National Aeronautics and Space Administration

www.nasa.gov

NASA ENGINEERING & SAFETY CENTER

TECHNICAL UPDATE

2015
NASA Engineering

& Safety Center

Technical Update

2015

For general information and requests

for technical assistance visit us at: 

nesc.nasa.gov

For anonymous requests write to:

NESC 

NASA Langley Research Center

Mail Stop 118

Hampton, VA 23681
1

Over the past decade, many things have changed at the NESC: the leadership has evolved, the number of technical discipline 

teams has increased, and the scope of work and the responsibilities 

the NESC takes on has expanded to meet the Agency’s priorities. 

What has not changed, however, is the core purpose of the NESC: 

the commitment to successful programs and projects by providing 

independent technical analysis and testing, the open environment and focus on 

safety, and the dedication to NASA’s overall mission. The NESC reflects some of 

the NASA community’s best ideals by working together across Center boundaries 

toward a common vision. I am extremely proud of how the NESC has progressed 

over the past 13 years, and look forward to the NESC’s continued support toward 

the success of Agency programs.

Ralph Roe, Jr., NASA Chief Engineer

The NESC is the “go to” technical resource for the Agency. This year the NESC continued to provide tremendous value 

to our ongoing programs — quickly addressing real-time issues, 

providing alternative designs for consideration when necessary, 

and taking the extra steps in testing and analysis for areas where 

the Agency needed further confidence around key technical risks. 

The collection of experts in the NESC forms the foundation and leadership of not 

only NASA’s renowned technical capabilities, but also has extensive reach into 

industry and academia to help tackle the Agency’s technical challenges. Also this 

year, the NASA Technical Fellows took on the added responsibility of assessing 

the overall Agency capabilities in their discipline areas. The Technical Fellows and 

their discipline teams developed the first ever comprehensive look at these Agency 

technical capabilities. These efforts lead the Agency in developing a more efficient 

operating model with regard to investing in those critical capabilities we hold not 

only for the Agency, but also for the Nation.

Robert Lightfoot, NASA Associate Administrator

From NASA Leadership

Table of Contents

From NASA Leadership .................. 1

NESC Overview .............................. 2

An Interview with

Director Tim Wilson ........................ 4

Workforce Development ................ 6

NESC at the Centers ...................... 8

Knowledge Products Overview ... 18

Assessments ................................ 20

Technical Bulletins ........................ 31

Knowledge Capture Features:

Aerosciences ........................... 32

Guidance, Navigation,

and Control .............................. 35

Nondestructive Evaluation ..... 38

Flight Mechanics ..................... 40

Space Environments ............... 42

Electrical Power ...................... 44

Software .................................. 46

NESC Honor Awards .................... 48

NESC Leadership Team ............... 50

NESC Alumni ................................ 51

Publications .................................. 52
2

3

technical experts and are the stewards of their respective 

disciplines. They are considered part of the NESC core 

team. Other members of the core team include the Principal 

Engineers, NESC Chief Engineers, the NESC Integration 

Office, the Management and Technical Support Office, and 

the NESC Director and the Director’s Office. An NESC Chief 

Engineer is resident at each Center and is a convenient 

way to contact the NESC. The TDT members and others 

who are not badged to the NESC, but who participate in 

assessments, make up the extended team. The extended 

team has approximately 700 people compared to about 60 

core team members. 

In 2015, the NESC accepted approximately 60 requests for 

either independent assessments or other support activities. 

As assessments are completed, the NESC provides findings 

and recommendations to the assessment stakeholders and 

also shares the results with NASA and the broader technical 

community through detailed engineering reports. The 

NESC also shares lessons learned and transfers knowledge 

from the TDT members through Technical Bulletins and the 

NESC Academy— a source of web-based, instructor-led 

courses covering a variety of technical discipline topics. 

The NESC Academy reached over 15,000 viewers in 2015. 

The NESC also led the Agency in a wide-ranging study 

of NASA’s technical capabilities throughout the Agency. 

This activity represented a new dimension of the Technical 

Fellows’ responsibilities, and the results are critical to 

understanding how the Agency can most effectively meet 

NASA’s mission priorities in the future.

The NESC was created because of a tragedy. The NESC 

exists to prevent the next one. It is important to not lose 

sight of some of the cultural and systemic causes of the 

Columbia accident and to create an environment for a 

strong safety culture driven by the engineering excellence 

that is a foundation of NASA. The NESC is a resource for 

the entire Agency to make these goals possible.

NESC Overview

NASA has always risen to meet some of the great challenges 

in human history: from landing men on the Moon, to exploring 

the solar system, to the technological achievements of the 

Space Shuttle and International Space Station. But the path 

of exploration and discovery has been crossed by moments 

of tragedy— when members of the NASA family were lost in 

the pursuit of these accomplishments. Knowing that space 

travel is inherently both challenging and perilous doesn’t 

make tragedies easier to accept. Nor should it. We owe 

it to those who have lost their lives to both continue the 

pursuit of space and to learn the lessons bought at such a 

high price to make space travel as safe as we can. This is 

a challenge as difficult, but as important, as anything NASA 

has achieved so far. 

NASA established the NASA Engineering and Safety Center 

(NESC) after the Columbia accident to help address some 

of the aspects of NASA’s culture that led to the tragedy. 

Too often, prior to the accident, tough technical discussions 

were missing an independent voice that was detached 

from and not beholden to the Space Shuttle Program. The 

NESC provides an independent voice. As a unit of the 

NASA Office of the Chief Engineer, it is separate from all of 

NASA’s programs, projects, and mission directorates and is 

also distributed across the Agency to avoid influence from 

any one particular Center. The NESC is an organization that 

derives its strength and credibility from experts from across 

the country and by encouraging diverse points of view in an 

open and inclusive decision making process.

The formal activities that the NESC undertakes are called 

assessments. An assessment team is formed to pursue 

a specific technical issue and is patterned after the “tiger 

team” concept. An objective from the start of the NESC 

was to provide a capability to quickly bring in engineers and 

scientists—with the highest level of technical knowledge and 

experience available—to form teams to pursue the toughest 

technical problems. The NESC’s Technical Discipline Teams 

(TDTs) serve as pools of engineering talent ready to feed into 

assessments as needed. Members of the TDTs come from 

throughout NASA and the federal government, as well as 

from academia and industry. There are a total of 20 TDTs: 

one for each of 18 engineering disciplines (see sidebar) plus 

one each for Robotics and Human Spaceflight Operations. 

The 18 discipline-specific TDTs are led by the NASA 

Technical Fellows. The Technical Fellows are NASA’s senior 

Aeronautics 

Research

1%

Science

18%

Broad Agency/

External

13%

Human Exploration

and Operations

65%

Space

Technology

3%

Accepted Requests by Mission Directorate Sources of Accepted Requests

Safety & Mission

Assurance at Centers 3%

Program

Management 

18%

NESC 19%

Engineering & Scientific 

Organizations 46%

Anonymous 

1% 

Other NASA

Offices 3%

Office of Chief 

Engineer 2%

Center 

Management 

2%

Office of Safety and

Mission Assurance 2% 

External to Agency 4%

Accepted Requests Since 2003: 669 total

Data as of December 31, 2015

NASA Office of Chief Engineer

NASA Engineering and Safety Center Core Team

PEs

NESC Principal

Engineers

NCEs

NESC Chief

Engineers

Office of the 

Director

NIO

NESC Integration

Office

MTSO

Management and 

Technical Support 

Office

NASA

Technical Fellows

Technical Discipline Teams (TDTs)

There are about 700 TDT members

Other Gov.

2%

Academia

3%

Industry

22%

NASA

73%

NRB

NESC Review Board

� Aerosciences � Avionics � Electrical Power � Flight Mechanics � Guidance, Navigation,

and Control

� Human Factors � Human Spaceflight

Operations

� Life Support/Active

Thermal

� Loads and Dynamics � Materials � Mechanical Systems � Nondestructive

Evaluation

� Nuclear Power and

Propulsion

� Passive Thermal � Propulsion � Robotic Spaceflight � Space Environments � Software � Structures � Systems Engineering

Meeting the Agency’s 

Technical Challenges
4 5

Can you provide examples of where NESC work supports 

mitigating the OCE’s Agency technical risks? 

One of the NASA Chief Engineer’s concerns is integration of 

the new exploration programs. With SLS, Orion MPCV, and 

GSDO, he’s concerned about how you ultimately pull those 

together into one operating program. So, one of our tasks 

is independent modeling and simulation for Exploration 

Systems Development (ESD) to develop tools that will 

give us insight on how they do integration and modeling, 

and will give them independent answers, or checks and 

balances, against work that they are doing internally. It is 

a good example of an assessment that specifically attacks 

an OCE key risk. And almost any assessment for Orion 

or SLS directly attacks what he calls “closing the gap,” or 

ensuring the new exploration programs have the technical 

support they need to accomplish their goals. Those are big 

pieces of the pie for us. 

When you look back over the NESC’s 600+ assessment 

portfolio, what stands out to you?

That we’ve made a positive impact on the Agency. We get 

good feedback — unsolicited feedback —that the work 

that we’ve done has added value and helped programs 

and projects be successful. Our work is spread well across 

NASA programs, from human exploration to the Science 

Mission Directorate, aeronautics, and technology, and has 

expanded over the years. The demand for our work comes 

from program managers and engineering organizations, 

which has grown as folks have come to learn about our 

capabilities and appreciate the products we provide.

I don’t see any of that changing. 

Where do you see the NESC in the next 10 years?

I think the pattern of moving from operational to 

developmental work is going to shift back in the other 

direction. We’re all counting on having two commercial 

partners flying within the next couple of years. And we’re 

going to have NASA exploration vehicles flying. So we’ll 

be back into an operational mode. We’ll still be supporting 

development work with science programs, but the big 

hitters will be in-flight programs at that point. I don’t see 

any slow-down, however. I think the demand will keep 

coming.

An Interview with Director Tim Wilson

I

n 2015, the NESC accepted almost 60 requests for 

assessments, bringing the total number of active 

assessments to nearly 100. That acceptance rate reflects 

a steady average of more than 50 requests per year since 

the organization began in 2003 in the wake of the Columbia 

accident. What the numbers do not show, however, is 

how the NESC decides, in a tough fiscal climate, which 

assessments to undertake. 

NESC Director Tim Wilson discusses how the decision 

to take on an assessment requires a careful, calculated 

approach — not only to understand the potential risks and 

benefits to a program but also to recognize how it fits into 

the bigger NASA picture. 

As the Space Shuttle Program came to a close, did the 

NESC workload decrease at all? 

The workload hasn’t decreased. In fact, it has gone up. 

In the early years we had two crewed programs running, 

Shuttle and the International Space Station (ISS). Now 

we have six, with Orion Multi-Purpose Crew Vehicle 

(MPCV), Space Launch System (SLS), their supporting 

ground systems [Ground Systems Development and 

Operations — (GSDO)], two commercial partners, and ISS. 

Demand has certainly not gone down. 

How does the NESC prioritize assessment requests 

as they come in? And how did the priority structure

come about?

When our budget started to shrink and it became clear 

that we were going to have to do more with less, as most 

government agencies have, we had to prioritize the requests 

to make sure we focus on the ones most important to the 

Agency. So we developed priority levels from 1 to 5. We first 

focus on requests for in-flight programs. Those are always 

priority 1. Priority 2 focuses on programs in the design 

phase, or near flight. Priorities 3 - 5 focus on work to avoid 

potential future problems or system improvements. We 

had to do that in order to manage demands on our budget.

Does the NESC only take on requests that meet level 1 

and 2 priorities?

We’re quickly getting to that point, but for now, we still 

have work underway in all of those categories. As requests 

come in, our normal process is to do initial evaluations. As 

part of that process, we look at the risk and the benefits to 

the program or project and the Agency as a whole, then 

decide what work to take on. But certainly, programs that 

are in flight, or about to fly, get the focus and consume the 

bulk of our resources. 

As an organization under the Office of the Chief Engineer 

(OCE), how do you support them in terms of mitigating 

engineering/technical risks faced by Agency programs?

The NASA Chief Engineer keeps a list of what he considers 

the Agency’s top technical risks. And as it turns out, 

the work we do maps very well to that list. Part of it is a 

natural by-product of our selection process, which uses 

risk matrices and asks tough questions during our initial 

evaluations. We’re also concerned about the same things 

he is — like new programs coming online and keeping the 

station flying. 

NESC Director Tim Wilson

21st Century technology 1%

Sustaining ISS 11%

JWST complexity 1%

CCP insight 

28%

ESD integration 7%

Other 10%

Closure of ESD 

designs

28% 

Reduced testing 14%

OCE Agency Technical Risks Currently

Supported by the NESC 

• Commercial Crew Partner (CCP) Insight into 

partner designs to enable their success and 

certify vehicles for human spaceflight

• ESD integration of the three human spaceflight 

programs using a new model

• Sustaining ISS through 2024

• James Webb Space Telescope (JWST) complexity with cryogenic systems and the number 

of mechanisms and deployments required for 

mission success

• Closure of ESD designs of MPCV/SLS/GSDO

• Reduced testing and heavy reliance on models 

and analysis, driven by constrained budgets, 

with limited anchoring to ground or flight tests

• 21st century technology tools and methods 

successfully incorporated into NASA programs 

and projects

Percent of NESC FY 2015 Assessments

Supporting OCE Agency Technical Risks

NESC Review Board NESC Review Board

NESC Core and Extended 

Team Members

Assessment Team

Request 

submitted

(by anyone)

Request

processed, evaluated,

and accepted

� Assessment team formed

� Plan developed and 

approved

Deliver final 

report to 

stakeholders

Document findings, 

observations, and 

recommendations

Proceed with assessment 

(testing, data collection, 

modeling, and analysis)

Approval Peer review and approval

Performing NESC Assessments

Submitted requests 

evaluated based on NESC 

task priorities

NESC Assessment Selection Priorities 1-5

Priority 1. Technical support of projects in the flight phase ...................19 %

Priority 2. Technical support of projects in the design phase .................66 %

Priority 3. Known problems not being addressed by any project ........... 7 %

Priority 4. Work to avoid potential future problems ............................... 5 %

Priority 5. Work to improve a system .................................................... 3 %

2015 In-Progress Requests by NESC Assessment Selection Priorities

Setting Priorities

How the NESC keeps its focus on key technical risks
6 7

she already has an idea of what she will take away from 

the experience as this is not her first time working with the 

NESC. She is also part of an assessment on launch vehicle 

buffet verification testing that started last year. 

“It’s a role outside my expertise so it’s been a huge learning 

experience,” she says. “It was my first time working with 

folks at other Centers. I’ve made great contacts that have 

helped on my core work with Orion.” The assessments offer 

her a “wider field of experience,” she says. “And it’s good 

to know whom to contact if you have questions and need 

expertise to handle problems as they come up.”

Dr. Rafael Lugo – Flight Dynamics and Flight 

Mechanics

Dr. Rafael Lugo was a graduate student until early 2014. 

Through his position at Analytical Mechanics Associates, 

Inc., he has worked with NASA on the Mars Atmosphere 

and Volatile EvolutioN (MAVEN) Mission. More recently 

however, he was asked to join the NESC assessment 

on Exploration Systems Independent Modeling and 

Simulation. “My background is flight dynamics and flight 

mechanics,” Dr. Lugo says. “I work heavily with figuring out 

how spacecraft will move through space,” which is what 

brought him to this assessment, where he is analyzing the 

possible trajectories of the Orion service module panels 

once they are jettisoned after liftoff to check for possible 

re-contact with the Space Launch System (SLS) core stage. 

