NESC evaluation of a proposed 

method for treating hydrazine and monomethylhydrazinecontaminated equipment with alpha-ketoglutaric acid 

(AKGA). The tests were prompted by suggested cost and 

operational benefits to NASA for flight hardware and ground 

support equipment decontamination, treatment of liquid 

waste, spill remediation, and possibly vapor control. The 

NESC and WSTF developed a quick-response team with Dr. 

Thomas Giordano from CH2MHILL to further examine the 

treatment processes proposed by CH2MHILL.

Science

Cables on the James Webb Space Telescope will be directly 

exposed to micrometeoroid impact in the Earth-Moon L2 

environment. WSTF’s Remote Hypervelocity Test Facility 

conducted hypervelocity impact testing, some at cryogenic 

temperatures, to support the NESC assessment of cable 

vulnerability and shielding requirements. WSTF personnel 

continued to assist the NESC assessment into ground test 

failures of pyrotechnically operated valves that are used in 

numerous NASA spacecraft. A novel approach to analysis 

of the heat transfer mechanisms inside the pyrovalve primer 

chamber assemblies was performed using a combination 

of computer analysis and test data. Recommendations for 

reliable operations were shared with NASA projects and 

programs such as the Solar Dynamics Observatory, Mars 

Science Laboratory, Phoenix Mars Lander, and Orion.

General

WSTF has supported the NESC Composite Pressure Vessel 

Working Group (CPVWG) in evaluating the effectiveness 

of nondestructive evaluation techniques for detection of 

manufacturing flaws and vessel aging indications and 

applied Raman spectroscopy for measurement of strain 

condition. WSTF has also developed a library of material 

properties and stress rupture data on carbon and Kevlar 

fiber materials. 

Dr. Nancy J. Currie

NESC’s Chief

Engineer at JSC

Ben Gonzalez, GeoControl Systems Inc., and Brooks Wolle, Jacobs 

Technology Inc., perform radiograph inspection of COPV weld anomalies 

at WSTF. 

Chris Keddy, Jacobs 

Technology Inc., verifies measurements on a 

sectioned COPV against 

a structural model generated in GENOA, a virtual testing and analysis 

software.

White Sands Test Facility

SEE ALSO: JWST electrical cables, Page 23
Astronaut John Young, Apollo X 

command module pilot, participates 

in simulation activity in the Apollo 

Mission Simulator at the Kennedy 

Space Center.

46

Featured Technical Paper

Risk-Driven Design Approach for CEV 

Electrical systems enable the crew and ground to control critical spacecraft functions. 

Balancing competing needs and requirements, infusing new technology, and meeting 

tight mass and power constraints argues for a top down risk informed design approach 

to achieve an optimized system.

– Michael Bay, Bay Engineering 44
47

Featured Technical Paper

1

Iterative Risk Driven Design Approach for CEV Avionics 

Michael Bay, NASA Engineering and Safety Center (NESC) 

Avionics Technical Discipline Team, BEI 

Mitchell Davis, NESC Avionics Technical Fellow, NASA 

Blake Putney, Principal Risk Analyst, Valador 

Abstract - An agency wide team led by the NASA Engineering and Safety Center (NESC) 

utilized an iterative, risk informed, build up design approach to decide where to apply mass 

resources to balance safety, performance, and affordability for Crew Exploration Vehicle (CEV) 

Avionics. The buildup approach started from a simple single string architecture to assure the 

solution was in the box, then identified weaknesses and risks to safety and mission success, 

considered operational alternatives to eliminate risks as well as the addition of backup systems 

and redundancy to restore adequate failure tolerance. The fundamental objective of the build up 

approach was to find the safest, most reliable and affordable system design by applying mass, 

power and other resources where they do the most good for safety and mission success.

TABLE OF CONTENTS

1. TEAM CHARTER ................................................ 1

2. BACKGROUND AND CHALLENGES .................... 1

3. ASSEMBLING AN INTEGRATED TEAM ............... 4

4. DESCRIPTION OF THE DESIGN APPROACH....... 6

5. CONCLUSION ................................................... 14

1. TEAM CHARTER

An agency-wide team led by the NASA 

Engineering and Safety Center (NESC) 

participated in a study chartered to assess 

driving requirements and consider alternative 

designs for the CEV that may reduce mass.1

The Smart Buyer Team was challenged to 

assess driving requirements and offer 

alternative approaches to reduce mass without 

adversely effecting safety and mission 

success. One of the tasks involved a study of 

the Avionics configuration for the CEV with 

the express purpose of identifying safety, 

reliability, and mass drivers, and identifying 

how the avionics configuration effects vehicle 

mass. In addition the team was to identify the 

requirements that drove vehicle mass and how 

changes to those requirements may allow 

mass reductions. To search for innovative 

solutions, the Smart Buyer Team united 

technical expertise and experience of the 

human spaceflight, robotic and research 

centers. 

2. BACKGROUND AND CHALLENGES

The CEV Smart Buyer Design Team (SBT) 

used the existing CEV design products as a 

starting point and was allowed the latitude to 

perform trade and design studies outside of the 

current baseline and to challenge the existing 

requirements if necessary. Several challenges 

guided the study effort: 

Mass Constraints. The Lunar mission design 

poses severe mass constraints on the Crew 

Exploration Vehicle as do most missions to 

the Moon, Mars and elsewhere beyond LEO. 

The physics of traveling to the Moon and 

Mars involves the “pushing” of mass to the 

destination requiring significant propellant 

and supporting structure. Power systems 

introduce a multiplicative effect on mass as 

power must be collected, stored, distributed 

and then shed as waste heat by the thermal 

system. These multiplicative factors argue for 

the judicious control of power to allow the 

application of scarce mass resources where 

they do the most good. 

Reducing Mass. The CEV design had 

proceeded through several design cycles. The 

link between mission objectives and the 

required functions were masked by a large 

number of lower level derived requirements 

including the application of two failure 

tolerance at a low level. The conceptual 

design had matured to the point that a 

significant number of derived requirements 

severely limited design options. The system 

was constrained to the point that alternative 

designs, even ones utilizing less mass, 

appeared to violate derived requirements. 
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Even after setting aside some derived 

requirements, the team found it hard to 

identify where to reduce mass and was not 

comfortable with “loping” off pieces of an 

existing system design without understanding 

how mass reductions would effect crew safety 

and mission success. The team was challenged 

to identify how to get the system back inside 

“the box”. Figure 1 shows a notional box with 

Risk, Performance, and Cost / Schedule 

boundaries. Valid solutions appear as surfaces 

inside the box boundaries. If a system design 

results in parameters outside the box, it is hard 

to lop off pieces to get back inside the box 

without compromising the integrity and 

cohesiveness of the integrated system. 

To avoid the drawbacks of loping pieces off 

the system, the study team started with a

minimal system whose performance and cost 

parameters were well inside the box, and risk 

parameters outside the box. The team then 

proceeded to build up the system, add to the 

minimal system reducing risk along the way 

until a balanced closed solution was found. 

Design Prescriptions and Rules. While 

evaluating alternatives, the team recognized 

that there is no predefined recipe or 

prescription for safety. There is no a priori 

prescription for the design of a safe human 

rated system. No single process or single rule 

such as two failure tolerance will by itself 

assure safety and mission success. Hazards 

exist in context of a design and an operational 

sequence and therefore are unique to each 

mission. When considering safety as the 

absence of uncontrolled hazards, we realize 

that we cannot write enough rules and 

requirements to preclude hazards and prevent 

latent defects. We cannot prove this 

"negative", i.e. that all hazards are controlled, 

or that there are no latent defects. 

Success during mission operations is assured 

by following procedures and rules. Procedure 

and rule development starts by exploring and 

anticipating what may go wrong and what can 

and should be done about it. Decisions are 

captured in procedures and flight rules and are 

followed in a disciplined manner. During 

operations, procedures and rules tend to drive 

what is done which is the opposite from 

upfront work where mission objectives, an 

operational sequence, and critical functions 

drive design. 

Absent a prescription for a safe design, the 

challenge then is to design the system for the 

minimum risk at the integrated mission level. 

Exploring alternate architectures along with 

their associated failure modes is critical to 

identifying the lowest risk and most robust 

solution. Upfront design work provides the 

most leverage in obviating or mitigating 

weakness and should result in an architecture 

with a predictable and coordinated response to 

failures threatening the critical functions 

necessary for safe crew return. A flexible 

iterative design loop is necessary to explore 

alternate designs and alternate operational 

approaches. 

Success in the high risk business of manned 

space flight is grounded in providing 

sufficient capabilities for “safe crew return” 

should system elements fail. Teams need to 

 Figure 1 Box Defining Boundaries
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explore system weaknesses, risks, hazards, 

etc, in context of the design’s operation and its 

exposure to the natural and induced 

environments. An essential part of the risk 

evaluation includes identifying specific 

functional failure modes of system elements. 

When unacceptable threats are identified, 

ideally eliminate them from the design first 

and if that is not possible reduce the severity 

of the threats by decoupling the threats from 

the susceptible system. Finally, design the 

susceptible system to tolerate the threats with 

the minimal impact or essentially survive the 

consequences of the threat. 

Top down and bottoms approaches are needed 

to explore and capture system weaknesses 

with an objective of finding safer alternates 

and or simple systems to preserve safe crew 

return. Not providing two failure tolerance, or 

not meeting a requirement is not necessarily a 

weakness of the system. Weaknesses exist in 

actual physical vulnerabilities of the end item 

rooted in the as built system acting in a 

manner that results in undesired 

consequences. 

Two failure tolerance provides one 

mechanism to minimize risk but such an 

approach must be balanced against the added 

complexity and the utilization of scarce 

resources. Additional complexity intended to 

enable a system to survive a failure may result 

in a higher likelihood of system failures 

offsetting the improved failure tolerance. 

