TABLE OF CONTENTS

Stakeholder Messages 2

Introduction 3 

NESC Overview 4

Technical Accomplishments 7

Featured Technical Paper 21

Fracture Mechanics Analysis of LH2

	 Feed Line Flow Liners

NESC Highlights from the Centers

Ames Research Center 31

Dryden Flight Research Center 32

Glenn Research Center 33

Goddard Space Flight Center 34

Jet Propulsion Laboratory 35

Johnson Space Center 36 

Kennedy Space Center 37

Langley Research Center 38

Marshall Space Flight Center 39

Stennis Space Center 40

White Sands Test Facility 41

NESC Honor Awards 42

Partnerships & Communication 45

NESC Academy 46

Biographies 48

NESC Alumni 54

Recent NESC Publications 55

Overhead view of Atlantis taken September 11, 2006 from

 the International Space Station during the STS-115 mission.
 NESC 2006 TECHNICAL UPDATE

I

n its third year, the NESC continued to provide me (and other Agency leaders and 

decision makers) with outstanding independent technical information to support our 

decisions involving the safety and mission success of Agency missions. The many 

mission successes of this year are a testament in substantial part to the hard work and 

dedicated efforts of the many diverse members of the NESC. A great example was 

the “Smart Buyer” initiative. Here, the NESC was able to quickly assemble a team of 

experts to analyze options and trade-offs for the next generation space vehicles for the 

Exploration initiative, showing once again that the NESC is a most valuable and unique 

resource to the Agency as we make decisions on the path back to the Moon.

I

’ve found the NESC, because of its ability to work across NASA and to bring the 

greatest talent within the Agency to bear on problems of the most diverse nature, 

to be among the most valuable resources available to me as Administrator. The 

NESC efficiently concentrates resources where needed, yet employs the advantages 

of a distributed architecture to do so. It has been one of our real post-Columbia success stories.

Dr. Michael D. Griffin

NASA Administrator

Christopher J. Scolese

NASA Chief Engineer

Bryan D. O’Connor

NASA Chief Safety 

and Mission Assurance 

Officer

STAKEHOLDER MESSAGES

The NESC, in its third year of operation, continues to offer a unique resource to 

NASA and other organizations. The unique ability of the NESC to bring together 

technical experts from across the Agency and the aerospace community has 

provided the expertise to resolve our most critical problems. The highest tribute one 

can provide to the NESC and its personnel is the recognition by their peers as reflected 

by the increase in requests, from all levels of the Agency, for their support in resolving 

problems, reviewing activities, and conducting special studies. These have ranged from 

detailed support of the Space Shuttle Program’s flight activities, to addressing unique 

issues associated with CALIPSO, to the Smart Buyer Study for the Constellation Program. Some examples are provided in this Technical Update. Further recognition of the 

contributions that the NESC is making to NASA is the fact that graduates of the NESC 

are in senior positions within NASA — from engineering leadership on major projects 

up to Center Director. The NESC is more than a problem-solving organization. It is also 

an engine for improving the competence of our engineering workforce through the opportunity to work on challenging problems, through exposure to other organizations 

within NASA, and through its promulgation of lessons learned to the Agency. Lessons 

learned are provided in the technical reports and through the NESC Academy courses. 

This Technical Update highlights some of those lessons, so take the time to read this 

issue and reflect on how these lessons could help in your particular activity. In closing, 

the NESC has established itself as a reliable, credible and respected organization within 

the Agency and is an outstanding example of Engineering Excellence in practice.
NESC 2006 TECHNICAL UPDATE 

INTRODUCTION

As the NASA Engineering and Safety Center (NESC) Leadership Team, we are proud 

 to provide you with this Technical Update for

 2006. In this update, we will present a crosssection of our technical activities, along with the 

broadly applicable lessons learned from our assessments. Sharing the knowledge gained from 

our efforts with the NASA technical community is 

an important goal for the NESC. In order to successfully provide value-added independent products to the Agency’s high-risk programs and projects, we must rely on the expertise and resources 

at the NASA Centers and operate as a true One 

NASA organization. In the NESC Center Highlights 

pages of this update, we describe how multiple 

NASA Centers contributed to each of the NESC’s 

technical efforts, and thus to the NASA mission.

During our third year of operation, the NESC has 

continued to support the Space Shuttle and International Space Station Programs, along with 

numerous robotic and science missions including 

Pluto New Horizons, Stardust and Phoenix. The 

year also marked a shift in our attention as we have 

become more actively engaged in the Constellation Program. We have conducted additional NESC 

Academy courses and continued to recognize engineering excellence through our NESC Honor 

Awards. In keeping with the model of the NESC, 

our team members continue to transition back to 

leadership positions at the Centers. The NESC periodically advertises for highly skilled and motivated 

individuals to join the NESC team and make a difference in the NASA Mission. Lastly, we hope that 

our technical update will be of value and that it provides a better understanding of the NESC Mission.

—NESC Leadership Team 2006

NESC Leadership Team – (left to right) Marc Hollander – former Manager of the Management and Technical Support Office, Dawn Schaible – Manager 

of the Systems Engineering Office, Ralph Roe – Director, Tim Wilson – Deputy Director, Kenneth Cameron – Deputy Director for Safety, Patricia Dunnington – Manager of the Management and Technical Support Office, and Dr. Charles Camarda – Deputy Director for Advanced Projects (not pictured).
 NESC 2006 TECHNICAL UPDATE

 NESC 2006 TECHNICAL UPDATE

NESC OVERVIEW

One of the tenets of an effective safety philosophy is to provide 

an avenue for independent assessment of the technical aspects 

and risks of critical systems. This is the charge of the NESC, an 

organization dedicated to promoting safety through engineering 

excellence. A resource for the Agency, it is a valuable asset for the 

high-risk programs that NASA has always undertaken.

At the core of the NESC is an established knowledge base of technical specialists pulled from the ten NASA Centers and from a group 

of partner organizations external to the Agency. This ready group 

of engineering experts is organized into 15 discipline areas called 

Technical Discipline Teams (TDTs — formerly known as Super Problem Resolution Teams or SPRTs). TDT members are from NASA, 

industry, academia, and other government agencies. By drawing 

on the minds of leading scientists and engineers from across the 

country, the NESC consistently solves technical problems, deepens its knowledge base, strengthens its technical capabilities, and 

broadens its perspectives, thereby 

further executing its commitment to 

engineering excellence.

Components of the NESC

The structure of the NESC is based on 

maintaining a diverse and broad base 

of knowledge, keeping informed and 

engaged with each Center and the 

Agency’s major programs, responding efficiently to requests for assistance, and retaining a high degree 

of independence. To achieve these 

goals, the NESC is organized into 

six offices: 

NESC Discipline Experts assemble and provide leadership for the 

TDTs and are stewards for their disciplines.

NESC Chief Engineers provide insight into their Centers’ programs 

and help to coordinate the facilities and resources of each Center 

when required to support NESC activities.

Principal Engineers use TDT members provided by the NESC Discipline Experts and resources arranged by the NESC Chief Engineers to lead technical reviews, assessments, tests, and analyses.

The Systems Engineering Office dispositions requests as they 

come in, performs proactive trending analysis and problem identification, and provides other integration and system engineering 

support. 

The Management and Technical Support Office is the business 

arm of the NESC, taking care of the contracting, budgeting, and 

management of the NESC’s infrastructure.

Under the leadership of the Director’s Office, these five components 

come together to form the heart 

of the NESC — the NESC Review 

Board (NRB). The life cycle of every formal activity performed by the 

NESC requires approval of the NRB. 

The NRB brings a diversity of thought 

to the decision-making process. It is 

an amalgam of people representing 

different Centers, programs, and engineering backgrounds. 

Michael Kirsch, NESC Principal Engineer (foreground), presents the results of a study to the NESC Review Board (NRB). The NRB is a vital peer 

review process for the NESC.

NESC Technical Discipline Teams (TDTs)

n Flight Sciences

n Fluids/Life Support/

 Thermal 

n Guidance, Navigation

 & Control (GNC)

n Human Factors

n Human Space Flight

 Operations

n Loads and Dynamics

n Materials

n Mechanical Systems

n Nondestructive

 Evaluation (NDE)

n Power & Avionics

n Propulsion

n Robotic Missions

n Software

n Structures

n Systems Engineering

Mission success starts with safety — safety starts with engineering excellence

LaRC
NASA 75 %

Industry

17 %

University

4 %

Other U.S. Gov.

4 %

Space Operations

58 %

Aeronautics Research

3 %

General (across multiple 

mission directorates)

10 %

Exploration

Systems

15 %

Science

14 %

Program Analysis 

& Evaluation 1%

Anonymous 2%

Safety Mission 

Assurance at Centers 4%

External to Agency 6%

Program

Management 

17%

NESC 30%

Engineering &

Scientific Organizations

31%

Office of Safety 

and Mission

Assurance 4%

Office of Chief Engineer 2%

Center Management 3%

NESC 2006 TECHNICAL UPDATE 

NASA 75 %

Industry

17 %

University

4 %

Other U.S. Gov.

4 %

Space Operations

58 %

Aeronautics Research

3 %

General (across multiple 

mission directorates)

10 %

Exploration

Systems

15 %

Science

14 %

Program Analysis 

& Evaluation 1%

Anonymous 2%

Safety Mission 

Assurance at Centers 4%

External to Agency 6%

Program

Management 

17%

NESC 30%

Engineering &

Scientific Organizations

31%

Office of Safety 

and Mission

Assurance 4%

Office of Chief Engineer 2%

Center Management 3%

NESC 2006 TECHNICAL UPDATE 

Products

After an activity performed by the NESC has concluded, results are 

delivered to the stakeholders in the form of written engineering reports that include solution-driven preventative and corrective recommendations. The NESC strives to set the example for the Agency by 

providing full and appropriate documentation of every activity. Along 

with each report, lessons learned are communicated to Agency leadership and to engineers through avenues such as the Agency lessons learned system, the reports themselves, and this publication. 

In addition to acting on requests from outside of the NESC, another 

important function of the NESC is to engage in proactive investigations to identify and address potential concerns before they become 

major problems. To further this goal, the NESC is currently leading 

NASA’s efforts for independent data mining and trend analysis. The 

NESC has established a Data Mining and Trending Working Group 

that includes representatives from all NASA Centers as well as external to the Agency. 

An Independent Resource

The NESC is organized under the NASA Office of the Chief Engineer 

and is closely aligned with the NASA Office of Safety and Mission Assurance, so it is not in-line with any Program or Mission Directorate 

either from a budgetary or an organizational standpoint. The NESC is 

available not only to program/project managers, but to anyone associated with NASA’s projects who requires independent testing, analysis, or assessment. By virtue of its distributed framework, access 

to the NESC is available through the Center NESC Chief Engineer 

or by emailing a request to nesc@nasa.gov There are approximately 

sixty NESC-badged employees, but through the TDTs, there are ten 

times that many people who participate in NESC activities. These 

matrixed employees are located at each Center and Headquarters 

and enjoy the benefits of working with and learning from the leaders 

in their fields.

2006 Technical Discipline

Team Composition

As a part of the NRB peer review process, Dr. Ivatury Raju, NESC 

Discipline Expert for Structures, examines a model of a Crew Exploration Vehicle crew module.

Accepted Requests By Mission

Directorate: 166 Total

Cumulative as of November 1, 2006

 Source of Accepted Requests:

166 Total

Cumulative as of November 1, 2006

NESC OVERVIEW
technical accomplishments

STS-114 launches July 4, 2006
TECHNICAL ACCOMPLISHMENTS

NESC 2006 TECHNICAL UPDATE 

Problem: Potentially damaging ice can grow 

on components of the Space Shuttle’s External Tank (ET) once it is filled with cryogenic 

hydrogen and oxygen. Areas along the liquid 

oxygen (LOX) feedline including the bellows 

and support brackets are susceptible to the 

formation of ice. Ice can also form in the ET/

Orbiter umbilical area, intertank flange, and 

on the umbilical baggie material. 

NESC Contributions:

Intertank Flange

To reduce ice buildup and release from the 

intertank flange area, the team has performed 

a series of cryogenic developmental tests on 

a simulated scale ET intertank flange to demonstrate the effectiveness of using Nanogel® 

insulating beads in reducing cryo-ingested nitrogen and subsequent ET foam loss. Test results are being shared with the Space Shuttle 

Program (SSP), and efforts are underway to 

perform the next level of tests on flight-like 

hardware. The NESC will provide recommendations to the SSP regarding Nanogel® bead 

characteristics for any upcoming SSP tests 

Shuttle Ice Liberation Coating 

A coating to reduce ice adhesion has been 

developed by the NESC team and has been 

tested on multiple substrate materials at temperatures down to -170oF. Shuttle Ice Liberation Coating (SILC) reduces the ice adhesion 

strength substantially on all surfaces (75 to 

100% reduction in adhesion strength) and 

could be applied to surfaces on the Space 

Shuttle that would benefit from early ice liberation. A patent has been applied for SILC. 

Flexible Foam

A flexible polyimide foam segment to insulate 

the area between the LOX feedline bracket 

and the feedline has been developed that allows the bracket to articulate while preserving 

the integrity of the ET and feedline insulating 

foam and prevents the formation of ice in 

the gap of the bracket. At White Sands Test 

Facility, the team is testing a PolyuMAC version of the flexible foam. The flexible foam 

showed that the quantity of ice could be reduced to acceptable levels for the LOX feedline bracket. Performance may be increased 

with the enhancements such as the use of an 

customized foam segment shape and application of SILC. The team has also developed 

an in-situ installation technique that relies on 

vacuum bagging the foam segment, and then 

removing the bag, allowing the foam to expand in the joint.

NESC Ice Mitigation Team Works to Reduce Ice Formation and Growth on External Tank

SILC on aluminum specimen with ice in double lap shear fixture. The specimen is pulled 

from the fixture to measure ice adhesion.

Glenn Durell (left) and Mike Ferrick (right) of the U.S. Army’s Cold Regions Research & Engineering Laboratory, Hanover, N.H., examine a double lap shear test coupon coated with SILC.

Vacuum-bagged flexible foam being inserted into a test fixture representative of the ET LOX 

feedline bracket gap.

MSFC

WSTF

MSFC
TECHNICAL ACCOMPLISHMENTS

10 NESC 2006 TECHNICAL UPDATE

Problem: Solid Rocket Booster (SRB) 

stud hang-ups have occurred over the life 

of the Space Shuttle Program. The SRBs 

are bolted to the Mobile Launch Platform by 

a Holddown Post (HDP) system. At the time 

of launch, these bolt studs are designed to 

quickly exit into the HDP allowing the Space 

Shuttle to liftoff. A stud hang-up at liftoff can 

increase loads at the SRB/External Tank attach points. 

NESC Contribution: The NESC undertook 

an extensive hardware test program to aid in 

determining root cause. This included development of a high fidelity stud and frangible 

nut model that was calibrated with data from 

the test project. The NESC found that a number of often violent factors work to slow or 

interrupt the stud’s descent and clearance 

from the SRB. The cause of stud hang-ups 

was determined to be a combination of 

contributing factors including: frangible nut 

pyrotechnic firing skew, nut half recontact, 

plunger seating and frangible link breakage, 

debris interaction, bore hole contact, frictional forces from the plunger, and movement of 

the SRB aft skirt prior to full stud ejection. At 

launch, the cumulative result of these factors’ 

individual effects on the stud, most of which 

are almost always in play but take place at 

variable levels of intensity, add up to slow 

down the stud’s descent enough that a hangup occurs. Extensive testing, modeling and 

simulation were used to arrive at this conclusion. The Space Shuttle SRB Project can now 

work toward modifications that reduce the 

number of these unwanted occurrences.

Lessons Learned: Testing that includes firing 

pyrotechnics produces its own set of problems. Pyrotechnic devices produce large 

quantities of smoke that will interfere with 

photographic analysis unless smoke mitigation steps are taken. Pyrotechnic devices 

function very quickly and require special 

instrumentation to measure pyrotechnic explosion timing. Accelerometers may perform 

poorly in a blast environment due to shock 

and reverberation from the initial blast.

Leslie Curtis, NESC Back-up Principal Engineer and Peggy Ritchie, Senior Aerospace Inspector with United Space Alliance performing borescope inspection of holddown post hardware 

after a stud hang-up occurred during NESC testing at KSC.

(Above) Test fixture with frangible HDP stud nut. Pyrotechnic 

devices are visible on either 

side of the nut. (Left) Location 

of one of four HDP stud nuts on 

the aft skirt of an SRB.

Space Shuttle Solid Rocket Booster Holddown Post Stud Hang-Up Root Cause Analysis

Photos KSC
TECHNICAL ACCOMPLISHMENTS

NESC 2006 TECHNICAL UPDATE 11

The NESC is currently leading the Agency’s 

efforts to perform independent data mining 

and trend analysis to identify unknown indicators of future problems. One of the NESC’s 

goals is to perform independent analyses 

within programs and across programs, while 

not duplicating the program-specific trending 

efforts. Through workshops, monthly telecons, 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 sharing of ideas, particularly regarding 

methodology and lessons learned.

The NESC-led Data Mining and Trending 

Working Group includes representatives from 

all NASA Centers as well as external experts 

from organizations such as the Federal Aviation Administration, the Department of Homeland Security, the National Transportation 

Safety Board, and the Institute of Nuclear 

Power Operations. This group 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, as well as a clustering 

tool under development by Ames Research 

Center, the Recurring Anomaly Detection System (ReADS). Mentoring activities and formal 

training are ongoing. This group also 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. 

NASA Engineering and Safety Center (NESC) Data Mining and Trending Working Group

Recurring Anomaly 

Detection System 

(ReADS) display 

of problem report 

clusters. Clusters of 

seemingly disparate problems may 

indicate a common 

problem.

ARC

Problem: Foam and ice debris can be shed 

from the External Tank (ET) Liquid Hydrogen (LH2) Tank Ice/Frost Ramps (IFRs) and 

pose an impact hazard to the Orbiter on ascent. The IFRs are aerodynamically shaped 

sections of insulating foam that are molded 

around the brackets that attach the gaseous 

oxygen and hydrogen repressurization lines 

and cable trays to the ET.

NESC Contribution: The NESC pursued an 

independent effort directed at a mid-term redesign of the LH2 IFRs to minimize the debris potential to the Orbiter. This approach 

supplemented the ET Project’s pursuit of an 

immediate-term modification of the existing 

LH2 IFRs. The goal of the NESC effort was 

to develop retrofit bracket design that ensured no surface temperature was less than 

32 degrees Fahrenheit (oF) through the prelaunch countdown and would survive ascent 

thermal and structural loading. The concept 

selected for investigation, seen below, was a 

thermally-passive titanium bracket consisting 

if an exposed upper plate and bracket which 

maximized the surface area to absorb heat 

from the ambient air while minimizing the embedded cross section which is in contact with 

the LH2 tank. The NESC design minimizes 

the embedded cross section by isolating the 

exposed section from the colder surfaces of 

the LH2 tank by means of thermally resistant 

spacers attached to an embedded lower plate 

that is attached to the tank surface.