“Working with a large group of people is very interesting,” he 

notes, which is different from his days as a student, working 

by and for himself. He has since worked as a technical 

lead on the NESC assessment, coordinated meetings, and 

done multiple presentations. “This was a big responsibility. 

I hadn’t done anything like that up until then. But I think 

I rose to the challenge. It’s been a lot of hard work, but 

rewarding.”

Dr. Lugo never anticipated working on a project of this size 

right after finishing his dissertation. “But it’s been a lot of 

fun and I’d love to continue being a part of it,” he says.

“They are the future,” says NESC Director Tim Wilson of 

engineers just beginning their careers at NASA. That is why 

he adds an early-career engineer to NESC assessments 

whenever the opportunity arises. “We have some of the 

most mature, seasoned engineers at NASA work on our 

assessments. And this is an opportunity for those new 

engineers to work directly with them, to talk to them, and 

understand how they work. It’s not every day they get that

kind of opportunity to interact with engineers of that caliber. 

It’s an opportunity we can’t afford to miss,” says Mr. Wilson. 

“There won’t be a NASA 20 years from now if these folks 

aren’t well-trained and well-versed in what we do and how 

we do it.” 

Workforce Development

“Hands-on” experience is one of the most valuable 

assets an engineer can have, and also one of the 

most difficult to obtain. To assist in preparing the next 

generation of engineers who will take us to Mars and 

beyond, the NESC includes an early-career engineer, who 

typically has fewer than 10 years in the NASA workforce, 

on most NESC assessments. Following are discussions 

with three such engineers who reflect on their experiences 

as team members on NESC assessments.

Dr. Alan Schwing – Computational Aerodynamics

Launching small, scaled models of an entry capsule at 

speeds of up to Mach 3.0 is going to help the NESC collect 

important flight data. It is part of an NESC assessment 

to measure backshell pressures the Mars 2020 capsule 

may experience during its descent to the red planet. 

The results will help guide the best placement for certain 

instrumentation on the vehicle.

For JSC engineer Dr. Alan Schwing, this NESC assessment 

is a chance to put his new doctorate in computational 

aerodynamic analysis to the test. A former co-op student 

with JSC, Dr. Schwing has been with NASA for just a few 

years, launching what will likely be a successful profession 

in aerospace engineering.

Drawing from the previously successful resident engineer 

program, the NESC strives to add early-career engineers 

to assessments that can offer opportunities to absorb as 

much knowledge as they can by working alongside some 

of the best and brightest in the Agency. It is a chance to 

be part of multi-discipline and multi-Center teams, build 

a network of contacts, and engage in important NASA 

missions.

Dr. Schwing has already seen the advantages of working on 

the NESC’s backshell pressure field assessment. “It’s very 

different from things I’ve worked on in the past,” he says. 

“But whenever you step outside your comfort zone and 

work with senior engineers, I think you have the opportunity 

to grow. It builds confidence and competency. I’ve learned 

a lot already, and it’s made me more self-sufficient.”

Used to working with a small group on Orion crew module 

flight testing, Dr. Schwing says the NESC assessment is 

broadening his horizons. “We have weekly meetings with 

several people across the Agency. In terms of collaboration, 

everyone is open and sharing. These people are some of 

the best at what they do. At some point this project will 

end, but I’ll have connections with these people who are 

much more seasoned and have been around the block with 

test programs,” he says. “It may not be quantifiable today, 

but will hopefully provide dividends in the future.” 

Jessica Powell – Computational Mathematical 

Engineering

Jessica Powell combines her work at NASA with her studies 

at Stanford University, where she is getting her master’s 

degree in computational mathematical engineering. On 

rotation to ARC from JSC, Ms. Powell is another earlycareer engineer working with the NESC on an assessment 

involving the application of system identification to 

parachute modeling. 

She is hoping that by improving current modeling and 

simulation techniques for parachutes, she’ll have knowledge 

she can take back to her work on Orion crew module 

aerodynamics. Though brand new to the assessment team, 

Professional Launchpad

Engineers draw experience from the NESC as they begin their careers

“It’s been a lot of hard work, but 

rewarding” — Dr. Rafael Lugo 

“It’s good to know whom to contact 

if you have questions and need 

expertise to handle problems as

they come up” — Jessica Powell

NESC Director Tim Wilson on early-career engineers

“It’s an opportunity we can’t afford to miss,” says NESC Director Tim Wilson. “There 

won’t be a NASA 20 years from now if those folks aren’t well trained and well 

versed in what we do and how we do it.”

“Whenever you step outside your 

comfort zone and work with senior 

engineers, I think you have the 

opportunity to grow”

 — Dr. Alan Schwing
8 9

NESC at the Centers NESC at the Centers

The Armstrong Flight Research Center (AFRC) 

provided engineering technical support and 

expertise to the NESC for numerous assessment 

activities including the Frangible Joints Design 

Testing, Shell Buckling Knockdown Factors 

(SBKF), the Vehicle Integrated Propulsion 

Research (VIPR) Experiment Impacts on 

the Test Aircraft Airframe, and commercial 

partners electrical power system review. AFRC 

collaborated with JSC to lead an assessment 

requested by the Stratospheric Observatory for 

Infrared Astronomy (SOFIA) Project to develop a 

technique called the Simplified Methodology to 

Estimate the Maximum LHe Cryostat Pressure 

from a Vacuum Jacket Failure. AFRC engineers 

were also invited by NASA Technical Fellows to 

give presentations to their Technical Discipline 

Teams (TDTs). 

Frangible Joint Testing

Because of his expertise in instrumentation and testing, 

Christopher Kostyk was requested to serve as the Data 

Team Lead on the Assessing Risks of Frangible Joint 

Designs Assessment. Mr. Kostyk enjoyed this role because 

it allowed him to contribute at a high level in helping to 

design the test series that would enable critical data 

collection, as well as leading the design of the high-speed 

instrumentation suite that would capture the ephemeral 

activity associated with the detonation event. Mr. Kostyk 

had the opportunity to learn various analytical tools, 

including how to use specialized software for extracting 

quantitative data from the high-speed video footage that 

greatly helped inform the team on various aspects of the 

short life of a frangible joint. In November, he received the 

NESC Engineering Excellence Award for his support of the 

frangible joint assessment. 

Composite Shell Buckling Knockdown Factor 

Francisco Peña, an aerospace engineer at AFRC, 

contributed to the SBKF activity by developing the 

instrumentation layout of fiber optic sensors to 

be installed onto an 8-foot diameter composite 

barrel structure. The SBKF activity is a multiCenter assessment focused on designing 

leaner and more efficient rocket shell structures 

through new designs, simulations, and advanced 

test technologies. The use of nearly 16,000 fiber 

optic sensors, located on the inner and outer 

surfaces of the barrel, will help the engineers 

verify their buckling prediction models for largescale shell structures with the goal of reducing 

mass and increasing payload. Through this 

activity, Mr. Peña has gained greater insight 

into the process of coordinating multiple sensor 

suites onto a large-scale space structure.

He has enjoyed participating on the SBKF 

team and has grown significantly from working

with expert structural engineers from multiple 

NASA Centers.

Passive Thermal Support

In 2015, Timothy Risch supported the NESC in a variety 

of activities. As AFRC’s continuing representative on the 

Passive Thermal TDT, Mr. Risch led an assessment of 

the Agency’s ablation modeling capability to help define 

NASA’s future direction for this work. He also worked 

cooperatively with NESC to help analyze and provide 

a solution to mitigate convective engine heating on a 

C-17 pylon. This activity supported ground testing for 

the Aeronautics Research Mission Directorate’s VIPR 

Program conducted jointly with the Air Force Test Center 

and AFRC. Mr. Risch also authored an NESC Academy 

lesson on radiative temperature measurement that 

outlined various methods and strategies for performing 

non-contact temperature measurements on heated 

objects commonly found in reentry, propulsion, and 

other high-temperature environments. Mr. Risch has 

appreciated the opportunity to contribute to NESC’s 

and the Agency’s missions by applying his skills and 

knowledge in heat transfer and thermal protection 

systems design and testing.

I

n 2015, Ames Research Center (ARC) personnel 

supported a diverse set of NESC assessments. A 

major area of contribution included providing key 

aerosciences expertise in support of investigations 

into the buffet environment of the Space Launch 

System (SLS). Of special interest was the interface 

between the SLS core stage and solid rocket 

booster. Another significant area of support was 

providing entry, descent, and landing expertise 

necessary to develop independent modeling and 

simulation of Commercial Crew Provider mission 

profiles. This effort will support NASA’s insight to 

the provider’s designs and will ultimately support 

independent analysis during mission operations. 

ARC personnel also supported investigations and 

independent reviews of Li-Ion battery thermal 

runaway risk reduction efforts for the International 

Space Station and also of fault detection, isolation, 

and recovery algorithms to be implemented in 

the Orion crew module guidance, navigation, and control 

system. The NASA Technical Fellow for Human Factors is 

resident at ARC.

Scrutinizing Stress 

ARC Structures Engineer Paul Lam specializes in stress 

analysis of flight vehicles and has worked with the NESC on 

several assessments. He has provided a crucial independent 

look at countless stress analysis reports for the SLS and the 

Multi-Purpose Crew Vehicle (MPCV) during critical design 

reviews, as well as commercial partner vehicles, providing 

valuable feedback to the NESC. 

“I typically review thousands of pages of stress analysis,” 

says Mr. Lam. “It may not be everyone’s idea of fun, but I 

enjoy it.” While he finds being mired in the details appealing, 

he also finds the overall work very rewarding. “It’s exciting 

to see the future of space exploration being developed right 

now. I imagine this could be similar to the dawn of aviation 

as we’re developing all new vehicles for spaceflight.” 

Mr. Lam says the work harkens back to his early days at 

NASA reviewing structural analyses for SOPHIA, NASA’s 

Stratospheric Observatory for Infrared Astronomy. 

“It was good training, reviewing tons of analysis 

and drawings to see what might be missing, what 

could be done differently, and how to validate that 

analysis.” 

Working with the NESC, says Mr. Lam, offers him the 

chance to work with multi-Center teams and to learn 

from senior members. “Usually they are looking at 

the broader picture, while I’m down in the details, but 

that’s okay. I’ve learned to listen to presentations, 

quickly assess large amounts of data, and decide 

on what to review in the time I have available. I’ve 

learned how to make the most effective use of my 

time and gain some good insight.” 

Applying Aeroacoustics

This year Nathan Burnside brought his expertise in 

aeroacoustics to bear on a key NESC assessment 

on buffet environments, fluctuating pressures that 

can generate loads on a vehicle. For this assessment, 

Mr. Burnside spent a large amount of time in the Ames 

11-foot wind tunnel calibrating more than 200 unsteady 

pressure transducers and verifying that each was accurately 

positioned on a vehicle model. “There were a lot of new 

measurement techniques involved and many of them would 

be verified and validated by the measurements we were 

making. And there were many groups interested in the data 

that would result from these tests,” he says. 

This assessment is not Mr. Burnside’s first with the NESC. 

In past years he has helped conduct wind tunnel tests on 

a model that would help determine the shape of the MPCV 

and tests on backshell pressures for reentry capsules. 

He says he is happy to answer when the NESC calls. “I 

look forward to working with the NESC. Their projects are 

interesting and they are always looking to solve a problem,” 

which he finds challenging. 

He also sees the work having a positive impact on his 

discipline. “I see a changing landscape of wind tunnel 

testing for aeroacoustics,” he says. “The measurements we 

took are very promising. I can see how they will be used a 

lot more in the future.” 

Dr. W. Lance 

Richards

NESC Chief

Engineer

10 AFRC 

employees 

supported 

NESC work

in FY15

Nans

Kunz

NESC Chief

Engineer

27 ARC 

employees 

supported 

NESC work

in FY15

Francisco Peña developed SBKF

instrumentation.

Christopher Kostyk analyzed high-speed 

video of frangible joint design tests.

Timothy Risch provided expertise in thermal 

Paul Lam, structures expert. Nathan Burnside, aeroacoustics expert. protection system design and testing.

Ames Research Center Armstrong Flight Research Center
10 11

NESC at the Centers NESC at the Centers

The Goddard Space Flight Center (GSFC) 

supported 15 assessments and investigations 

in 2015, leading the assessments for Modeling and 

Simulation of System Behavior at Space Launch 

System/Multi-Purpose Crew Vehicle to Ground 

Systems Development and Operation Interfaces; 

Spacecraft Guidance, Navigation, and Control (GNC) 

Component Open Source Benchmarking; Exploration 

Systems Development Integrated Avionics and 

Software Verification and Validation Plan; and Effects 

of Storage and Humidity on Dry Film Lubricant 

(DFL) Performance. GSFC provided expertise to 14 

Technical Discipline Teams in 2015 with 77 engineers, 

technicians, and scientists. GSFC is the resident 

Center for the NASA Technical Fellows for Software, 

GNC, Mechanical Systems, and Avionics.

Effects of Storage and Humidity on Dry Film 

Lubricant Performance for the James Webb

Space Telescope

The NESC is conducting an assessment aimed at evaluating 

the effects of humidity on the performance of cryogenic 

mechanisms that have sliding/rolling mechanical surfaces. 

The James Webb Space Telescope (JWST) has numerous 

mechanisms with DFLs to minimize wear, reduce friction, 

and extend the usable life of the mechanisms. This 

assessment, led by Claef Hakun, will meet the request by 

the JWST Project to test substrates lubricated with flight 

Molybdenum Disulfide 

(MoS2) coatings in order 

to predict the performance 

and life impacts that 

humidity exposure has on 

these critical mechanisms 

during flight.

GSFC has the capabilities 

and expertise in mechanisms, materials, and 

tribology to fully assess 

the long-term impact 

that humidity has on the 

degradation of DFLs. The 

joint GSFC and GRC team 

will leverage experience 

and knowledge of 

tribology and material 

science experts and the 

capabilities of the spiral 

orbiting tribometer (SOT) 

to determine the performance of the MoS2 substrates. In 

addition, the assessment utilizes an x-ray photoelectron 

spectrometer (XPS) and scanning electron microscope to 

characterize the reaction kinetics behind oxide formation 

over exposure time to humidity. In addition to the assessment 

lead, Mr. Hakun, core GSFC participants in the assessment 

included Calinda Yew, Liqin Wang, and Bruno Muñoz.

Ms. Yew is an aerospace engineer with a chemical 

engineering background. For the assessment, 

she executed sample tests using the SOT and 

XPS equipment. Ms. Yew stated that on this 

assessment, “I learned how to work in a diverse 

group of individuals from different technical 

backgrounds and experiences. I enjoyed the 

exposure this assessment has given me to 

collaborate with individuals from other disciplines 

and other Centers, and to be able to tackle the 

challenges together.”

Mr. Wang is a staff consultant with an expertise 

in metallic materials and microanalysis. Mr. Wang 

studied the humidity and temperature effect on the 

MoS2 coating and assessed the risk of long-term 

storage of the hardware with such coatings under 

ambient conditions. Mr. Wang stated that this 

assessment “would greatly enrich our knowledge 

base on the coatings and improve our capability to perform 

future analysis and quantitative assessment of long-term 

storage risk on flight hardware.”