Resources need to be applied where they do 

the most good for the total system. Once 

resources are consumed they cannot be used in 

other areas to improve their safety. Stated 

differently, a two failure tolerant system 

design should not result in a less safe system 

over other alternatives.

Requirements. The team operated under the 

assumption that requirements can 

inadvertently constrain the design and 

potentially eliminate safer or lighter options. 

A proliferation of requirements, rules, and 

other prescriptions can lead to the false 

confidence that compliance with those rules 

will result in a safe and proper system. The 

sheer volume of rules / requirements and the 

massive effort to show compliance with those 

rules can lead to the illusion that the system 

must be a good and safe one. The irony of all 

the rules and prescriptions is they can 

inadvertently reduce the discussions and 

exploration on the very risks that the rules 

seek to prevent, and can unintentionally 

remove the onus for a safe and reliable system 

from the designers and place it on the rule 

writers. 

It was therefore important to distinguish 

between requirements establishing program 

needs and objectives from derived 

requirements intended to constraint the 

solution space. The team identified the 

requirements establishing needs and 

objectives that if met make the program 

worthwhile. These served as the validation 

bases for subordinate derived requirements. 

The derived requirements were candidates for 

change and could be solidified later after a 

design reference mission and a design 

approach has been considered and evaluated 

from a risk standpoint.

Safety and Mission Success. For the purposes 

of the study, a distinction was made between 

Safety (loss of crew) and Reliability (mission 

success). This distinction was important since 

a human rated vehicle fundamentally 

preserves safe crew return over mission 

success. Safety and reliability objectives often 

work together, but can also compete. The two 

work together when margins are added to the 

system to ensure its continued operation from 

both safety and mission success perspectives. 

They compete when safety objectives seek to 

prevent a hazardous condition that also 

interrupts mission success. For example, a 

human rated system would set safety limits 

prior to the point of failure to allow a crew 

abort scenario. An early or false abort may 

occur at the expense of mission success. Such 
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limits preserving abort are not present in 

unmanned vehicles.

Complexity. Complexity is often the antithesis 

of safety and reliability as complexity can 

obscure unintended and unexpected 

interactions and coupling of system elements.2

Robustness is achieved by knowledge of how 

the system responds to intended actions or 

faults and complexity obscures the 

predictability of the system’s response. A 

robust system is predictable, and does not 

produce surprises. A complex system with a 

large array of interactions and stimuli will 

harbor unexpected and undesirable responses.

Interactive complexity threatens to obscure 

safety risks. The system can become so 

complex that there are “no obvious” safety 

risks. Complexity should therefore be limited 

to the minimum necessary to accomplish the 

mission objectives.

Complexity is a relative term as no 

meaningful absolute scale exists. Complexity 

must be linked to the ability to predict the 

systems’ response and is not necessarily 

related to part count. Finding the correct level 

of complexity is the hard part and requires 

good systems engineering. To determine the 

minimum complexity the team established a 

minimal floor for the system design as driven 

by the critical functions necessary for meeting 

mission objectives. 

A large part of the systems engineering effort 

involved identifying where separate pieces 

were necessary to support critical functions, 

where they should be separated and 

decoupled, and then integrating those pieces 

into a cohesive whole.

A driving consideration in minimizing the 

complexity of space systems design involves 

balancing centralized versus distributed 

architectures with respect to safety. Due to 

complexity, systems are centralized so a single 

element can orchestrate the integrated vehicle. 

However from a failure standpoint systems are 

decentralized to limit the coupling and the 

cascading of failures from one subsystem into 

others and to allow the crew to utilize backup 

systems and simple manual methods to control 

critical vehicle functions.

3. ASSEMBLING AN INTEGRATED TEAM

The study effort expanded the term 

“Avionics” to the more global “Electrical 

Systems”. The electrical systems team 

included representatives of all subsystem 

elements that control the flow of electrons as 

well as software, mission design, and 

operations. The electrical system was defined 

to include all electronics components on the 

spacecraft, from where the current or voltage 

is generated in a sensor or a power source to 

where the current or voltage ends in an 

actuator, or the signals leave the spacecraft. 

This broad view enabled a holistic 

understanding of the complete system and 

rapid appreciation and evaluation of risk and 

alternatives. 

The team also included Reliability, Safety and 

Risk analysts who provided a skeptical “what 

can go wrong” mindset complementing the 

engineer’s optimism in expecting the design to 

work. 

The electrical systems team included 

representatives from Electrical Power, 

Command & Data Handling, Communications 

& Tracking, Guidance Navigation & Control, 

and Software disciplines as shown in Figure 2.

For the crew interface, Environmental Control 

And Life Support System & thermal, a clearly 

defined interface was established to the 

electrical systems allowing independent 

evaluation of the non-electrical systems. 

Representatives of the electrical systems team 

worked closely with the Systems Engineering 

and Integration to coordinate issues that 

crossed discipline boundaries.

The electrical system team’s study efforts 

relied heavily on a risk driven cyclic loop to 

attack risk drivers in a systematic top down 
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fashion as shown in Figure 3 and described in 

the rest of this paper.

Each functional element of the electrical 

system was assigned to a team member and 

team members were encouraged to 

communicate and collaborate to ensure 

individual system elements combine into a 

cohesive integrated system. Functions and

interfaces were established with minimal

overlap and without holes. The wellcoordinated electrical systems design team 

was guided by the following objectives:

• Establish an integrated view of electrical 

components, sensors to actuators

• Identify where common designs reduce box 

count and complexity

• Identify where common cause failure 

threatens safety and reliability

• Identify design overlaps and holes in design

• Provide a clear and integrated interface to 

Safety and Reliability Analyses

• Integrate results with the overall vehicle 

systems engineering team

Safety and reliability analysts were also part 

of the team providing a “skeptical” view and 

seeking to continually encourage “what can go 

wrong” type questions along with analyzing 

the system design. A key contribution of the 

reliability team is the linkage of the design 

reference mission to the design, to identify 

system level failure and recovery scenarios 

that are used to evaluate back up redundancy 

alternatives. This helps designers to envision 

the role of their system in its entire context 

beyond the written requirement, allowing 

Figure 3 Electrical Systems Risk Driven Design Loop

Figure 2 Electrical Systems Team Members
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them to conceive of designs that achieve high 

reliability with maximum simplicity.

4. DESCRIPTION OF THE DESIGN APPROACH

WITH EXAMPLE

A buildup approach was fundamental to the 

performance of the study.3,4 The approach 

started with the minimal incarnation of the 

system to:

a. provide rationale for the system design 

including efficient utilization of scarce 

mass and power resources,

b. identify whether the system has any 

hope if being “in the box”,

c. establish a “floor” for the complexity 

of the system.

In this case the minimal system was single 

string. Building up the system from this 

baseline provides rationale for every system 

element, every watt, and every kilogram of 

mass based on system weaknesses and risk. 

The single string system provides a direct link 

between the required functions and 

performance requirements without the 

complexity of redundancy. The addition of 

backups, redundancy, and failure tolerance 

was addressed later after assessing weaknesses 

and risks of the single string system.

A secondary objective of establishing a 

minimalist system was to make sure the 

simplest solution is in the box, if it is not, then 

alternate designs or even alternate mission 

objectives and constraints maybe necessary. If 

the minimalist system is in the box, then 

margin to box limits were available to 

improve safety and mission success based on 

risk drivers.

Figure 4 shows the systems engineering 

approach starting with mission needs and 

objectives driving the identification of an 

operational sequence and critical functions 

that in turn then drive an iterative design loop.

An iterative design loop was necessary to 

assure the requirements, the system design, 

and the design reference operations concept 

mission are developed in a cohesive manner 

assuring consistency.

Figure 4 Systems Engineering Approach
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Identify high level driving requirements. The 

study started with the identification of those 

requirements that establish program needs and 

objectives as distinguished from derived 

requirements that specify solutions. Due to the 

overall goal of reducing mass, the team had 

the flexibility to question requirements and 

identify those that if changed would result in 

mass savings.

Capture the concept of operations in a design 

reference mission. Understanding the 

operational sequence as captured in the design 

reference mission was critical for the 

subsequent work. The time ordered sequence 

of activities necessary to meet mission 

objectives, their time criticality, and 

sequencing constraints became design drivers.

Identify Critical Functions. The time ordered 

sequence of activities helped define not only 

the critical functions necessary for 

accomplishing mission objectives but also the 

critical functions for safety returning the crew. 

Critical functions for both safety and mission 

success were defined and tracked separately.5

Safety critical and mission critical functions 

were then used to identify the simplest design 

capable of implementing the functions. During 

the risk analysis described below, alternative 

approaches including back ups were identified 

to protect these critical functions.

4.1 Identify the simplest design of the system, 

“Make it Work”.

6

 For the purposes of this 

study the system was reduced to the simplest 

system that performs the critical functions 

necessary to accomplish the mission 

objectives. In this case a single string system 

with one computer was selected. It was 

recognized that such a simple system would 

not be “flyable”. However establishing a 

minimal system was critical for establishing a 

floor for the minimum complexity of the 

system and determining whether a solution 

existed within box boundaries. Starting with a 

simple system also serves to identify the 

system’s weakest links as well as those 

elements whose failure response is 

inconsistent with the system’s critical 

functions.

The following considerations were important 

for the configuration of the single string 

design and balancing a distributed versus

centralized approach:

Network for Internal Communications –

drivers were reliability (the simplest, lowest 

data rate necessary), low power, robust to 

failures (fail high, low, blabber mouth), along 

with upgradeability and extensibility. Limiting 

bus data rates below the 100 – 200 MBbs 

range minimizes power consumption and 

dissipation at all the network nodes. 

Additionally, limiting these rates significantly 

reduces the complexity of testing the system. 