The knowledge gained from the independent 

NESC investigation significantly influenced 

and facilitated the ET Project’s efforts at developing bracket redesign concepts to replace the interim modifications to the existing 

LH2 IFRs.

External Tank (ET) Liquid Hydrogen (LH2) Tank Ice/Frost Ramp (IFR) Design Modification

Upper plate

Exterior Tank 

acreage foam

Lower plate

Cutout in External Tank

acerage foam to

accomodate lower plate

Minimal Insulation 

Ramp

Extended

Insulating Spacers

Barrymount &

Cable Tray Support

LaRC
TECHNICAL ACCOMPLISHMENTS

12 NESC 2006 TECHNICAL UPDATE

Problem: In August, 2005 the Space Shuttle 

Program’s (SSP) External Tank (ET) Project 

initiated a Protuberance Air Load (PAL) Ramp 

Removal / No PAL Ramp ET design assessment. PAL Ramp removal required detailed 

test and analysis to certify the new design for 

flight. A team of experts in unsteady aerodynamics, loads and structural dynamics to support the re-design activity. Subsequently the 

SSP finalized the removal of the PAL Ramps 

on ET-119 for STS-121. The NESC team was 

directed to provide an independent assessment of the adequacy of the SSP’s certification of this new Shuttle Launch Vehicle configuration.

NESC Contribution: The NESC team served 

as a technical consultant during SSP-sponsored test and analysis activities conducted 

to certify the no PAL Ramp Shuttle Launch 

Vehicle configuration. This team of experts 

provided detailed insight by real-time participation in SSP PAL Ramp removal team 

activities, data package, reviews, and design 

reviews. The NESC team was an active participant in the planning and conducting of the 

SSP sponsored wind tunnel test program to 

define certification loads, the evaluation of 

the loads and stress results and the definition 

of the certification design load environments 

including the ET Critical Design Review and 

Design Certification Review. The initial wind 

tunnel test derived loads significantly exceeded the preliminary design loads, in part due 

to unnecessary conservatism. The NESC assessed the dynamic test data processing and 

recommended and implemented alternate 

industry standard methods for analysis which 

improved prediction of a realistic dynamic 

load environment. The NESC team continued 

to evaluate the STS-121 and STS-115 flight 

data which demonstrated the acceptable load 

environment for the No-PAL Ramp ET configuration. 

The SSP approached the redesign with a success oriented plan which required the SSP 

to analytically determine design certification 

loads prior to validation with actual wind tunnel testing. To meet near term schedule milestones and accommodate facility availability, 

testing was conducted at a smaller, less capable tunnel than that originally planned, which 

reduced the number of measurements and 

compromised the ability to gather all relevant 

test conditions. The wind tunnel test results 

did not correlate well with the pre-test certification loads. The nature and limitations of 

the test data base created a post-processing 

challenge which required extrapolation and 

special processing of the results to define a 

conservative certification loads update. Iterations were required to finalize the certification 

database for the STS-121 flight.

STS-121 flight data acceleration measurements confirmed that the cable tray loads 

were well within the design environment and 

not significantly impacted by the PAL Ramp 

removal indicating that the driving load for the 

hardware was indeed the base vibration and 

not the unsteady aerodynamic environment. 

Lessons Learned: Facility capabilities often limit the ability to verify expected flight 

environments. These limitations need to be 

considered in establishing the certification approach. Flight data is invaluable when assessing complex environments.

Rendering of the redesigned ET 

without PAL Ramp that was successfully flown on STS-121 and STS-115 

(Top). ET with PAL Ramp (Middle). 

Photo taken from the ISS (Bottom) 

shows briefcase-size foam loss from 

the PAL Ramp on STS-114. 

External Tank Protuberance Air Load (PAL) Ramp Removal Feasibility Independent Assessment

MSFC

JSC
TECHNICAL ACCOMPLISHMENTS

NESC 2006 TECHNICAL UPDATE 13

Problem: The NESC (in coordination with 

Langley Research Center Fundamental Hypersonics) sponsored the High Altitude Observation Aircraft (HALO II) to capture Orbiter 

surface temperature distributions using infrared (IR) camera observation of Discovery’s entry during the STS-121 mission. HALO II was 

flown in conjunction with other aircraft (NASA 

WAVE and Navy Cast Glance) — sponsored 

by the Space Shuttle Program — to demonstrate capability. The primary objective associated with HALO II was to demonstrate the 

entry imaging capability by obtaining spatially 

resolved, calibrated (multi-spectral), thermal 

imagery of the Orbiter underside during or 

after Boundary Layer Transition (BLT) to turbulent flow. Protruding gap fillers identified 

while Discovery was in orbit provided an opportunity to characterize the effectiveness of 

these as BLT initiators.

NESC Contribution: The HALO II acquired 

Discovery during entry flight on July 17, 2006 

via a Long Wave Infrared (LWIR) acquisition 

camera. Discovery was manually tracked 

and approximately 400 seconds of total data 

collection was recorded (see Fig. 1). These 

HALO II observations encompassed the 

Mach 10 to 7 entry flight regime. Based on 

Orbiter surface thermocouple measurements, 

complete lower surface BLT occurred at approximately Mach 7.2. Additionally, a gap filler protruding just forward of the external tank 

umbilical door caused a localized early BLT 

that was captured by the LWIR entry imagery 

as a classic turbulent wedge downstream of 

the gap filler site, evident in Fig. 1 and in the 

Cast Glance image using a Near Infrared (NIR) 

detector (Fig. 3).

The STS-121 HALO II observations achieved 

the primary objectives by demonstrating that 

valuable entry BLT information can be derived 

via aircraft based imaging. Entry infrared imaging during STS-121 demonstrated capability to acquire and track the Orbiter during 

entry flight and differentiate between laminar 

and turbulent flow regions on the Orbiter 

lower surface. However, during STS-121 

the Medium Wave Infrared (MWIR) camera 

images became saturated (see Fig. 2), compromising the potential to derive quantitative 

results from these multi-spectral observations. Based on the HALO II and Cast Glance 

system performance during STS-121, entry 

infrared imaging shows promise for providing 

quantitative surface temperature measurements with sufficient resolution to resolve 

laminar–to-turbulent transition boundaries on 

the windward surface of the Orbiter. 

The Space Shuttle Program has continued 

this effort with observations on STS-115 and 

planned observations for STS-116.

Lessons Learned: Entry infrared imaging 

techniques using aircraft-based systems can 

provide quantitative surface temperature data 

collection. In order to fully achieve this objective and maximize the data return, the entry 

trajectory and corresponding dispersions 

must be fully understood and accounted for 

in preflight planning and operational flexibility. To mitigate saturation issues, radiance 

models used to determine appropriate detector gains and filters settings must be better 

characterized. Wide Field of View (WFOV) 

optics are necessary to capture the Orbiter as 

it breaks horizon. Because of the uncertainty 

in the actual Orbiter BLT time for any given 

entry, multiple aircraft are required to ensure 

the targeted data are collected.

NESC-Sponsored Orbiter Infrared Observation During STS-121 Entry 

Fig. 3 Cast Glance Image of STS-121

Fig.1 HALO II STS-121 LWIR Image

USN

NASA

Fig. 2 HALO II STS-121 MWIR Image

NASA
TECHNICAL ACCOMPLISHMENTS

14 NESC 2006 TECHNICAL UPDAT

Problem: While transporting a mobile launch 

platform, one of the shoes on the KSC Crawler Transporter (CT) cracked and failed. The 

shoe was relatively new with low mileage as 

all CT shoes were replaced prior to the STS114. A shoe failure during roll-out increases 

the exposure of the vehicle to the possibility 

of damage from lightening and is a potential 

hazard to ground personnel while repairs are 

made. Metallurgical analysis of the failed shoe 

showed that the crack initiated at an internal 

shrinkage void and then rapidly propagated 

through a large region of weaker material containing slag inclusion particles. Fabrication 

records indicated that the failed shoe was a 

“last pour” during the casting process. The 

NESC Nondestructive Evaluation (NDE) TDT 

was asked to review the near-term NDE efforts at KSC to inspect the CT shoes and to 

evaluate phased-array ultrasonic methods 

as an improved technique for longer-term inspection of the shoes. 

NESC Contribution: The NESC NDE TDT 

reviewed the near-term NDE efforts of KSC, 

USA, and Wyle personnel to inspect the CT 

shoes. These efforts included reviewing NDE 

documentation from the manufacturer, applying visual borescope and magnetic particle 

methods to all CT shoes, and applying conventional ultrasonic and high energy radiographic 

methods to selected spare shoes focusing on 

other “last pour” shoes. Additionally, KSC 

initiated an investigation of the applicability of 

modal testing methods to detect defects and 

damage in shoes. The NDE TDT provided 

concurrence with these efforts and actively 

participated in the review and analysis of test 

results. In particular, the NESC funded the 

high energy radiographic testing and provided 

modeling and analysis support for the testing 

effort. A smaller surface crack was found in a 

second CT shoe through the use of magnetic 

particle testing, but the radiographic testing 

did not indicate any regions of slag inclusions 

in the selected set of spare “last pour” shoes. 

Additionally, the NDE TDT demonstrated the 

capability of phased array ultrasonic methods 

on CT shoe specimen with simulated flaws. 

The phased array ultrasonic test (UT) method 

offers the advantages of more readily inspecting beneath the curved surface of the shoes 

and faster inspection times as compared to 

conventional single element ultrasonic transducers. A phased array UT inspection procedure has been developed and training for 

inspectors at KSC is planned. The improved 

phased array UT method will then be used to 

inspect the CT shoes to ensure that no additional casting flaws remain.

Kennedy Space Center Crawler Transporter Shoe Cracking 

Jeff Leak of the NDE TDT at NASA MSFC uses a phased array ultrasonic system to image 

simulated flaws in a crawler transporter shoe calibration standard. (Inset) KSC Crawler.

Problem: Multiple projects 

across the Agency are currently 

or will soon use 0.25-micron 

or 0.15- micron technology 

Radiation Tolerant (RT) Field 

Programmable Gate Arrays 

(FPGAs) to implement digital 

circuitry for flight applications. 

They offer significant advantages over older technologies previous versions in terms of capacity and capability. However, 

field failures in 2003 identified problems on 

a SX-S series part. At that time, many NASA 

applications using the SX-S were under development, causing significant cost 

impacts and higher mission risks. 

In response to these failures, the 

FPGA manufacturer instituted device foundry changes and antifuse 

programming algorithm changes. 

NESC Contribution: The NESC 

sponsored evaluation studies of the 

SX-S series part changes. Early test 

results indicate improved SX-S reliability. The NESC is also sponsoring 

reliability evaluation and risk reduction testing 

of the new RTAX-S parts with the goal of accelerating the detection of any potential problems. The RTAX-S provides greater capability 

and improved resistance to electrostatic discharge over the SX-S series parts. An NESC 

Agency-wide team is engaged to review 

results. Overall, the results from the NESCsponsored SX-S and RTAX-S testing will benefit NASA by reducing risk through identifying 

problems (if any) early enough to allow projects to more effectively resolve them.

Lesson: Evaluation of complex parts under 

higher stress conditions than typically seen in 

user applications is important to detect potential problems and to establish limits and margins of the devices.

Field Programmable Gate Array Risk Reduction and Programmed Antifuse Reliability Evaluation

NASA/OLD

RTAX-S FPGA showing 

package cavity, die, and 

wire bonds.

PHOTOS/KSC
TECHNICAL ACCOMPLISHMENTS

NESC 2006 TECHNICAL UPDATE 1

Problem: The International Space Station 

(ISS) has four Control Moment Gyros (CMGs) 

that maintain attitude control. After operating 

nominally for 1.5 years, ISS CMG-1 failed on 

June 8, 2002. An ISS Root Cause Investigation Team (RCIT) was formed by the ISS Program in an attempt to understand the failure 

at that time.

After the failed unit was retrieved during STS114 in August 2005, the ISS Program Manager 

reactivated the RCIT and requested the NESC’s involvement to investigate and analyze 

the root cause(s) of the CMG-1 failure. The 

ISS RCIT conducted a rigorous investigation 

of the failure, which included detailed study 

of the failed bearing components, metrology 

of the non-failed bearing and the inner gimbal 

structure, thermal effects on bearing alignment, structural capability of the retainer, and 

condition of the lubrication system. 

NESC Contribution: The NESC team reviewed the telemetry data from the failure 

event and other relevant operational data on 

the CMGs; reviewed and concurred on the 

RCIT disassembly procedures; reviewed RCIT 

inspection and test results and fault tree; reviewed CMG design; and supported and consulted with the NESC Guidance, Navigation & 

Control TDT and the ISS RCIT. 

The NESC team’s findings, observations, and 

recommendations were derived from two 

primary sources including the data and test 

results generated by the thorough ISS RCIT 

investigation and a detailed dynamic bearing analysis using the ADORE software. The 

NESC analysis evaluated the possibility of 

excessive retainer forces and the effect of 

race out-of-roundness, supporting analyses 

to strengthen the argument that failure of the 

pre-load system was the most probable cause 

of failure, and inspected/requested inspection 

of key components.

The NESC team concluded that although the 

analysis of existing data does not permit a 

single root cause to be positively determined, 

the most probable cause of the failure is loss 

of bearing pre-load due to binding of the outer 

race or races, stick-slip of the pre-load spring, 

and misalignment resulting from out-of-flat 

gimbal covers and the transient thermal conditions. The NESC team developed 20 recommendations in three general categories: 

bearing system design, safety, and orbital operational procedures.

Control Moment Gyro-1 (CMG-1) Root Cause Analysis

CMG-1 

through CMG4 mounted 

in the ISS 

Z1 truss 

with shroud 

removed.

Problem: The NESC was part of a team to determine the root cause of the anomalous behavior observed in the Space Shuttle Engine 

Cut-Off (ECO) sensor system during ET tanking tests and launch attempts on STS-114. A 

theory was developed that would explain how 

a sensor could show an apparent failure on 

first exposure to liquid hydrogen (LH2), but 

show no indication of anomalous behavior 

when returned to ambient temperature or on 

subsequent exposure to LH2. 

NESC Contribution: The NESC team performed cryogenic cycling of 50 fully instrumented flight grade sensors between ambient 

and LH2 temperatures to determine the validity of the theory. Both nondestructive and 

destructive physical analysis techniques were 

employed to characterize a limited number of 

the sensors. All 50 sensors behaved nominally, 

and there were no measurable indications of 

faulty or changing electrical performance during or as a result of cryogenic cycling. However, nondestructive and destructive physical 

analysis indicate a number of issues with the 

material selection and process variability used 

in the fabrication of a swaged circuit board 

connection that could be highly sensitive to 

human factors in the assembly process and 

result in lot-to-lot variability. The nondestructive x-ray techniques for analysis of the sensor’s swage connections, developed as part 

of this assessment, became the basis for the 

techniques used by the ET Project to evaluate 

replacement sensors for the ET-119. 

Lessons Learned: During the assessment, 

the NESC team became aware of a well intentioned practice by the ET manufacturer of 

removing sensors if they showed a greater 

than 2 ohm resistance shift. However, since 

these sensors had not exceeded the allowable limits, they were not considered failures, 

and were not fully destructively analyzed. The 

result was a short term improvement in the 

quality of the sensors delivered in the tanks 

at the expense of masking manufacturing defects which resulted in an overall reduction in 

sensor reliability. 

Space Shuttle Engine Cutoff Sensor Anomaly and Reliability Investigation

GSFC

Manufacturing issues in an ECO sensor 

electrical terminal connections are visible in 

this x-ray image. 

NASA

Asymmetric Swage

Terminal #2 Terminal #1

Bent 

terminal
TECHNICAL ACCOMPLISHMENTS

16 NESC 2006 TECHNICAL UPDAT

Problem: Existing aerodynamic, aerothermodynamic, and thermal protection system 

material response models have not been fully 

assessed against actual reentry data.

NESC Contribution: As the Stardust Sample 

Return Capsule (SRC) entered the Earth’s 

atmosphere at 12.8 km/s, the fastest manmade object to traverse our atmosphere, an 

ARC-led NESC-sponsored team of researchers imaged the event aboard the NASA DC8 airborne observatory. With the SRC not 

having any on-board flight instrumentation, 

the NESC sponsored data are the only time 

resolved record of the performance of the 

entry system. The radiative signals from the 

SRC and surrounding shock layer gasses 

were measured by 15 of 18 instruments that 

had various combinations of spectral range, 

spectral resolution, and temporal resolution. 

The data were assessed to be of very good 

quality and sufficient to address all observation objectives: absolute radiance, spectral 

resolution of shock layer emission, and wake 

train evolution. Analysis of these observation 

data and the recovered SRC heatshield will 

provide an assessment of the fidelity of the 

models and ground tests used to design the 

SRC. This assessment directly supports the 

Exploration Systems initiative in that these 

models and tests are being used in the design

of the Crew Exploration Vehicle.

Lesson Learned: Ground photography of 

the entry event was an invaluable aide to 

trajectory reconstruction. These supplemental photographs to the imagery obtained 

aboard the aircraft provided an effective stereoscopic view of the entry thereby enabling 

trajectory reconstruction in the hypersonic 

regime prior to radar tracking.

NESC Sponsored StarDust Entry Observation Campaign

Problem: The Atlas V first-stage fuel tank qualification test article failed catastrophically during hydrostatic testing, revealing a flaw in the attachment of 

internal ring stiffeners leading to localized cracking 

that over time and repeated load that could lead to 

tank structural failure. Internal borescope inspection of the particular tank to be used for the Pluto/New Horizons launch vehicle did not reveal the 

presence of any such cracks, however other tanks 

in the inventory did have such cracks. 

NESC Contribution: The NESC was requested 

to participate in the failure analyses and provide a 

risk assessment for using the planned tank for the 

Pluto/New Horizons mission. The NESC conducted 

independent materials testing of the first-stage 

tank aluminum to define the local anisotropy contribution to the cracking, determine the minimum 

detectable flaw size, and crack propagation characteristics. In addition, the NESC performed 

detailed local iso-grid structural finite-element 

modeling to verify the contractor’s tank-level finite 

element modeling assumptions, and advised the 

Launch Services Program and the contractor on 

local/global and nonlinear structural finite element 

analysis methods.