Mr. Muñoz is a senior engineer with an expertise in vacuum 

systems and test integration. On this assessment, he 

modified the SOT to enhance its capabilities to provide and 

maintain humidification levels inside the SOT. Mr. Muñoz 

stated that, “I’m always extremely pleased to be able to help 

the NESC perform their critical work.”

Mr. Hakun is the Associate Branch Head of 

the Electromechanical 

Systems Branch. He has 

expertise in cryogenic 

mechanism development 

and tribology. As the 

assessment lead, he 

organized the team, 

devised test methodology, 

reviewed mechanism 

designs, and assessed 

the critical interfaces. 

Mr. Hakun said that as a 

result of this work, “we 

will have a much better 

understanding of the 

effects of humidity and 

perhaps other factors 

like repeated exposure 

from humid to vacuum 

environments on the performance of MoS2 films.” As for 

the benefits of participating on an NESC activity, Mr. Hakun 

said, “I think working on this assessment with multipleCenter interaction shows how a team can work together for 

their mutual benefit. Also, it has been a pleasure to work 

with early-career engineers and to see their dedication and 

enthusiasm at NASA is alive and well.”

The Glenn Research Center (GRC) provided a 

broad spectrum of technical expertise in support 

of NESC assessments and the NESC Technical 

Discipline Teams (TDTs). GRC supported 20 NESC 

assessments and 17 of the NESC TDTs with 60 

engineers. These activities supported all mission 

directorates as well as some crosscutting discipline 

activities. Significant contributions this year were in 

support of Li-Ion battery assessments as well as 

bearing and tribology related assessments. The 

Discipline Deputies for both the Propulsion and 

Electrical Power TDTs are resident at GRC.

Providing Battery Expertise

Robert Christie is an aerospace engineer with 50 

years of technical experience in the aerospace 

industry. Mr. Christie has a very diverse multiphysics 

background in mechanical engineering, mechanics 

of materials, aviation electronics, and system modeling. 

For the Li-Ion Battery Thermal Runaway Assessment, 

he performed thermal analyses of different battery pack 

configurations as well as reduction of experimental 

data from dozens of calorimeter tests. The analysis task 

generated several best practice design guides describing 

the benefit of a properly designed heat spreader in mitigating 

thermal runaway propagation and the serendipitous thermal 

benefit that insulating sleeves, added to prevent electrical 

shorting, had in impeding heat rejection to adjacent 

cells. Mr. Christie creatively used the calorimeter test 

data to determine the bounds of energy released and the 

magnitude of the uncertainty in the data. He also provided 

insight into how calorimetric testing can be improved, and 

these recommendations were implemented on subsequent 

testing.

Brianne DeMattia is an energy storage specialist who 

works on battery components and systems. Under the 

NESC’s International Space Station (ISS) Large Cell Thermal 

Runaway activities, Ms. DeMattia served as the task lead for 

large cell accelerated rate calorimetry (ARC) testing of Li-Ion 

cells. While the ARC testing did produce some useful data, 

further assessment showed that the standard ARC 

test setup historically used for smaller cells does 

not adequately translate to use with much larger, 

higher energy cells. The NESC team will investigate 

new test setups that will be unique to NASA’s test 

needs and hopefully provide the data that is lacking 

due to current test limitations. “My knowledge base 

has really broadened after leading this task and will 

continue to grow as I apply what I’ve learned to my 

other projects. One of the best parts of this job was 

collaborating with NESC team members across the 

Centers, all with different areas of expertise. I always 

came away from a meeting learning something new.”

Providing Bearing and Tribology Expertise

Dr. Robert Bruckner is an aerospace engineer 

at GRC with over 26 years of experience. His 

expertise ranges from aircraft engine systems to 

hydrodynamic bearings and tribology. In 2015, Dr. Bruckner 

contributed to two assessments for the NESC. He was 

the deputy assessment lead for the Vehicle Integrated 

Propulsion Research Experiments Impacts on the C-17 

engine-pylon interface where he coordinated the engine 

environment simulations, and he was the lead and principal 

investigator for the assessment of Minimum Wear Life for 

the ISS pump control valve package rotor-bearing system. 

In the latter assessment, Dr. Bruckner developed an 

analytic methodology to calculate the remaining wear life 

of the ISS ammonia pumps given only the pump current 

draw as an input. For this assessment he also developed 

a new tribometer, the Extreme Environment Tribometer, 

which is capable of simulating the exact conditions of the 

ammonia pump bearings and was critical in generating the 

experimental database that grounds the new methodology. 

According to Dr. Bruckner, “Being involved with NESC 

assessments are the high points in my career. They provide 

the opportunity to apply my expertise to unique applications 

important to NASA missions, gain valuable experience 

across the Agency, and work with talented individuals.”

Robert S.

Jankovsky

NESC Chief

Engineer

60 GRC 

employees 

supported 

NESC work

in FY15

Glenn Research Center

Left to right, Claef Hakun, Bruno Muñoz, Liqin Wang and Calinda Yew, front.

77 GSFC 

employees 

supported 

NESC work

in FY15

George L.

Jackson

NESC Chief

Engineer

Brianne DeMattia, left, in front of environmental 

test chambers in one of GRC’s battery 

characterization laboratories. Robert Christie, 

above, modeling Li-Ion battery pack. Dr. Robert 

Bruckner, right, in the lab with the Extreme 

Environment Tribometer.

Goddard Space Flight Center
12 13

NESC at the Centers NESC at the Centers

The Johnson Space Center (JSC) and the 

White Sands Test Facility (WSTF) provided 

engineering analysis, design, and test expertise 

for the continuous operation of the International 

Space Station (ISS), development of the Orion MultiPurpose Crew Vehicle (MPCV), and consultation 

for commercial crew vehicles. The NESC Deputy 

Director for Safety; an NESC Principal Engineer; 

NASA Technical Fellows for Life Support/Active 

Thermal, Loads and Dynamics, and Passive Thermal; 

and an NESC Integration Office Engineer are 

resident at JSC. JSC personnel provided expertise 

and leadership to numerous assessments within the 

Agency such as Orion MPCV Avcoat studies and ISS 

Li-Ion Battery Thermal Runaway analyses and tests. 

The JSC NASA Technical Fellows joined with other 

Agency discipline leaders to strengthen technical 

community connections through joint sponsorship 

and participation in activities such as the Thermal and 

Fluids Analysis Workshop, Capability Leadership Teams to 

help define the future of NASA technical disciplines, and 

a joint NASA/Department of Defense thermal protection 

system familiarization technical interchange meeting. 

Finally, JSC personnel engaged in standing review boards 

for the Stratospheric Aerosol and Gas Experiment III on ISS, 

the Human Research Program, Tropospheric Emissions: 

Monitoring of Pollution, Cyclone Global Navigation Satellite 

System, and the Asteroid Redirect Mission.

ISS/EVA Li-Ion Battery Thermal Severity 

Runaway Reduction Measures

Dr. Eric Darcy is the Battery Technical Discipline Lead in 

the JSC Propulsion and Power Division and has over 30 

years of experience working with battery technologies. 

Dr. Darcy has supported several NESC assessments of 

the thermal runaway hazard of Li-Ion batteries, and was a 

singular voice in the NASA battery community postulating 

that these high energy batteries could be designed to 

safely support missions and maintain viable energy density.

Dr. Darcy has provided visionary guidance in the redesign 

of ISS Extravehicular Activity (EVA) and Orion MPCV Li-Ion 

batteries to resist thermal runaway. As part of this effort, 

he developed an internal short circuit device to 

induce a battery cell failure for testing thermal 

runaway resistant battery designs. This device has 

garnered worldwide attention. Dr. Darcy credits 

his involvement with the NESC battery effort for 

making this possible.

WSTF Frangible Joint Testing

Larry Starritt is a project leader with Jacobs 

Technology at WSTF and supports NESC’s efforts 

to assess the risks of commercial crew vehicle 

frangible joints. With over 20 years of experience 

working with propellants, high energy explosives, 

and pyrotechnics, Mr. Starritt has been responsible 

for supervising over 85 successful frangible joint 

tests that are providing invaluable data on the 

function of these devices for the safety of future 

NASA crewmembers flying on commercially 

provided spacecraft.

MPCV Avcoat Assessments

Stan Bouslog, Dr. Michael Fowler, Dr. James Smith, and 

Thomas Modlin, all from the JSC Structures Division, 

have provided a wide range of technical expertise to the 

Orion MPCV Avcoat assessments. Mr. Bouslog is the 

Entry, Descent, and Landing/Thermal Protection Systems 

Technical Discipline Lead; Dr. Fowler is a materials engineer; 

Dr. Smith is the Structures Design & Analysis Technical 

Discipline Lead; and Mr. Modlin is a structural engineer 

with over 50 years of experience in spacecraft design and 

analysis. Together they performed root cause analysis of the 

Orion MPCV Exploration Flight Test-1 (EFT- 1) heat shield 

Avcoat strength discrepancies and enabled the successful 

flight of EFT-1 and now support follow-on assessments to 

ensure the safety of the upcoming Orion MPCV Exploration 

Mission-1 (EM-1) and EM-2 missions. All agreed that 

their participation in these NESC assessments yielded 

better corporate knowledge in this area for the Structures 

Division, and Dr. Smith noted, “Despite having several 

decades of analysis experience, the various Avcoat-related 

assessments have allowed me to stretch my knowledge in 

the field.”

From left, Avcoat team members Thomas Modlin, 

Dr. James Smith, Stan Bouslog, and Dr. Mike Fowler.

The Jet Propulsion Laboratory (JPL) has provided 

engineering support for 20 assessments and 

actively supports the NESC Technical Discipline 

Teams (TDTs). Several of the JPL staff have 

served as deputy TDT leads supporting the NASA 

Technical Fellows in their respective disciplines. 

The investigations supported modeling and 

simulation, Exploration Systems Development 

Verification and Validation, Orion Multi-Purpose 

Crew Vehicle (MPCV) Environmental Control and 

Life Support, several Commercial Crew Program 

(CCP) assessments, vibroacoustic environments, 

and others. JPL leads the Composite Overwrapped 

Pressure Vessel (COPV) working group and related 

COPV assessments, the Robotic Spaceflight TDT, 

and the RAD750 qualification testing effort. The 

Soil Moisture Active Passive (SMAP) Project was 

supported by NESC in the study of the deployment 

of its mesh antenna. The NESC Chief Scientist is 

resident at JPL.

Loads and Dynamics

Ali Kolaini has been at JPL for 11 years and is an expert 

in the loads and dynamics area. Mr. Kolaini and his team 

are developing nonlinear dynamic models for the Applied 

Physics Laboratory’s Solar Probe Plus Whip configuration/ 

restraint options. He is also reviewing and assessing the 

development of the nonlinear slosh dynamics models for the 

Space Launch System (SLS) flight control design. Mr. Kolaini 

was part of the NESC independent team to review the SLS, 

Ground Systems Development and Operations, and Orion 

MPCV Programs’ plans for modal testing, development 

flight instrumentation, and dynamic model correlation.

Mr. Kolaini and his team have been developing a new and 

novel method to reduce shock levels (by more than 10 dB) 

at shock sources, which can easily be implemented into the 

existing separation devices. This method is currently being 

implemented into the Surface Water and Ocean Topography 

Project to help reduce environments. Also, a different shock 

attenuation mechanism was developed for the path from 

separation devices to critical flight components. Such a 

system was designed, qualified for launch environments, 

and included in the SMAP observatory.

Providing COPV Expertise

Dr. Lorie Grimes-Ledesma has 

worked at JPL for 15 years and is an 

expert in COPVs. She leads related 

assessments and the NESC 

Composite Pressure Vessel 

Working Group (CPVWG), which 

is responsible for understanding 

and communicating issues 

and risks associated with the 

current state of the art as well as 

emerging composite pressure vessel technology. It 

is also tasked with the development of appropriate 

strategies, approaches, and methodologies to 

minimize technical risk associated with composite 

pressure vessels and create/revise technical 

requirements to mitigate this risk for future human 

and robotic space missions.

The CPVWG coordinates with programs and 

projects throughout NASA, and has been working 

proactively to address COPV mechanical modeling 

concerns, nondestructive testing, lifetime 

assessment issues, and standards development. 

In particular, the CPVWG has been supporting the 

CCP and the Orion MPCV Program in the past year. 

The CPVWG has been helping those programs 

interpret COPV requirements and lessons learned 

from prior NASA programs.

Dr. Grimes-Ledesma says, “Working with the NESC has 

allowed me to collaborate with experts at other Centers so 

we can all improve the Agency’s knowledge base to enable 

better understanding of COPV risk.”

Telecommunications Community

of Practice Leadership

Dr. Daniel Roscoe acts as the Chief Engineer for 

Telecommunications at JPL, and has been supporting the 

NASA Technical Fellow for Avionics as one of his community 

of practice (CoP) leaders. The Telecommunications CoP 

discusses a broad range of telecom-related topics, with 

several sessions devoted to the proliferation of CubeSat 

missions, which are now poised to go beyond low Earth orbit.

According to Dr. Roscoe, “I find that the associations being 

made with others via e-mail and WebEx are especially 

helpful to me when I need to find expertise for specialized 

topics, like multipaction and ionization inside high power 

radio frequency hardware.”

Annually, the team assesses the state-of-the telecommunications discipline and NASA’s ability to meet the needs 

of future missions. He also says, “I continue to enjoy the 

professional and personal relationships that come from our 

community gatherings and look forward to more in 2016.”

61 JSC 

employees 

supported 

NESC work

in FY15

T. Scott West

NESC Chief

Engineer

Larry Starritt with the frangible 

joint test rig at WSTF.

Dr. Eric Darcy, left, and Kandler Smith of the National Renewable 

Energy Laboratory prepare to test Li-Ion batteries.

Photo: Pat Corkery

Dr. Lorie Grimes-Ledesma. Dr. Daniel Roscoe provided leadership in telecommunications.

R. Lloyd

Keith

NESC Chief

Engineer

104 JPL 

employees 

supported 

NESC work

in FY15

Jet Propulsion Laboratory Johnson Space Center
14 15

NESC at the Centers NESC at the Centers

The Langley Research Center (LaRC) continues 

to support the NESC mission to address the 

Agency’s high risk programs and projects. LaRC 

engineers and scientists contributed wide-ranging 

technical expertise to lead and support multiple 

NESC assessments. The assessments reached 

across the Aeronautics Research, Human Exploration 

and Operations, Science, and the Space Technology 

Mission Directorates. LaRC is the host Center for the 

NESC Director’s Office, Principal Engineers Office, 

NESC Integration Office, and the Management and 

Technical Support Office. LaRC is also home to the 

NASA Technical Fellows for Aerosciences, Flight 

Mechanics, Materials, Nondestructive Evaluation, 

and Structures.