Any interfaces requiring higher data rates

were hardwired point to point as necessary.

Method for connecting to the network –

through a robust terminal with low power 

interfaces that interface to the bus on the front 

end and to the user at the back end through 

digital, serial and analog input and output 

interfaces.

Computer System Architecture – A central 

computer was chosen to orchestrate functions 

performed by network terminals while 

balancing central control and limiting 

coupling and interactions should terminals 

fail. The design solution assigned safety 

critical functions to appropriate terminals, Bus 

Interface Units (BIU,) and subsystem 

electronics boxes. The BIU design would 

provide predictable end item functionality in 

the event of communication loss with the main 

computer, thus increasing the independence 

(robustness) of the subsystems. Additional 

computational power necessary for Automated 

Rendezvous and Docking was provided by an 

Auxiliary computer that can be added as part 

of a mission kit when needed along with 

sensors. 
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Separation of Functions – Care was exercised 

to limit the coupling of disparate functions. A 

driving consideration for isolating functions 

was to limit collateral damage in the presence 

of failures and to allow simple backup control 

of only the function that failed. The central 

computer was not given control over low level 

functions, rather the BIU defaulted to a 

predictable and known operational mode that 

maintained low level functionality. Balancing 

centralized control with distributing low level 

functions allows simple backup or manual 

controls to only replicate the failed higher 

level function. 

4.2 Explore risks to safety, and then “Make it 

Safe”. This step in the buildup approach was 

designed to identify aspects of the design that 

protects safety critical functions necessary to 

meet mission objectives. The set of safety 

critical functions identified in the previous 

steps were used to guide safety risk

assessments. Risk assessments evaluated the 

basic single string design along with candidate 

design approaches seeking to obviate or 

mitigate risk through alternatives that 

eliminate the risk, utilize system elements 

already on-orbit in different ways, point 

design solutions such as backups, or additional 

like redundancy. 

Integrated risk analysis. An integrated risk 

analysis brought together the operations 

sequence from the design reference mission, 

the system design, the physics applicable for 

the situation, and safety and reliability 

analysis results as shown in Figure 5. Event 

Sequence Diagrams were used as the 

mechanism for capturing specific scenarios 

and the resulting effects of failures. Failure 

Modes and Effects Analysis (FMEA) were 

performed from a top down functional 

standpoint as actual design details were not 

yet complete. Historical failure rates were 

used for bottoms up reliability analysis to 

represent the general likelihood of the type of 

system component and as a representation for 

the complexity of the design. Engineering 

fears and threats based on historical data and 

engineering judgment were also used to

evaluate weaknesses of the simple system. 

Critical to this process was the collection and 

ranking of all risks from all sources. This 

sorting and ranking part of the process is 

critical for systematically considering and 

attacking the biggest risk drivers first.

As risk drivers are attacked, alternative 

approaches to the operations sequence and or 

the design were fed back into the loop for 

reevaluation.

It is important to note that this type of analysis 

performed early in the project’s life cycle 

focuses more on a functional level than on a 

hardware level. It was too early in the program 

to rely on "bottoms up" reliability analysis 

alone. Without an actual design that would 

Figure 5 Integrated Risk Analysis Flow
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exist at CDR time, it is difficult to identify all 

the physical failures that can result in loss of 

crew. As the design matures specific failure 

modes of the exact design will replace 

functional failure modes. 

Component based models that only assume

hard failures may overlook important system 

failures that surface when individual 

components and software interact in 

unforeseen and adverse ways. The more 

complex the system becomes, the harder it is 

to anticipate all the ways it can fail especially 

this early in the design. It is for this reason 

that it is advantageous to look for the simplest 

most robust and easiest to understand solution 

that attacks each weakness and preserves 

critical functions. The team identified what 

functions might fail so that the system can 

protect those functions.

The team also recognized that there are 

significant error bars, up to a factor of 10, 

around any predictive analysis. So the team 

needs to be careful when relying on failure 

rate estimates beyond the first significant 

figure. Thus the analysis provided the means 

to rank the different architectures relative to 

each other without focusing on the absolute 

failure prediction of any given architecture. At 

this point the objective of the numbers is to 

help in the ranking and sorting of risks from 

all sources.

The risk analysis started with the end of the 

mission, safe crew return, and sequenced 

backwards to launch. Four critical mission 

phases were evaluated “Entry, Descent, and 

Landing”, “Critical Burn”, “Lunar Loiter”, 

and “Ascent” and captured in event sequence 

diagrams. Figure 6 provides an example of the 

type and format of the Event Sequence 

Diagrams that were created for each of the 

critical mission phases. The event sequence 

diagram helped to visualize the responses and 

Figure 6 Example of the Event Sequence Diagram
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downmodes that could protect the crew. The 

iterative risk analysis loop, shown in Figure 5, 

along with the event sequence diagrams, 

Figure 6, allowed an exploration of risk along 

the operational sequence and an evaluation of 

alternatives that eliminate the risk, designs 

that inherently should not fail, utilize system 

elements already in orbit in different ways, 

point design solutions, or redundancy.

Exploring alternatives for mitigating each risk 

was critical and requires creative 

"engineering" and compromise among often 

competing needs. The team looked for the 

most mass efficient method to reduce risk. 

Some alternatives mitigate more than one risk, 

and finding these synergistic solutions 

attacking multiple risks was important. The 

team looked at all the risk on the table and let 

the risks drive solutions and design decisions. 

The integrating risk analysis identified major 

drivers that resulted in the following three 

additions to the simple single string system: 

a) a simple manual control while crewed, 

b) a simple “safemode” to protect a power 

positive and stable vehicle attitude while 

uncrewed, and 

c) a low power mode to enable an Apollo 13 

style manual, minimal power return.

It is significant to note that the first elements 

added to the minimal single string vehicle 

were not additional strings of like full 

performance redundancy. The team sought to 

add simple diverse systems for manual control 

while crewed and simple safemode while 

uncrewed to protect safe crew return at 

reduced, but adequate performance. Figure 7 

provides a functional diagram for the 

Safemode and Manual System. Manual 

control or providing simpler systems to 

control actuators is utilized on modern aircraft 

such as the 777. Simple systems or 

“safemodes” protecting health and safety are 

often utilized on unmanned spacecraft to 

provide time and opportunity for the ground to 

apply appropriate corrective action.

Figure 7 Safehold and Manual System Functional Diagram
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An uncrewed safemode also provides a last 

line of defense, a “never give up” function 

preserving the vehicle health and safety 

should the primary system fail. Safemode 

provides a power and thermal safe attitude as 

well as a stable attitude for Lunar Ascent 

Module Docking using simple coarse sensors 

and a gyro controlled by a simple hardware 

based controller.

Safemode was focused on assuring crew 

safety through robustness enabled by an 

alternate means to control critical vehicle 

systems. This independent system becomes 

even more powerful from a reliability 

perspective if it remains simple containing 

fewer parts and fewer connections. The simple 

safemode is lower performance than the prime 

system, although it has the requisite 

performance to enable safe crew return. 

Simplicity in the dissimilar system can also 

significantly mitigate the cost burden of 

having to design, certify and maintain full 

performance “backup” systems. The goal is to 

achieve a significant improvement in overall 

reliability for a fraction of the cost of the 

primary system. Simple systems are more 

easily manufactured and tested due to their 

lower complexity and are more reliable due to 

fewer failure modes and better test coverage.

Safemode provided a Sun Pointing Mode, an

Attitude Hold Mode and worked in 

conjunction with manual crew control. In 

addition, some critical subsystems such as 

power and ECLSS had enough local "smarts" 

in the BIU to control battery charging, load 

shedding, and control of the breathable air and 

temperature autonomously. Communications 

with the ground are via 4 pi Omni antennas 

that did not require any onboard switching 

logic to achieve a minimally functioning 

forward and return link. 

With the safemode added to the system, 

failure of the central computer or its network 

had minimal immediate effect on system 

health and safety. The vehicle can enable safe 

return of the crew using simple low power 

systems even under an Apollo 13 type or ISS 

Computer Loss scenario after primary systems 

suffer unexpected failures. 

Safety improvements to power generation and 

distribution systems considered the coupling 

between power and data functions to assure 

that failures in the power strings minimize 

collateral damage, i.e. coupling, to other 

subsystems. For example, power and data 

paths were defined such that failures in a data 

path would not couple into power distribution 

and failures in power generation and storage 

would limit the effects on data paths. For 

example, failure of a power feed switch results 

in loss of the load’s function and needs to be 

tracked that way. Safety critical functions 

were protected from switch failures by diverse 

or alternate power feeds. The Safemode and 

manual control function was given a 

separately powered safemode and emergency 

power bus with its own emergency battery.

Uncrewed operation also required a certain 

number for “special” hardware decoded 

commands that enable reset, recovery, and 

reconfiguration of the primary system without 

requiring the primary system to do so. The 

team provided recovery methods such that 

prime system failures do not prevent 

utilization of redundant and safemode 

systems.

The team utilized a litmus test for assessing 

the “independence” of prime system elements 

from the systems protecting the capability to 

safely return the crew. The test involves 

encircling system elements on a system block 

diagram that are necessary for crew return 

using the prime system and then encircling 

elements necessary for safemode. Any 

overlaps, or circling of common elements 

between the prime system and the safemode 

system warns the system designer of the 

potential for common cause failures that need 

to be addressed.
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Risk Analysis Results. Reliability analysis 

supported the integrated risk assessments by 

providing failure rate estimates that were used 

to rank risk drivers. To thoroughly evaluate 

failure likelihood, two "knobs" were applied 

to the reliability models, one is the 

"statistically independent" or random failure 

rate and the other is the "dependent" or 

correlated / "common cause" failure rate.