Based on these analyses, the NESC provided the 

Program with a risk rationale for use of the firststage tank. The rationale for increased risk was 

relative to accepted engineering structural qualification practices, development of correlated mathematical models for qualified structure, and the 

development of flight rationale based on correlated 

mathematical models.

Atlas V Tank Failure Investigation

(Right) Atlas V launch vehicle 

Pluto/New Horizons satellite

ARC

NASA

Investigator Michael Winter (University of 

Stuttgart) fine-tuning slit spectrometer with 

assistance from Principal Investigator Peter 

Jenniskens of the Search for Extraterrestrial 

Intelligence Institute. SRC entry visible (right) 

above wing of NASA’s DC-8 Airborne

Laboratory.
TECHNICAL ACCOMPLISHMENTS

NESC 2006 TECHNICAL UPDATE 1

Phoenix Mars Mission Structural Safety Margins Analysis

Problem: The Phoenix Mars Mission will use 

many components of a spacecraft originally 

built for the 2001 Mars Lander, which was 

kept in storage after that mission was cancelled. Phoenix inherited its flight system from 

the Mars01 Project. Phoenix’s primary structure was analyzed and static tested in 1999 

to factors lower than typically used by NASA 

today. Safety factors and proof factors were 

less than specified by NASA-STD-5001.

NESC Contribution: The NESC performed an 

independent review for the Phoenix Project 

structural analysis processes. Recommendations were made, including reassessing margins against more current loads, which the 

Project accepted, to ensure structural integrity for all phases of the mission.

Phoenix Mars Mission Thruster

Valve Leak Analysis

Problem: The Project performed a hot-fire 

test to assess performance of the descent 

propulsion system and any interactions with 

the control system, showed that some of the 

thrusters leaked. The effort to identify the most 

probable cause of the thruster valve leak had 

been comprehensive and methodical. 

NESC Contribution: The NESC was requested to provide an independent assessment of the problem, the likely causes, and 

the Project’s plans for mitigation. Following 

detailed briefings from the Project the NESC 

team formulated recommendations for additional test/analysis to support the root cause 

identification process. The NESC also evaluated the performance of the Guidance, Navigation and Control (GNC) system to deliver 

the lander safely in the face of various leakage 

scenarios. The NESC team concluded that 

the Project had properly evaluated the risks, 

performed proper root cause analysis, and 

had a robust GNC design to accommodate 

any reasonable leakage scenarios. 

More specifically, the NESC found that absent 

a definitive root cause, there was reasonable 

evidence of limited valve degradation behavior. They also found that by implementing a 

strategy of evaluating terminal descent control cases, the Project is showing, through 

detailed Monte Carlo analysis, that adequate 

margins exist in the control of the spacecraft 

during descent.

The Phoenix Mars Mission satellite being prepared for an August 2007 launch. 

Hot fire test of Phoenix Mars Mission

descent propulsion system thrusters. 

NASA/JPL

NASA/JPL
18 NESC 2006 TECHNICAL UPDATE

Paul Mirabal, of the WSTF Hypervelocity Test Team, prepares a projectile representative of a micrometeorite or orbital debris that will be accelerated to approximately 

7 km/s and impacted on candidate CEV composite crew module materials.
TECHNICAL ACCOMPLISHMENTS

NESC 2006 TECHNICAL UPDATE 1

NESC Supporting the Constellation Program

NESC Director Ralph Roe, Jr. leads a panel discussion during the Smart Buyer kick-off meeting. Seated from left, Dr. Michael Griffin (NASA Administrator), Dr. Scott Horowitz (Associate Administrator for Exploration Systems), William Gerstenmaier (Associate Administrator for Space Operations), Doug Cooke (Deputy Associate Administrator for Exploration Systems) and Jeffrey Hanley (Constellation Program Manager).

Problem: The Associate Administrator for the 

Exploration Systems Mission Directorate requested that the NESC examine the aerodynamic drag sensitivity to the launch abort tower 

geometry parameters (length, diameter, nose 

bluntness) for both the Launch Abort System 

(LAS) and the Crew Launch Vehicle (CLV) with 

an alternate side mounted Service Module 

abort motor (referred to as the LAS-2B) configuration.

NESC Contribution: The NESC conducted a 

study using a combination of Computational 

Fluid Dynamics (CFD) analyses and wind tunnel testing. The results of the CFD study on the 

LAS tower geometry indicated that the primary 

geometric parameters affecting drag are the 

nose tip shape and the tower diameter. The 

LAS tower length was only a secondary parameter in the overall drag sensitivity, and a short 

tower design can be as effective as a longer 

tower to reduce the total drag. The results of 

the wind tunnel test indicated that the transonic 

and low supersonic drag associated with the 

Alternate LAS-2B strap-on motors was significantly higher than the baseline LAS tower configuration, and resulted in reduced payload-to 

-orbit capability of the CLV.

Crew Exploration Vehicle Launch Abort System Aero Evaluation

The NESC has been increasingly involved in 

supporting the Constellation Program’s Crew 

Exploration Vehicle (CEV) and Crew Launch 

Vehicle (CLV) Projects. This past January, a 

CEV Smart Buyer Team was formed at the request of the Constellation Program Manager to 

identify major design drivers and develop innovative design concepts for the CEV. The NESC 

organizational structure was used to bring together over 200 members with representation 

from each of NASA’s 10 Centers, Headquarters and industry. This intense 8-week effort 

not only produced a detailed design, but also 

demonstrated that NASA has the in-house capability to perform a multi-Center, integrated 

design. The NESC is now engaged in numerous assessments that have grown out of the 

Smart Buyer activity.

At right, Schlieren photos of CEV wind tunnel 

models of the Baseline Tower LAS (top) and 

the alternate Side Mount LAS (bottom).

LaRC

MSFC
TECHNICAL ACCOMPLISHMENTS

20 NESC 2006 TECHNICAL UPDATE

Crew Exploration Vehicle Crew Module Water Versus Land Landing Assessment 

Crew Exploration Vehicle Composite Crew Module Feasibility Study

Problem: While the Agency has significant 

experience with composite design and 

fabrication, there is a need to increase expertise in habitable composite spacecraft. 

Following the CEV Smart Buyer effort, the 

NESC took on the task of developing a 

composite CEV crew module as a means 

to assess the viability, of a composite design, while allowing the Agency to build on 

its composite structure expertise.

NESC Contribution: The spacecraft community had identified potential technical 

design drivers in the use of composite materials for the primary structure of the crew 

module and the NESC team evaluated the 

challenges and identified solutions or strategies for managing those technical challenges. The design drivers including mass, 

geometry, manufacturability, inspectability, 

repairability, damage tolerance, crashworthiness, and radiation shielding.

Three different composite concepts were 

identified: a geometrically stiffened laminate, a stiffened honeycomb sandwich, and 

a monocoque that integrates the aeroshell 

and pressure vessel into one thick layup. 

All three concepts had design, analysis, 

and sizing iterations and all three concepts 

were evaluated for the design drivers described before. The NESC concluded that 

preliminary composite solutions are technically competitive with the metallic solutions 

but the team did not quantify a significant 

discriminator driving toward a composite 

solution for the CEV crew module. 

Problem: The Systems Engineering & Integration Office within the Constellation 

Program requested that the NESC independently evaluate the risk and life cycle cost of 

landing the Crew Exploration Vehicle (CEV) 

on water versus land.

NESC Contribution: The NESC team based 

the analysis on the current CEV design, augmented by historical Apollo Command Module (CM) operational water landing and land 

impact testing. Quantitative risk analyses 

were performed for water and land landing 

vehicles. Potential system faults that could 

result in a contingency land impact were 

evaluated for the early phases of liftoff, including pad-abort, as well as the return entry, descent and landing phases. Life cycle 

costs of the two landing configurations were 

developed along with estimated recovery 

costs for both land and water recoveries. 

Landing risks to the crew were analyzed using landing simulations of CEV models and 

analysis of Apollo water and land impact 

test data. Analysis revealed that the relative 

risk to the crew is substantially lower by one 

or two orders of magnitude for a water-only 

vehicle design. Further, a contingency land 

landing in a water-only design increases risk 

to the crew. 

This latter conclusion was developed from 

analysis of the Apollo land impact tests. 

Apollo land impact accelerations, measured 

within the bodies of crash test dummies, 

were subjected to modern analyses techniques and revealed that the crew would 

likely sustain injury for most land impacts. 

Apollo impact data also revealed that simulated hypergolic fluids stored below the 

pressure vessel entered the crew cabin after 

some impacts. The NESC advised the Program to flight test a water landing capability 

prior to the nominal water landing capability 

and recommended several design features 

for the CEV Earth Landing System to mitigate risks to both the crew and vehicle while 

maximizing reusability. At termination of the 

Apollo Program, each subsystem lead engineer developed an engineering document 

which chronicled the design, development 

and testing of their subsystem. This data 

was invaluable when developing the CEV 

design. 

Lessons Learned: Detailed engineering descriptions of legacy systems and engineering decisions are invaluable when designing 

new systems and should be developed or 

compiled and formally archived at the end 

of a program. 

Stiffened honeycomb sandwich.

Renderings/GRC

LS-Dyna ® simulation of a CEV water landing.

Geometrically stiffened laminate Monocoque that integrates the aeroshell 

and pressure vessel.
TECHNICAL ACCOMPLISHMENTS

NESC 2006 TECHNICAL UPDATE 21

Problem: The Crew Launch Vehicle (CLV) 

pursued a risk mitigation approach to potentially unrecognized structural or control 

issues by soliciting an independent evaluation of the vehicle design by the NESC. 

The NESC was requested to identify barriers to vehicle design that require resolution 

prior to the investment of detailed analysis 

resources. 

NESC Contribution: The NESC effort identified structural and guidance, navigation 

and control design guidelines from historical and discipline reference information and 

other applicable design experience. These 

design principles were evaluated against 

the Exploration Systems Architecture Study 

(ESAS) base configuration, primarily at the 

maximum aerodynamic pressure conditions, 

in an effort to identify any design barriers. 

This design configuration was evaluated 

because models of the proposed five-segment solid propellant first stage/J-2X liquid 

propellant upper stage concept were not 

available and any issues identified would 

probably be a concern for any concept with 

a greater total vehicle height. The assessment did not reveal any “physical barriers” 

at the current maturity of the CLV design that 

would prohibit structural or control viability. 

However, a number of design watch topics 

were identified that include several vehicle 

control and first stage structural limits that 

require detailed investigation to determine 

their criticality. 

Lessons Learned: Proactive requests seeking independent technical review during 

the preliminary concept phases are invaluable risk mitigation initiatives at identifying 

critical design limitations. The recognition 

of configuration issues at the earliest opportunity in the design development vastly 

improves the likelihood of meeting mission 

objectives.

Problem: The Crew Launch Vehicle (CLV) is 

an aerodynamically unstable configuration 

with a center of pressure significantly forward of the center of gravity. Consequently, 

the pitch and yaw control provided by the 

first stage solid rocket motor nozzle will 

be critical for trajectory control. The CLV 

Reaction Control System (RCS), located 

near the aft end of the upper stage, will be 

the sole reaction method to all torque inducing forces acting upon the CLV during 

flight. The CLV Project requested that the 

NESC examine the known contributors to 

roll torque and assess if the current RCS 

concept provides sufficient margin to account for all design requirements. The CLV 

Project also solicited an independent assessment of methods for characterizing the 

magnitude of roll torque contributions from 

a full-scale horizontal static firing of the first 

stage motor.

NESC Contribution: The NESC did not 

identify any additional roll torque contributors beyond first and second stage systems 

tunnel, the first stage nozzle centerline offset, and solid propellant combustion products rotational flow. Examination of the 

thrust and propellant weight sizing analysis 

and associated assumptions and boundary conditions indicates the proposed RCS 

is adequately positioned and proportioned 

to counter predicted roll torque contributions. The NESC also provided specialized 

technical expertise in areas of Design of 

Experiments (DOE) and Response Surface 

Methodology in recommended changes to 

the test plan for attempted roll torque measurements during a full scale horizontal firing of the first stage motor.

Lessons Learned: Complex load measurement devices should be calibrated as 

a system with external inputs applied to 

sufficiently characterize the force response 

uncertainties. Failure to recognize the system load measuring attributes can result in 

error band uncertainties greater than the 

force measurements themselves.

MSFC

Schlieren photograph of supersonic flow 

around a model of the CLV. The NESC analyzed aerodynamic data as part of the assessment.

Crew Launch Vehicle Roll Torque Evaluation

Crew Launch Vehicle Ares Preliminary Design Assessment

Test firing of a Space Shuttle Solid Rocket 

Motor at ATK Thiokol in Promontory, Utah. 

T-97 test stand will be instrumented for roll 

torque measurements.

Photos/ATK Thiokol
featured technical paper

Space Shuttle Main Engine (SSME)
NESC 2006 TECHNICAL UPDATE 23

FEATURED TECHNICAL PAPER

American Institute of Aeronautics and Astronautics

1

Fracture Mechanics Analysis of LH2 Feed Line Flow Liners

Mark A. James

Presently, ALCOA Technical Center, ALCOA Center, PA 15069

David S. Dawicke

Analytical Services and Materials, Inc., Hampton, VA 23666

Matthew B. Brzowski

Presently, Lockheed Martin Commercial Space Systems, Newton, PA 18940

Ivatury S. Raju *, Kenny B. Elliott, and Charles E. Harris†

NASA Langley Research Center, Hampton, VA 23681

Inspections of the Space Shuttle Main Engine revealed fatigue cracks growing from slots

in the flow liner of the liquid hydrogen (LH2) feed lines. During flight, the flow liners

experience complex loading induced by flow of LH2 and the resonance characteristics of the

structure. The flow liners are made of Inconel 718 and had previously not been considered a

fracture critical component. However, fatigue failure of a flow liner could have catastrophic

effect on the Shuttle engines.

A fracture mechanics study was performed to determine if a damage tolerance approach

to life management was possible and to determine the sensitivity to the load spectra, material

properties, and crack size. The load spectra were derived separately from ground tests and

material properties were obtained from coupon tests. The stress-intensity factors for the

fatigue cracks were determined from a shell-dynamics approach that simulated the

dominant resonant frequencies. Life predictions were obtained using the NASGRO life

prediction code. The results indicated that adequate life could not be demonstrated for

initial crack lengths of the size that could be detected by traditional NDE techniques.

I. Introduction

URING an inspection of the Space Shuttle Main Engine, fatigue cracks were found in the flow liner of the

liquid hydrogen feed line. The flow liner was designed as a non-structural member that is used to maintain

laminar flow of the fuel in the feed line and has not been considered to be fracture critical. Because the flow liner is

not a structural member, it became apparent that the loading that initiated and propagated the fatigue cracks was

induced by the complex flow physics of the liquid hydrogen interacting with the resonant characteristics of the flow

liner. As a result, the analysis of the crack growth behavior required a multi-disciplinary approach that derived input

from a variety of sources, including flow physics, dynamics, existing and new experimental results, destructive and

non-destructive evaluation results, and existing and new fracture mechanics analyses. Detailed investigations and

laboratory testing indicated that the vibration could be characterized by several dominant resonant frequencies, one

during each of the various major stages of launch and flight into orbit [1].

This paper describes a fracture mechanics-based evaluation that was undertaken to determine if a damage

tolerance approach to life management was possible and to determine sensitivity to loads, material properties, and

crack size. The approach used was to develop a fracture mechanics-based stress-intensity solution for the various

crack growth scenarios. Then, the loading derived in cooperation with the flow physics and dynamics teams was

applied. Life predictions were made using the fracture mechanics software NASGRO [2]. Several initial crack sizes

were considered, and for each of these crack sizes, the life prediction calculations were performed. Several ranges

of the magnitude of welding residual stresses, material crack growth rate characteristics, and other salient variables

 

*

 Fellow, AIAA

†

 Associate Fellow, AIAA

D

This paper was presented at the 47th AIAA Structures Dynamics and 

Materials conference in Newport, Rhode Island, May 1-4, 2006
24 NESC 2006 TECHNICAL UPDAT

FEATURED TECHNICAL PAPER

24 NESC 2006 TECHNICAL UPDAT

American Institute of Aeronautics and Astronautics

2

were also considered. For each of these combinations, the life prediction calculations were performed to provide

insight into flight safety, inspection intervals, and inspection criteria.

II. Flow Liner Configurations

The upstream liner is a cylindrical shell and the downstream liner is a doubly curved cylindrical shell; both are

about 12 inches in diameter and about 3 inches wide by about 0.05 inches thick, (see Figure 1). The liners are each

welded at opposite ends (as indicated by the green hash marks of Figure 1) of the main structure at a joint in the feed

line, and the liners overlap in the middle to maintain the laminar flow through the joint. Each flow liner has slots

oriented in the direction of the flow. Fatigue cracks initiated and propagated from the slots both axially at locations

A and D and circumferentially at locations B and C in Figure 2.

Cracks that initiate at locations A and D have been shown to be self limiting [1]. At location A, the crack is

growing from the thin sheet liner into the thick structure that is near the weld, and thus the driving force is reduced.

However, the residual stresses are highest at this location because of its proximity to the weld. For location D,

detailed shell finite element analyses showed that crack growth away from a slot towards the edge of the liner

initially increases, but then decreases because the structure resonance changes with crack growth. The two

circumferential locations, locations B and C, have approximately the same stresses, but location B has a higher

residual stress because it is closer to the weld. The current investigation selected location B for detailed examination

because the residual stresses make location B more critical than location C, and the crack growth does not appear to

be self limiting like at locations A and D.

Failure of a circumferential crack in a liner occurs when the crack has grown across the entire ligament (a length

of 0.75 in.). A completely cracked ligament can form a tab that can break off and get ingested into the engine. Such

an ingestion can cause catastrophic damage to the engine and the Shuttle. The current analysis defines failure when

the circumferential crack grows to a length of 0.6 in. This is a slightly more conservative assumption than the crack

growth across the complete ligament length of 0.75 in. (The difference in lives for a crack length of 0.6 in. in

comparison to 0.75 in. is shown to be negligible [1].)

III. Loading

The flow liners are subjected to complex loading due to the resonant response to the liquid hydrogen flow field.

The computational fluid dynamics (CFD) and the flow-physics teams investigated large scale unsteady motions of

the mean flow, back flow, and changes in the acoustic modes. The loads and the dynamics team, utilizing flow tests

performed at Stennis Space Center [1] intended to simulate flight conditions, as well as flow-physics/CFD results,

identified a predominant 3500 Hz complex 9ND mode (complex here refers to both membrane and bending modes

acting simultaneously) for the upstream liner and 3ND (1650 Hz), C4ND (3300 Hz), and 5ND (1070 Hz) modes for

the downstream liners. (jND here refers to the j-nodal diameter mode shape, and C denotes complex mode shape.)