Promoting Statistical Engineering

As the Statistical Engineering Team Lead in LaRC’s 

Engineering Directorate, Dr. Peter Parker brought his 

expertise in the strategic application of statistical methods 

to several NESC assessments. He developed a test strategy 

and analysis methodology to support sizing requirements 

of the roll torque reaction control system for an NESC 

assessment on the Crew Launch Vehicle Project. He also 

assessed the adequacy of existing reliability predictions 

and guided recommendations on experimental drop test 

program strategies for the Capsule Parachute Assembly 

System. On another NESC assessment, Dr. Parker co-led 

the development of an independent, statistically based 

analysis of lidar sensor systems performance. “I gained 

an in-depth appreciation of several NASA systems and 

technologies that I would have not been exposed to without 

my NESC experience,” says Dr. Parker. “It was amazing to 

see how we collectively developed the assessment results, 

truly integrating input from each team member’s expertise, 

that we could not have achieved individually.”

Commercial Crew Program Entry, Descent, and 

Landing

Flight dynamics engineer Carlie Zumwalt brought her 

knowledge of simulation-based parachute performance 

to the NESC’s wind tunnel testing of subscale 

ringsail and disk-gap-band parachutes. She 

played an integral role in test design, test article 

fabrication, wind tunnel testing, and postprocessing of data to develop aerodynamic 

models. “I now understand the steps to go from 

a full-scale parachute, to a sub-scale wind tunnel 

model, to a parachute aerodynamic model ready 

for use in simulation. It was a fantastic opportunity 

to move a little outside of my comfort zone and 

learn about parachutes from some of the best in 

the world,” says Ms. Zumwalt.

Her understanding of computer-based simulation 

and how vehicles perform during entry, descent, 

and landing (EDL) also aided the NESC in 

developing EDL simulations of commercial partner 

vehicles. “This project not only provided me with 

a better understanding of how our commercial 

crew partners are designing their spacecraft, but also the 

invaluable experience of interacting with engineers and 

leaders from most of the NASA Centers, as well as the 

partners themselves.”

Assessing Frangible Joints

Research materials engineer Paul Leser is analyzing scans 

and producing a 3D model of frangible joints as part of 

an NESC assessment to evaluate any potential risks in 

their designs. Using a model that he built, along with 

inputs from the NESC team, Mr. Leser is running 3D finite 

element models of frangible joints and conducting post-test 

dimensional analysis of the test articles. He has run finite 

element models using NASA’s high performance computing 

assets before, but this assessment was Mr. Leser’s first 

experience with modeling shock physics. This work on flight 

hardware is also a departure from his primarily researchdriven background. “Modeling the operation of a frangible 

joint has expanded my knowledge on modeling fracture,” 

he says. “I have made a lot of great contacts with people 

from diverse fields working on this assessment from around 

NASA and outside the Agency, while getting first-hand 

experience with the important work that the NESC is doing.”

The NESC was involved in multiple activities and 

projects at the Kennedy Space Center (KSC). 

Likewise, KSC continues to provide expertise to 

a wide variety of NESC assessments and testing 

across the Agency and membership on 15 different 

NESC Technical Discipline Teams (TDTs). The NASA 

Technical Fellow for Electrical Power and a Deputy 

for the Materials TDT reside at KSC. KSC expertise 

plays a role in resolving many of the Agency’s 

difficult problems and was engaged in a variety of 

NESC assessments this past year. Some of those 

assessments include: Commercial Crew Program 

(CCP) frangible joint sensitivity testing; CCP avionics 

system reviews and parts testing; Exploration 

Systems Development (ESD) independent flight 

modeling; International Space Station Plasma 

Contactor Assessment; Orion crew module heat 

shield independent analysis and testing; The 

Cyclone Global Navigation Satellite System electrical power 

board consultation; and ESD Integrated Avionics Software 

Verification Assessment.

Providing Frangible Joint Expertise

Kevin Vega is the CCP Integrated Performance Lead Engineer 

and a consulting member of NESC’s assessment of the risks 

of frangible joint designs. The assessment is an empirical 

test to determine the effects that various design parameters 

and environmental factors have on frangible joint separation. 

The NESC is using high-rate cameras and instrumentation 

to get an unprecedented look at what happens during the 

microseconds of time before, during, and after a frangible 

joint separation in an attempt to understand design 

sensitivities. Mr. Vega has prior experience with pyrotechnic 

separation system design, development, and testing. He is 

helping the NESC define and evaluate technical requirements 

necessary to alleviate engineering and program concerns. 

Mr. Vega is inspired by the level of detail he and the NESC 

team encounter during testing to get answers. “Three million 

frames per second says a lot — when you look at the number 

and fidelity of the cameras, instrumentation, data storage, 

communication protocols, cabling, interfaces, test fixtures, 

test configurations, processes, and safety procedures to get 

three-tenths of a second of data” says Mr. Vega.

Ensuring a Clear View

The Orion Multi-Purpose Crew Vehicle (MPCV) 

Program has particular requirements that flight 

windows have minimal distortion and flaws. 

KSC’s Susan Danley and the NESC have taken 

a wavefront measurement technique developed 

at LaRC and applied it to a system capable of 

measuring distortion in the Orion crew module 

flight windows. Ms. Danley is a mechanical systems 

engineer and has been the lead window engineer at 

KSC for 11 years on Space Shuttle, Orion MPCV, 

and commercial crew programs. She believes that 

multiple programs could benefit from this window 

wavefront measurement technique. Ms. Danley 

honed her technical and project management 

skills as the project manager and lead engineer for 

this project. “I learned more about project management. 

I learned how to document and design a system that 

can serve the needs of multiple programs.” This NASAdeveloped capability is available to support other programs 

and projects.

A Passion for Figuring Out How Things Work, or 

Why They Don’t

The KSC engineering development and failure analysis 

laboratories play important roles in NESC assessments. 

Thad Johnson, an electrical engineer and failure analysis 

investigator, and Lawrence Ludwig, KSC Engineering 

Development Lab Manager, applied their expertise and lab 

facilities in support of the Electrical Power TDT on several 

NESC activities. Comprehensive testing of wire sizing and 

overcurrent protective features for CCP and investigative 

testing for the ARC arc jet mishap investigation are some 

examples. Combined, they have over 50 years experience 

in electrical failure analysis, including: digital microscopy, 

digital radiography, programmable microcontrollers, and 

computed tomography. Both Mr. Johnson and Mr. Ludwig 

agree that their NESC work helped them understand the 

scope of large-scale investigations and the importance of 

valuable expertise available across the Agency.

Carlie Zumwalt has supported NESC-sponsored 

wind tunnel testing of aerodynamic decelerators 

and currently provides EDL expertise.

Materials engineer Paul Leser developed 

models of frangible joints to better understand their reliability.

126 LaRC 

employees 

supported 

NESC work

in FY15

Jill L. Prince

NESC Chief

Engineer

(Through

Aug. 2015)

Langley Research Center

Dr. Peter Parker 

provides expertise 

in statistical engineering to NESC 

assessments.

41 KSC 

employees 

supported 

NESC work

in FY15

Stephen A. 

Minute 

NESC Chief

Engineer

Kevin Vega is the 

CCP Integrated 

Performance Lead 

Engineer in KSC’s 

Engineering

Directorate.

Susan Danley is KSC’s lead window engineer and 

Project Manager for the Wavefront Measurement 

System.

Lawrence Ludwig, left, is KSC’s Engineering Development Lab Manager. Thad Johnson is an electrical 

engineer and failure analysis investigator.

Kennedy Space Center
16 17

NESC at the Centers NESC at the Centers

The Stennis Space Center (SSC) provided expert 

technical support to the NESC, including 

laboratory facilities for the evaluation, testing, 

and qualification of a propulsion oxygen system 

cleaning solvent. SSC has members on several 

NESC Technical Discipline Teams and on the 

Propulsion Capability Leadership Team. The NESC 

utilized the unique capabilities and expertise 

from SSC’s Engineering and Safety and Mission 

Assurance Directorates on assessments including 

the Exploration Systems Development Integrated 

Hazard Development Process, Assessing Risks 

of Frangible Joint Designs, and Glenn Extreme 

Environments Rig Independent Review.

Rocket Test Detonation Modeling

As a follow-on effort to a recent NESC investigation, 

a Center Innovation Fund Project was conducted at 

SSC by Dr. Danny Allgood to enhance current capabilities 

in predicting rocket propellant detonations during test and 

launch activities. The goal of the project was to systematically 

demonstrate valid computational fluid dynamics (CFD) 

methodologies for predicting cryo-vapor cloud detonations. 

The ability to predict the probability of detonation and their 

blast environments is critical for the safety of the facility and 

project success. All model development was conducted 

within the framework of the Loci/CHEM CFD tool, which 

has a demonstrated robustness and accuracy in predicting 

high-speed combusting flows associated with rocket 

engines and plumes. Verification and validation studies were 

completed for hydrogen-fueled detonation phenomena 

such as shock-induced combustion, confined detonation 

waves, vapor cloud explosions, and deflagration-todetonation transition (DDT) processes. The DDT validation 

cases included predicting flame acceleration mechanisms 

associated with turbulent flame-jets and flow-obstacles. The 

CFD methodology was then applied to a relevant problem 

in which a detonation event had occurred during rocket 

testing at SSC. The favorable results demonstrated the 

code’s capability in predicting a rocket test detonation event 

and its associated blast environment. Dr. Allgood stated, “It 

was a great opportunity to continue the work our 

NESC team had begun on developing modeling 

techniques for rocket propellant detonations. I 

believe this program enabled critical research to be 

performed in the area of vapor cloud detonations 

that will be helpful in ensuring safe rocket testing 

and launch programs for NASA. Additionally, the 

general scientific and engineering communities 

should benefit by the further development of robust 

and validated methodologies for predicting DDT 

phenomena.”

Solvent Replacement Evaluation

NASA’s rocket propulsion test facilities at MSFC and 

SSC have relied upon hydrochlorofluorocarbon-225 

(HCFC-225) to safely clean and verify the cleanliness 

of large propulsion oxygen systems. The purchase 

of HCFC-225 was prohibited starting in 2015. A 

team of engineers, laboratory personnel, and end users from 

MSFC, SSC, WSTF, and the NESC collaborated to identify, 

test, and qualify a safe, effective replacement cleaner. Two 

solvents were downselected for comprehensive testing from 

an initial list of eight. The results of the study recommended 

Solstice Performance Fluid for applications at NASA 

propulsion test facilities where HCFC-225 is currently used.

Richard Ross, an SSC gas and materials science expert, 

stated, “Working on the project with the team was a very 

challenging and rewarding experience. Without providing a 

replacement solvent for precision cleaning, it would not be 

possible to test rockets that use LOX [liquid oxygen] and 

to clean propulsion hardware for engine testing and flight. 

Everyone on the team had a different discipline or perspective, 

which produced several eclectic ideas. The opportunity to 

help create something useful, tackling important elements 

for a critical process for the aerospace community, and 

seeing progress by working with extraordinary folks across 

the Agency was very satisfying. I feel privileged to represent 

SSC and the NESC and to present the LOX compatibility 

findings to the international community.”

I

n 2015, the Marshall Space Flight Center (MSFC) 

provided engineers, scientists, and technicians 

to over 30 ongoing and completed NESC 

investigations. These activities involved exploration 

systems development, space operations and 

environmental effects, science, and crosscutting 

discipline activities. Some of the more significant 

efforts included: advanced chemical propulsion, 

shock loading characterization in composites, 

additive manufacturing, environmentally friendly 

solvents, launch vehicle to spacecraft interface 

modeling and simulation, and human factors 

task analyses. The NASA Technical Fellows for 

Propulsion, Space Environments, and Systems 

Engineering, and Discipline Deputies for Human 

Factors, Propulsion, Software, and Space Environments Technical Discipline Teams (TDTs) are 

resident at MSFC. MSFC provided critical support 

to 16 of 20 NESC TDTs.

Propulsion TDT Support

Christopher Popp is a propulsion engineer with over 18 

years experience with NASA. He provided critical support to 

the Propulsion TDT through activities including independent 

subject matter expert reviewer for the Orion Multi-Purpose 

Crew Vehicle (MPCV) propulsion system critical design 

review (CDR), and the Commercial Crew Program (CCP) 

SpaceX and Boeing delta CDRs, as well as related propulsion 

system and component variance reviews. Involvement in 

these reviews and their corresponding preliminary design 

reviews provided Mr. Popp with broad perspectives for a 

diverse variation in propulsion system design, analysis, test, 

and verification approaches. This involvement provided 

the opportunity to mentor and challenge early-career and 

senior engineers at multiple NASA Centers on propulsion 

system and component-level design and lessons learned.

Mr. Popp said he “gained invaluable insight in a greater scope 

of activities being performed by the Agency involving new 

spacecraft propulsion system development, which would not 

have been provided without involvement with the NESC.”

SRM Insulation and Nozzle Liner Characterization

Sarah Howse is a materials engineer with 14 years of 

NASA experience in the areas of high temperature ablative 

materials supporting Space Shuttle, Ares, and 

Space Launch System (SLS) Program Solid Rocket 

Motors (SRM). Ms. Howse was the materials and 

processes lead for the SLS Program Block I Booster 

Element Polybenzimidazole Insulation Performance 

Characterization Assessment, which investigated 

concerns on insulation/propellant slag interactions. 

This experience increased her understanding 

of alternate internal motor insulation and nozzle 

liner materials for future SRM development and 

analysis validation of nozzle liner erosion. Ms. 

Howse indicated, “Working with the NESC has 

allowed us to be able to address risks or concerns 

of the engineering community by co-funding the 

efforts with the SLS Program, in an environment 

where funding is limited. In addition to answering 

the risk concerns, we have been able to improve 

instrumentation capabilities; advance analytic models 

supporting the full-scale motor for propellant, insulation, 

and nozzle materials; and partner with the Army and other 

NASA Centers for mutual benefit.”

Predicting Shock Response on Composite 

Materials Subjected to Pyroshock Loading

Prior to joining NASA 8 years ago, David Ordway worked 

for more than 23 years in industry developing expertise in 

pyrotechnic components and systems for the Department 

of Defense, expendable launch vehicles, and NASA crewed 

space applications. Mr. Ordway was the NESC technical lead 

studying the effects of pyroshocks on composite structures. 

Mr. Ordway feels, “this project was successful in establishing 

a methodology for evaluating the quality of acceleration 

time history data including developing algorithms for postprocessing the data, which may be used for future higherfidelity pyroshock testing of composites.” Mission programs 

using this information include the SLS and CCP partners. 

In addition to the pyroshock of composites investigation,

Mr. Ordway has been a critical member of a number of 

NESC assessments that included the MPCV Docking 

Mechanism Jettison System Cheater Cut Testing, Launch 

Services Program Launch Vehicle Fairing Instrumentation, 

and Assessing Risks of Frangible Joint Designs.

Michael D. 

Smiles

NESC Chief

Engineer

13 SSC

employees 

supported 

NESC work

in FY15

79 MSFC 

employees 

supported 

NESC work

in FY15

Steven J. 

Gentz

NESC Chief

Engineer

Richard Ross analyzes solvent test samples. Dr. Danny Allgood of the SSC Design and Analysis Group.

Sarah Howse in NASA’s National Center for 

Advanced Manufacturing.

David Ordway in the MSFC Pyrotechnic Shock Facility 

Control Room.

Christopher Popp, propulsion system 

subject matter expert and TDT member.