Since system component selection and 

detailed design remains in flux, failure rates of 

similar hardware elements were used in the 

analysis. Failure rate sources included 

databases of Shuttle, ISS, and robotic 

spacecraft experience.

Common cause failure probabilities and 

uncertainties that were used in the reliability 

analysis are shown in Figure 87. The lower left 

corner includes a notional probability that the 

first string will fail. The broad bands above 

the first string failure probability represent the 

estimates for the probability of a second string 

failing given that the first string has failed, the 

probability of a third string failing given that 

two strings have failed, and the probability of 

a fourth string failing given that three strings 

have failed, respectively. While there have 

been no studies that provide definitive 

estimates for these values for spacecraft 

components, some limited studies have been 

performed on Space Shuttle components, and 

other non-aerospace sources (see references 

Figure 8) that do offer insights particularly for 

second string failures. As shown in the green 

block a range was determined from each of 

these sources which are all in relatively good 

agreement to estimate a range for the second 

string avionics failures.

Many alternatives were evaluated during the 

course of the risk analysis. Results are 

summarized in Figure 9 providing a relative 

comparison of single string to quad redundant 

systems with common cause factors and 

component failure rate along with applied 

uncertainties8

. Results show that common 

cause failures tend to limit the reliability 

improvements above 2 or 3 strings. A sweet 

spot is evident somewhere around 2 strings 

and 3 strings with a diverse safemode 

providing additional benefits. From a safety 

and reliability standpoint the team felt that an 

optimized “sweet spot” exists in a 2 to 3 string 

prime system with a diverse independent 

safemode as depicted in Figure 8. Adding a 

second prime string does significantly 

improve the system failure rate with a 

relatively low contribution from common 

cause failure and appears mass efficient for 

the reliability benefit. Adding more than 3 

strings for the purpose of reducing the random 

portion of the failure rate does not appear 

necessary and brings with it a significant 

Figure 8 Conditional Probabilities of Multiple Failures in Identical Components

12

Risk Analysis Results. Reliability analysis 

supported the integrated risk assessments by 

providing failure rate estimates that were used 

to rank risk drivers. To thoroughly evaluate 

failure likelihood, two "knobs" were applied 

to the reliability models, one is the 

"statistically independent" or random failure 

rate and the other is the "dependent" or 

correlated / "common cause" failure rate.

Since system component selection and 

detailed design remains in flux, failure rates of 

similar hardware elements were used in the 

analysis. Failure rate sources included 

databases of Shuttle, ISS, and robotic 

spacecraft experience.

Common cause failure probabilities and 

uncertainties that were used in the reliability 

analysis are shown in Figure 87. The lower left 

corner includes a notional probability that the 

first string will fail. The broad bands above 

the first string failure probability represent the 

estimates for the probability of a second string 

failing given that the first string has failed, the 

probability of a third string failing given that 

two strings have failed, and the probability of 

a fourth string failing given that three strings 

have failed, respectively. While there have 

been no studies that provide definitive 

estimates for these values for spacecraft 

components, some limited studies have been 

performed on Space Shuttle components, and 

other non-aerospace sources (see references 

Figure 8) that do offer insights particularly for 

second string failures. As shown in the green 

block a range was determined from each of 

these sources which are all in relatively good 

agreement to estimate a range for the second 

string avionics failures.

Many alternatives were evaluated during the 

course of the risk analysis. Results are 

summarized in Figure 9 providing a relative 

comparison of single string to quad redundant 

systems with common cause factors and 

component failure rate along with applied 

uncertainties8. Results show that common 

cause failures tend to limit the reliability 

improvements above 2 or 3 strings. A sweet 

spot is evident somewhere around 2 strings 

and 3 strings with a diverse safemode 

providing additional benefits. From a safety 

and reliability standpoint the team felt that an 

optimized “sweet spot” exists in a 2 to 3 string 

prime system with a diverse independent 

safemode as depicted in Figure 8. Adding a 

second prime string does significantly 

improve the system failure rate with a 

relatively low contribution from common 

cause failure and appears mass efficient for 

the reliability benefit. Adding more than 3 

strings for the purpose of reducing the random 

portion of the failure rate does not appear 

necessary and brings with it a significant 

Figure 8 Conditional Probabilities of Multiple Failures in Identical Components

12

Risk Analysis Results. Reliability analysis 

supported the integrated risk assessments by 

providing failure rate estimates that were used 

to rank risk drivers. To thoroughly evaluate 

failure likelihood, two "knobs" were applied 

to the reliability models, one is the 

"statistically independent" or random failure 

rate and the other is the "dependent" or 

correlated / "common cause" failure rate.

Since system component selection and 

detailed design remains in flux, failure rates of 

similar hardware elements were used in the 

analysis. Failure rate sources included 

databases of Shuttle, ISS, and robotic 

spacecraft experience.

Common cause failure probabilities and 

uncertainties that were used in the reliability 

analysis are shown in Figure 87. The lower left 

corner includes a notional probability that the 

first string will fail. The broad bands above 

the first string failure probability represent the 

estimates for the probability of a second string 

failing given that the first string has failed, the 

probability of a third string failing given that 

two strings have failed, and the probability of 

a fourth string failing given that three strings 

have failed, respectively. While there have 

been no studies that provide definitive 

estimates for these values for spacecraft 

components, some limited studies have been 

performed on Space Shuttle components, and 

other non-aerospace sources (see references 

Figure 8) that do offer insights particularly for 

second string failures. As shown in the green 

block a range was determined from each of 

these sources which are all in relatively good 

agreement to estimate a range for the second 

string avionics failures.

Many alternatives were evaluated during the 

course of the risk analysis. Results are 

summarized in Figure 9 providing a relative 

comparison of single string to quad redundant 

systems with common cause factors and 

component failure rate along with applied 

uncertainties8. Results show that common 

cause failures tend to limit the reliability 

improvements above 2 or 3 strings. A sweet 

spot is evident somewhere around 2 strings 

and 3 strings with a diverse safemode 

providing additional benefits. From a safety 

and reliability standpoint the team felt that an 

optimized “sweet spot” exists in a 2 to 3 string 

prime system with a diverse independent 

safemode as depicted in Figure 8. Adding a 

second prime string does significantly 

improve the system failure rate with a 

relatively low contribution from common 

cause failure and appears mass efficient for 

the reliability benefit. Adding more than 3 

strings for the purpose of reducing the random 

portion of the failure rate does not appear 

necessary and brings with it a significant 

Figure 8 Conditional Probabilities of Multiple Failures in Identical Components

Author’s addendum as of 12/9/08

Subsequent research and study of space flight 

failures indicates significantly lower mission ending 

common cause failure probabilities than the 

references suggest.
59

Featured Technical Paper

13

common cause 

contribution that does 

not make it mass 

efficient. There are other 

reasons to add multiple 

strings as discussed 

later. These reasons 

include voting out 

failures under time 

critical scenarios.

Figure 10 compares the 

failure contributors of a 

three string system, to a 

three string plus 

safemode, and a four 

string system. 

Examination of the 

figure shows that the 

safemode reduces the 

system failure 

probability by half. 

Failure modes that the 

safemode backs up essentially disappear (e.g. 

Crew Interface Displays) due to the credit for 

independent backup, while the failure rate 

contribution of other system elements that are 

not protected by the safemode (e.g. S/A 

Regulator) merely reduce. The benefit of 

adding a fourth string is limited relative to 

adding a safemode by the potential for 

common cause failures.

4.3 Explore risks to Mission Success, and 

then “Make it Reliable”. The set of mission 

critical functions, as opposed to safety critical 

functions discussed in 4.2 above, were used to 

guide the exploration of threats to mission 

success. These threats were captured and 

attacked from most significant to least 

significant. Many threats to mission success 

surfaced during the safety discussions and 

analyses described in the previous step and 

were addressed in this step. In general a 

second string of like redundancy was added to 

the prime system to improve the probability of 

mission success. 

In general it appeared that two strings may 

provide sufficient reliability as indicated by 

the results shown in Figure 8, however 

identifying which of the two strings has failed 

may be difficult. Most failures could probably 

be isolated by built in self tests or by 

comparing inputs and / or outputs against 

expected results. However the possibility of 

dilemma cases requires a tie breaker. Use of 

the diverse safemode may aid in breaking a 

tie, although safemode’s reduced performance 

may not provide sufficient precision and 

accuracy. Therefore a third string was added 

to resolve dilemma cases for time critical 

functions allowing a simpler voting scheme 

among three strings. There was a mass penalty 

for the third string, however modern low 

power and low mass components alleviated 

some of the inefficiency. 

Figure 9 Example Comparison of Alternatives vs. Probability of 

Loss of Crew Improvement Including Uncertainty
60

Featured Technical Paper

14

4.4 Look at resources 

including development costs 

and then “Make it 

affordable”. Life cycle costs 

were factored into some of the 

decisions that were drivers. 

Cost drivers included 

nonrecurring software 

development as well as 

maintenance. Drivers from a 

safety and reliability 

standpoint included Fault 

Detection, Isolation and 

Recovery (FIDR) and 

Integrated System Health 

Monitoring (ISHM). A major 

supporting driver included the 

consideration of additional 

redundancy to enable voting 

over more extensive FIDR and 

built in test. In general the 

addition of a third string 

simplified software 

development by enabling 

voting algorithms.

5. CONCLUSION

The Smart Buyer design effort was successful 

in identifying risk based design drivers, 

recommending requirement changes along 

with innovative design alternatives that could 

reduce mass while improving safety and 

reliability.

• Merging of technical expertise and 

experience of the human spaceflight, robotic 

and research centers was effective in 

identifying alternate concepts that reduce 

complexity, power and mass. In particular, 

techniques utilized by robotic spacecraft to 

keep the vehicle safe directly apply during 

the operational phases where the CEV is 

“uncrewed” in lunar orbit. Robotic 

spacecraft experience complemented the 

experience of the manned space flight 

centers in utilizing the crew’s capabilities 

for enhancing mission success and safety. In 

addition, some low power and low mass 

technology routinely utilized by robotic 

spacecraft can be transferred to manned 

spacecraft. 