Weld A

B B

C

D

C

Mid-ligament strain location

0.75 in.

Figure 2. Schematic of cracking locations around a typical

slot and locations of strain measurement.

Figure 1. Upstream and downstream

flow liners.
NESC 2006 TECHNICAL UPDATE 2

FEATURED TECHNICAL PAPER

American Institute of Aeronautics and Astronautics

3

Based on the test data and analytical results, fatigue-loading spectra were developed [1] to simulate the loads

experienced during engine operation in one flight. (In one flight the engines run for about 500 seconds). These

spectra are used in the current fracture mechanics analyses.

The loading spectra are based on strains measured in the flow liner test article at the mid ligament locations

between the slots (see Figure 2) during tests performed at Stennis Space Center [1]. These strains are used as scale

factors on the loading spectra to evaluate the stress-intensity factors. A high level of uncertainty exists in the

magnitude and sequence of the flight spectra due to the complexity of the flow field and reliance on ground

simulations. The details of this approach were described in Reference 1.

IV. Life Prediction Modeling

The life prediction code NASGRO Version 4.11 [2] is used for all crack growth predictions. The stress-intensity

factors are entered using a 1-D data table (DT01) option. The user dimension, D, is 0.75 in. (the width between the

slots). The loading spectra are entered as separate load cases for mean bending, alternating bending, and alternating

membrane. The load cases are superimposed in NASGRO during the life calculations. All life calculations are

performed using the NASGRO non-interaction model to ensure the most conservative life calculations. The noninteraction model performs linear accumulated damage crack growth and deactivates plasticity induced retardation

models.

Load ratio (R) effects, such as plasticity or roughness-induced crack closure, are extrinsic effects that decrease

the crack growth rate by reducing the amount of damage caused by the cyclic loading and thus extend life. These

effects are strongly dependent on the order and magnitude of loads in the flight spectra. The inclusion of crack

closure into a life prediction analysis will produce less conservative results and cannot be justified when the

uncertainty of load spectra is high. The loading used in this analysis had a high level of uncertainty, thus the load

ratio effects were excluded from the life analysis.

For positive load ratios, the crack growth rate relationship is described by a modified form of the NASGRO

equation that results from enabling the load ratio bypass option:

q

c

p

n th

K

K

K

K C K

dN

da















 





 







  

=

max 1

1

 (R  0) (1)

Where K is the stress-intensity factor range, Kmax is the maximum stress-intensity factor, Kc is the fracture

toughness, Kth is the threshold stress-intensity factor range, and C, n, p, and q are curve fit (Paris-like) parameters

[2]. In Eq. (1), the entire K range contributes to crack growth. The Kth term is still a function of R and allows Eq.

(1) to fit the high R data near threshold.

For negative load ratios, the NASGRO equation reduces to:

q

c

p

n th

K

K

K

K C K

dN

da















 





 







  

=

max

max

1

1

 (R < 0) (2)

Thus, for negative load ratios, only the tensile part of the load cycle is active and the crack is assumed to be closed

during the compressive part of the load cycle. The loading of the flow liners is predominantly high mean stress

loading with an alternating component that is smaller than the mean stress. Thus, Eq. (2) will have an insignificant

influence on the NASGRO life predictions for the flow liner loading spectra.

V. Material and Material Model

The flow liners are constructed using Inconel 718 and operate at a temperature of -423 F. The material data

used for the analyses was generated using liquid helium (LHe @ -423° F) by researchers and engineers at NASA

Marshall Space Flight Center. The liquid helium test was performed using a temperature controlled spray technique
26 NESC 2006 TECHNICAL UPDAT

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4

that allowed simulation of a liquid hydrogen temperature using the inert helium. Tests were performed to

characterize the closure free (at or above high load ratios of R= 0.7) intrinsic fatigue crack growth response over a

wide range of rates from threshold to fracture. Tests were also performed to characterize the low load ratio (R=0.1)

in the Paris regime to establish the effect of plasticity induced closure; however, as mentioned above, only the high

load ratio results were used in the life calculations.

The loading for the orbiter flow liner is approximated by spectra developed from flow tests intended to simulate

flight conditions; however, a high level of uncertainty exists for the actual loading. The fracture mechanics-based

life predictions rely on accurate loads, and in particular, an accurate description of the load ratio R (the ratio of

minimum to maximum load). High load ratio crack growth rate data describes intrinsic material behavior. Low

load ratio crack growth rate data describes material behavior that is affected by extrinsic effects such as plasticity

induced crack closure. These extrinsic effects can have a significant influence on crack growth rate, thus on the life

predictions as well. For example, R = 0.1 data commonly has crack growth rates that are a factor of 5 lower than R

= 0.9 data at the same value of K. The inclusion of load ratio effects could increase the calculated fatigue life

(making predictions less conservative) in a manner that cannot be supported due to uncertainties in the assumed

loading. Thus, the crack growth rate behavior for all load

ratios is forced to coincide with the R = 0.9 crack growth

rate curve approaching threshold.

Figure 3 is a schematic of the material model for the

crack growth rate data. The two NASGRO parameters,

Smax/Flow = 1 and Alpha = 5.845, are used to minimize

the load ratio effect. This is referred to as the NASGRO

load ratio bypass option. Three additional NASGRO

parameters, p, DK1, and Cth, control the fit to the high

load ratio data in the threshold regime. The curves shown

in Figure 3 exhibit no load ratio effect at threshold. In

addition, the ‘Cth value option’ was set to ‘mat’l file value

throughout’ to enforce that the fit to the high load ratio

data was consistent throughout the analysis. The Kmax

(near-fracture) behavior was allowed to maintain the load

ratio influences, as indicated by the separation of the

curves at large K values, as in Figure 3.

VI. Threshold and Crack Size Considerations

Experimental evidence from ground test articles indicate that the flow liner cracks initiate as corner cracks from

surface defects that are of the size of the material microstructural features (e.g., grain size). Linear elastic fracture

mechanics (LEFM) may not be applicable for cracks that are small relative to the material microstructure. Two

fundamental limitations for small crack modeling are: (1) microstructurally and mechanically small cracks cannot be

represented by simple continuum LEFM crack models, and (2) microstructurally small cracks may have different

threshold behavior than the long crack material data available for the material models. To overcome the first of

these limitations, the crack size must be large enough that the crack can be approximated as a continuum crack. A

continuum crack has a cyclic plastic zone that is small compared to the length of the crack, but large relative to the

size of the microstructural features. A crack that has a length greater than 10 grain sizes can generally be considered

a continuum crack. Inconel 718 has reported grain sizes of 5 – 40 m (0.0002 – 0.0015 in.) [1]. This grain size

would require that a crack be 50 – 400 m (0.002 – 0.015 in.) long to be considered a continuum crack. Therefore,

the analyses consider cracks larger than 0.02 in. to maintain LEFM applicability.

VII. Approach for Stress-Intensity Factors

A shell dynamics-based approach is used in the evaluation of stress-intensity factors. In this approach, a modal

dynamic analysis of an uncracked shell model of a flow liner is performed. The representative mode of excitation in

the shell is identified, a crack is introduced into the model, and the strain energy release rates at the crack tip are

calculated using the eigenvector of the corresponding shell mode. The stress-intensity factors are then evaluated

from the strain energy release rates using the deformed mode shapes that the liner experiences.

R = 0.9

K

R = 0.5

R = 0.1

da/dN

Kth

R = 0.9

K

R = 0.5

R = 0.1

da/dN

Kth

Figure 3. Notational material model for the crack

growth rate data.
NESC 2006 TECHNICAL UPDATE 2

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5

A typical shell finite element model of the upstream liner is shown in Figure 4. Using this model, a modal

analysis is performed to isolate the dominant mode shapes (i.e. C9ND for the upstream liner). The deformed shape

of the upstream liner, based on the eigenvector corresponding to this mode shape, is shown in Figure 5. Typical

values of the normalized axial stress at the mid-ligament locations are plotted in Figure 6 for all of the ligaments an

uncracked flow liner. As

expected, the distribution shows

a certain amount of cyclic

symmetry for the C9ND mode

shape. Similarly, the axial

stresses at location B in all the

slots are examined and the slot

with the highest stress at

location B is isolated. (There

may be more than one slot with

the same peak stress. In such a

case, any one of those slots is

chosen). The slot with the

highest axial stress at location B

is at  = 340°. A

circumferential crack is

introduced at this slot, as shown

schematically in Figure 7, and a

0.75 in.

 (a) Typical full liner model. (b) Typical refined mesh near the crack.

Figure 4. Typical shell finite element model.

Crack Location

(maximum Location B strain)

Far Field

Mid-Ligament

Location

Figure 5. Far-field ligament for scaling the eigen-value results.

-1.0

-0.5

0.0

0.5

1.0

0 90 180 270 360

Angle,  , degrees

Normalized Axial Stress



Mid-ligament

locations

-1.0

-0.5

0.0

0.5

1.0

0 90 180 270 360

Angle,  , degrees

Normalized Axial Stress



Mid-ligament

locations

Figure 6. Typical normalized axial mid-ligament stress for the C9ND mode

shape.
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new shell finite element model with the

crack is developed and re-analyzed.

The mode shape corresponding to the

C9ND mode is isolated for the new

model with the crack. The quantifiable

values of the liner deformations are

obtained by scaling the eigenvector with

the strain gage data collected in previous

ground flow liner tests [1]. The scaling

process matches the maximum midligament strain to strain gage

measurements made at the same location.

The C9ND analysis found three midligament locations with nearly the same

peak value, so the scaling is based on the

one that is farthest ( = 180°) from the slot with the crack. This location is used to scale all deformations and forces

for each crack length analyzed. The process is repeated for the downstream liner.

VIII. Stress-Intensity Factors

The stress-intensity factors are calculated from the strain energy release rates using virtual crack closure

techniques, as shown in Figure 8 [5, 6]. Fx, Fy, and Fz are the respective forces at the crack-tip node in the x-, y-,

and z-directions; Mx, My, and Mz are the respective moments about the x-, y-, and z-directions; ux, uy, and uz are the

respective displacements at a node behind the crack-tip along the x-, y-, and z-directions; and x, y, and z are the

respective rotations at a node

behind the crack about the x-,

y-, and z-directions. t is the

thickness of the shell and c

is the length of the element

behind the crack tip. The

finite element models have a

fine mesh in the crack region

with elements of the same

size both behind and ahead of

the crack tip (element size c = 0.005 in, as shown in Figures 4 and 8).

The individual mode stress-intensity factors are calculated from the energy release rates as

III III

II II

I I

K EG

K EG

K EG

=

=

=

(3)

where E is the Young’s modulus.

In addition, a total stress-intensity factor is calculated from the total energy release rate.

( ) KTOTAL = E GI+ GII + GIII (4)

Figure 9 presents stress-intensity factor as a function of crack length calculated for the single active mode

(C9ND) in the upstream liner. For each crack length, the C9ND mode shape is isolated and the stress-intensity

factors are calculated from the energy release rates. The values presented in this figure are scaled to a unit value of

far-field mid-ligament stress. Mode I is nearly constant and is dominant for crack lengths less than 0.3 in. (where

most of the fatigue life is accumulated). The Mode III contributions increase with increasing crack length with the

Mode III about equal to the Mode I component for crack lengths greater than 0.4 in. The Mode II component is

insignificant.

Crack Location

(maximum Location B strain)

Far Field

Mid-Ligament

Location

Weld

c

Figure 7. Schematic showing the circumferential crack at the slot

with the highest location B stress.

G = [F (u - u )] 1

2 c II  

1 2

G = [F (u - u )  ] 1

2 c t II  

1 2



G = [F (u - u ) + M ( - )] 1

III 2  y y y

1 2 1 2

G = z z z [F (u - u ) + M ( - )] 1

III 2  y y y

1 2 1 2

z z z

1

2 c t III y y y

1 2 1 2

z z z

G = [F (u - u ) + M (- ) + M (- )]

2



1

2 c I z z z

1 2 1 2 1

y y  G = y  [F (u - u ) + M (- ) + M (- )]

2



1

2 c t I z z z

1 2 1 2 1

y y  y 

1

2 c I z z z

1 2 1 2 1

y y  u y 

1

z

u

2

z

Fz

z y



B

c

u

1

z

u

2

z

Fz

z y



t

c

G = [F (u - u )] 1

2 c II  

1 2

G = [F (u - u )  ] 1

2 c t II  

1 2



G = [F (u - u ) + M ( - )] 1

III 2  y y y

1 2 1 2

G = z z z [F (u - u ) + M ( - )] 1

III 2  y y y

1 2 1 2

z z z

1

2 c t III y y y

1 2 1 2

z z z

G = [F (u - u ) + M (- ) + M (- )]

2



1

2 c I z z z

1 2 1 2 1

y y  G = y  [F (u - u ) + M (- ) + M (- )]

2



1

2 c t I z z z

1 2 1 2 1

y y  y 

1

2 c I z z z

1 2 1 2 1

y y  u y 

1

z

u

2

z

Fz

z y



B

c

u

1

z

u

2

z

Fz

z y



t

c

u

1

z

u

2

z

Fz

z y



B

c

u

1

z

u

2

z

Fz

z y



t

c

Figure 8. Schematic showing crack tip coordinate system and energy release

rate equations [6].
NESC 2006 TECHNICAL UPDATE 2

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7

The largest crack length considered in the

shell-dynamic analysis for this comparison and for

the life predictions is 0.6 in. because longer crack

lengths exhibit a considerable Mode III component

of the stress-intensity factor. The material data

used to characterize crack growth behavior was

derived from Mode I crack growth rate tests and is

not necessarily appropriate for Mode III dominated

crack growth. Most of the life is consumed while

the crack is a corner crack (or short through-thethickness crack), so stopping the life prediction at

0.6 in. is conservative and makes little difference

to the overall calculated life.

The analysis presented above for the upstream

liner is repeated for the downstream liner. Recall

that in the downstream liner there are three modes,

3ND, C4ND, and 5ND, that are active. The stressintensity factors are calculated for various crack

lengths using the shell-dynamics approach for the

three modes and are presented in Figures 10 - 12.

The stress-intensity factors for the four modes

considered show wide ranging behavior in Figures

9 - 12. In all cases, when the crack is small

(compared to the ligament), the stress-intensity

factor is dominated by the Mode I value. However,

as crack growth and load redistribution occur, each

of the four modes responds differently. In all of the

cases, the Mode I stress-intensity factor continues

to contribute to a varying degree. The C9ND shape

leads to near equal contributions of Modes I and

III that monotonically increase, with an

insignificant Mode II. In contrast, the total stressintensity factor for the C4ND shape decreases after

a peak value that occurs at about 0.1 in. of growth.

These results indicate that modal deformations can

lead to complex fracture mechanics behavior.

0.0

0.2

0.4

0.6

0.8

1.0

0.0 0.1 0.2 0.3 0.4 0.5 0.6

Crack Length (inch)

K (ksi inch 1/2 )

Ktotal

KI

KIII

KII

Figure 9. Stress-intensity factors for the shell-dynamics

model for the C9ND mode – upstream liner.

0.0

0.1

0.2

0.3

0.4

0.5

0.0 0.1 0.2 0.3 0.4 0.5 0.6

Crack Length (inch)

K (ksi inch1/2)

Ktotal

KI

KII

KIII

Figure 10. Stress-intensity factors for the shell-dynamics

model for the 3ND mode – downstream liner.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0.0 0.1 0.2 0.3 0.4 0.5 0.6

Crack Length (inch)

K (ksi inch1/2)

Ktotal

KIII

KII

KI

Figure 11. Stress-intensity factors for the shelldynamics model for the C4ND mode – downstream

liner.

0.0

0.1

0.2

0.3

0.4

0.5

0.0 0.1 0.2 0.3 0.4 0.5 0.6

Crack Length (inch)

K (ksi inch 1/2 )

Ktotal

KIII

KII

KI

Figure 12. Stress-intensity factors for the shelldynamics model for the 5ND mode – downstream

liner.
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IX. Results

The shell-dynamics KTOTAL stress-intensity factors are used in the NASGRO calculations. The loading spectra

are calculated as mid-ligament stresses and are used to scale the modal stress-intensity factor results. These new

results are then used to calculate fatigue lives for both liners at location B, as summarized in Table 1. An alternate

procedure, termed the “transfer factor (TF)

approach”, is used to evaluate the life of

the liners in Reference 1, and the results

are included in this table for comparison.

The transfer factor approach is very

conservative and predicts lives of less than

one flight.

As seen from this table, the shelldynamic approach predicts longer life for

the upstream liner compared to when the

TF approach is used. The predicted fatigue

life for the downstream liner is also longer

using the shell-dynamics approach.

However, even with an initial crack length

as small as 0.02 in., failure of the

downstream liner is predicted in about 1

flight using the shell-dynamics approach.

These results suggest that either (or both)

the uncertainty in the load spectra leads to

overly conservative life predictions or that

the structure cannot tolerate cracks that can

be found with traditional detection

techniques. The flow liner cracking problem can be mitigated using any of the three following approaches:

1. Refine the load analysis to reduce the uncertainty in the load spectra, allowing the analysis to take

advantage of the benefits of load sequence effects.

2. Refine the fatigue crack growth to account for the non-LEFM behavior of small cracks.

3. Develop inspection techniques that allow for the reliable detection of smaller fatigue cracks (<< 0.02 in.)

and a process for eliminating the cracks from the structure.

The approach 3 above was chosen and the flow liner fatigue cracking issue was resolved by developing an

inspection process that used a high resolution surface replication technique to detect cracks as small as 0.002 in.

The process involved replicating a mold of the slot surface and examining the mold with a high magnification

scanning electron microscope. The flow liners in the fleet of the three orbiters were examined (684 individual slots)

and 50 cracks with lengths of 0.002 in. to 0.05 in. were detected. The texture of the slot surfaces was also examined

and locations with the potential to initiate cracks (i.e. scratches and dents) were identified. The cracks and locations

with surface damage were polished in an attempt to return the structure to a pristine condition. The flow liners were

inspected with the surface replication technique after polishing and again after the Shuttle flight. No new cracks or

additional surface damage were detected.

X. Concluding Remarks

A fracture mechanics-based study is performed for cracks detected in the flow liners in Space Shuttle Main

Engines. The flow liners experience complex loading induced by complex flow and the resonance characteristics of

the liner. A circumferential crack at the edge of the slot near the weld is considered because this location

experiences the highest combined stresses. Fatigue loading spectra are developed by the loads and dynamics team,

and these spectra are used to evaluate the life of the liners.