Stennis Space Center

Marshall Space Flight Center
18 19

Most Viewed Videos by Discipline

1. Aerosciences ...................... Ares Launch Vehicle Transonic Buffet

2. Avionics .............................. Electromagnetic Compatibility (EMC): Antennas, Part 1

3. Electrical Power .................. High Voltage Engineering Techniques for Space

 Applications: Part 1, Background Engineering Discussion

4. Flight Mechanics ................. Standard Check-Cases for Six-Degree-of-Freedom

 Flight Vehicle Simulations

5. Guidance, Navigation,

 and Control ........................ Autonomous Deep Space Navigation

6. Human Factors ................... Human Error in Maintenance, Part 1 of 3

7. Life Support/ EVA Development and Verification Testing at NASA’s

 Active Thermal .................. Neutral Buoyancy Laboratory 

8. Loads and Dynamics .......... Force Limited Vibration Testing: A Review of Existing and

 New Methods

9. Materials ............................. Apollo 13 Pressure Vessel Failure

10. Mechanical Systems ........... An Overview of Fastener Requirements in the new

 NASA-STD-5020

11. Nondestructive Introduction to Probability of Detection (POD) for

 Evaluation .......................... Nondestructive Evaluation (NDE)

12. Passive Thermal .................. Rationale for Selected MIL-STD-1540E Thermal Test

 Requirements

13. Propulsion ........................... Saturn Launch Vehicles: Engine Restart and Propellant

 Control in Zero-g

14. Structures ........................... Buckling, Shells, Knockdown Factors, and Validation Testing

15. Systems Engineering .......... Model-Centric Engineering, Part 1: Introduction to

 Model-Based Systems Engineering

NESC Academy Online

The NESC Academy is an innovative video library featuring 

nearly 500 informative lessons on topics relevant to current 

NASA issues and challenges. In 2015, more than 150 new 

video lessons were released with such varied topics as the 

JSC U.S. Spacesuit Knowledge Capture Series to the most 

viewed webcast, Autonomous Deep Space Navigation.

The NESC Academy offers the audience a virtual classroom 

experience based on a state-of-the-art video player for 

education, which enables dual video streams for content, typically one for the 

presenter and another for presentation materials.

A popular feature of the NESC Academy is live technical webcasts provided as 

a service to the discipline communities, which are archived for later viewing. 

Viewers can send in questions to the presenter during the broadcasts.

Significant enhancements this year include the ability to perform keyword 

searches across the entire video library. A keyword search will result in links to 

the location within a video where the keyword appears in the audio (based on 

the closed captioning) and in the presentation materials. Further, the NESC 

Academy now supports playback on most popular mobile devices.

The NESC Academy videos have received more than 35,000 views since 

inception, with more than 15,000 views in 2015 alone, illustrating the popularity 

of this approach among NESC Academy users. The NESC Academy video 

catalog is available at nescacademy.nasa.gov.

Knowledge Products Overview

NESC Knowledge Products

Capturing and preserving knowledge for the future

NASA is engaged in activities to effectively cultivate, identify, retain, and share knowledge in order to meet our 

future challenges. To capture and disseminate that knowledge to all who may need it — within NASA, industry, 

and academia — the NESC offers a wide variety of knowledge products that can be readily accessed from 

technical assessments and reports to technical bulletins and video libraries.

NESC

Assessments 

and Support 

Activities

nesc.nasa.gov

Assessment Engineering Reports

The detailed engineering and analyses generated from each assessment, 

available as Technical Memorandums (TM) ntrs.nasa.gov

Technical Bulletins

Critical knowledge captured from NESC assessments in the form of 

new engineering information or best practices in a one-page format 

Lessons Learned

Captured knowledge or understanding gained on NESC

assessments that would benefit the work of others

Scholarly Papers and Conference Proceedings

Written by members of the NESC and NESC Technical Discipline Team (TDT) 

to capture and convey new knowledge learned on NESC assessments

NESC Technical Update

Annual summary of NESC assessment activities that includes critical

knowledge articles authored by the NASA Technical Fellows

and NESC TDT members 

LLIS

Agency-Level Lessons 

Learned Information

System (LLIS)

llis.nasa.gov

NESC Academy Online

Video library of 500+ informative

lessons relevant to current NASA

issues and challenges

nescacademy.nasa.gov

NESC Technical Discipline Teams

Led by NASA Technical Fellows, provide the primary workforce

for NESC assessments and support activities, and includes

communities of practice nen.nasa.gov
20 21

Assessments Assessments

liquid helium dewar after the loss of vacuum insulation. The 

method is intended to enable the university-based science 

instrument development teams to conservatively determine 

the cryostat’s vent neck sizing during preliminary design 

of new Stratospheric Observatory for Infrared Astronomy 

science instruments. This work was performed by AFRC and 

JSC. NASA/TM-2015-218810

Mars Curiosity Rover Wheel Consultation: After a lengthy 

period of successful operation on the rough Martian 

surface, the Mars Curiosity rover began to show signs of 

wheel damage. The NESC provided consultation to the JPL 

tiger team for the Mars Curiosity wheel by contributing 

expertise relative to wheel damage testing and 

predictive modeling. Analysis was performed to 

develop wheel damage mitigation strategies 

and wheel life predictions relative to 

materials durability and damage 

tolerance issues. This work was

performed by LaRC. 

Support for the Ames Arc Jet Rectifier Snubber Failure 

Mishap: The Ames Arc Jet Complex provides testing 

capabilities for the development of thermal protection systems 

for NASA space programs as well as other government and 

commercial customers. The NESC was requested to provide 

technical support and consulting services to a mishap 

investigation team to determine the proximate cause of a 

component failure in the Arc Jet Complex. This work was 

performed by ARC, KSC, and LaRC.

 Priority 1: ongoing work in 2016

� ISS Solar Boom Array 

Thermal Issues

� Hubble Space Telescope 

Attitude Observer Anomaly 

Follow-On Technical Support

� Human Spaceflight-1 

Mishap Recurring Factor 

Study

� Minimum Wear Life for 

the ISS Pump Control Valve 

Package Rotor Bearing 

System

� Kepler Spacecraft Hybrid 

Attitude Control Concepts 

Evaluation 

� Materials, Structures, and 

Nondestructive Evaluation 

Consulting Support for ISS 

Micrometeoroid and Orbital 

Debris

� Ground Testing to Assess 

the ISS Ultrasonic Leak 

Location Concept

� Assessment of ISS/

Extravehicular Activity Li-Ion 

Battery Thermal Runaway 

Severity Reduction Measures

� Multi-Purpose Oxygen 

Generators Swelling

� Evaluation of Solar Array 

Batten Micrometeoroid and 

Orbital Debris Damage

� Composite Overwrapped 

Pressure Vessel Liner 

Inspection Capability

� Simplified Aid for 

Extravehicular Activity Rescue 

Battery Assessment

� ISS Columbus Interface Heat 

Exchanger Thermal Response

� ORB-3 Independent Review 

Team Support

� Mars Organic Molecule 

Analyzer Wide Range Pump 

Qualification Module Failure 

Review Board Support Activity

� Robonaut Battery Safety

� Extravehicular Mobility Unit 

Water Pump Redesign

� Support to Soil Moisture 

Active and Passive Anomaly 

Circuit Investigation 

� ISS Carbon Dioxide Removal 

Assembly Blower Speed 

Range Extension

Priority 1: completed work in 2015

ISS CMG Bearing Contaminant Assessment: Given the 

history of issues with the International Space Station (ISS) 

control moment gyroscopes (CMG), the NESC identified the 

need to test CMG flight bearings to evaluate the hypothesis 

that a dewetting event could produce a telemetry signature 

similar to a lubricant dewetting event on an ISS CMG bearing in 

October 2006. The NESC also evaluated the results obtained 

from previous tests that supported lubricant dewetting as a 

possible root cause for the CMG-1 and CMG-3 anomalies. 

This work was performed by GRC, GSFC, and JSC.

Portable Fire Extinguisher Evaluation: The NESC 

was anonymously requested to provide an independent 

assessment of burst-tested portable fire extinguisher (PFE) 

qualification hardware to determine the fatigue/burst test 

failure mode and provide recommendations, if necessary, for 

additional testing and/or analyses. PFEs are used onboard 

the ISS. The primary objectives of this assessment were to 

independently determine the failure progression from fatigue 

and burst testing and, if necessary, perform sensitivity studies 

to the structural analysis and provide recommendations for 

additional testing and/or analyses. This work was performed 

by MSFC.

ISS Plasma Contactor Unit Utilization Plan Assessment 

Follow-on: The ISS Space Environments Group requested 

the NESC revisit and increase fidelity of a calculation included 

in an NESC report, “ISS Plasma Contactor Unit Utilization 

Plan Assessment Update.” The calculation addressed the 

possible amount of current the extravehicular activity (EVA) 

crewmembers can accumulate while outside the ISS. The 

current collection drives the severity of the positive charging 

hazard to EVA crewmembers while outside of the ISS. This 

work was performed by KSC, GSFC, and JPL.

ISS Anomalies Trending Study: The NESC proactively 

addressed the need to identify trends and significant issues 

from ISS problem data (e.g., problem reporting databases 

and the Problem Analysis Resolution Tool) to enable NESC 

Technical Discipline Teams to investigate and document any 

areas of concern. This work was performed by KSC, JSC, and 

LaRC. NASA/TM-2015-218991

Simplified Methodology to Estimate the Maximum LHe 

Cryostat Pressure from a Vacuum Jacket Failure: The 

NESC was requested to provide an alternative simplified 

methodology or tool to estimate the maximum pressure in a 

Location of 

PCU

The SOFIA aircraft carries sensors cooled by liquid helium. Ames Arc Jet Complex.

Wheel

damage

on Mars

Curiosity

rover.

 NASA/JPL-Caltech/MSSS

Four double-gimbal CMGs for the ISS.

Approach to enhancing ISS nonconformance reports.

Location of the plasma contactor unit on the ISS.

NESC Priority 1

Technical support of projects in the flight phase 
22 23

Assessments Assessments

Computing Buffet Environments for SLS 

Configurations: The SLS Chief Technologist 

requested independent assessment by the NESC 

of the capability of advanced computational fluid 

dynamics (CFD) tools to characterize the unsteady 

flow caused by booster-to-core attach hardware 

and the resultant buffet loads. The assessment’s 

scope included numerically assessing unsteady 

aerodynamic loading effects of SLS booster 

geometric variations; conducting wind tunnel 

validation experiments leveraging SLS models; 

and considering nose cone variations. The 

NESC team applied advanced hybrid Reynolds 

Averaged Navier-Stokes/Large Eddy Simulation 

(RANS/LES) CFD techniques to the problem of 

predicting highly unsteady launch vehicle buffet 

environments. The hybrid CFD was used to 

design and evaluate several new SLS booster 

nose cone shapes, which demonstrated varying 

levels of reduction in the buffet environments. 

The hybrid RANS/LES technique and new nose 

cone designs were validated through wind tunnel 

tests performed in cooperation with the SLS 

Program. This work was performed by LaRC.

Advancing the State-of-the-Practice for

Liquid Rocket Engine Combustion 

Stability Assessment: The SLS Advanced 

Development Program Manager requested 

the NESC advance the predictive capability 

of state-of-the-practice combustion stability 

methodologies and tools for SLS using 

higher-fidelity, physics-based models 

from state-of-the-art CFD simulations. 

This work was performed by MSFC.

NASA/TM-2015-218771

SLS Program Booster Element Qualification Motor-1 

Aft Segment Unplanned/Unintended Event or Condition 

Investigation: The SLS booster element experienced aft 

segment propellant issues adjacent to the liner/insulation. 

The NESC provided input from subject matter experts from 

NASA Technical Fellows and/or their Technical Discipline 

Teams. Support included review of engineering reports, test 

and inspection results, and presentation material related to the 

investigation and process development activities. This work 

was performed by MSFC.

Peer Review of the SLS, GSDO, and MPCV Programs’ 

Modal Test, DFI, and Dynamic Model Correlation Plans: 

As a proactive measure, the NESC assembled an independent 

team to review the SLS, GSDO, and MPCV Programs’ modal 

test, development flight instrumentation (DFI), and dynamic 

model correlation plans. The scope of this assessment 

included peer review of program test planning for structural 

dynamic model verification, structural dynamic model 

correlation planning, and structural DFI planning; identification 

of concerns and gaps within these plans and schedules 

that affect program ability to support an integrated system 

verification loads analyses for EM-1, EM-2, and subsequent 

missions; and proposal of mitigations by test or analysis 

that address the concerns or gaps identified. This work was 

performed by JSC, GSFC, JPL, KSC, and MSFC.

Technical Support to the MPCV CPAS Pendulum 

Assessment Team: In certain conditions, the Orion crew 

module can experience an unexpected vehicle pendulum 

motion during one-main-parachute-out operation, which 

under certain circumstances, could produce unacceptably 

high loads on the crew module at splashdown. The Chief 

Engineer for the Orion MPCV Capsule Parachute Assembly 

System (CPAS) requested the NESC participate on a tiger team 

to address this issue. The NESC provided technical support to 

the CPAS Project to investigate parachute pendulum motions 

through theory, ground test, and flight test. This work was 

performed by LaRC.

JPSS MMOD Assessment: The Joint Polar Satellite System 

(JPSS) Project requested the NESC perform an independent 

evaluation of Orbital Debris Environment Model 3.0, the 

Micrometeoroid and Orbital Debris (MMOD) model used in 

the latest JPSS MMOD risk assessment, and compare it to 

other models used by the European Space Agency (ESA) and 

the Aerospace Corporation’s Center for Orbital and Reentry 

Debris Studies. As part of this review, the NESC team 

provided recommendations concerning current JPSS MMOD 

protection. This work was performed by LaRC, GSFC, JPL, 

JSC, and MSFC. NASA/TM-2015-218780

Modeling and Simulation of System Behavior at SLS/

MPCV/GSDO Interfaces: The Exploration Systems 

Development (ESD) Standing Review Board requested 

the NESC provide a model of the Space Launch System 

(SLS), Multi-Purpose Crew Vehicle (MPCV), and Ground 

Systems Development and Operations (GSDO) system 

interfaces to provide critical detail of the systems 

behavior in nominal and off-nominal scenarios. The 

model was used to identify gaps and completeness 

of system interfaces. The NESC also performed 

systems architecture analysis for the GSDO Program 

to ensure the communications, command, and 

control range design met vehicle ground processing/

prelaunch requirements within an appropriate level 

of architectural complexity. As a proactive objective, 

lessons learned in the use of the modeling tools 

were identified along with any requirements issues 

due to using model-based system engineering 

on this assessment. This work was performed by 

GSFC, JPL, KSC, LaRC, and MSFC.

ESD Integration Independent Review: The ESD

Division Chief Engineer requested the NESC 

perform an independent review of the ESD 

cross-program integration construct as currently 

baselined and to identify any integration 

functions potentially missing. The assessment’s 

scope for Exploration Mission-1 (EM-1) and 

EM-2 included: independently developing a list 

of critical integration functions for a large launch 

vehicle, launch complex, and crewed cislunar 

space capsule, then comparing these 

functions with current ESD cross-program 

integration functions to identify potential 

gaps; reviewing additional integration 

functions such as integrated scheduling 

and system safety; and highlighting any 

potential gaps. This work was performed by 

LaRC, KSC, and MSFC.