• There are no a priori prescriptions taken by 

themselves that result in a safe design, 

therefore the design team must design for 

the minimum mission risk. Even a two 

failure tolerant design should not be chosen 

over a safer alternative. Minimizing risk 

centers around exploring system weaknesses 

and unpredictability in context of the 

operational scenario and then attacking 

those risks from highest to lowest. 

• Designers must control complexity that may 

obscure hazards and unintentional 

interactions and coupling of system 

elements. Teams should avoid complexity 

that results in “no obvious safety risks”. 

Early design and analysis work should focus 

Figure 10 Example Comparison of Electrical Systems 

Element Contribution to PLOC
61

Featured Technical Paper

15

on preserving critical functions and 

introducing complexity only where it is 

necessary for safety and mission success. 

• An effective approach to defend against 

interactive failures obscured by system 

complexity is through simple, easy to 

understand diverse systems that protect 

those functions critical for safe crew return. 

• It is important that teams identify and collect 

risks in a systematic, top down fashion and 

assure they remain visible and are 

communicated to team members. 

• A “build up” approach is effective in 

limiting complexity to the minimum 

necessary and providing a risk informed 

rationale for not only the system design, but 

also the rationale for the existence of every 

component and the utilization of power and 

mass resources. The buildup approach 

balances each risk in light of all the other 

risks present in the vehicle. Accepting risks 

is also balanced against the utilization of 

power and mass resources and increased 

complexity. 

Severe mass constraints require the wise 

utilization of scarce mass resources to protect 

safety and mission success. Both the Crew 

Exploration Vehicle and the Lunar Access 

Surface Module projects are utilizing variants 

of the build up approach described above to 

not only design their vehicles but also balance 

risks. Additional information about this risk 

informed, systems engineering technique is 

available in the NESC Report RP-06-108_05-

173, “Design, Development, Test, and 

Evaluation (DDT&E) Considerations for Safe 

and Reliable Human Rated Spacecraft 

Systems, Volume I” May 1 2007, 

http://www.nasa.gov/pdf/176245main_RP-06-

108_05-173_DDT%26E_Final_04-30-

07_(Vol[1]._1Master).pdf

The authors would like to recognize and 

acknowledge the significant contribution of: 

Julie Kramer White of NASA, (current CEV 

Chief Engineer,) NESC Discipline Expert in 

Mechanical Analysis, Reliability Lead during 

the performance of the Smart Buyer Study and 

the initial NESC DDT&E Report team lead. 

Dawn Schaible of NASA, NESC Systems 

Engineering Office Manager, for her role as 

the Systems Engineering Lead for the study. 

TK Mattingly, Rear Admiral, USN, Ret. Apollo 

16 Command Module Pilot and Commander 

of Shuttle Missions STS-4 and STS-51C, for 

his wise advice and focus on simplicity and 

assuring safe crew return. 

Agency wide Smart Buyer Study Team. 

References: 

1

 “Crew Exploration Vehicle ‘Smart Buyer’ 

Design Team Final Report”, NASA 

Engineering and Safety Center, May 2006 

2

 Discussions with TK Mattingly 

3

 Build up approach from manned spaceflight 

experience suggested by TK Mattingly Apollo 

16 CM Pilot and Shuttle Mission Commander, 

Jerry Gilmore based on Apollo Guidance 

System design at Draper Labs, Joseph Fragola 

based on Apollo LM design techniques at 

Grumman 

4

 Build up approach from robotic spacecraft 

experience: Bay, Michael, “MIDEX / MAP 

Project Reliability Program Overview”, Sept 

1997 

5

 See “Safety and Mission Success” under 

section 2. 

6

 Description of the build up approach as 

“make it work”, “make it safe”, and “make it 

affordable” from discussions with Joseph 

Fragola 

7

 “Design Development Test and Evaluation 

(DDT&E) Considerations for Safe and 

Reliable Human Rated Spacecraft Systems, 

Volume I”, NESC RP-06-108_05-173, May 1 

2007, Figure 3.4-1. 

8

 Adapted from data in “Crew Exploration 

Vehicle ‘Smart Buyer’ Design Team Final 

Report”, NESC, May 2006, Section 4.1. 
62

PHOTO

Tommy Yoder, Jacobs Technology at 

WSTF, places fiduciary markers on a 

large Kevlar® COPV being prepared 

for pressure testing.

Cross-Agency teaming: 

“In my experience as a NASA researcher, cross-Agency teaming occurred only when 

self-initiated by researchers. The NESC brought team members with unique expertise 

together from seven Centers. I was impressed by how effectively they all leaned on and 

learned from each other.” 

— Dr. Terry St. Clair, Consultant Team Member, Retired Materials Research Branch Manager, LaRC

60
63

Leadership Core Team Biographies

Ralph R. Roe, Jr.

NESC Director

Mr. Ralph R. Roe, Jr. serves as NESC’s Director at Langley Research Center (LaRC). Mr. Roe 

has over 25 years of experience in human space 

flight program management, technical management, and test engineering. Mr. Roe previously held several key 

positions in the Space Shuttle Program, including Vehicle Engineering Manager, Launch Director, and Kennedy Space Center 

Engineering Director.

Timmy R. Wilson 

NESC Deputy Director

Mr. Timmy R. Wilson is NESC’s Deputy Director. 

Mr. Wilson was formerly the NESC’s Chief Engineer at Kennedy Space Center (KSC). Prior to 

joining NESC, Mr. Wilson served as Deputy Chief 

Engineer for Shuttle Processing at KSC. Mr. Wilson has over 27 

years of engineering and management experience supporting 

the Space Shuttle Program.

Kenneth D. Cameron

NESC Deputy Director for Safety

Mr. Kenneth D. Cameron is the acting NESC 

Chief Astronaut and NESC’s Deputy Director 

for Safety and is resident at the Johnson Space 

Center (JSC). Mr. Cameron was formerly an 

NESC Principal Engineer serving at Langley Research Center 

(LaRC). Mr. Cameron joined NESC after 7 years in private industry and a career in the U.S. Marine Corps. Mr. Cameron has 

over 28 years of experience in aeronautics and astronautics as 

a Naval Aviator, Test Pilot, and Astronaut, and is the veteran of 

three Space Shuttle missions: Pilot of STS-37 and Commander 

of STS-56 and STS-74. 

Dr. Charles J. Camarda

NESC Deputy Director for Advanced

Projects

Dr. Charles J. Camarda is the Deputy Director 

for Advanced Projects and is resident at the 

Johnson Space Center. Dr. Camarda began his 

NASA career in 1974 as a thermal structures research scientist at 

the Langley Research Center. He has over 34 years of technical 

and management experience in thermal structures and materials 

research for aircraft, spacecraft, and space launch vehicles. He 

was selected as an astronaut candidate in 1996, and flew aboard 

STS-114 as a Mission Specialist. 

Dr. Daniel Winterhalter

NESC Chief Scientist

Dr. Winterhalter is NESC’s Chief Scientist and is 

resident at the Jet Propulsion Laboratory (JPL). 

Dr. Winterhalter has over 30 years of experience 

as a research scientist at JPL. His research interests include the 

spatial evolution of the solar wind into the outer reaches of the 

heliosphere, as well as its interaction with and influence on planetary environments. In addition, as a member of several flight 

teams, he has been intimately involved with the planning, launching, and operating of complex spacecraft and 

space science missions.

Patricia L. Dunnington

Manager, Management and Technical

Support Office

Ms. Patricia L. Dunnington is the Manager of 

the Management and Technical Support Office 

at Langley Research Center (LaRC). Prior to joining NESC, Ms. 

Dunnington served as the Agency’s Chief Information Officer 

(CIO) at NASA Headquarters. Ms. Dunnington began her NASA 

career in 1982 as a Presidential Management Intern. Ms. Dunnington has held several positions in the Agency, including the 

Deputy CIO and the CIO for the NASA Langley Research Center. 

Dawn M. Schaible

Manager, Systems Engineering Office

Ms. Dawn M. Schaible is Manager of NESC’s 

Systems Engineering Office at Langley Research 

Center (LaRC). Prior to joining NESC, Ms. Schaible worked in the International Space Station/

Payload Processing Directorate at Kennedy Space Center. Ms. 

Schaible has over 21 years of experience in systems engineering, 

integration, and ground processing for the Space Shuttle and International Space Station Programs.

NESC Core Leadership
64

Biographies

Wayne R. Frazier

NASA Headquarters Senior SMA

Integration Manager

Mr. Wayne R. Frazier currently serves as Senior Safety and Mission Assurance Manager in the Office of 

Safety and Mission Assurance (OSMA), where he is 

assigned as the Liaison Officer to NESC, the Office 

of the Chief Engineer, the Software Independent Verification and Validation Facility in West Virginia, and other remote activities of OSMA. 

He was formerly Manager of System Safety in the OSMA at NASA 

Headquarters and has over 33 years of experience in System Safety, 

Propulsion and Explosive Safety, Mishap Investigation, Range Safety, 

Pressure Systems, Crane Safety and Orbital Debris Mitigation.

NASA Headquarters Liaison

Steven J. Gentz

NESC Principal Engineer

Mr. Steven J. Gentz is a Principal Engineer with 

NESC at Langley Research Center (LaRC). Mr. Gentz 

joined NESC from the Marshall Space Flight Center 

with over 25 years of experience involving numerous 

NASA, Department of Defense, and industry failure 

analyses and incident investigations, including Challenger, Columbia, 

Tethered Satellite System, and the TWA 800 Accident Investigations.