A shell-dynamics approach is used to simulate the dominant resonant frequencies experienced by the liner. The

modes that correspond to these frequencies are prescribed on the shell, and the slot with the highest stress is

identified. A circumferential crack is assumed to exist at the edge of this slot and near the weld. The stress-intensity

Table 1. Predicted lives for upstream and downstream liners.

(Crack assumed at location B, LHe crack growth data at -423° F)

Upstream Liner

Life (flights)

Initial Crack

Length, ci (in)

Shell-Dynamics

Approach TF Approach

0.075 21 0.1

0.02 39 0.3

Downstream Liner

Life (flights)

Initial Crack

Length, ci (in)

Shell Dynamics

Approach TF Approach

0.075 0.2 0.1

0.02 1.0 0.2
NESC 2006 TECHNICAL UPDATE 31

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9

factor for this crack is evaluated using the dominant mode shapes. The stress-intensity versus crack length for the

liner is evaluated. This stress-intensity factor-vs-crack length curve is used with the fatigue spectra to evaluate the

life of the flow liners using NASGRO. While the upstream liner shows adequate life, the downstream liner results

show that failure will occur within one flight for an initial crack length of 0.075 in.

The flow liner fatigue cracking issue was resolved by developing an inspection process that used a high

resolution surface replication technique to detect cracks as small as 0.002 in. The process involved making a mold

of the slot surface and examining the mold with a high magnification scanning electron microscope. The detected

cracks and locations with surface damage were polished to return the structure to a pristine condition. The flow

liners were inspected with the surface replication technique after polishing and again after a Shuttle flight. The flow

liners in the orbiter showed no new cracks or additional surface damage.

References 1 Harris, C. E., et al., “Orbiter LH2 Feedline Flowliner Cracking Problem,” NASA/TM-2005-213787/Version 1.0, NESCRpP-04-11/04-004-E, July 2005. 2 NASGRO Version 4.11 Manual, Southwest Research Institute, February 2004. 3 Metallic Materials Properties Development and Standardization (MMPDS), DOT/FAA/AR-MMPDS-01, Federal Aviation

Administration, Office of Aviation Research, Washington D.C., January 2003. 4 Newman, Jr., J.C. and Raju, I.S., “Stress-intensity Factor Equations for Cracks in Three-Dimensional Finite Bodies

Subjected to Tension and Bending Loads,” Computational Methods in Mechanics of Fracture, S.N. Atluri, Ed., Elsevier, 1986,

pp. 311-334. 5 Rybicki, E.F. and Kanninen, M.F., “A Finite Element Calculation of Stress Intensity Factors by a Modified Crack Closure

Integral,” Eng. Fracture Mech., Vol. 9, pp. 931-938, 1977. 6 Wang, J.T., Raju, I.S., Davila, G., and Sleight, D., “Computation of Strain Energy Release Rates for Skin-Stiffener Debonds

Modeled with Plate Elements,” 34th AIAA SDM Conference, La Jolla, California (April 19-21, 1993).
NESC highlights from the centers

Rollback of Discovery to the Vehicle Assembly 

Building to replace the External Tank.

Rollback of Discovery to the Vehicle Assembly 

.
NESC 2006 TECHNICAL UPDATE 33

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

Ames Research Center (ARC) provided expertise to a variety of NESC assessments with 

high activity in areas of flight sciences, information technology, and human factors.

Flight Sciences

ARC supported the NESC team’s independent review of the decision to remove the 

Protuberance Air Load (PAL) Ramp from the 

Space Shuttle External Tank by providing essential experience in wind tunnel testing, unsteady aerodynamics, and computational fluid 

dynamics. ARC also supported the NESC 

Orbiter tile gap filler activity 

via thermal protection system expertise through the 

engineers that help create 

the original gap fillers. As 

members of the NESC peer review team for 

the CEV Aerosciences Project, ARC personnel 

assessed the computational and experimental plans for developing the aerodynamic and 

aerothermodynamic databases for the CEV 

design. ARC also led the NESC-sponsored 

Stardust entry observations.

Information Technology

ARC researchers supported NESC efforts in 

the area of data mining and trending. They 

developed new algorithms and processes 

for the Recurring Anomaly Detection System 

(ReADS), designed to automatically detect 

recurring anomalies from Problem Reporting 

and Corrective Action databases. During initial testing, the tool found all but one recurring anomaly previously identified by subject 

experts and discovered several new ones. 

These and other results were presented at 

the Data Mining Applications in Aeronautics 

and Space Exploration Workshop hosted at 

ARC. As participants in the NESC-organized 

CEV Smart Buyer Team, ARC provided expertise in Integrated System Health Management (ISHM) by assessing the relationship 

of ISHM capability to avionic and software 

requirements. 

Human Factors

The NESC Discipline Expert for Human Factors is resident at ARC. ARC Human Factors 

experts from the NESC Human Factors TDT 

were part of several NESC assessment teams 

including CEV Smart Buyer and the follow-on 

CEV Water versus Land Landing trade study. 

Also arranged through the NESC TDT organizational structure, ARC personnel were members of the Genesis and ASTRO-E2 Mishap 

Investigation Boards uncovering human factor 

contributions to the accidents. ARC personnel 

also examined the installation procedures for 

using LoctiteTM on fasteners to improve their 

reliable use on the ISS.

In addition to the broad discipline areas described above, ARC scientists and engineers 

were part of several other NESC assessment 

teams: Reliability for Space Systems, Composite Crew Module, and Field Programmable 

Gate Array manufacturing standards. Finally, 

the ARC Supercomputing Facility was used 

for computer intensive simulations on several 

NESC assessments. 

AMES RESEARCH CENTER

ARC

DFRC

WFF

JSC

SSC

GSFC

KSC

MSFC

NASA HQ

GRC

WSTF

LaRC

JPL

ARC at a glance

4 %

2

n NESC 

employees at 

ARC

n Percent of 

ARC technical 

work force who 

supported NESC 

assessments

Dr. Dean

Kontinos

NESC’s Chief

Engineer at ARC

Ian Fernandez and Hiro Miura from ARC discuss merits of a geometrically stiffened carbon 

composite Crew Exploration Vehicle Crew Module design concept. The ARC 80 x 120 ft wind 

tunnel is in the background.

ARC

ARC

Dr. Franziska Harms of the University of Stuttgart, Germany, and Dr. George Raiche of NASA 

Ames Research Center install a cooled CCD camera onboard NASA’s DC-8 Airborne Laboratory. 
34 NESC 2006 TECHNICAL UPDAT

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

Dryden Flight Research Center (DFRC) employees contributed to many NESC multidiscipline teams in addressing the Agency’s 

toughest problems. DRFC acting Chief Engineer, Brad Flick, believes the NESC helps 

to ensure technical excellence. “The strength 

of the NESC lies in the network of disciplinary technical experts across the Agency, 

which can bring their collective knowledge 

and access to unique tools and test facilities together to solve problems that might 

otherwise go unsolved. The significant contributions by DFRC’s Mike 

Kehoe and Dr. Kajal Gupta 

to the [NESC] analysis of 

the acoustic environment in 

the SOFIA aircraft is an example of Dryden’s participation in efforts that 

will ultimately lead to the safe and successful 

accomplishment of a NASA mission.” 

This year DFRC scientists and engineers supported NESC assessments in the areas of 

Space Shuttle safety, the Constellation Program, and Nondestructive Evaluation.

Space Shuttle Safety

Dr. Kajal Gupta was a member of several multiCenter team assessments of issues such as 

the Space Shuttle Solid Rocket Booster holddown post stud hang-up, the Space Shuttle’s 

External Tank alternative Ice Frost Ramp design concept assessment, the Space Shuttle 

wing leading edge impact dynamic analysis 

assessment and the Space Shuttle Protuberance Air Loads (PAL) Ramp removal feasibility assessment. NESC assessments have allowed Dr. Gupta to collaborate effectively with 

other national experts in and outside of NASA. 

His continued activities in the NESC also gave 

him a broad view of technical problems facing 

NASA. Other researchers involved have appreciated the One NASA concept in building 

a consensus on their findings.

Constellation Program

Former Space Shuttle and Apollo astronaut 

Vance Brand, who serves as Dryden’s Deputy 

Associate Director for Programs, provided 

his expertise to the NESC in the evaluation 

of land versus water landings for the Crew 

Exploration Vehicle, participating as a member of the assessment’s Apollo peer review 

team. In addition, DFRC also provided testing 

and system engineering expertise to the CEV 

Smart Buyer Team through participation by 

Vicki Regenie.

Nondestructive Evaluation

When it comes to embedding fiber optics 

in composite materials, that’s a specialty of 

Dryden’s Dr. Lance Richards, who is providing 

consultation to an Agency working group responsible for testing Composite Overwrapped 

Pressure Vessels, or COPVs. As a member of 

the NESC Nondestructive Evaluation TDT, Dr. 

Richards is concerned with nondestructive 

evaluation and structural health monitoring. 

Richards has consulted with multi-Agency 

teams regarding sensor installation and measurement interpretation.

DRYDEN FLIGHT RESEARCH CENTER

DFRC at a glance

2

2.8 %

n NESC 

employees at 

DFRC

n Percent of 

DFRC technical 

work force who 

supported

NESC assessments

Dr. James 

Stewart

NESC’s Chief

Engineer at DFRC

ARC

DFRC

WFF

JSC

SSC

GSFC

KSC

MSFC

NASA HQ

GRC

WSTF

LaRC

JPL

NESC Dryden Chief Engineer Dr. James Stewart and Acting Dryden Chief Engineer Brad 

Flick agree that the NESC plays a key role.

Dr. Kajal Gupta has contributed to several 

NESC assessments for Space Shuttle safety. 

Dr. Lance Richards, Senior Research 

Engineer describes an embedded fiber optic 

sensor system for composite materials. 
NESC 2006 TECHNICAL UPDATE 3

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

The NESC efforts this year at the Glenn Research Center (GRC) included solid research 

into Space Shuttle safety, participation in the 

Smart Buyer activity and exciting new efforts 

in the Constellation Program. 

Space Shuttle Safety

The NESC formed a Bracket Ice Mitigation 

Team to investigate methods to reduce or 

eliminate the ice from the brackets that hold 

the Liquid Oxygen (LOX) feedline to the ET. 

As a team member, GRC engineers worked 

on the development of a 

flexible foam solution that 

helps prevent ice formation and also allows for the 

movement of the feedline 

during tanking, pre-pressurization, launch, 

and ascent. GRC is responsible for the 

thermal and mechanical testing and evaluation of candidate materials to eliminate weak 

performers and to establish guidelines for potential suppliers. Several types of foam were 

characterized and tested in GRC’s full-scale 

feedline test article that mimics the bracket 

movements relative to the feedline.

Smart Buyer Participation 

Over 40 GRC employees participated on the 

CEV Smart Buyer Team and hosted the Service Module design activity led by Rick Manella, Engineering & Technical Services Directorate (ETSD), and Derrick Cheston, NESC Chief 

Engineer at GRC. The team performed four 

separate design iterations and presented two 

design recommendations to the Constellation 

Program and NASA Administrator. GRC personnel led the integration of key disciplines. 

James Soeder, Advanced Electrical Systems 

Branch, led electrical power, while Rex Delventhal, Constellation Systems Project Office, 

led the propulsion element. 

Constellation Program

GRC is providing support to the Constellation 

Program by performing risk analysis in association with the landing strategy for the Crew 

Exploration Vehicle. GRC has developed vehicle and landing simulations to examine the 

stresses on the vehicle and accelerations to 

the crew during landing on water and land. 

GRC ETSD employees Paul Salano and Chip 

Redding also led the mechanical system design for the Crew Module

GLENN RESEARCH CENTER

GRC at a glance

n NESC 

employees at 

GRC

n Percent of 

GRC technical 

work force who 

supported

NESC assessments

8.4 %

1

Derrick Cheston

NESC’s Chief

Engineer at GRC

JSC

SSC

KSC

MSFC

GRC

WSTF

LaRC

JPL

“ ...when I joined the Agency, I never 

imagined in my wildest dreams that 

I’d be contributing directly to the 

Shuttle Program at this stage of

my career. ” – Dr. Lynn Capadona,

member of the Bracket Ice

Mitigation Team at GRC

PHOTOS/GRC

NESC Chief Engineer, Derrick Cheston, (far left), NESC Director, Ralph Roe, Jr. (on Cheston’s 

left) and GRC team members participate in Smart Buyer activities from GRC’s Integrated Design 

and Analysis Center (IDAC). The GRC was tied to design centers at GSFC, JSC and MSFC.

Dr. Lynn Capadona in the Orbiter Processing 

Facility at KSC.

Dr. Charles Lawrence, describes NESC activities underway at GRC.
36 NESC 2006 TECHNICAL UPDAT

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

The Goddard Space Flight Center (GSFC) 

participated in a wide range of NESC activities, using both NESC personnel resident at 

GSFC, and matrixed GSFC personnel supporting NESC activities. The NESC Discipline 

Experts for Guidance, Navigation & Control 

(GNC), Power and Avionics and Software are 

resident at GSFC. Over the last year, Goddard 

personnel have been instrumental participants on many of the NESC teams investigating issues in Space Operations and Science 

Mission Directorates.

Space Operations

GSFC scientists and engineers focused on the External Tank (ET) liquid oxygen 

feedline and bracket ice prevention efforts, 

ET Engine Cut-off sensor performance, Orbiter Rudder/Speed Brake and Body Flap Actuator lubrication, and tin whiskers in Orbiter 

avionics boxes. GSFC also supported NESC 

teams investigating issues for the ISS, including: the Control Moment Gyro-1 failure, Corona effect on an S-band RF electronics box, 

fiber optic workmanship, Station-to-Orbiter 

Power Transfer Unit reliability, the safety of the 

Orbital Repair Maneuver, and the ISS camera 

shutdown anomaly. GSFC also served as the 

focal point for the Agency-wide Smart Buyer 

activity. 

Science Missions

The technical aspects of some GSFC programs have also been the subject of NESC 

review. GSFC Center-level management requested an independent review of the flight 

adequacy of the GOES-N Composite Overwrapped Pressure Vessels (COPV’s) installed 

in the Delta IV 1st and 2nd stages. The GSFC 

Engineering Director later asked for an independent assessment of the current health and 

adequacy of processing plans for the GOESN battery prior to launch. This support helped 

resolve a difference of opinion between GOES 

management and the in-line engineers. 

Goddard engineering also asked the NESC 

to independently review ST-5 separation 

dynamics analyses in support of the ST-5 

launch. Recently the Solar Dynamics Observatory (SDO) propulsion lead requested the 

NESC investigate recent failures of the Conax 

Y-PCA pyrovalve during pyroshock ground 

testing. Led by the NESC Chief Engineer at 

GSFC, test and analysis is being performed 

by a diverse set of experts at multiple NASA 

Centers and industry.

The NESC has also initiated proactive work in 

Field Programmable Gate Array reliability and 

Hitachi Electrically Erasable Programmable 

Read Only Memory performance, which benefits multiple programs. Goddard personnel 

also supported NESC activities associated 

with science missions at other Centers. While 

program managers and engineers maintain 

their in-line responsibility for safety, the NESC 

complements them by providing independent 

review, using independent funding. GSFC 

support is critical to allowing the NESC to fulfill its mission

GODDARD SPACE FLIGHT CENTER

GSFC at a glance

4

Michael

Hagopian

NESC’s Chief

Engineer at GSFC

3.4 %

n NESC 

employees at 

GSFC

n Percent of 

GSFC technical 

work force who 

supported

NESC assessments

ARC

DFRC

WFF

JSC

SSC

GSFC

KSC

MSFC

NASA HQ

GRC

WSTF

LaRC

JPL

PHOTOS/GSFC

Gary Davis, GSFC, SDO Propulsion Lead (far left), requested 

assistance from the NESC to assess a “non-firing” pyrotechnic 

valve on the SDO spacecraft (background). Orlando Figueroa, 

GSFC Director of Engineering (middle), and Michael Hagopian, 

NESC discuss the pyrotechnic valve (inset).

“The NESC continues to fulfill its promise as an Agency-wide technical resource for 

NASA programs and projects, as well as engineering and safety organizations. Goddard has benefited from the NESC, and its ability to quickly summon strong technical 

personnel from across the Agency, when we’ve encountered tough problems on our 

programs which have required an independent second look. We are also pleased to 

have supplied some of Goddard’s considerable technical expertise to the NESC...”

– Mike Ryschkewitsch/Deputy Director of GSFC
NESC 2006 TECHNICAL UPDATE 3

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

In 2006, JPL participated in numerous NESC 

studies for the Science, Exploration Systems 

and Space Operations Mission Directorates. 

Science Missions

JPL personnel engaged in independent 

NESC assessments of the Phoenix Lander 

mission to Mars to evaluate a factor-of-safety 

structures issues and also potential issues 

with “leaky” thruster valves that will be used 

during descent to the surface of Mars. The 

Dawn mission to orbit two of the solar systems largest asteroids, required analysis of its large 

Composite Overwrapped 

Pressure Vessel (COPV) 

Xenon propellant tank to 

determine flightworthiness. 

JPL personnel are also contributors in determining the root cause of a recent series of 

fail-ures in pyrotechnically-operated valves 

that are used on many NASA spacecraft. JPL 

is developing methods of visualizing the energetic release of gases and particles within 

the device using the JPL Pyrolab. The pyro 

devices are fired into a gelatin-filled cylinder 

while being photographed using ultra highspeed cameras to aid in detailed analysis. 

The NESC also contributed to the resolution 

of a major power outage (high power and high 

power output application) at the Deep Space 

Network’s Goldstone facility that is used by all 

of NASA’s deep space missions.

JPL has also been instrumental in the development of design and validation guidelines 

for next generation Field Programmable Gate 

Arrays used in many NASA and commercial 

spacecraft.

Exploration Systems Missions 

Using expertise gained from the Mars entry, 

descent and landing (EDL), JPL engineers 

and scientists were a part of a Smart Buyer 

follow-on activity to evaluate landing the 

Crew Exploration Vehicle (CEV) in water versus land. JPL contributed to quantifying the 

risk and likelihood of failures in various EDL 

designs. JPL personnel led the risk analysis 

for the team that quantified risks to the crew, 

vehicle and public. JPL personnel are also 

leading a follow-on study to evaluate the existing NASA and new contractor CEV landing 

and recovery architectures.

Space Operations Missions

JPL continues to be engaged in the analysis of 

the long-term safety of COPVs for the Space 

Shuttle and is also active in data mining and 

trending of existing problems and failures 

and issues looking for the trends in data to 

improve flight safety. JPL has also had three 

proactive proposals accepted to advance robotic exploration.