Review of Fatigue Cycle-Counting/

Fatigue Spectra Cycle-Counting 

Methodology: 

The NESC augmented an MSFC team 

with fatigue spectra counting expertise 

to evaluate the rainflow and spectrum 

methodologies and document the 

inherent assumptions, limitations, and 

best practices to determine if one or 

multiple methods should be used on 

the SLS Program. Results and lessons 

learned will be incorporated in the next 

update to NASA-HNBK-7005 Dynamic 

Environmental Criteria. This work was 

performed by MSFC and JSC.

Priority 2: completed work in 2015

Burn down uncertainty, decrease risk

Full vehicle Element Component

DFI/PID

Twang test

OMA (rollout)

Core stage modal test

Component/element

modal testing

Stiffness/influence

testing of interfaces

Component structural strength testing 

stiffness extraction

No testing

SLS test validation philosophy.

NESC Priority 2

Technical support of projects in the design phase CFD results for 

sharp on-axis, 

far left, and 

canted solid 

rocket booster 

nose cones, 

left.

Continued next page

Saturn V

F-1 engine

Conceptual illustration of JPSS on-orbit.

CPAS drop test of one-main-parachute-out configuration.
24 25

Assessments Assessments

The LDSD Project requested the NESC perform comparison 

subscale wind tunnel tests of the proposed Supersonic Ringsail 

(SSRS) and the flight proven disk-gap-band (DGB) to measure 

the static aerodynamic coefficients of these two designs at 

subsonic speeds. The assessment’s scope included obtaining 

SSRS and DGB parachute aerodynamic data to create models 

to simulate the dynamics of payloads descending at subsonic 

speeds on Mars, as well as data that will allow performance 

comparisons between the two parachutes. This work was 

performed by LaRC and JPL.

Solar Probe Plus Water-Cooled Solar Array Peer Review: 

The Solar Probe Plus mission uses photovoltaic technology 

to produce electrical power during all mission phases and 

presents unique design challenges. The NESC provided 

subject matter expertise, chaired a preliminary design-level 

peer review, and supported critical design reviews of the solar 

array cooling system. This work was performed by JSC.

Ground Operations Human Factors Task Analysis: An 

NESC request for technical support was submitted by the 

GSDO Chief Engineer, after the GSDO Preliminary Design 

Review, to investigate a gap identified by the NESC in-ground 

operations task design and analysis methodologies. This work 

was performed by KSC, ARC, JSC, and MSFC.

MSFC Additive Manufacturing Specification Review: The 

NESC formed a team of materials experts who completed a 

detailed review and provided comments on the MSFC draft 

additive manufacturing specification entitled “Engineering 

and Quality Standard for Additively Manufactured Spaceflight 

Hardware.” This work was performed by LaRC, GRC, GSFC, 

KSC, JPL, JSC, and MSFC.

Flight Test Support for an Engineering Test Article: The 

Commercial Crew Program Integration Team Guidance, 

Navigation, and Control Lead requested flight test expertise 

support for an independent review team for a commercial 

partner drop test. NESC members participated in reviews, 

reviewed plans and documentation, and provided flight test 

expertise. This work was performed by AFRC.

Technical Support to GSDO Landing and Recovery Trade 

Study for Crew Module Recovery: The NESC defined and 

assessed trades for the concept of operations for nominal 

end-of-mission crew module recovery for the EM-2 flight 

crew as soon as possible after splashdown. This work was 

performed by KSC.

Empirical Model Development for Predicting Shock 

Response on Composite Materials Subjected to 

Pyroshock Loading: The SLS Chief Technologist requested 

the NESC develop an analysis model based on both 

the frequency response and wave propagation analysis 

for predicting shock response spectrum on composite 

materials subjected to pyroshock loading. The model would 

account for the near-field environment dominated by direct 

wave propagation, mid-field environment characterized by 

wave propagation and structural resonances, and far-field 

environment dominated by lower frequency bending waves 

in the structure. The assessment’s scope included the 

development of an analytical tool to accurately predict the 

maximum expected flight environment for pyroshock induced 

into a composite material. This work was performed by MSFC 

and LaRC. NASA/TM-2015-218781

Wind Tunnel Testing of Subscale SSRS and DGB 

Parachutes: Larger parachutes with improved capabilities 

will be needed to land larger payloads on Mars. The Low 

Density Supersonic Decelerator (LDSD) Project is developing 

a new, large-diameter supersonic parachute and performing 

necessary supersonic testing to qualify it for use at Mars. 

ESD Integrated Avionics and 

Software V&V Plan Assessment: 

The ESD Chief Engineer requested 

the NESC perform an independent 

assessment of the ESD’s integrated 

avionics and software verification 

and validation (V&V) plan to 

include level of risk incurred by the 

existing approach and its level of 

completeness. The assessment’s 

scope focused on how ESD’s 

cross-program plans were defined 

by what means and methods 

various simulators, emulators, 

and test beds were scheduled, 

delivered, and integrated in 

support of EM-1 system V&V. 

The level of risk being assumed 

from widely distributed integrated 

testing avionics and software 

systems was also assessed. This 

work was performed by GSFC, 

GRC, JPL, JSC, KSC, and MSFC.

NASA/Johns Hopkins University Applied Physics Laboratory

Right problem?

Right solution?

Validate

Right problem?

Right solution?

Validate

Right problem?

Right solution?

Validate

Right problem?

Right solution?

Validate

Verifi cation planning

Integration planning

Validate (to Stakeholder needs)

Validate (to Mission Need)

Verify (to Specifi cation)

Verify (to Specifi cation)

Verifi cation planning

Integration planning

Verifi cation planning

Integration planning

Verifi cation planning

Integration planning

Verifi cation planning

Integration planning

Final

product Validate Operate Dispose Stakeholder 

needs

Qual. Accept

Qual. Accept

Qual. Accept

Qual. Accept

Component

verifi cation

Architecture

verifi cation

System

verifi cation

Element

verifi cation

Subsystem

verifi cation

System

defi nition

Element

defi nition

Subsystem

defi nition

Component

defi nition

Build and

manufacture

Architecture

defi nition

Level I

Exploration architecture

Level II

Programs

Level III

Program elements

Level IV

Element subsystems

Level V

Components

Initial 

operational

capability

Integrate

into next higher

assembly

Qualifi cation

Verify Verify Verify

- - - Level n

- - - Level n+1

Verify

Integrate Acceptance

Practice recovery of the Orion crew module. Composite panel instrumented for measurement of pyroshock loading.

Systems engineering life-cycle “V” model.

Illustration of Solar Probe Plus on orbit.

Supersonic ringsail parachute in LaRC’s Transonic Dynamics Tunnel. Task analysis of Orion crew module launch abort system integration.

Continued next page

Sierra Nevada Corp. Dream Chaser during ground testing.
26 27

Assessments Assessments

in the component space. This collaborative activity was in 

support of the independent NASA and ESA GNC technology 

roadmapping activities. This work was performed by GSFC.

AK-225 Solvent Replacement Evaluation: The Rocket 

Propulsion Test Program Manager requested NESC 

technical support in identifying a replacement for the 

hydrochlorofluorocarbon solvent (AK-225) used for precision 

cleaning of large liquid and gaseous oxygen system 

components and field service at SSC and MSFC. The 

activity’s scope included testing of selected chemicals to 

verify cleaning capability and compatibility with materials used 

in rocket propulsion and testing facility systems. This work 

was performed by MSFC, SSC, and LaRC.

MPCV Heat Shield Carrier Structure Alternate Design:

The Orion MPCV Chief Engineer requested the NESC develop 

alternate MPCV heat shield carrier structural designs with the 

goal of reducing the structural system mass by 25% from 

the existing baseline. The final NESC design was estimated 

to have achieved double the original goal. Even though the 

NESC’s alternative design was not selected by the Orion 

MPCV Program, it promoted the aggressive redesign of the 

current baseline and the net result was a significant reduction 

of overall mass. This work was performed by LaRC, AFRC, 

GRC, GSFC, JSC, and MSFC. NASA/TM-2015-218683

GEER Independent Review: The Glenn Extreme Environments Rig (GEER) is designed to simulate the temperature, 

pressure, and atmospheric compositions of bodies in the solar 

system, including those with acidic and hazardous elements. 

The Science Mission Directorate Associate Administrator 

requested the NESC provide an independent review of the 

GEER hazards assessment, sufficiency of the design, and 

operational controls to mitigate hazards. The assessment’s 

scope included a review of existing GEER documentation, onsite inspection of the rig/facility, and a tabletop review with 

the project/facility engineering team who designed and built 

the GEER. This work was performed by GRC, JPL, and SSC. 

NASA/TM-2015-218809

Continued next page

CYGNSS Peak Power Tracker Board Consultation: The 

Cyclone Global Navigation Satellite System (CYGNSS) 

consists of a constellation of eight microsatellites scheduled 

to launch in October 2016, which will use Global Positioning 

Satellites to measure ocean surface wind speed. When a 

problem developed with a system component, the CYGNSS 

team formed a group of outside experts, including the NESC, 

to work the problem. NASA’s Earth System Science Pathfinder 

Program Office Mission Manager for CYGNSS also requested 

NESC expertise with power supply, peak power tracking, and 

analog circuitry background to improve performance of the 

existing design. This work was performed by KSC.

Support to ARM Robotic Concept Integration Team: The 

NESC was requested to provide technical support to the 

Asteroid Redirect Mission (ARM) Robotic Concepts Integration 

Team and Independent Review Team to help determine the 

mission concept and configuration of the robotic portion of 

the ARM, as well as integrate the robotic and crewed mission 

segments. The NESC team worked with ARM project teams, 

performed a comprehensive risk assessment, and made 

recommendations for risk mitigation to the project teams. This 

work was performed by JSC, GSFC, JPL, KSC, and MSFC.

Inconel 718 Additive Manufacturing Mechanical Property 

Investigation: An NESC team provided independent 

oversight and technical expertise in the investigation of 

apparent anomalous ambient temperature tensile test data 

from Inconel 718 test specimens. The investigation team 

provided a comprehensive summary of the most probable 

cause of the anomalous tensile test results. Metallurgical 

analysis of supplemental test specimens generated during 

the investigation provided conclusive data on the cause and 

lessons learned from this investigation and will be incorporated 

in the draft Agency additive manufacturing certification 

requirements document. This work was performed by MSFC 

and GRC.

Spacecraft GNC Component Open Source Benchmarking:

Using open-source data, an industry-wide survey of globally 

available guidance, navigation, and control (GNC) sensors, 

namely star trackers, gyros, and sun sensors, was undertaken 

jointly by NASA and the ESA GNC teams. Data on reaction 

wheels (RW) and control moment gyros (CMG) were also 

collected. The survey intent was to identify gaps in the 

available capabilities. Mission types that are not currently 

well-served by the available components were considered, as 

well as some missions that would be enabled by filling gaps

5000

2400

10

0.1

Available 

reaction

wheels

Control 

moment

gyros

RW torque gap

RW momentum 

gap

Momentum (N-m-sec)

Torque (N-m)

Spacecraft agility

Increasing cost & complexity

0.01 2 5 20 4200

Spacecraft size

Carbon laminate/

stringer heat shield

Avcoat ablator

Crew module

Illustration of Orion MPCV 

heat shield components

Demonstration of Solstice PF Solvent use at the SSC Component Processing Facility (CPT) with Jon Herdlein, left, a Honeywell chemist, and 

Darrin Spansel, Lockheed Martin, CPT technician.

 GEER stainless steel pressure vessel.

Conceptual illustration of potential capture mechanism for the ARM.

Illustration of a CYGNSS microsatellite on orbit. Test specimens developed by additive manufacturing with unique 

identifiers included on ends.

Momentum-torque space chart showing available values for RWs and CMGs.
28 29

Priority 3: completed work in 2015

Technical Support to STMD Brazing Tiger Team: The NESC 

provided metallic materials and manufacturing subject matter 

expertise to the Space Technology Mission Directorate (STMD) 

Brazing Tiger Team. This effort was the impetus behind the 

creation of an Agency brazing team to provide review and 

guidance to future programs/projects utilizing this joining 

method. Investigation results of team activity is documented 

in the Agency’s Lessons Learned Information System Entry: 

14001. This work was performed by MSFC, GRC, GSFC, JPL, 

JSC, KSC, and LaRC.

Shell Buckling Knockdown Factors (SBKF) 

Update: Composite Structures

The SBKF assessment was chartered to develop and 

experimentally validate new analysis-based buckling 

knockdown factors for stability-critical metallic and composite 

launch vehicle structures. The assessment team has provided 

new metallic structure knockdown factors for the Space

Launch System (SLS) core stage, which resulted in 

documented mass, cost, and schedule savings. In order to 

make similar gains for composite structures, the SBKF Team 

is planning to perform five large-scale validation tests by 

partnering with additional Agency, industry, and international 

organizations. The first large-scale validation test—the 

buckling failure and subsequent test and analysis correlation 

of an 8-foot diameter composite cylindrical test article—is 

scheduled for May 2016. The test article is a honeycombcore sandwich composite with an out-of-autoclave, singlepiece construction that was provided by Northrop Grumman. 

The test article will be extensively instrumented and tested to 

failure under axial compression. The test article construction 

is typical of most dry launch vehicle structures, and the test 

article will be the first large-scale composite structure tested 

as part of this effort.

The test is being jointly funded by the NESC, MSFC, 

SLS, and the LaRC Space Technology and Exploration

Directorate. In addition to this test, in FY16 the remaining 

four test articles will be designed and a joint NASA-industry 

technical interchange meeting will be held on shell buckling.