Clinton H. Cragg

NESC Principal Engineer

Mr. Clinton H. Cragg is a Principal Engineer with 

NESC at Langley Research Center (LaRC). Mr. Cragg 

came to NESC after retiring from the U.S. Navy. Mr. 

Cragg served as the Commanding Officer of the 

U.S.S. Ohio and later as the Chief of Current Operations, U.S. European Command. Mr. Cragg has over 30 years of experience in supervision, command, and ship-borne nuclear safety.

Michael T. Kirsch

NESC Principal Engineer

Mr. Michael T. Kirsch is a Principal Engineer with 

NESC at Langley Research Center (LaRC). Mr. 

Kirsch joined NESC from the NASA’s White Sands 

Test Facility (WSTF) where he served as the Deputy 

Manager responsible for planning and directing developmental and operational tests of spacecraft propulsion systems 

and related subsystems. Mr. Kirsch has over 19 years of experience 

in managing projects and test facilities.

NESC Principal Engineers

NESC Principal Engineers Con’t.

Dr. Michael G. Gilbert

NESC Principal Engineer

Dr. Michael G. Gilbert is a Principal Engineer with 

NESC at Langley Research Center (LaRC). Dr. Gilbert was formerly the NESC Chief Engineer at LaRC. 

Before joining NESC, he was Head of the LaRC 

Systems Management Office. Dr. Gilbert has over 

30 years of engineering, research, and management experience with 

aircraft, missile, spacecraft, Space Shuttle, and International Space 

Station Programs.

Dennis B. Dillman

NESC Chief Engineer 

Mr. Dennis B. Dillman is NESC’s Chief Engineer at 

NASA Headquarters. Mr. Dillman came to NESC 

from the NASA Goddard Space Flight Center 

(GSFC), where he chaired design reviews for major 

projects, including the Hubble Space Telescope Servicing Missions, the James Webb Space Telescope, and several Earth 

Observing System satellites. Prior to his time at GSFC, Mr. Dillman 

worked at the NASA Johnson Space Center managing Shuttle Orbiter 

sustaining engineering efforts and training Shuttle flight crews.

Dr. Nancy J. Currie

NESC Chief Engineer

Dr. Nancy J. Currie is NESC’s Chief Engineer at 

Johnson Space Center (JSC). Dr. Currie came to the 

NESC from JSC, where she served as the Deputy 

Director of the Engineering Directorate. Dr. Currie 

has over 20 years of expertise in robotics and human 

factors engineering. Dr. Currie was selected as an astronaut in 1990, 

is a veteran of four space shuttle missions, and has accrued 1000 

hours in space.

NESC Chief Engineers

Stephen A. Minute

NESC Chief Engineer

Mr. Stephen A. Minute is NESC’s Chief Engineer at 

Kennedy Space Center (KSC). Mr. Minute came to 

the NESC from KSC, where he served as the Chief 

of the Shuttle Safety, Quality, and Mission Assurance 

Division. Mr. Minute has over 24 years of engineering and management experience in the Space Shuttle and International Space Station Programs.

R. Lloyd Keith

NESC Chief Engineer

Mr. R. Lloyd Keith is NESC’s Chief Engineer, as well 

as the Deputy Center Chief Engineer at the Jet Propulsion Laboratory (JPL). Mr. Keith has over 31 years 

of experience working in both technical and managerial positions. Mr. Keith has supported a number 

of flight projects including the Mars Pathfinder Project, SeaWinds, 

Stardust, Mars ’98, New Millennium Deep Space 1, and the Flight 

Hardware Logistics Program.
65

Leadership Core Team Biographies

NESC Chief Engineers Con’t. NESC Chief Engineers Con’t.

Michael L. Aguilar

NASA Technical Fellow

Mr. Michael L. Aguilar is the NASA Technical Fellow 

for Software and is resident at Goddard Space Flight 

Center (GSFC). Mr. Aguilar joined the NESC from 

GSFC where he served as the James Webb Space 

Telescope (JWST) Instrument Software Manager. 

Mr. Aguilar has over 32 years of experience on embedded software 

development.

NASA Technical Fellows

Mitchell L. Davis

NASA Technical Fellow

Mr. Mitchell L. Davis is the NASA Technical Fellow 

for Avionics and is resident at the Goddard Space 

Flight Center (GSFC). Mr. Davis was the Chief Engineer of the Electrical Systems Branch at GSFC prior 

to joining the NESC. Mr. Davis has over 26 years of 

experience in power and avionics.

Cornelius J. Dennehy

NASA Technical Fellow

Mr. Cornelius J. Dennehy is the NASA Technical 

Fellow for Guidance Navigation and Control (GNC) 

systems and is resident at Goddard Space Fight 

Center (GSFC). Mr. Dennehy came to NESC from 

the Mission Engineering and Systems Analysis Division at GSFC, 

where he served as the Division’s Assistant Chief for Technology. Mr. 

Dennehy has over 28 years of experience in the architecture, design, 

development, integration, and operation of GNC systems, and space 

platforms for communications, defense, remote sensing, and scientific mission applications.

Dr. Tina L. Panontin

NESC Chief Engineer

Dr. Tina L. Panontin is the NESC Chief Engineer at 

Ames Research Center. Dr. Panontin also serves as 

the ARC Chief Engineer and formerly served as the 

Chief of the Failure Analysis and Materials Group at 

ARC. Dr. Panontin has over 25 years of experience 

in solving complex problems, assessing the health of systems and 

organizations, investigating anomalies and failures, and developing 

tools that support systems engineering processes. 

Dr. Charles F. Schafer

NESC Chief Engineer

Dr. Charles F. Schafer is NESC’s Chief Engineer at 

Marshall Space Flight Center (MSFC). Dr. Schafer 

came to the NESC from MSFC where he served as 

the Deputy Manager of the Propulsion Research 

Center of the Science and Technology Directorate. Dr. Schafer has over 42 years of experience in leading research 

and technology activities in advanced earth-to-orbit and in-space 

propulsion, including work in nuclear propulsion, plasma propulsion, 

advanced chemical propulsion, and new chemical propellents.

Steven S. Scott

NESC Chief Engineer

Mr. Steven S. Scott is NESC’s Chief Engineer at 

Goddard Space Flight Center (GSFC). Mr. Scott 

also serves as the GSFC Chief Engineer. Mr. Scott 

formerly served as the NESC Discipline Expert (now 

called NASA Technical Fellow) for Software. Mr. 

Scott has over 18 years experience in satellite software engineering. 

Michael D. Smiles

NESC Chief Engineer

Mr. Michael D. Smiles is NESC’s acting Chief Engineer at Stennis Space Center (SSC). Mr. Smiles 

joined the NESC from SSC, where he served as the 

Safety and Mission Assurance (S&MA) Manager. 

Mr. Smiles has over 23 years of management and 

technical experience with NASA at SSC and Marshall Space Flight Center. 

Bryan K. Smith

NESC Chief Engineer

Mr. Bryan K. Smith is NESC’s Chief Engineer at 

Glenn Research Center (GRC). Mr. Smith joined the 

NESC from GRC where he served as Deputy Chief 

of the Power and In-Space Propulsion Division and 

Chief of the Space Flight Project Office. Mr. Smith 

has over 21 years of engineering and management 

experience leading the development of space flight systems.

Dr. James F. Stewart

NESC Chief Engineer

Dr. James F. Stewart is NESC’s Chief Engineer at 

Dryden Flight Research Center (DFRC). Dr. Stewart 

joined the NESC from DFRC where he served as the 

Dryden Exploration Mission Director. Dr. Stewart 

has over 42 years of management and technical experience leading 

missile and aircraft programs.

Clayton P. Turner

NESC Chief Engineer

Mr. Clayton P. Turner is NESC’s Chief Engineer at 

the Langley Research Center (LaRC). Mr. Turner 

also serves as the LaRC Chief Engineer. He has 

over 18 years of management and technical experience including serving as the technical/programmatic lead for several projects including the Gas Permeable Polymer 

Materials (GPPM) Project and the Gas and Aerosol Monitoring Sensorcraft (GAMS) Project.

Continued on next page...
66

Biographies

Roberto Garcia

NASA Technical Fellow

Mr. Roberto Garcia is the NASA Technical Fellow 

for Propulsion and is resident at Marshall Space 

Flight Center (MSFC). Mr. Garcia came to NESC 

from the Solid Propulsion Systems Division where 

he served as Division Chief. Mr. Garcia has over 17 years of experience in performing aerodynamic, hydrodynamic, and engine 

system design and analysis of rocket propulsion.

Dr. Curtis E. Larsen

NASA Technical Fellow

Dr. Curtis E. Larsen is the NASA Technical Fellow 

for Loads and Dynamics and is resident at Johnson Space Center (JSC). Prior to joining NESC, 

Dr. Larsen was the Technical Discipline Manager 

for Cargo Integration Structures in the Space Shuttle Program’s 

Flight Operations and Integration Office. Dr. Larsen has over 

28 years of engineering experience with expertise in stochastic 

structural dynamics, structural safety, and probabilistic engineering applications.

Daniel G. Murri

NASA Technical Fellow

Mr. Daniel G. Murri is the NASA Technical Fellow 

for Flight Mechanics and is resident at Langley Research Center (LaRC). Mr. Murri served as Head of 

the Flight Dynamics Branch at LaRC before joining 

the NESC. He has over 27 years of engineering experience conducting numerous wind-tunnel, simulation, flight-test, and theoretical studies in the exploration of new technology concepts and 

in support of aircraft development programs.

Dr. Cynthia H. Null

NASA Technical Fellow

Dr. Cynthia H. Null is the NASA Technical Fellow 

for Human Factors and is resident at Ames Research Center (ARC). Before joining NESC, Dr. 