JPL at a glance

5.3 %

2 n NESC

employees

at JPL

n Percent of 

JPL technical 

work force who 

supported

NESC assessments

Brian Muirhead

NESC’s Chief

Engineer at JPL

JET PROPULSION LABORATORY

JSC

SSC

KSC

MSFC

GRC

WSTF

LaRC

JPL

JPL

Thomas Rust (left) and Joe Lewis, from the Propulsion and Materials Engineering Section, 

measure a proof-test version of the COPV used to carry Xenon gas for the ion propulsion 

system for the Dawn satellite.

JPL

The 70-meter antenna at the Goldstone Deep 

Space Communications Complex

JF&A

JPL led an NESC study to determine the 

risks of water versus land landings for the 

CEV Crew Module.
38 NESC 2006 TECHNICAL UPDATE

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

The NESC continued to support the Space 

Shuttle Program (SSP) and International 

Space Station (ISS) Program and initiated 

support to the Constellation Program. Support included technical assessments and 

independent evaluations, testing, and analyses which utilized expertise from across 

government, industry and academia. NESC 

representatives at JSC include the NESC 

Discipline Experts for Fluids/Life Support/

Thermal, Mechanical Systems, Flight Sciences, and Loads and Dynamics. The NESC Chief 

Astronaut is also resident 

at JSC. 

Return to Flight Activities

The NESC supported the five person Agency-wide ET Tiger Team, which provided senior NASA leadership an independent assessment of the ET foam losses on STS-114. 

Other issues/tasks supported by the NESC 

included the thermal protection system repair, reaction jet device redundancy, Composite Overwrapped Pressure Vessel life, ET 

Protuberance Air Load (PAL) removal effort 

for STS-121, engine cutoff sensor evaluation, and ISS specific issues including postproof testing of European modules, control 

moment gyro failure, trailing umbilical system 

failure and subsequent launch replacement 

unit loads/margins, and numerous other 

tasks supported by the NESC.

NESC representatives kept abreast of Program/Project activities and day-to-day issues 

with emphasis on Space Shuttle return-toflight. The NESC provided face-to-face presence with the SSP and ISS Program Managers at the monthly NESC activities status 

briefings as well as Boards and mission related tagups. The JSC NESC Chief Engineer 

(NCE) provided periodic status reports to the 

NCE team on key human spaceflight activities and special briefings on Space Shuttle 

return-to-flight efforts at each NESC face-toface meeting. The NESC provided JSC Center organizations senior management with 

quarterly updated synopses of each NESC 

Human Spaceflight related NESC tasks and 

results. The NCE represented the NESC as a 

member of the SSP Program Requirements 

Control Board and ISS Program Control 

Board. NESC representatives provided inputs on Program technical issues based on 

NESC technical assessments, as well as expert opinions. The NCE represented NESC at 

all Stage Operations Readiness Reviews for 

all Soyuz and Progress vehicle launches to 

the ISS in the critical down period between 

STS-114 and STS-121. 

Constellation Program

NESC TDT members from JSC participated 

in several studies for the Constellation Program. The Smart Buyer Team activity was 

supported by a number of experts from JSC. 

The team was recognized at an awards presentation where the JSC Director presented 

a group achievement award to each member 

from JSC.

JOHNSON SPACE CENTER

JSC at a glance

Dave Hamilton

NESC’s Chief

Engineer at JSC

8

2.6 %

n NESC

employees 

at JSC

n Percent of

JSC technical 

work force

who supported

NESC assessments

C

RC

WFF

JSC

SSC

GSFC

KSC

MSFC

NASA HQ

GRC

WSTF

LaRC

JPL

KSC

The successful launch of STS-121 on the 4th 

of July, 2006 completed the second of two 

test flights for SSP RTF activities. 

JSC

Astronaut Joseph R. Tanner, STS-115 mission specialist, during the first of three spacewalks. Over 60 

percent of NESC activities supported the Space Operations Mission Directorate in 2006.
NESC 2006 TECHNICAL UPDATE 3

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

KENNEDY SPACE CENTER

KSC at a glance

Stephen Minute

NESC’s Chief

Engineer at KSC

5

4%

n NESC

employees 

at KSC

n Percent of 

KSC technical 

work force who 

supported

NESC assessments

The NESC continues to support Agency and 

program goals through its efforts at the Kennedy Space Center (KSC). The NESC team 

was well supported by 45 KSC personnel of 

various disciplines who were active in NESC 

assessments and studies this year. Twentysix NASA personnel at KSC are members 

of the NESC’s Technical Discipline Teams. 

These discipline expert teams are the primary 

workforce the NESC calls upon when performing assessments and studies. 

The NESC assessed and 

studied numerous Space 

Shuttle Program issues 

this year. Many of those 

required significant KSC participation. The 

Cryogenic Test Laboratory (CTL) and Launch 

Equipment Test Facility (LETF) provided necessary support for several NESC activities. 

Testing for the Space Shuttle External Tank 

Intertank Aerogel insulation was performed at 

the CTL. 

Similarly, flammability and water absorption 

testing for the NESC-funded Shuttle Ice Liberation Coating (SILC) project is in work at 

several different KSC laboratories. Weather 

testing for SILC was performed at KSC’s 

beach corrosion facility. KSC Space Shuttle 

processing facilities and United Space Alliance helped with the Space Shuttle LO2 

Bracket Ice study. Foam application for Prototype bracket hardware was sprayed at the 

Vehicle Assembly Building and machined at 

the Prototype Lab to simulate ET foam. Potential foam replacements were waterproofed 

at the Orbiter Processing Facility.

In addition, KSC personnel and capabilities played a key role in numerous other 

NESC studies. For example: Space Shuttle 

Crawler/Transporter shoe crack nondestructive evaluation techniques; recurring anomaly 

studies for Space Shuttle and ISS; Vehicle 

Assembly Building explosive quantity distance study; data mining techniques; design 

standard development for systems control in 

safety critical applications; Space Shuttle tile 

gap filler consultation; and the Smart Buyer 

activity are some of the projects sponsored 

by NESC that depended on KSC resources. 

Several KSC experts were recognized for 

their efforts on the Smart Buyer activity with 

a Group Achievement Award by the Director 

of the NESC.

An Aerogel bead backfilled shroud is 

installed over the Space Shuttle ground 

umbilical carrier plate quick disconnect in 

preparation for cryogenic testing at KSC’s 

launch equipment test facility.

PHOTOS/KSC

Adam Pender (left) of Lockeed-Martin and Wayne Crawford of Arctic Slope Research Corporation (ASRC) install instrumentation onto a primer carrier assembly in support of the NESC 

Conax pyrotechnic valve testing.

C

FRC

WFF

JSC

SSC

GSFC

KSC

MSFC

NASA HQ

GRC

WSTF

LaRC

JPL

Jeffrey Chrisafulli from ASRC at KSC prepares for a test firing of a pyro assembly as 

a part of the NESC SRB HDP Stud Hang-Up 

Assessment.
40 NESC 2006 TECHNICAL UPDAT

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

Langley Research Center (LaRC) hosts the 

NESC Management Office and is the resident site of the NESC Discipline Experts for 

Structures, Materials, and Nondestructive 

Evaluation. LaRC engineers and scientists 

contributed wide-ranging technical expertise to NESC technical assessments and 

investigations in the areas 

of structures, materials, 

nondestructive evaluation, 

flight sciences, loads and 

dynamics, mechanisms, guidance navigation 

and control, and avionics.

Expendable Launch Vehicles

LaRC materials engineers tested pin-loaded 

machined rib specimens to determine anisotropic material effects on fracture characteristics of the Atlas V fuel tank in support of 

the Pluto/New Horizons mission launched 

in January 2006. For the CALIPSO mission, 

LaRC structural dynamics experts investigated the time-dependent dynamic response 

signatures of Delta-II rocket engine nozzle 

reinforcement band welds before flight, and 

LaRC radiographic nondestructive evaluation 

experts helped validate the accuracy of x-ray 

based wall thickness measurements on the 

Solar Terrestrail Relations Observatory (STEREO) mission Delta-II upper stage fuel tank.

Human Space Flight

and Exploration

LaRC aeroelasticity engineers were instrumental in the wind-tunnel testing and data 

analysis leading to the Protuberance Air Load 

(PAL) Ramp foam removal from the Space 

Shuttle External Tank, and design experts 

from around the Center supported alternative design studies for Space Shuttle External Tank Ice Frost Ramps. LaRC avionics, 

systems, thermal, structures, materials, and 

impact dynamics engineers contributed extensively to the Constellation Program Crew 

Exploration Vehicle (CEV) Smart Buyer study 

to provide NASA with critical technical risks 

and design solutions. LaRC structures, aerodynamics, and impact dynamics engineers 

continued on with Smart Buyer follow-on 

studies of composite material CEV concepts, 

land versus water CEV landing trade-offs, 

and alternative CEV launch-abort system 

configurations.

Science and Aeronautics

LaRC’s capabilities and expertise in planetary entry, descent, and landing were tapped 

by the Cassini/Huygens mission to Saturn to 

provide an independent assessment of readiness, trajectory, and residual risk for the Huygens descent to the Saturnian moon Titan. 

The NESC also relied extensively on LaRC 

materials and fracture mechanics expertise 

in assessing the 8-Foot High Temperature 

Tunnel Liquid Oxygen Run-Time Tank failure 

criteria, fracture margins, and recertification 

requirements.

LANGLEY RESEARCH CENTER

 LaRC

David Paddock of the Langley Mechanical Systems Branch built several rapid-prototype models of

composite material CEV concepts.

JSC

SSC

KSC

MSFC

GRC

WSTF

LaRC

JPL

LaRC

Dr. Ivatury Raju (left) and Eric Hoffman analyzed 

the fracture mechanics of the LaRC 8-foot High 

Temperature Tunnel Liquid Oxygen Run-Time 

Tank.

“Engineers at Langley Research Center really enjoy working on NESC technical assessments because of the importance to Agency missions. The experience gained by 

participating in these assessments makes our engineers more valuable to NASA projects 

being implemented at Langley.”

— Dr. Charles Harris, Director, LaRC Research & Technology Directorate

LaRC at a glance

30

11.2 %

n NESC

employees at 

LaRC

Dr. Michael

Gilbert

NESC’s Chief

Engineer at LaRC

n Percent of 

LaRC technical 

work force

who supported

NESC

assessments
NESC 2006 TECHNICAL UPDATE 4

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

This year, NESC personnel at Marshall Space 

Flight Center (MSFC) assisted in the completion of several major assessments into Space 

Shuttle hardware and also began supporting the Vision for Exploration. Resident at 

the MSFC is the NESC Discipline Expert for 

Propulsion, who has consulted on several projects 

and programs in need of 

propulsion expertise.

Space Shuttle Hardware

NESC personnel at MSFC completed three 

major assessments this year. The first two 

were assessments into the Orbiter’s Body 

Flap Actuator and Rudder/Speed Brake bearing wear. The NESC team performed extensive testing of bearings to determine if previously flown bearings were fit for reuse.

Another major Space Shuttle assessment 

completed was the investigation into the root 

cause of the Holddown Post Stud Hang-Ups. 

This assessment involved personnel from 

MSFC, LaRC and KSC and involved extensive testing of flight hardware. 

Constellation Program

Aerodynamic measurements on an alternate 

Launch Abort System (LAS) configuration 

were performed in the MSFC Aerodynamic 

Research Facility Tri-Sonic Wind Tunnel. This 

effort was a part of an NESC task aimed at refining the Service Module strap-on solid motors LAS concept. This concept compared 

the Baseline LAS model with the Alternative 

LAS configuration, which was found to have 

significantly higher forebody axial force (drag) 

coefficients in the transonic to Mach 2 portion 

of the flight.

MSFC personnel also participated in the 

Agency’s Smart Buyer activity and MSFC is 

now responsible for project management of 

the Ares I first stage. The Smart Buyer participants were honored by the NESC in a special 

ceremony.

MSFC at a glance

5

4.6 %

n NESC

employees at 

MSFC

n Percent of 

MSFC technical 

work force

who supported

NESC

assessments

Dr. Charles 

Schafer

NESC’s Chief

Engineer at MSFC

MARSHALL SPACE FLIGHT CENTER

RC

FRC

WFF

JSC

SSC

GSFC

KSC

MSFC

NASA HQ

GRC

WSTF

LaRC

JPL

Test engineer Alonzo Frost, prepares a CEV model for testing in the MSFC Aerodynamics Facility Tri-Sonic 

Wind Tunnel. Both the Baseline LAS (above left) and the Alternative LAS (above right) were tested.

MSFC

Workers help guide the body flap toward the orbiter Atlantis for installation. NESC personnel at 

MSFC performed extensive testing of the body flap actuator. 

KSC
42 NESC 2006 TECHNICAL UPDAT

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

Stennis Space Center (SSC) personnel supported several noteworthy NESC efforts in 

2006 planning for the future Constellation 

Program launch vehicles and support of the 

Space Shuttle operations.

In planning for the next generation of launch 

vehicles, the Propulsion Test Deputy Chief 

Engineer and senior engineers from the test 

contractor Jacobs Sverdrup assisted the 

KSC Vehicle Assembly Building (VAB) Quantity-Distance Consultation. The safety of 

storing five-segment Solid 

Rocket Motors (SRMs) in 

the VAB was assessed. 

These five-segment SRMs 

will be needed for the Crew 

Launch Vehicle. Sverdrup also took heat flux 

data on a motor segment disposal burn as 

a demonstration of future needs to support 

VAB safety. 

The NESC Smart Buyer Team effort was 

supported by two experts from SSC in the 

area of CEV Service Module main propulsion 

systems. The individuals were recognized by 

the SSC Center Director at the SSC senior 

staff meeting as part of the Smart Buyer 

Team awards.

In a separate activity, a cryogenic helium 

manifold, already on-hand at SSC from foam 

ice/frost growth characterization work in 

2005, was shipped to KSC to facilitate returnto-flight ET intertank testing. 

Several Apollo-era J-2 engines and related 

hardware were delivered from the NASA Michoud Assembly Facility to SSC, MSFC and 

Rocketdyne Canoga Park. SSC’s A-1 test 

stand will be used to test the J-2 powerhead 

and engine in support of the Exploration Mission Directorate’s J-2X engine development 

activities.

In 2006, NASA SSC personnel were in recovery mode for the first part of the fiscal 

year in the aftermath of Hurricane Katrina, 

a category 5 hurricane whose eye passed 

directly over SSC when it made its second 

landfall. One-fourth of the Stennis workforce 

(NASA and other entities) had to seek longterm temporary housing during this period. 

In spite of the hardship conditions, all normal 

test activities resumed successfully by the 

beginning of 2006.

SSC at a glance

n NESC

employees at 

SSC

n Percent of 

SSC technical 

work force who 

supported

NESC assessments

Dr. Shamim

Rahman

NESC’s Chief

Engineer at SSC

STENNIS SPACE CENTER

C

RC

WFF

JSC

SSC

GSFC

KSC

MSFC

NASA HQ

GRC

WSTF

LaRC

JPL

Stennis Space Center, located just 30 miles from downtown New Orleans, took a direct hit from 

Hurricane Katrina on August 29, 2005.

Aft segment of a solid rocket motor. NESC 

studied the explosive safety implications of 

storing five-segment SRMs in KSC’s VAB 

in support of the Ares I and Ares V launch 

vehicles. 

NOAA

Engine test stand A-1 will be converted to 

support testing of the Ares I and Ares V 

launch vehicles. 

3.9 %

1

KSC

SSC
NESC 2006 TECHNICAL UPDATE 4

N E S C C E N T E R H I G H L I G H T S

NESC 2006 TECHNICAL UPDATE

Since its inception, the NESC has depended 

on assistance from the White Sands Test Facility (WSTF) in many areas. This year, WSTF 

personnel have supported NESC efforts for 

the Space Operations, Science, and Exploration Mission Directorates.

Space Operations Activities

WSTF personnel supported NESC safety assessments of carbon and Kevlar® Composite 

Overwrapped Pressure Vessels (COPVs) for 

both the Orbiter and ISS. The WSTF COPV 

Team has assisted the NESC 

by providing expertise in the 

areas of Nondestructive Evaluation (NDE) and completing 

test and failure analyses. Activities have led to 

rationale for flight certification deviations allowing STS-114 and STS-121 to safely complete their missions. 

WSTF personnel also supported the NESC efforts in the Orbiter’s Primary Reaction Control 

System (RCS) thruster injector crack investigation with the development of NDE techniques. WSTF, with the NESC, developed a 

thruster NDE system that was chosen by the 

Orbiter Configuration Control Board, which 

funded completion of development and associated standards. WSTF is also supporting 

NESC activities into ice elimination from the 

External Tank LOX feedline.

Constellation Program 

Hypervelocity impact test facilities at WSTF 

are being employed on the NESC Composite 

Crew Module (CM) pressure vessel feasibility investigation. The objective is to produce 

a composite design that will serve as a CM 

structure, provide thermal protection, and 

protection from micrometeoroid orbital debris. 

A series of tests were run to evaluate potential 

configurations and materials. Ballistic limits 

are being established for each of the different 

concepts. WSTF has performed a total of 48 

tests to support this evaluation.

Science Mission Activities

WSTF engineers are supporting an NESC 

assessment into the failures of pyrotechnically operated valves. WSTF is supporting the 

NESC investigation of five recent pyrotechnically operated valve failures. WSTF designed 

and fabricated many special test apparatus 

that uses laser light illumination to view the 

pyrotechnic plume as it moves through the 

flow paths inside the valve itself. 

WHITE SANDS TEST FACILITY

WSTF

Thomas Hanson and Marene Carillo of the WSTF COPV Team are performing instrumentation 

check-out measurements on a 22-inch COPV to evaluate numerous NDE techniques and the 

data systems used to study stress/strain behavior of the Kevlar COPV’s .

C

WFF

JSC

SSC

GSFC

KSC

MSFC

ASA HQ

GRC

WSTF

LaRC

JPL

WSTF

Jayme Baas (left) and Brad Forsyth install a thruster chamber laser profilometer into an RCS 

thruster nozzle. The inspection tool uses the Laser Techniques Company profile mapping 

system and a thruster nozzle vacuum interface developed at WSTF to map the surface of the 

thruster chamber to detect and track growth of chips in the chamber coating.