Assessments Assessments

Priority 4: ongoing work in 2016

� Micrometeoroid and Orbital 

Debris Pressure Vessel Failure 

Criteria

� Shell Buckling Knockdown 

Factor Proposal

� Implementation of JR-A 

Methodology into the NASGRO/

Fracture Analysis by Distributed 

Dislocations Codes to Improve 

Crack Instability Analysis 

� Rad750 Qualification Testing

� Layered Pressure Vessel 

Technical Consultation

� Space Technology Mission 

Directorate Formulation of 

Extreme Environments Power 

Semiconductor Project

� Support for Development of 

Softgoods Design Factors of 

Safety

 Priority 3: ongoing work in 2016

 Priority 2: ongoing work in 2016

� Independent Modeling and 

Simulation for Commercial Crew 

Program Entry, Descent, and 

Landing

� Assessing Risks of Frangible 

Joint Designs

� SpaceX Electrical Power System 

Review 

� Development of a Manned 

Vehicle Reentry Thermal 

Protection System Damage 

Assessment and Decision Plan 

�Engine Hot Fire Acceptanc

Test Procedure Requirements

� Electrical, Electronic, and 

Electromechanical Parts Testing 

for Commercial Crew Program

� Support to Commercial Crew 

Program Crew Orientation Tiger 

Team

� Commercial Crew Program 

Avionics Architecture Review

� Commercial Crew Program 

Aerodynamics Peer Review

� Materials and Processes 

Requirements for SpaceX Orbital 

Tube Weld Acceptance of Class 

A Welds

� Electrical, Electronic, and 

Electromechanical Parts Statistical 

Analysis Support

� Exploration Systems 

Independent Modeling and 

Simulation

� Model of Space Launch System/

Multi-Purpose Crew Vehicle/

Ground Systems Development 

and Operations Stack on the Pad

� Exploration Systems 

Development Verification and 

Validation Plan 

� Independent Verification of 

Abort Loads

� European Service Module 

Hyper System Valve Bellows Peer 

Review

� Support for Plumbrook 

6-Degree of Freedom Shaker 

Table

� Effects of Humidity on Dry 

Film Lubricant Storage and 

Performance

� James Webb Space Telescope 

Space Environment Launch 

Constraints

� Peer Review of the MultiPurpose Crew Vehicle 

Aerodynamic/Aerothermal 

Database Models and Methods

� Remote Imaging for Exploration 

Flight Test-1 Entry Heating Risk 

Reduction

� Space Launch System 

Aerosciences Independent 

Consultation and Review

� Space Launch System 

Advanced Booster Composite 

Case/Internal Polybenzimidazole 

N-butyl Rubber Insulation 

Development

� Space Launch System RS-25D 

Main Engine Ignition Acoustics 

and Initial Overpressurization 

Design Load Determination

� Analysis of Anthropomorphic 

Test Dummy Response for 

Proposed Orion Crew Impact 

Attenuation System

� Orion Multi-Purpose Crew 

Vehicle Tube Weld Digital 

Radiography Assessment

� Multi-Purpose Crew Vehicle 

Avcoat Study

� Ascent Abort Loads Tool 

Development

� Attitude Control Motor 

Carbon/Carbon-Silicon Carbide 

Component Performance Testing 

Approach for Certification

� Human Vibration Modeling for 

Orion Multi-Purpose Crew Vehicle 

Coupled Loads Analysis

� Orion Multi-Purpose Crew 

Vehicle Program Window 

Wavefront Measurement 

Assessment

� Launch Vehicle Buffet 

Verification Testing

� Stability and Flight Readiness of 

the Space Launch System Flight 

Control System with Adaptive 

Augmentation

� Orion Crew Module 

Environmental Control and Life 

Support System Assessment

� Nonlinear Slosh Damping 

Analysis for Launch Vehicles

� Evaluation of Micrometeoroid 

and Orbital Debris Risk 

Predictions with Available On-orbit 

Assets

� Risk Reduction of Orion Crew 

Module Government-Furnished 

Environmental Control and Life 

Support 

� Review of Space Launch 

System Flight Software

� Technical Support for Space 

Launch System Vibroacoustics 

Plans and Analysis (Follow-On)

� Orion Multi-Purpose Crew 

Vehicle Organizational Safety 

Assessment Technical Support

� Assessment of Ascent Abort-2 

Downgrade

� Alternative Orion Multi-Purpose 

Crew Vehicle Small Cell Battery 

Design Support

� Application of System 

Identification to Parachute 

Modeling

� Bond Verification Plan for the 

Orion Crew Module Molded 

Avcoat Block Heat Shield Design

� Orion Multi-Purpose Crew 

Vehicle Titanium Hydrazine Tank 

Weld - Sustain Load Cracking 

Issue

� Space Launch System Program 

Block I Booster Element Alternate 

Internal Insulation Risk Reduction 

Assessment

� Review of the Orion MultiPurpose Crew Vehicle-European 

Service Module Interfaces

� Analyze Variable Effects 

on Oxygen Impact Reaction 

Sensitivity of Aerosol Solstice 

Performance Fluid

� Orion Multi-Purpose Crew 

Module Guidance, Navigation, 

and Control Fault Detection, 

Identification, and Recovery 

Independent Review 

� Space Launch System Interim 

Cryogenic Propulsion Stage 

Frangible Joint Assembly Integral 

Manifold Attachment Preliminary 

Design Review Evaluation

� Launch Abort System Risk 

Mitigation

� Reaction Wheel Performance on 

NASA Missions

� Modal Mass Acceleration Curve 

Loads Analysis Methodology

� Carbon Fiber Strand Failure 

Dynamic Event Characterization

� Stress Ruptures Composite 

Overwrapped Pressure Vessel

� Composite Pressure Vessel 

Working Group

� Modeling of Crawler/

Transporter, Mobile Launcher, and 

Forcing Functions

� Soil Moisture Active and Passive 

Reflector Boom Assembly 

Deployment Risk Assessment

� Independent Assessment of 

the Backshell Pressure Field 

for Mars Science Laboratory 

Entry, Descent, and Landing 

Instrumentation 2 (Mars 2020)

� Maxwell Single Board Computer 

Panels Assessment (Lot 2 - 

follow-on task)

� Helium Composite Overwrapped 

Pressure Vessel Qualification 

Review

� Infrared Laser Sensor 

Technology Readiness and 

Maturation

� Global Ecosystem Dynamics 

Investigation Laser Side-Lobes 

Review Team Chair

� Independent Review of Additive 

Manufacturing Development Plans

� Evaluation/Validation of Range 

Safety Blast Distance Focusing 

Overpressure Model

� United States Navy Multi-Stage 

Supersonic Target

� Human Factors Review of 

Space Network Ground System 

Sustainment Project

� Vehicle Integrated Propulsion 

Research Experiment Impacts on 

the C-17 Engine-Pylon Interface

� Stratospheric Aerosol and Gas 

Experiment-III Interface Adapter 

Module Subsystem Anomaly 

Support

� Solar Probe Plus Fields Whip 

Antenna Assessment

� Review Committee Support: 

Radiation Exposure Testing of 

Europa Clipper Composites

� Review of Ultem 9085 Material 

Properties Characterization 

Document

� Support to NASA In-Space 

Manufacturing Project

� Support to Additively 

Manufactured Metals in Oxygen 

Systems Project

� Support to NASA Standard

5009 Development

SBKF’s 8-foot diameter composite shell test article.

NESC Priority 4

Work to avoid potential future problems

NESC Priority 3

Known problems not being addressed

by any project
30 31

Assessments � Empirical Launch Vehicle 

Explosion Model Evaluation � Fracture Control Standard and 

Handbook

� Support for Orion Alternate 

Heat Shield Study

Priority 5: ongoing work in 2016

NESC Priority 5

Work to improve a system 

Priority 5: completed work in 2015

Support to NASA MagicDraw Cloud License Project:

An NESC team provided expertise to an Agency-wide 

initiative to license MagicDraw, a systems engineering 

software tool currently in use by NASA Centers as a cloudbased application. This work was performed by GSFC, JPL, 

and JSC.

Assessing Risks of Frangible Joint Designs Update:

The NESC Frangible Joint Design Assessment is an empirical 

test program undertaken at the request of the Commercial 

Crew Program (CCP) to determine the effects that various 

design parameters and environmental factors have on single 

mild detonating fuse joint separation capability. The objective 

is to characterize the interactions and sensitivities of the key 

design parameters, which could provide design guidance for 

safe and reliable frangible joints supporting human spaceflight. 

There have been 79 tests to date of different frangible joint 

designs representative of the CCP configurations. Two-and 

three-dimensional LS-DYNA models are being developed and 

correlated to the test data. Testing, data analysis, and model 

development is expected to conclude in the fall of 2016.

TB 15-01: Preventing Incorrect Installation of Polarized Capacitors

Concerns that the incorrect installation of polarized capacitors has continued, 

despite lessons learned from past installation issues, Dr. Christopher Iannello, 

NASA Technical Fellow for Electrical Power, and Andrew Ging, an industry partner 

on the NESC Electrical Power Technical Discipline Team, initiated this technical 

bulletin to shed new light on a timeworn problem. Using an NESC assessment of 

an anomaly on board the International Space Station as an example, Dr. Iannello 

and Mr. Ging highlight the ways in which reverse installation can occur, and 

provide a short list of best practices— from procedure review to the correct use 

of symbols on schematics— to help eliminate any future issues with reverse 

installation. 

TB 15-02: Best Practices for Use of Sine Burst Testing

For more than two decades, sine burst testing has provided a method of strength 

testing for aerospace hardware that not only minimizes potential for damage to 

the test item, but can be performed on a shaker table along with other tests to 

maximize efficiency. But with all testing comes potential risk. In this Technical 

Bulletin, Mr. Daniel Kaufman, NESC Discipline Deputy for Loads and Dynamics, 

identifies top risks such as unintended over-test or erroneous calculations, and 

provides best practices to help mitigate those risks and take full advantage of 

what sine burst testing provides.

TB 15-03: Best Practices for Use of Sine Vibration Testing

Sine vibration testing replicates the low-frequency launch environment. This test 

method is used mainly on flight articles to determine if they can survive the harsh 

launch environment. Testing involves accepting calculated risk, but failure to 

follow best practices for sine vibration testing has resulted in avoidable damage 

to flight hardware. Dr. Curtis Larsen, NASA Technical Fellow for Loads and 

Dynamics; Mr. Daniel Kaufman, NESC Discipline Deputy for Loads and Dynamics; 

and their Technical Discipline Team identified top risks and documented best 

practices to help mitigate those risks and take full advantage of what sine 

vibration testing has to offer.

NESC Technical Bulletins can be found at nesc.nasa.gov

George Quezada of Jacobs Technology measures a frangible joint.

NESC Technical Bulletins
32 33

Continued next page

Transonic Flight

In transonic flight, a spacecraft is transitioning from subsonic to supersonic 

flight, but portions of the vehicle can generate supersonic flow before it 

actually goes supersonic. The ring structure in the CFD run pictured at left 

is a region of supersonic flow embedded in subsonic flow. Likewise, even 

after the vehicle has gone supersonic, portions of the flow can decelerate 

into subsonic. It is that mix of subsonic and supersonic that causes the 

chaotic air flow around the spacecraft.

Who Benefits from Improved Buffet Environment Prediction?

NASA’s commercial partners, the aeronautics industry, the launch vehicle 

community, and the spacecraft community could benefit from new prediction 

methods, says Schuster. “For a long time we focused our computations on 

steady flows. Now we’re pushing those codes to try and predict unsteady 

flow, which helps with maneuvering aircraft, buffet, and many other things, 

so understanding these techniques for unsteady flow has a wide range of 

application across the industry. We spent about 20 years perfecting steady 

flow,” he says. “I see us spending another 20 getting our capability up to 

speed on unsteady flow as well.” 

diameter. “Air flow accelerates around these corners, can’t 

make the turn, and then separates and starts rolling off,” 

Dr. Schuster states. 

Whatever their cause, buffet environments can elicit a 

buffet response in the spacecraft, causing things to shake. 

And for critical systems, like avionics, that shaking can 

cause these systems to fail.

“And if they fail, then the vehicle fails,” he notes. In addition, 

spacecraft tend to enter the transonic range at the same 

time they reach their maximum dynamic pressure, or the 

maximum loads the vehicle will encounter during its flight. 

“So these buffet fluctuations are hitting the vehicle right at 

the worst time. That’s why the whole buffet problem is so 

important.”

New Computational Approaches

When the SLS Program requested an assessment to 

help determine the potential for high buffet environments 

on specific areas of the spacecraft, Dr. Schuster’s NESC 

team needed to investigate both old and new techniques 

for acquiring buffet data. “We haven’t designed a new 

launch vehicle in quite a while,” says Dr. Schuster, and 

because the Orion/SLS will carry astronauts to the Moon 

and beyond, “there are more stringent requirements when 

we put humans in the loop.” 

Existing data from Apollo was a starting point, but ultimately, 

“a lot of what we had at our disposal from the Apollo era 

isn’t applicable to SLS,” he explains. “It has to do with 

the Orion/SLS shape. The problem is very geometry 

dependent. SLS has boosters strapped on the outside. 

And we’ve added the new Alternate Launch Abort System. 

It looks very different from what we sent up with Apollo, so 

it generates a very different buffet environment.” 

Because computational methods used in the past were 

not always successful in predicting these environments, 

NASA needed a new approach. The NESC team worked 

with an engineering team at LaRC who had developed 

a hybrid computational fluid dynamics (CFD) method 

using Reynolds Average Navier Stokes and Large Eddy 

Simulation. The NESC team used that hybrid method to 

predict the buffet environment on a specific area of the 

SLS. Then they compared those results with data gathered 

from recent NESC wind tunnel tests to confirm whether the 

CFD code was accurate in its predictions. “We found out 

this was doing a better job than we had ever experienced 

before,” Dr. Schuster says. “It was looking like that hybrid 

scheme was a real possibility.” 

Excited with the preliminary results, the team wanted to 

take it a step further. “Since we knew we had a high buffet 

environment in a specific region,” Dr. Schuster says, “could 

we use that CFD code to change certain design parameters 

on the vehicle and lessen the buffet problem?”

The answer was yes. “We started focusing on the shape of 

the booster nose cones,” he says. Currently, the SLS nose 

cones resemble those flown on Shuttle, a conical shape 

with a spherical nose cap. The team examined different 

designs with more aerodynamically streamlined shapes. 

“The CFD code was telling us that we could affect the buffet 

environment pretty significantly by changing the nose cone 

shape. We could easily cut the buffet environment in half.”

But the proof would come from testing these new designs in 

a wind tunnel, which they did by taking the most promising 

designs, building them, and attaching them to an SLS 

model. “We were able to demonstrate that the wind tunnel 

predicted the same buffet environment drops as the CFD 

code.” That was big news, Dr. Schuster adds. “Now we 

Aerosciences

There is a very short window of time, about 

30 seconds, between launch and a rocket’s 

transition from subsonic to supersonic flight, when 

the airflow around the vehicle begins a chaotic 

dance of sorts. It is called buffet, and it likes to 

occur in the so-called transonic flight regime. 

NASA engineers and the aerospace industry 

have been wrestling with the unpredictability 

of transonic flight for over half a century, since 

before Chuck Yeager successfully piloted the Bell 

X-1 beyond the sound barrier and launched us 

into the space age. 

Today, as the design of the Orion Multi-Purpose 

Crew Vehicle and the Space Launch System 

(SLS) takes shape, the challenge persists. Orion/

SLS is a larger, more geometrically complex 

spacecraft than those flown during the Apollo era, 

and engineers are facing new challenges as they 

navigate Orion’s journey through the transonic 

flight regime (see box next page). 

Through NESC assessments, Dr. David Schuster, 

NASA Technical Fellow for Aerosciences, has been 

tackling some of these challenges, most recently 

with buffet environments, which can occur during 

transonic flight. 

“The buffet environment is the fluctuating pressure 

that generates an oscillating load on the vehicle,” 

says Dr. Schuster. That fluctuating pressure can 

cause shock waves, which interact with the 

boundary layer or the flow of air closest to the 

vehicle. “The shock wave can cause that flow to 

detach or separate,” he explains. “And when it 

does, it becomes very chaotic and generates this 

fluctuating pressure that can affect the structure 

and other systems on the vehicle.”

Besides shock waves, buffet environments can 

also be triggered by abrupt changes in vehicle 

geometry, for example, where support hardware is 

located or where there are changes in the vehicle’s 

CFD was used to investigate the contribution of buffet to booster interface loads on core/booster launch 

vehicle configurations. From left: (A) Sharp on-axis booster nose — pressure on core stage and solid rocket 

booster is the base line configuration; (B) Sharp canted nose configuration indicates reduced pressure on 

core stage but increased pressure on booster, and (C) Canted ogive indicates reduced pressure on both 

booster and core stage. These data were verified by wind tunnel tests.

SLS model with canted ogive booster nose configuration in LaRC’s Transonic Dynamics Tunnel. 

Effects of canting booster nose on unsteady pressures.

(A) Sharp on-axis 

booster nose.

(B) Sharp canted 

booster nose.

(C) Canted ogive 

booster nose.