Null was a scientist in the Human Factors Division and Deputy Program Manager of the Space Human Factors 

Engineering Project. Dr. Null has 22 years of experience lecturing 

on Human Factors, and another 17 years of experience in Human 

Factors applied to NASA programs. 

Joseph W. Pellicciotti

NASA Technical Fellow

Mr. Joseph W. Pellicciotti is the NASA Technical Fellow for Mechanical Systems and is resident at Goddard Space Flight Center (GSFC). 

Mr. Pellicciotti served as the Chief Engineer for 

the GSFC Mechanical Systems Division before 

joining the NESC. Mr. Pellicciotti has over 20 years of combined 

private industry and NASA experience designing structure and 

mechanisms for commercial, military, and civil spacecraft.

Dr. Robert S. Piascik

NASA Technical Fellow

Dr. Robert S. Piascik is the NASA Technical Fellow 

for Materials and is resident at Langley Research 

Center (LaRC). Dr. Piascik joined NESC from the 

LaRC Mechanics of Materials Branch and the Metals and Thermal Structures Branch, where he served as a Senior 

Materials Scientist. Dr. Piascik has over 24 years of experience in 

the commercial nuclear power industry and over 16 years of experience in basic and applied materials research for several NASA 

programs.

Dr. William H. Prosser

NASA Technical Fellow

Dr. William H. Prosser is the NASA Technical Fellow for Nondestructive Evaluation and is resident 

at Langley Research Center (LaRC). Dr. Prosser 

joined the NESC from the Nondestructive Evaluation Sciences Branch at LaRC. Dr. Prosser has over 21 years of 

experience in the field of ultrasonic and acoustic emission sensing 

techniques.

Dr. Ivatury S. Raju

NASA Technical Fellow

Dr. Ivatury S. Raju is the NASA Technical Fellow 

for Structures and is resident at Langley Research 

Center (LaRC). Dr. Raju was the Senior Technologist in the LaRC Structures and Materials Competency prior to joining the NESC. Dr. Raju has over 33 years of experience in structures, structural mechanics, and structural integrity. 

Henry A. Rotter

NASA Technical Fellow

Mr. Henry (Hank) A. Rotter is the NASA Technical 

Fellow for Life Support/Active Thermal and is resident at Johnson Space Center (JSC). Mr. Rotter 

joined the NESC from the JSC Crew and Thermal 

Systems Division and the Space Launch Initiative Program, where 

he was Engineering Manager and the Orbital Space Plane Team 

Leader for life support and active thermal control teams. Mr. Rotter has over 41 years of life support and active thermal control 

systems experience during the Apollo, Shuttle, and Orbital Space 

Plane Programs.

Dr. David M. Schuster

NASA Technical Fellow

Dr. David M. Schuster is the NASA Technical Fellow for Aerosciences and is resident at Langley 

Research Center (LaRC). Prior to joining the 

NESC, Dr. Schuster was the Branch Head for the 

Structural and Thermal Systems Branch in the 

Systems Engineering Directorate. Dr. Schuster has over 30 years 

experience in the aerospace industry with expertise in aeroelasticity and integrated aerodynamic analysis.

NASA Technical Fellows Con’t.
Frank H. Bauer

NESC Discipline Expert for Guidance 

Navigation and Control (2003–04) Currently serving as the Exploration Systems Mission Directorate Chief Engineer at NASA HQ

J. Larry Crawford

NESC Deputy Director for Safety (2003–

04) Left NESC to become Director of 

Safety and Mission Assurance at the 

Kennedy Space Center (KSC) and has 

since retired

Steven F. Cash

NESC Chief Engineer at Marshall 

Space Flight Center (MSFC) (2005)

Currently the Manager, Shuttle Propulsion Office at MSFC

Derrick J. Cheston

NESC Chief Engineer at Glenn Research Center (2003–07) Left the NESC 

to participate in the Senior Executive 

Service Candidate Development Program (SESCDP)

Freddie Douglas, III

NESC Chief Engineer at Stennis Space 

Center (SSC) (2007–08) Currently the 

Manager, Office of Safety and Mission 

Assurance at SSC

Dr. Michael S. Freeman

NESC Chief Engineer at Ames Research 

Center (ARC) (2003–04), Retired

T. Randy Galloway

NESC Chief Engineer at Stennis Space 

Center (SSC) (2003–04) Currently the 

Director of the Engineering and Test Directorate at SSC

Dr. Edward R. Generazio

NESC Discipline Expert for Nondestructive Evaluation (2003–05) Currently 

a Senior Research Engineer, Research 

& Technology Directorate, LaRC

Dr. Richard J. Gilbrech

NESC Deputy Director (2003–05) Left 

the NESC to become the LaRC Deputy 

Center Director, in 2006 was named as 

the Stennis Space Center Director, and 

is currently the Associate Administrator 

for the Exploration Systems Mission 

Directorate

Michael Hagopian

NESC Chief Engineer at Goddard 

Space Flight Center (GSFC) (2003–07) 

Currently the Chief Engineer in the 

Engineering Directorate at GSFC

David A. Hamilton

NESC Chief Engineer at Johnson Space 

Center (JSC) (2003–07) Retired

Dr. Charles E. Harris

NESC Principal Engineer (2003–06) Currently the Director, Research & Technology Directorate at LaRC

Dr. Steven A. Hawley

NESC Chief Astronaut (2003–04) Left 

the NESC to become the Director of 

Astromaterials Research and Exploration Science at Johnson Space Center 

(JSC) and has since retired

Marc S. Hollander

Manager, Management and Technical 

Support Office (2005-06) Currently Associate Director for Management, National Institutes of Health

George D. Hopson

NASA Technical Fellow for Propulsion 

(2003–07), Retired

Keith L. Hudkins

NASA Headquarters Office of the Chief 

Engineer Representative (2003–07),

Retired

Danny D. Johnston

NESC Chief Engineer at Marshall Space 

Flight Center (MSFC) (2003–04) Left the 

NESC to work a detailed assignment at 

MSFC in the NASA Chief Engineer’s Office and has since retired

Michael W. Kehoe

NESC Chief Engineer at Dryden Flight 

Research Center (DFRC) (2003–05) Left 

the NESC to become the DFRC Liaison 

in the Crew Exploration Vehicle Flight 

Test Office at JSC and has since retired

Robert A. Kichak

NESC Discipline Expert for Power and 

Avionics (2003–07) Retired

Dr. Dean A. Kontinos

NESC Chief Engineer at Ames Research Center (ARC) (2006–07) Left the 

NESC to work a detailed assignment as 

the Technical Integration Manager of 

the Fundamental Aeronautics Program 

in the Aeronautics Research Mission 

Directorate at NASA HQ. Has since returned to ARC in the Office of the Chief 

Engineer 

Julie A. Kramer White

NESC Discipline Expert for Mechanical 

Analysis (2003–06) Currently the Chief 

Engineer, Crew Exploration Vehicle 

Office at JSC

Steven G. Labbe

NESC Discipline Expert for Flight Sciences (2003–06) Currently the Chief 

Engineer, Constellation Program Office 

at JSC

Matthew R. Landano

NESC Chief Engineer at NASA’s Jet 

Propulsion Laboratory (JPL) (2003–04) 

Returned to his assignment at JPL as 

the Director of Office of Safety and Mission Success

David S. Leckrone

NESC Chief Scientist (2003–06) Currently the Senior Project Scientist for 

the Hubble Space Telescope at GSFC

John P. McManamen

NASA Technical Fellow for Mechanical Systems (2003–07) Currently the 

Chief Engineer, Shuttle Program Office 

at JSC

Brian K. Muirhead

NESC Chief Engineer at NASA’s Jet 

Propulsion Laboratory (JPL) (2005–07) 

Currently the Program Systems Engineer in the Constellation Program’s 

Systems Engineering Office at JSC

Dr. Paul M. Munafo

NESC Deputy Director (2003–04)

Left the NESC to become the Assistant 

Director for Safety and Engineering at 

Marshall Space Flight Center (MSFC) 

and has since retired

Stan C. Newberry

Manager of NESC’s Management and 

Technical Support Office (2003–04) Left 

NESC to become the Deputy Center Director at Ames Research Center (ARC) 

and has since left NASA to accept a 

position at DoD

Dr. Shamim A. Rahman

NESC Chief Engineer at Stennis Space 

Center (2005–06) Currently the Deputy 

Director of the Engineering and Test Directorate at SSC

Jerry L. Ross

NESC Chief Astronaut (2004–06) Currently the Chief of the Vehicle Integration Test Office at JSC

John E. Tinsley

NASA Headquarters Senior Safety and 

Mission Assurance Manager for NESC 

(2003–04) Left NESC to become the Director of the Mission Support Division 

at NASA Headquarters and has since 

left NASA to accept a position with 

Northrop Grumman

Ames

Research 

Center

Dryden Flight 

Research Center Wallops Flight

Facility Marshall Space 

Flight Center

Wallops Flight

Facility Langley Research 

Center

Johnson Space 

Center

Stennis Space 

Center

Marshall Space 

Flight Center

Goddard Space Flight 

Center

Kennedy Space 

Center

NASA Headquarters

Glenn Research 

Center

Jet Propulsion 

Laboratory

67

NESC Alumni

3

2

2

7

6 9

9

14

14

8

4 5

17

17

18

18

15

15

16

16

11

11

13

13

10

10

12

12

1

3

4

5

6

1 7

8
68

NESC Honor Awards

From left (back row): Ralph Roe, Jr. (NESC Director/Presenter); Norman Knight, Jr. (General Dynamics); Erik Weiser (LaRC); Jon Haas (WSTF); 

Jerry Stuart (Northrop Grumman); Lawrence Pelham (MSFC); David Dawicke (AS&M, Inc.); David Roberts (LaRC); Walter McCabe (ATK);

From left (front row): Kenny Elliott (LaRC); Kenneth Hodges (JSC); Erik Tyler (AMA); Michael Dube (GSFC); Anna Jackson (LaRC); David Shemwell 

(independent consultant); Darcy Miller (KSC); James Beaty (LaRC); William Sipes (independent consultant); Raymond Lanzi (WFF); George Slenski 

(ATK Space); Ivatury Raju (NESC); Henning Leidecker (GSFC); James Fesmire (KSC); Kenneth Cameron (NESC Chief Astronaut/Presenter); Tim Wilson 

(NESC Deputy Director/Presenter). Not pictured: John Graf (JSC)

NESC DIRECTOR’S AWARD

Michael J. Dube 

In recognition of technical excellence in 

the support and resolution of anomalies 

for NASA projects across the Agency 

including the Space Shuttle, International 

Space Station, and multiple robotic 

spacecraft.