WSTF

Dave Hamilton

NESC’s Chief

Engineer at Johnson Space 

Center for the White Sands 

Test Facility
44 NESC 2006 TECHNICAL UPDA

NESC HONOR AWARDS

NESC DIRECTOR’S AWARD

Mr. Raoul E. Caimi

Honored for personal determination 

and professional integrity in promoting the full and open discussion of 

the technical risks for the Pluto/New 

Horizons Launch Vehicle

Mr. Robert W. Cooke

Honored for exceptional technical 

contributions to the analysis and 

investigation of the Space Shuttle 

External Tank Liquid Hydrogen Engine 

Cut-off Sensor malfunction

Mr. Richard B. Katz

Honored for exceptional contributions 

to the Field Programmable Gate Array 

Reliability Technical Assessment 

Dr. Henning W. Leidecker

Honored for exceptional contributions 

to the Orbiter Avionics Tin Whiskers 

Evaluation

Dr. Rebecca A. MacKay 

Honored for providing exemplary 

technical leadership in the pursuit of 

root causes associated with cracking 

and pitting in Orbiter Injector Cracking

and Rudder Speed Brake Conical 

Seal Panel Pitting

Dr. Stephen W. Smith

Honored for technical contributions to 

the Reaction Control System Injector 

Cracking Root Cause Analysis

NESC ENGINEERING

EXCELLENCE AWARD

Ms. Terresita Y. Alston 

Honored for her outstanding contributions as the NESC Academy Program 

Manager 

Continued on next page

NESC Honor Awards, Orlando, Fla. January 31, 2006: From left: Jerry Ross (NESC Chief Astronaut/presenter), Dr. Vickie Parsons (LaRC retired), Phillip Hall (MSFC), Paul Roberts (LaRC), Steve Gentz (LaRC), Erin 

Moran (Swales Aerospace), Roy Hampton (ARC retired), Dr. Rebecca MacKay (GRC), David Lowry (JSC), Dr. 

John Lin (LaRC), Dr. Norman Knight (General Dynamics), Terresita Alston (Remtech Services), Ralph Roe, 

Jr. (NESC Director/presenter).

NESC honor awards are part of our incentive and recognition 

program. They are given each year to NASA Center employees, industry representatives, and other stakeholders for 

their efforts and achievements in the areas of engineering, leadership, 

teamwork, and communication.

These honorary awards formally identify individuals and groups who 

have made outstanding contributions to the NESC’s mission and who 

demonstrate the following characteristics:

– Engineering and technical excellence

– Fostering an open environment

There are four NESC Honor Award categories. The NESC Director’s 

Award honors individuals who take personal accountability and ownership in initiating clear and open communication on diverse and controversial issues. A key component of this award is based on the process 

of challenging engineering truths. The NESC Engineering Excellence 

Award honors individual accomplishments of NESC job-related tasks 

of such magnitude and merit as to deserve special recognition. The 

NESC Leadership Award honors individuals who have had a pronounced effect upon the technical activities of the NESC. The NESC 

Group Achievement Award honors a team of employees comprised 

of government and nongovernment personnel. The award is in recognition of outstanding accomplishment through the coordination of 

individual efforts that have contributed substantially to the success of 

the NESC’s mission.

The NESC 2006 Honor Award recipients
NESC 2006 TECHNICAL UPDATE 

NESC HONOR AWARDS

NESC Engineering

Excellence Awards continued

Mr. Roy W. Hampton 

Honored in recognition for lifelong 

technical service and exemplary support to the structural assessment of 

the International Space Station European Modules that did not receive a 

post proof nondestructive evaluation

Dr. Norman F. Knight 

Honored for outstanding contributions 

to the Reinforced Carbon-Carbon 

Impact Debris Assessment for the 

Return to Flight STS-114 mission

Dr. John C. Lin 

Honored for outstanding contributions to the U.S. Navy in correcting 

flow-induced, unsteady loads on the 

advanced seal delivery system minisubmarine

Mr. David R. Lowry 

Honored for outstanding contributions 

to the Reinforced Carbon-Carbon 

Impact Debris Assessment for the 

Return to Flight STS-114 mission

Ms. Erin Moran 

Honored for outstanding contributions 

as a NASA Engineering and Safety 

Center technical writer

Dr. Vickie S. Parsons

Honored for outstanding technical 

leadership and dedication to the improvement of data mining and trending across the Agency

Mr. P. Michael Bay

Honored for outstanding technical 

excellence and leadership in developing the innovative concept that 

enabled the successful completion of 

the Design, Development, Test and 

Evaluation Considerations for Robust 

and Reliable Spacecraft Assessment

Mr. William M. (Mike) Langford

Honored for the innovative concept 

development and exemplary design 

and manufacturing expertise for the 

independent redesign of the Space 

Shuttle External Tank Ice Frost Ramp

Mr. Frank R. Zimmerman

Honored for exceptional technical 

service in the identification, development and validation of the Orbiter 

OV-105 Rudder Speed Brake Conical 

Seal Panel Repair techniques

NESC LEADERSHIP AWARD

Mr. Edward J. Devine

Honored for technical excellence and 

leadership that enabled the successful completion of the Control Moment 

Gyro 1 Failure Root Cause Analysis 

Technical Assessment

NESC GROUP

ACHIEVEMENT AWARD

ISS Cooling Water Chemistry

Honored for the investigation into 

International Space Station Internal 

Active Thermal Control System Cooling 

Water Chemistry 

Orbiter Rudder Speed Brake

Gear Margins

Honored for the investigation into the 

Orbiter Rudder Speed Brake Gear 

Margins

Space Shuttle Main Engine High 

Pressure Oxygen Turbo Pump

Seal Cracking

Honored for determining the root cause 

on the Space Shuttle Main Engine High 

Pressure Oxygen Turbo Pump Seal 

Cracking 

Continued on next page

NESC Honor Awards, Albuquerque, New Mexico, September 26, 2006: From left: Ralph Roe, Jr. (NESC Director/presenter), Michael Dube (GSFC), 

David Jordan (ARC), Edward Devine (Swales Aerospace), Dr. Stephen Smith (LaRC), Raoul Caimi (KSC), Frank Zimmerman (MSFC), Jay Leggett 

(JSC) accepting for Michael Bay (Bay Engineering Innovations, Inc,), Steven Labbe (LaRC), Julie Kramer White (JSC), Dr. David Leckrone (GSFC), 

William Langford (LaRC), Paul Roberts (LaRC), Robert Cooke (SAIC), Dr. Henning Leidecker (GSFC), Leslie Curtis (LaRC), Jim Miller (LaRC), 

Mitchell Davis (GSFC) accepting for Richard Katz, and Dr. Charles Camarda (NESC Deputy Director for Advanced Projects/presenter).
46 NESC 2006 TECHNICAL UPDA

NESC HONOR AWARDS

NESC Recipients of NASA Honor Awards, September 18, 2006, NASA Headquarters. From left: Ralph Roe, Jr. (NESC Director/presenter), Henry 

Rotter (Exceptional Service Medal), Dr. Charles Harris (Exceptional Service Medal), David Hamilton (Exceptional Service Medal), Steven Labbe 

(Exceptional Achievement Medal), John McManamen (Exceptional Engineering Achievement Medal), Tim Wilson (Exceptional Achievement Medal), 

Chris Scolese (NASA Chief Engineer/presenter). Not pictured are Dr. Richard Gilbrech (Outstanding Leadership Medal) and Julie Kramer White 

(Exceptional Achievement Medal).

NESC Employees Receive Agency Honor Awards

Several NESC employees were recognized by the Agency and received prestigious NASA medals for their outstanding contributions to the 

NASA/NESC mission. The presentation was hosted in September at NASA Headquarters by the NASA Office of the Chief Engineer.

NESC Group Achievement

Awards continued...

Control Moment Gyro-1 Root Cause

Honored for technical expertise and 

leadership in the root cause assessment of the International Space Station Control Moment Gyro 1 Failure

Design, Development, Test and 

Evaluation Considerations

for Robust and Reliable Spacecraft

Honored for technical excellence and 

innovation in establishing the design, 

development, test and evaluation 

considerations for robust and reliable 

spacecraft

Space Shuttle External Tank Liquid 

Hydrogen Tank Ice Frost Ramp 

Redesign

Honored for exceptional technical support and innovative concept identification for the independent redesign 

of the External Tank Liquid Hydrogen 

Ice/Frost Ramps

Orbiter Rudder Speed Brake

Conical Seal Panel Repair

Honored for exceptional technical support for the evaluation of the Orbiter 

Rudder Speed Brake Conical Seal 

Panel Repair techniques

Solid Rocket Booster Holddown 

Post Stud Hang-Ups

Honored for exemplary efforts in determining the root cause of the Solid 

Rocket Booster Holddown Post Stud 

Hang-Ups

Stardust Hypervelocity Entry

Observation Campaign

Honored for outstanding technical 

contributions to the NESC Hypervelocity Entry Observation Campaign
NESC 2006 TECHNICAL UPDATE 

PARTNERSHIPS & COMMUNICATION

Professional Partnership and Training with

the National Transportation and Safety Board 

The NESC and the National Transportation and Safety Board (NTSB) 

have joined forces for the 2nd year to provide professional development 

and instruction that benefits both organizations. Through a formal interagency agreement, the NESC partnered with the NTSB to construct 

and deliver professional development and instruction for members of 

the NESC on how to manage and direct safety investigations. This 

collaborative effort, led by Ken Cameron, NESC Deputy Director for 

Safety, is an example of efforts to reach out to other professional federal organizations and learn from their experts.

Members of the NESC attended the training course and invited members from the Department of the Navy Aviation Safety community who 

provided a comprehensive education instruction to those who conduct 

independent accident investigations.

This training used actual investigators and professionals from the safety industry. The latest tools and analysis/problem solving techniques 

were introduced to aid participants with future investigations. 

. 

NESC Communications

The NESC website, found at: www.nesc.nasa.gov incorporates a list 

of NESC activities, including final reports detailing the description of 

the problem, findings, recommendations, and, if applicable, lessons 

learned. All lessons learned derived from our reports are entered 

through the Agency lessons learned system that serves as a communication tool for the technical community. 

The NESC publishes biannual NESC Technical Updates, which include 

a snapshot of current NESC activities, lessons learned, recent publications and other NESC related information. These updates are also sent 

across the Agency to senior management officials.

More formal communication opportunities take place several times 

a year when the NESC Director, Ralph R. Roe, Jr., presents periodic 

leadership briefings to the NASA Administrator and staff. This level 

of communication is critical to assure the Agency that the NESC is 

continuing its commitment to engineering excellence and conducts 

value-added activities.

The NESC conducts a dynamic outreach program to increase awareness of what the NESC is, how it functions, and how the NESC resources can be accessed to solve technical and safety issues. The 

NESC outreach targets federal, industrial and academic communities 

to convey important technical information and lessons learned from 

our assessments. 

Andreas Dibbern (far left) practices as a lead investigator presenting the results of an investigation to other students who are playing the part of 

the NTSB panel members.
48 NESC 2006 TECHNICAL UPDAT

The NESC Academy moved forward to its 

second successful year of operation, presenting two, 3-day course offerings: one course 

in Power and Avionics and one course in 

Satellite Attitude Control Systems. In August 

2006, the NESC Academy also began the next 

phase of instruction by offering online versions 

of the classroom courses via the NESC Academy website. 

The NESC Academy was established to capture, share, and preserve the lifetimes of experiences and knowledge of NASA scientists 

and engineers and guide the next generation 

of Agency’s technical staff, as they develop 

expertise in technical problem-solving. NESC, 

the National Institute of Aerospace (NIA), and 

CIBER partner to design, develop and deliver 

these courses that are led by selected NESC 

Discipline Experts.

Classroom Instruction

The NESC Academy offered its third knowledge-capture course at the University of Maryland from December 6-8, 2005. The course, 

“Power and Avionics: Learning from the Past 

and Looking to the Future with Robert Kichak 

and Colleagues,” focused on electrical systems, power, avionics, and troubleshooting. 

Mr. Kichak, NESC Discipline Expert for Power 

and Avionics, GSFC, served as the primary 

lecturer, discussing lessons learned, and the 

victim-source-coupling troubleshooting approach. The course allowed Kichak and other 

NASA personnel to share their experiences 

and problem-solving approaches not readily 

found in a traditional educational course.

Twenty-nine students representing the electrical engineering disciplines at several NASA 

Centers attended the course. They received 

additional expert insight from Mitchell Davis, 

NESC Deputy Discipline Expert for Power and 

Avionics, and Richard Katz, specialist in digital 

systems for Space Flight from the NASA Office of Logic Design. 

Mr. Cornelius Dennehy, NESC Discipline Expert for Guidance, Navigation, and Control, 

led the effort and served as the principal lecturer for the fourth NESC Academy course. 

“Satellite Attitude Control Systems: Learning 

from the Past and Looking to the Future” was 

held at the Jeong H. Kim Engineering Building 

at the University of Maryland from June 27-29, 

2006. Other instructors included Frank Bauer 

and Richard Burns from Goddard Space Flight 

Center, Dr. Sanjay Garg from Glenn Research 

Center, and Henry Hoffman with Swales Aerospace, Inc. 

Topics covered in this course included, the 

engineering process, lessons learned, spaceborn global positioning system and implementation of multivariable control systems. 

The classroom participants included technical personnel from several NASA Centers 

who left with a wealth of information to take 

back to their organization and use throughout 

their careers. Additional courses have been 

planned.

NESC ACADEMY

NESC Academy – Learning from the Past, Looking to the Future

Neil Dennehy,

NESC Discipline

Expert for Guidance, Navigation

& Controls, (GNC) 

leads the instruction during the 

3-day Satellite 

Attitude Control 

Systems NESC 

Academy Course.

(Above) Students in the Satellite 

Attitude Control Systems course. 

(Left) Neil Dennehy discusses the 

finer points with a student.
NESC 2006 TECHNICAL UPDATE 

NESC ACADEMY

Starting August 28, 2006, the NESC Academy 

offered online versions of the first three classroom courses through their website at: http://

www.nescacademy.org. For those who are 

unable to attend the classroom version of the 

course, an option is to tap into the knowledge 

and experience of these NASA experts from a 

computer. The three courses available online 

are: Space Life Support Systems led by Hank 

Rotter, NESC Discipline Expert for Fluids/Life 

Support/Thermal, Propulsion Systems led by 

George Hopson, NESC Discipline Expert for 

Propulsion, and Power and Avionics led by 

Robert Kichak, NESC Discipline Expert for 

Power and Avionics. An online features allows 

participants to track their progress through the 

course, access knowledge capture transcripts, 

review lessons, and take tests associated with 

each specific course. As future courses are 

developed, each of them will be available online. 

Another feature of the online course is to allow Academy participants to have a dialogue 

with fellow students and instructors through a 

forum to discuss issues and share ideas. Instructors can post information about a course 

and the public can read testimonials from previous participants.

“I’m fresh out of college so I don’t 

have a lot of real world engineering 

experience. So this gives me an opportunity to look at case studies and 

look at a lot of practical engineering 

problems...”

— Kyle Gregory

Electronics Engineer

“..the greatest benefit of the course 

is that you actually get to talk to the 

engineers who have solved real engineering problems and go through 

the case studies or follow the problems that they have solved.”

— Muzar Jah

Electronics Engineer, GSFC

“...this type of course, is great, because it gives you that systems-level 

understanding that you — there’s no 

way you can get in college — of attitude control systems.”

— Milton Davis

Mechanical Engineer, GSFC

Online NESC Academy Courses

Norman Helmold, from GFSC, leads a discussion of digital systems for space flight during the 

Power and Avionics NESC Academy course.

Power and Avionics lead instructor Robert Kichak, NESC Discipline Expert for Power and 

Avionics (right) and Mitchell Davis, NESC Deputy Discipline Expert for Power and Avionics 

discuss a circuit design problem with a student.

PHOTOS/NASA
50 NESC 2006 TECHNICAL UPDAT

BIOGRAPHIES

Dr. Daniel Winterhalter

NESC Chief Scientist

Dr. Daniel Winterhalter is NESC’s 

Chief Scientist and 

is resident at the Jet 

Propulsion Laboratory (JPL). Dr. Winterhalter has over 

28 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 operation 

of complex spacecraft and space science 

missions.

Ralph R. Roe, Jr.

NESC Director

Mr. Ralph R. Roe, Jr. 

serves as the NESC 

Director at Langley 

Research Center 

(LaRC). Mr. Roe has 

over 23 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 Shuttle Processing Engineering Director.

Jerry L. Ross

NESC Chief Astronaut

Mr. Jerry L. Ross is 

NESC’s Chief Astronaut and is resident 

at Johnson Space 

Center (JSC). In addition to Mr. Ross’ 

NESC assignment, 

he will continue in his 

current position as 

Chief of the Vehicle 

Integration Test Office at JSC. With over 36 

years of flight, technical, and managerial experience with the U.S. Air Force and Space 

Shuttle Program, Mr. Ross is the veteran of 

seven Space Shuttle flights, including nine 

extravehicular activities, and was a Flight 

Test Engineer prior to joining NASA in 1979.

Kenneth D. Cameron

NESC Deputy Director for Safety

Mr. Kenneth D. Cameron is an astronaut 

and NESC’s Deputy 

Director for Safety 

at Langley Research 

Center (LaRC). Mr. 

Cameron was formerly an NESC 

Principal Engineer 

serving at LaRC. 

Mr. Cameron joined the NESC after 7 years 

in private industry and a career in the U.S. 

Marine Corps. Mr. Cameron has over 26 

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. 

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 the 

NESC, Mr. Wilson 

served as Deputy 

Chief Engineer for Shuttle Processing at 

KSC. Mr. Wilson has over 25 years of engineering and management experience supporting the Space Shuttle Program.

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 32 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.

OFFICE OF THE DIRECTOR
NESC 2006 TECHNICAL UPDATE 5

BIOGRAPHIES

Dawn M. Schaible

Manager, Systems

Engineering Office

Ms. Dawn M. 

Schaible is Manager 

of the NESC Systems Engineering 

Office at Langley 

Research Center 

(LaRC). Prior to joining the NESC, Ms. 

Schaible worked 

in the International 

Space Station/Payload Processing Directorate at Kennedy Space Center. Ms. Schaible 

has over 18 years of experience in systems 

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

Marc S. Hollander

Manager, Management and

Technical Support Office

Mr. Marc S. Hollander is the former 

Manager of the Management and Technical Support Office 

at Langley Research 

Center (LaRC). Prior 

to joining the NESC 

in February 2005, Mr. 

Hollander was the Deputy Assistant Secretary and Chief Financial Officer for the Science and Technology Directorate, Department of Homeland Security. In September 

of 2006, Mr. Hollander accepted an assignment with the National Institute of Health as 

the Associate Director for Management. 

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 

the 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 31 years 

of experience in System Safety, Propulsion 

and Explosive Safety, Mishap Investigation, 

Range Safety, Pressure Systems, Crane 

Safety and Orbital Debris Mitigation.