Kenny B. Elliott

In recognition of technical excellence in 

the load redefinition and redirection of 

the Max Launch Abort System flight test 

vehicle.

John C. Graf

In recognition of technical excellence in 

the investigation of the Self Contained 

Oxygen Generator explosion on a British 

Royal Navy submarine.

NESC LEADERSHIP AWARD

Larry I. Pelham

In recognition of outstanding leadership 

of a diverse team of Agency and industry 

experts to design and manufacture the 

NESC composite crew module full and 

subscale hardware.

NESC ENGINEERING

EXCELLENCE AWARD

Raymond J. (Jim) Lanzi

In recognition of exceptional technical 

support in the fundamental design of the 

NESC’s Max Launch Abort System flight 

test vehicle.

James R. Beaty

In recognition of exceptional technical 

support in flight mechanics stability and 

control engineering for the NESC’s Max 

Launch Abort System Flight Test Vehicle 

system concept development.

David S. Dawicke

In recognition of exceptional technical 

support in the testing of the Ares I-X Upper 

Stage Simulator welds.

Kenneth L. Hodges

In recognition of exceptional technical 

excellence in the design, development, 

and implementation of state-of-theart nondestructive techniques for the 

composite crew module project.

Norman F. Knight, Jr.

In recognition of exceptional technical 

excellence in the analyses contributions to 

the Ares I-X Upper Stage Simulator Critical 

Initial Flaw Size.

Walter Thomas McCabe, Jr.

In recognition of exceptional technical 

excellence in the manufacture of the 

composite crew module.

David M. Shemwell 

In recognition of outstanding technical 

leadership in the investigations into 

innovative crew seat concepts for the Orion 

Crew Module and alternative approaches 

to occupant impact tolerance modeling.

George A. Slenski

In recognition of exceptional technical 

expertise in the failure analysis of the STS115 fuel cell motor anomaly.

Jerry L. Stuart 

In recognition of exceptional technical 

excellence in the design and manufacture 

of the NESC composite crew module.

Erik D. Tyler

In recognition of exceptional technical 

excellence in the computational aerodynamics and structural analysis of Max 

Launch Abort System concepts enabling 

efficient development of the flight test 

vehicle.

2008 NESC Honor Award Recipients:
69

NESC Honor Awards

NESC GROUP

ACHIEVEMENT AWARD

Self Contained Oxygen Generator 

Failure Mechanisms Investigation Team

In recognition of outstanding efforts in 

reproducing the Self Contained Oxygen 

Generator mishap, successfully identifying 

the contributing factors, and developing 

effective corrective actions (award 

accepted by Jon Haas on behalf of the 

team).

8% Max Launch Abort System

Model Team

In recognition of outstanding efforts in 

designing, fabricating, and testing the 8% 

Max Launch Abort System model (award 

accepted by David Roberts on behalf of 

the team).

External Tank Intertank/LH2 (Liquid 

Hydrogen) Flange Y-joint Evaluation 

Assessment Team

In recognition of outstanding technical 

support for the External Tank Intertank/

Liquid Hydrogen Flange Y-joint evaluation 

(award accepted by James Fesmire on 

behalf of the team).

Human Factors Pathfinder Core Team 

for Ground System Designers

In recognition of outstanding contributions 

to the engineering excellence of 

Constellation ground systems through 

the human factors engineering pathfinder 

activity (award accepted by Darcy Miller 

on behalf of the team).

Ice Mitigation Approaches for Space 

Shuttle External Tank Team

In recognition of technical excellence 

to develop, test, and successfully 

demonstrate two innovative solutions that 

mitigate risks posed by ice liberating from 

the external tank (award accepted by Erik 

Weiser on behalf of the team).

Langley Research Center Mission

Support Team

In recognition of exceptional service, 

dedication and a proactive approach to 

providing the mission support services 

which have enabled the NESC to 

accomplish critical mission objectives 

(award accepted by Anna Jackson on 

behalf of the team).

NESC Ares I-X Upper Stage Simulator 

Critical Initial Flaw Size Analysis Team

In recognition of technical excellence in the 

analysis and engineering guidance for the 

design, development, and manufacturing 

of the Ares I-X Upper Stage Simulator 

(award accepted by Ivatury Raju on behalf 

of the team).

Pyrovalve Y-PCA (Primer Carrier Assembly) Assessment Team

In recognition of outstanding contributions 

investigating the Pyrovalve Y-PCA booster 

failures (award accepted by William Sipes 

on behalf of the team).

Space Shuttle Program Engine Cut-Off 

System Investigation Team

In recognition of technical excellence in 

the evaluation of the operational anomalies 

and reliability improvements associated 

with the Space Shuttle Engine Cut-Off 

system (award accepted by Henning 

Leidecker on behalf of the team).

IN MEMORIA

Paul D. Guy, recipient of the 2007 NESC Engineering Excellence Award for his leadership 

and contributions to the independent review for the Phoenix Project, unexpectedly 

passed away in November 2007.

Dr. Gopal M. Rao, a key contributor to NESC’s NASA Aerospace Flight Battery Program, 

also passed in May 2008.

Both are missed and will be remembered for their significant contributions to the NESC 

and Goddard Space Flight Center.

Awards Con’t.
70

Recent NESC Publications

All photos used in this publication are credited to NASA except where indicated

ET Ice Mitigation ................................................................................................................................ TM-2008-215324 & 215325

Prebreath Protocol for Extra-Vehicular Activity Technical Consultation Report ................................................ TM-2008-215124

Eight-Foot High Temperature Tunnel (HTT) Oxygen Storage Pressure Vessel Inspection Requirements ........ TM-2008-215316

ISS Fiber Optics Workmanship .......................................................................................................................... TM-2008-215525

Engine Cut-Off (ECO) Sensor Reliability Testing ................................................................................................ TM-2008-215332

CMG1 Root Cause Analysis ............................................................................................................................... TM-2008-215329

Design Development Test & Evaluation (DDT&E) Considerations for Robust

 and Reliable Human Rated Systems ............................................................................................................... TM-2008-215126

Conax Y-PCA (Primer Chamber Assembly) Booster Anomaly Investigation ..................................................... TM-2008-215548

External Tank (ET) Foam Thermal Analysis Project ............................................................................................ TM-2008-215102

Composite Crew Module Pressure Vessel ......................................................................................................... TM-2008-215125

Crew Launch Vehicle (CLV) Project Reaction Control System (RCS) Thrust and Propellant Weight Sizing........ TM-2008-215101

ISS S-Band Corona Discharge Anomaly ............................................................................................................ TM-2008-215100

ET Bipod Bolt Locking Feature Verification ....................................................................................................... TM-2008-215099

CEV LAS Aero Evaluation ................................................................................................................................... TM-2008-215098

Feasibility of Conducting J-2X Engine Testing at the GRC Plum Brook Station B-2 Facility ........................... TM-2008-215104 

DC/DC Converter Unit Investigation ................................................................................................. TM-2008-215352 & 215354

Ares I-X USS Fracture Analysis Loads Spectra Development ........................................................................... TM-2008-215335

Ares I-X USS Stress Analysis ............................................................................................................................. TM-2008-215339

Ares I-X USS Material Testing ............................................................................................................................ TM-2008-215338 

Ares I-X Upper Stage Simulator Structural Analyses Supporting the NESC Critical

 Initial Flaw Size Assessment ........................................................................................................................... TM-2008-215336 

Ares I-X USS Weld Residual Stress Analysis ..................................................................................................... TM-2008-215339 

Constellation Mass and Performance Independent Assessment ...................................................................... TM-2008-215326

GN&C Engineering Best Practices for Human-Rated Spacecraft Systems ....................................................... TM-2008-215106 

The NASA Engineering & Safety Center (NESC) GN&C Technical Discipline Team (TDT):

Its Purpose, Practices and Experiences ............................................................................................................ TM-2008-215128

Guidelines for Reliable DC/DC Converters for Space Use, J. Plante, Components for

Military and Space Electronics, February 10-14, 2008, San Diego, California

Guidelines for Reliable DC/DC Converters for Space Use, J. Shue, J. Plante,

MAPLD 2008, September 15–18, 2008, Annapolis, Maryland

Rescuing EDL Data , Elmain Martinez, Adrian Tinio, Mike Gangl, Robert Powers,

Keith Shackelford, Alan Wood, Russel Westbrook, International Planetary Probe Workshop,

Atlanta, Georgia, June 23-27, 2008

NASA Experience with Pogo in Human Spaceflight Vehicles, C. Larsen, NASA Johnson

Space Center, United States, AVT-152 Symposium on Limit Cycle Oscillation and Other

Amplitude-Limited Self Excited Vibrations, North Atlantic Treaty Organization

Reports

Presented Papers
71
72

National Aeronautics and Space Administration

Langley Research Center

Hampton, VA 23681

www.nasa.gov

NP-2008-12-135-LaRC