Keith L. Hudkins

NASA Headquarters Office

of the Chief Engineer Representative

Mr. Keith L. Hudkins 

is the representative from the NASA 

Headquarters Office 

of the Chief Engineer 

to the NESC. Mr. 

Hudkins is resident 

in the Office of the 

Chief Engineer at 

NASA Headquarters, 

where he serves as the NASA Deputy Chief 

Engineer. Mr. Hudkins has over 36 years of 

experience in systems engineering and engineering management, served as the Chief 

Engineer for the Space Shuttle Program, and 

was the Space Shuttle Orbiter Program Director.

NASA HEADQUARTERS LIAISON

Patricia L. Dunnington

Manager, Management and Technical 

Support Office

In September 2006, 

Ms. Patricia L. Dunnington was selected as Manager 

of the Management 

and Technical Support Office at Langley Research Center 

(LaRC). Prior to joining the 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. 
52 NESC 2006 TECHNICAL UPDAT

BIOGRAPHIES

Dr. Michael G. Gilbert

NESC Chief Engineer

Dr. Michael G. Gilbert is the NESC 

Chief Engineer at 

Langley Research 

Center (LaRC). 

Before joining the 

NESC, he was 

Head of the LaRC 

Systems Management Office. Dr. 

Gilbert has over 29 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 the NESC 

Chief Engineer at 

NASA Headquarters. 

Mr. Dillman came 

to the NESC from 

the 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 Space Shuttle flight crews.

Derrick J. Cheston

NESC Chief Engineer

Mr. Derrick J. 

Cheston is the NESC 

Chief Engineer at 

Glenn Research 

Center (GRC). Mr. 

Cheston joined the 

NESC from his prior 

position at GRC as 

Chief of the Thermal/Fluids Systems 

Branch. Mr. Cheston has 22 years of experience in aerospace engineering and management, including mechanical design and testing and thermal/fluids analysis.

Steven J. Gentz

NESC Principal Engineer

Mr. Steven J. Gentz 

is a Principal Engineer with the NESC 

at Langley Research 

Center (LaRC). Mr. 

Gentz joined the 

NESC from the Marshall Space Flight 

Center with over 23 

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 the NESC 

at Langley Research 

Center (LaRC). Mr. 

Cragg came to the 

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 28 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 the NESC 

at Langley Research 

Center (LaRC). Mr. 

Kirsch joined the 

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 17 

years of experience in managing projects 

and test facilities.

NESC PRINCIPAL ENGINEERS

NESC CHIEF ENGINEERS
NESC 2006 TECHNICAL UPDATE 5

BIOGRAPHIES

Stephen A. Minute

NESC Chief Engineer

Mr. Stephen A. Minute is the NESC Chief 

Engineer at Kennedy Space Center 

(KSC). Mr. Minute 

came to the NESC 

from KSC, where he 

served as the Chief 

of the Space Shuttle 

Safety, Quality, and 

Mission Assurance Division. Mr. Minute has 

over 23 years of engineering and management experience in the Space Shuttle and 

International Space Station Programs.

Dr. Charles F. Schafer

NESC Chief Engineer

Dr. Charles F. Schafer 

is the 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 41 years of experience in leading research and technology 

activities in advanced earth-to-orbit and inspace propulsion, including work in nuclear 

propulsion, plasma propulsion, advanced 

chemical propulsion, and new chemical propellant development.

Dr. Dean A. Kontinos

NESC Chief Engineer

Dr. Dean A. Kontinos 

is the NESC Chief 

Engineer at Ames 

Research Center 

(ARC). Before joining 

the NESC, he was 

Chief of the Reacting 

Flow Environments 

Branch at ARC, performing and managing research and development in aerothermodynamics, arc-jet testing, and planetary 

entry design tools. He has over 15 years of 

experience in computational modeling of hypersonic flowfields and the thermal response 

of hypervelocity vehicles.

Dr. James F. Stewart

NESC Chief Engineer

Dr. James F. Stewart 

is the NESC 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 41 years of management and technical experience leading missile and aircraft 

programs.

Michael Hagopian

NESC Chief Engineer

Mr. Michael Hagopian is the NESC Chief 

Engineer at Goddard 

Space Flight Center 

(GSFC). Mr. Hagopian came to the 

NESC from his position as Associate 

Chief of the Mechanical Systems Division 

at GSFC. Mr. Hagopian has over 22 years of 

experience in the development of space and 

Earth science satellites.

David A. Hamilton

NESC Chief Engineer

Mr. David A. Hamilton is the NESC 

Chief Engineer at 

Johnson Space 

Center (JSC). Mr. 

Hamilton came to 

the NESC from JSC, 

where he served as 

Chief of the Shuttle/

Station Engineering 

Office and also as the Chairman of the Shuttle Chief Engineers Council. Mr. Hamilton 

has over 39 years of combined experience 

in NASA manned space flight programs, including Apollo, Skylab, Apollo-Soyuz, ISS, 

Space Shuttle, and Mir.

Brian K. Muirhead

NESC Chief Engineer

Mr. Brian K. Muirhead is the NESC 

Chief Engineer, as 

well as the Center 

Chief Engineer at the 

Jet Propulsion Laboratory (JPL). Prior to 

his position with the 

NESC, Mr. Muirhead 

was Chief Engineer 

for the Mars Science Laboratory. Mr. Muirhead has over 29 years of combined experience managing space science missions and 

experience in spacecraft and instrument 

systems design, development, integration, 

test, and operations, including the Galileo, 

SIR-C, Mars Pathfinder, and Deep Impact 

missions.

Dr. Shamim A. Rahman

NESC Chief Engineer

Dr. Shamim A. Rahman is the NESC 

Chief Engineer at 

Stennis Space Center (SSC). Dr. Rahman came to the 

NESC from SSC, 

where he served as 

the Chief Engineer 

for the Propulsion 

Test Operations Division. Dr. Rahman has 19 years of experience in the engineering of space launch 

vehicles and test systems, primarily in fluid, 

thermal, and propulsion systems. In September of 2006, Dr. Rahman was selected 

as the Propulsion Test Program Manager at 

SSC.

NESC CHIEF ENGINEERS
54 NESC 2006 TECHNICAL UPDA

BIOGRAPHIES

John P. McManamen

NESC Discipline Expert

Mr. John P. McManamen is the NESC Discipline Expert for Mechanical Systems and 

is resident at Johnson 

Space Center (JSC). 

Prior to joining the 

NESC, Mr. McManamen served in a dual 

role capacity as the 

Engineering Directorate’s Chief Engineer of 

the International Space Station and as Deputy 

Chief of the Shuttle/Station Engineering Office. 

Mr. McManamen has over 19 years of experience in mechanical systems of the Shuttle Orbiter and International Space Station.

Robert A. Kichak

NESC Discipline Expert

Mr. Robert A. Kichak 

is the NESC Discipline Expert for Power and Avionics and 

is resident at Goddard Space Flight 

Center (GSFC). Mr. 

Kichak came to the 

NESC from the Electrical Engineering 

Division at GSFC, 

where he served as 

the Division’s Chief Engineer. Mr. Kichak has 

over 37 years of experience in spacecraft 

power, electrical, and avionics systems.

Steven G. Labbe

NESC Discipline Expert

Mr. Steven G. Labbe 

was the NESC Discipline Expert for 

Flight Sciences and 

is resident at Johnson Space Center 

(JSC). Prior to joining 

the NESC, Mr. Labbe 

served as Chief of the 

Applied Aeroscience 

and Computational Fluid Dynamics Branch at 

JSC. Mr. Labbe has over 22 years of experience in aerodynamics research applied to programs that include Space Shuttle and X-38. In 

September of 2006, Mr. Labbe was selected 

to be the Chief Engineer for the Constellation 

Program Office at JSC.

George D. Hopson

NESC Discipline Expert

Mr. George D. Hopson 

is the NESC Discipline 

Expert for Propulsion and is resident at 

Marshall Space Flight 

Center (MSFC). Mr. 

Hopson came to the 

NESC from the Space 

Shuttle Main Engine 

Project Office, where 

he served as Director. Mr. Hopson has over 44 

years of combined experience in Space Shuttle main engine, space propulsion, space systems dynamics, and project management.

Cornelius J. Dennehy

NESC Discipline Expert

Mr. Cornelius (Neil) J. 

Dennehy is the NESC 

Discipline Expert 

for Guidance, Navigation and Control 

(GNC) systems and is 

resident at Goddard 

Space Fight Center 

(GSFC). Mr. Dennehy 

came to the 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 26 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. Curtis E. Larsen

NESC Discipline Expert

Dr. Curtis E. Larsen 

is the NESC Discipline Expert for Loads 

and Dynamics and is 

resident at Johnson 

Space Center (JSC). 

Prior to joining the 

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 26 years of engineering experience with expertise in stochastic structural dynamics, structural safety, and 

probabilistic engineering applications.

Dr. Robert S. Piascik

NESC Discipline Expert

Dr. Robert S. Piascik 

is the NESC Discipline Expert for Materials and is resident 

at Langley Research 

Center (LaRC). Dr. 

Piascik joined the 

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 22 years of experience in the 

commercial nuclear power industry and over 14 

years of experience in basic and applied materials research for several NASA programs.

Dr. Cynthia H. Null

NESC Discipline Expert

Dr. Cynthia H. Null is 

the NESC Discipline 

Expert for Human 

Factors and is resident 

at Ames Research 

Center (ARC). Before 

joining the 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 20 years 

of experience lecturing on Human Factors, 

and another 15 years of experience in Human 

Factors applied to NASA programs.

Michael L. Aguilar

NESC Discipline Expert

Mr. Michael L. Aguilar 

is the NESC Discipline Expert 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 30 years 

of experience on embedded software development.

NESC DISCIPLINE EXPERTS
NESC 2006 TECHNICAL UPDATE 

BIOGRAPHIES

Dr. William H. Prosser

NESC Discipline Expert

Dr. William Prosser is 

the NESC Discipline 

Expert 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 19 years of experience in the field 

of ultrasonic and acoustic emission sensing 

techniques.

Dr. Ivatury S. Raju

NESC Discipline Expert

Dr. Ivatury S. Raju is 

the NESC Discipline 

Expert 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 31 years of experience in structures, structural mechanics, and structural

integrity. 

Henry A. Rotter

NESC Discipline Expert

Mr. Henry (Hank) A. 

Rotter is the NESC 

Discipline Expert 

for Fluids, Life Support, and Thermal 

Systems, 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 39 years of life support and active 

thermal control systems experience during 

the Apollo, Space Shuttle, and Orbital Space 

Plane Programs.

NESC DISCIPLINE EXPERTS 
56 NESC 2006 TECHNICAL UPDA

Frank H. Bauer

NESC Discipline Expert for Guidance Navigation and Control (2003-04)

Currently serving as the GSFC focal point 

for Constellation Program Systems Engineering and Integration 

J. Larry Crawford

NESC Deputy Director for Safety (2003-04)

Left NESC to become Director of Safety 

and Mission Assurance at KSC and has 

since retired

Steven F. Cash

NESC Chief Engineer at MSFC (2005)

Currently the Deputy Manager, Shuttle 

Propulsion Office at MSFC

Dr. Michael S. Freeman

NESC Chief Engineer at ARC (2003-04) 

Retired 

T. Randy Galloway

NESC Chief Engineer at Stennis Space 

Center (SSC) (2003-04)

Currently the Acting Director of the Engineering and Science 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 and currently is the 

Center Director at SSC

Dr. Charles E. Harris

NESC Principal Engineer (2003-05)

Currently the Director, Research & Technology Directorate at LaRC

Dr. Steven A. Hawley

NESC Chief Astronaut (2003-04)

Currently the Director of Astromaterials 

Research and Exploration Science at JSC

Marc S. Hollander

Manager, NESC Management and Technical Support Office (2005-06)

Currently Associate Director for Management, National Institutes of Health

Matthew R. Landano

NESC Chief Engineer at JPL (2003-04)

Returned to his assignment at JPL as the 

Director of Office of Safety and Mission 

Success 

Danny D. Johnston

NESC Chief Engineer at 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 (2003-05)

Currently the DFRC Liaison in the Crew Exploration Vehicle Flight Test Office at JSC 

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

Dr. David S. Leckrone

NESC Chief Scientist (2003-05)

Currently the Senior Project Scientist for 

the Hubble Space Telescope at GSFC

Dr. Paul M. Munafo

NESC Deputy Director (2003-2004)

Currently the Assistant Director for Safety 

and Engineering at MSFC

Stan C. Newberry

Manager of NESC’s Management and 

Technical Support Office (2003-2004)

Left NESC to become the Deputy Center 

Director at 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 Propulsion Test Program 

Manager at SSC

Steven S. Scott

NESC Dio05)

Currently the Chief Engineer at GSFC

John E. Tinsley

NASA Headquarters Senior Safety and 

Mission Assurance Manager for NESC 

(2003-04)

Currently the Director of the Mission Support Division at NASA Headquarters

NESC ALUMNI

Leadership Team Alumni

Current Positions of

Selected NESC Alumni
NESC 2006 TECHNICAL UPDATE 

RECENT NESC PBUBLICATIONS IOGRAPHIES

1. NASA/TM-2005-213231, Cloud-Aerosol 

LIDAR and Infrared Pathfinder Observation 

(CALIPSO) Spacecraft. NESC Report RP-04-

01/03-001-E.

2. NASA/TM-2005-213757, AIAA Conference 

Paper. Guidance for Repairing Cracks in the 

Flowliner. 

3. NASA/TM-2005-213750, Space Shuttle Orbiter Reaction Jet Driver (RJD). NESC Report 

RP-05-18/04-037-E. 

4. AIAA-2005-2255, AIAA Conference Paper. NASA Structural Analysis Report on the 

American Airlines Flight 587 Accident – Local 

Analysis of the Right Rear Lug. 

5. American Society of Mechanical Engineers 

(ASME), Conference Paper. Searching “Unknown Unknowns” and Project Performance: 

How to Assess the Early Stages. 

6. American Society of Mechanical Engineers 

(ASME), Conference Paper. Project Performance: How to Assess the Early Stages. 

7. NASA/TM-2005-213787, Orbiter Flowliner 

Feedline LH2 Cracking Problem Report. NESC 

Report RP-04-11/04-004-E.

8. NASA/TM-2005-213792, NESC Peer-Review of the Flight Rationale for Expected 

Debris Report. NESC Report RP-05-82/05-

010-E. 

9. NASA/TM-2005-213916, Technical Consultation of the Hubble Space Telescope (HST) 

Nickel Hydrogen (NiH2) Battery Charge Capacity Prediction. NESC Report RP-04-08/04-

050-E. 

10. NASA/TM-2005-213917, Technical Consultation of the Hubble Space Telescope (HST) 

System Health Assessment - Analysis of HST 

Health. NESC Report RP-04-12/04-060-E. 

11. NASA/TM-2005-213918, Technical Consultation of the International Space Station Internal Active Thermal Control System (IATCS) 

Cooling Water Chemistry. NESC Report RP05-71/04-018-E. 

12. NASA/TM-2005-213922, Technical Consultation of the Space Shuttle Main Engine 

(SSME) High Pressure Oxidizer Turbopump 

(HPOTP) Knife Edge (KE) Seal-Cracking and 

Debris Generation. NESC Report RP-05-

61/05-014-E. 

13. NASA/TM-2005-213928, Inspection of the 

Math Model Tools for On-Orbit Assessment of 

Impact Damage Report. NESC Report RP-05-

104/05-011-E. 

14. NASA/TM-2005-213942, Structural Integrity of the Wing Leading Edge Spar and 

Reinforced Carbon-Carbon Attach Hardware 

Technical Assessment Report. NESC Report 

RP-05-86/04-059-I.

15. NASA/TM-2005- 213948, NASA Engineering and Safety Center’s Materials Super Problem Resolution Team Activity Report Fatigue 

Crack Growth Rate of Inconel 718 Sheet at 

Cryogenic Temperatures. 

16. NASA/TM-2005- 213949, Independent 

Assessment of the Effect on the Shuttle Wing 

Leading Edge Spar and Attach Hardware, 

NESC Report RP-05-86/04-059-I.

17. Aircraft Aging Conference Paper, Evaluation of Risk and Possible Mitigation Schemes 

for Previously Unidentified Hazards. 

18. NASA-TM-2006-214289, Technical Assessment of Orbiter Vehicle (OV)-105 Rudder 

Speed Brake (RSB) Right Hand (RH) #4 Conical Seal Panel Surface Indications. NESC Report RP-05-130/04-158-E. 

19. NASA/TM-2006-214506, Solid Rocket 

Booster Holddown Post Stud Hang-up (Volume I). NESC Report RP 06-013/04-070. 

20. NASA/TM-2006-214517, Space Shuttle 

Program (SSP) Thermal Protection System (TPS) Cure in Place Ablative Applicator 

(CIPAA) Utilizing Shuttle Tile Repair (STA)-54 

for On-Orbit Tile Repair Technical Assessment 

Report. NESC Report RP-06-76/05-007-E. 

21. NASA/TM-2006-214521, Space Shuttle 

Orbiter Radiator Retract Assembly Flexhose 

Cracking Technical Report. NESC Report RP06-60/06-007-E. 

22. NASA/TM-2006-214525, Improved Understanding of the NASA Lockheed Martin 

(LM) Divot/No-Divot External Tank (ET) Foam 

Debris Model Report NESC Report RP-06-

57/06-008-E. 

23. AIAA Conference Paper, Fracture Mechanics Analysis of LH2 Feed Line Flow Liners Presented at the 47th AIAA/ASME/ASCE/AHS/ASC 

Structures, Structural Dynamics, and Materials Conference. 

24. 33rd Annual Review of Progress in Quantitative Nondestructive Evaluation Conference 

Paper, NASA Engineering and Safety Center 

NDE Super Problem Resolution Team. 

25. ICCES 05 - International Conference on 

Computational & Experimental Engineering 

and Sciences Conference Paper, Cracks in 

Flow Liners and Their Resolution. 

26. ICCES 05 - International Conference on 

Computational & Experimental Engineering 

and Sciences Conference Paper, CoarseGrain Parallel Computations - Two Cases in 

Structural Mechanics. 

27. Paper - Reliability Modeling Of The StressRupture Performance Of Kevlar 49/Epoxy 

Pressure Vessels: Revisiting a Large Body of 

Stress Rupture Data To Develop New Insights.

28. Paper - A theoretical investigation of composite overwrapped pressure vessel (COPV) 

mechanics applied to NASA full scale tests. 

29. 42nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit Conference Paper, Pitting and Repair of the Space Shuttle’s 

Inconel® Honeycomb Conical Seal Panel.