New Approaches to Refining the 

Launch Vehicle Buffet Environment
34 35

Guidance, Navigation, and Control

Propelling technology forward normally involves building 

on past accomplishments. That is what prompted 

Cornelius (Neil) Dennehy, NASA Technical Fellow for 

Guidance, Navigation, and Control (GNC), to take a look 

back at NASA’s first space rendezvous. A half-century ago, 

two crewed Gemini spacecraft, Gemini 6A and Gemini 7, 

conquered the technological milestone of meeting up with 

one another while orbiting 160 nautical miles above the 

planet. 

Though engaged in the study of space rendezvous for more 

than 20 years, Mr. Dennehy was struck by the enormity 

of the task that lay before those early astronauts and 

engineers. “They had to start with a clean sheet of paper,” 

he says. “They had to work out the question of relative 

motion, the radar sensors, the modeling and simulation, 

the training. They had to create it all. Back then, they didn’t 

know what they didn’t know, so they were unencumbered 

and creative. They were excited about breaking new 

technical ground.”

A fresh look at this first proximity flight in low Earth orbit 

inspired Mr. Dennehy, bringing a renewed vigor to his 

current work on rendezvous and capture capabilities. 

And it reminded him that today’s state-of-the-art sensors, 

which are guiding unmanned resupply spacecraft to their 

docking ports at the International Space Station (ISS), and 

the plans that are underway for a rendezvous mission with 

an asteroid, were built on that earlier Gemini success and 

the subsequent refinement of rendezvous with Apollo and 

Shuttle. And it cemented his conclusion that continued 

evolution in rendezvous technology will be the key to 

getting humans to Mars.

“The fundamental physics have already been flight 

proven,” explains Mr. Dennehy. Following that first space 

rendezvous in 1965, NASA refined its capabilities in 

later Gemini missions, achieving the first docking of two 

spacecraft. From there, Apollo missions honed NASA’s 

Earth orbit rendezvous skills. Apollo 10 saw the first lunarorbit rendezvous. Then the Shuttle Program saw more 

than 50 rendezvous and docking missions, with satellites 

in need of upgrades or repairs, with Mir, the Hubble Space 

Telescope, and in-space assembly and docking of the ISS. 

“Our rendezvous operations became a very polished, wellorchestrated process,” he says. “We know how to do it. 

Now we need to focus on increasing the performance of 

these technologies, driving costs down, and finding ways 

to do rendezvous more autonomously. There are still 

challenges out there for us.” 

To that end, Mr. Dennehy is leading a system-level 

capability leadership team for the Agency focused on 

rendezvous and capture, and for the past 5 years has also 

been running a grass roots autonomous rendezvous and 

docking community of practice. Last summer he gave a 

lecture in Europe on the numerous lessons learned over 

the years from relative motion missions. “It’s an active area 

of study right now,” he says. “We’re working hard to make 

sure we have the right capabilities for the future needs 

of rendezvous and capture — workforce, facilities, tools, 

testbeds — all of the ingredients we’ll need on a journey 

to Mars.” 

Advancing Existing Technology

Mr. Dennehy describes rendezvous and capture as more 

than just a single-discipline endeavor. “It is a true systems 

capability — it’s GNC, software, mechanical systems, 

avionics, sensors, vision processing— a true multidisciplinary feat.” A unique combination of planning tools 

on the ground, onboard processing, control algorithms, 

navigation algorithms, docking mechanisms, and capture 

hardware are required for a successful meet-up in space. 

But the area where Mr. Dennehy has focused much 

attention is lidar, also know as Light Detection and 

Continued next page

Aerosciences

have a computational tool that we can use, outside of the 

wind tunnel, to cycle through numerous designs before we 

actually go and commit to building hardware.” 

For now, there are limits to using this new CFD tool. It is 

expensive to run as it ties up computer resources for weeks 

at a time. “But for specific problems where we want to look 

at the detailed physics of what’s going on,” Dr. Schuster 

says, “this tool gives us a capability that we never had 

before.” 

To make this new CFD tool an accessible, functioning 

engineering tool will take time. “What we really want is to 

get this into the hands of the engineers so they can use it. 

But first we have to reduce the time it takes to generate 

data so it doesn’t bog down computer resources. There’s a 

lot of work to do, but it really shows a lot of promise.” 

Validating CFD Approaches with

New Wind Tunnel Measurement Technology

In the meantime, wind tunnels are still the main resource 

for gathering buffet environment data, so work continues 

to make them better at that job. “The wind tunnel tests 

to measure this buffet issue require that we measure the 

pressure at a large number of locations on the surface of the 

vehicle,” says Dr. Schuster. To do that, engineers employ 

unsteady pressure transducers, up to 400 of them on a 

single SLS model. But the transducers are expensive and 

add significant costs to the wind tunnel testing process. 

And even with 400 transducers, engineers are limited in 

how closely together they can be applied, which leaves 

gaps in the data measurement. 

“It’s just not enough to get the resolution we need to 

accurately predict what is happening on the vehicle. So 

we’re always doing a lot of interpolation and trying to use 

engineering judgment to account for these gaps.”

But a new technology has recently emerged to fill these 

gaps. Late in 2015, the NESC team assisted in testing 

unsteady pressure sensitive paint (uPSP). When painted on 

a model, the uPSP can respond to pressure on the model 

at such a fast rate that engineers can measure the buffet 

frequencies. “The model is bombarded with light so that 

we can see every nook and cranny on the vehicle. Then we 

videotape the model with high resolution cameras.”

The result is hundreds of thousands of pixels, each denoting 

a pressure point. Instead of being limited to four or eight 

transducers placed around a circumference of the model, 

uPSP leaves no gaps. “It allows us to get a much more 

comprehensive view point of the fluctuating pressure field 

on the vehicle, without having to worry if some phenomenon 

occurred between our sensors that we didn’t pick up.” 

Weighing the Benefits of Buffet Prediction

This is an exciting time for Dr. Schuster and the 

Aerosciences community. Adapting new CFD codes and 

pressure sensitive paint to the process of predicting buffet 

environments is shaping up to be a tangible advancement 

in the discipline. But he sees the benefits taking an even 

further leap forward.

“If we want to go to Mars,” he says, “we could just build 

margin into our vehicles so they’ll be robust to this buffet 

problem. But we’d likely build a vehicle that’s three times 

stronger than it needs to be, just to be sure it can survive 

the buffet, and make up for any uncertainties we might 

have in our ability to predict it.” 

But that makes the vehicle a lot heavier than it needs to 

be, when weight would already be at a premium on longterm missions. “Being able to predict buffet environments 

more accurately will allow us to reduce the margin, reduce 

the weight, and give us a more efficient vehicle. Then we 

can use that weight to actually execute the mission,” says

Dr. Schuster. “That’s the real benefit.”

Mach 0.8

Mach 0.92

Mach 1.1

Far left, Gemini 7 seen 

from Gemini 6A during the 

first U.S. rendezvous and 

station-keeping between 

two crewed spacecraft. 

Left, Gemini 8 rendezvous 

with the Gemini Agena

Target Vehicle to perform 

the first U.S. docking

between two spacecraft.

Generic launch vehicle configuration of Coe and Nute in the ARC Unitary 

Plan Wind Tunnel. The model is covered with pressure sensitive paint to 

investigate new means of measuring fluctuating pressures (see below).

Pressure loads on the generic launch vehicle wind tunnel model were 

determined by time-averaged pressure sensitive paint measurements.

Space Rendezvous

Tomorrow’s technology will build on historical breakthroughs

New Approaches to Refining the Launch Vehicle Buffet Environment, continued
36 37

Aside from advances in lidar, “we’ll also need higher 

degrees of autonomy and operational flexibility,” states 

Mr. Dennehy, for managing a rendezvous that could be 

happening millions of miles away from Earth. In a mission 

like OSIRIS-REx, ground operations will be doing navigation 

and flight dynamics, but only up to a point. “The time it 

will take a signal to travel to the spacecraft and back for 

processing on the ground will be on the order of minutes,” 

Mr. Dennehy says. “When OSIRIS-REx is doing its TAG 

maneuver, it will have to do it autonomously since the 

ground can’t realistically be in the loop.” 

What is learned from OSIRIS-REx can then be applied 

to another mission— a Mars sample return. “A lander 

will go down to the surface, gather samples of soil, and 

launch itself back to orbit and rendezvous with an orbiting 

craft.” This could mean in-space assembly of assets that 

would involve rendezvous and docking with platforms and 

other spacecraft— even further out into the solar system. 

“Autonomous rendezvous and capture will be an integral 

element of going to Mars,” he says.

Autonomous rendezvous could also lead to lower 

operational costs. More autonomy may eventually reduce 

the workload for on-ground crews or the pilots and crews in 

the spacecraft itself. “But we’ll have to work up to that very 

carefully, by advancing this system capability in a careful 

and well-thought-out manner.” 

“We‘ve certainly come a long way, but we have a long 

way to go,” says Mr. Dennehy. That is why building on 

what has already been accomplished is so important. 

“The environment has changed and we have to find more 

affordable ways to do this. We can’t afford the development 

of entirely new spacecraft-unique rendezvous solutions 

each time a future mission application arises. As creative 

engineers, we’d all like to start with that clean sheet of 

paper and show how innovative we are, but we need to 

both leverage our existing rendezvous architecture for our 

future missions and increase the levels of autonomous 

operations,” he says. “That will get both implementation 

and operations costs down so that we can fly even more 

missions, and that’s what we all want to do here at NASA.”

Notional representation of the Vision Navigation System flash lidar illuminating the ISS to determine range and bearing relative navigation information.

Guidance, Navigation, and Control

Ranging. “Lidar has become one of the basic relative 

navigation sensors we use on missions,” he says. 

“Lidar sensors are most useful when there are mission 

requirements for obtaining lighting-independent relative 

navigation information or when there is a direct ranging 

requirement. It comes down to the sensors. If you can’t get 

data about where the target is relative to your position, you 

won’t have the data needed to accomplish a rendezvous.

It won’t occur without the right sensor technology.”

There’s an art to selecting the appropriate relative navigation 

sensor suite for each rendezvous mission application. 

Typically, a combination of wide-angle and narrow-angle 

visible cameras, infrared cameras, laser range finders, and 

more recently flash or scanning lidar relative navigation 

sensors are used, all of which are optical-based sensors. 

The shift from radar-based to optical-based sensors for 

rendezvous, which occurred over the decades since the 

first radar-guided Gemini rendezvous, was driven by the 

desire to develop a fully autonomous rendezvous, proximity 

operations, and docking functional capability. 

“Over the past few years, optical relative navigation 

sensors have successfully been used on the European 

Space Agency’s Automated Transfer Vehicle, the Japan 

Aerospace Exploration Agency’s H-II Transfer Vehicle, 

as well as the U.S. commercial Cygnus and Dragon 

spacecraft, to rendezvous with ISS for cargo resupply. The 

one noteworthy exception is with Russian spacecraft that 

rendezvous with the ISS. They employ radar-based relative 

navigation sensing, which has been their legacy approach 

since the 1960’s.” 

Radars will continue to have a role as a GNC relative 

navigation sensor, particularly for planetary landing mission 

applications where they are used for altimetry and velocity 

measurement, Mr. Dennehy says. “In fact, every single 

spacecraft, robotic or manned, that landed on the Moon 

or Mars, has used radar. With continued investments in 

lidar technology development, I can foresee the day when 

planetary landings will be accomplished with relatively 

small, low power, high-performance lidar sensors, 

potentially replacing radars. There is also the possibility of 

multi-functional lidar sensors for future mission applications 

that will perform direct relative range and range rate 

measurements as well as providing the raw data needed 

for target attitude pose estimation and hazard detection.” 

Over the past decade, lidar sensors have become an 

increasingly intriguing relative navigation option for GNC 

engineers designing rendezvous missions. Lidar works 

similarly to radar, but uses laser light pulses instead of 

radio-frequency electromagnetic pulses to measure the 

distance from and bearing to a target object, like another 

spacecraft. The laser return data collected must then be 

processed in order to reach a relative navigation state. 

Lidar sensors cannot only provide the range and bearing 

to the target but can also provide the attitude orientation 

(or “pose”) of the target relative to the chase spacecraft. 

Several NESC assessments, led by Mr. Dennehy, have 

focused on lidar technology. “We want to help characterize 

their performance and the flight software algorithms that 

process the data.” It is a step forward toward improving 

the reliability and lifecycle length needed for prolonged 

missions in space. 

Mr. Dennehy recently led an NESC assessment to evaluate 

the lidar-based natural feature tracking technology planned 

for OSIRIS-REx (Origins-Spectral Interpretation-Resource 

Identification-Security-Regolith Explorer). “It’s an asteroid 

sample return mission set to launch in September 2016. 

The spacecraft will rendezvous with an asteroid and 

through a controlled touch-and-go (TAG) maneuver, will 

collect a sample and bring it home.” What complicates 

this mission is the rendezvous target. The motion of small, 

distant bodies is often not well-known or characterized. 

It is not another known cooperative spacecraft. It is not 

engaging with a well-defined docking port on ISS. “It’s a 

rendezvous between a spacecraft and a natural object, a 

primitive body,” he says. 

“Autonomous rendezvous and 

capture will be an integral 

element of going to Mars”

(A) Lidar sensor located in Space Shuttle orbiter payload bay. (B) 

Lidar-sensed intensity image of ISS docking adaptor. (C) Lidar-sensed 

closeup of ISS docking adaptor.

A

B C
38 39

computer. There are a lot of enhancements you can do to 

the images, using digital filters within the software, which 

make it easier to find defects. Then you can print your 

report and you are ready to go.” 

During the assessment, the NESC team used commercially 

available CR equipment to put the technology to the 

test. They used tube weld samples of various diameters, 

thicknesses, and materials, such as stainless steel and 

titanium. The team looked at good welds, as well as 

those where lack of fusion and porosity defects were 

manufactured into the samples. Overall, they evaluated 

examples of some of the hardest and easiest scans 

currently being done on the Orion crew module, looking at 

more than 100 defects. After careful study of the results, 

what they ultimately found was that for finding the flaws in 

tube welds, CR was doing a better job than film. 

“Until recently, the pixel size on CR detectors wasn’t nearly 

as fine as the grain size of the film,” says Dr. Prosser. 

“Historically we could get better results with film because 

we had better media to record the images. But now CR 

plates and scanners have gotten much better.”

Opening the Door for Digital

Results from the NESC assessment have opened the 

door for production use of CR, states Dr. Prosser. Proving 

the technology will work for the Orion MPCV Program in 

certain applications will hopefully stimulate more in depth 

probability of detection studies. “It also opens the door to 

trying CR on other problems where we typically use film.”

The transition will not be a fast one, though. Baselines for 

radiography in NASA Standard 5009 are based on film. 

“But now that we’ve had some success, it will pave the way 

to doing the work required to get into the NASA standard 

and applying the technology on a wider scale. It will help 

us transition from film and bring significant advantages 

in capabilities and cost savings,” to NASA as well as its 

commercial crew partners, Dr. Prosser adds. “There’s 

still more work to be done, but this is an important step. 

To include CR in the NASA standard will be a big change 

across the Agency and for every program.” 

Tube weld sample specimens with 

small dual-pore and large single-pore 

defects, far left, and lack-of-fusion 

defects, left, were used to evaluate 

x-ray NDE techniques. The ability of 

inspectors to detect the defects using 

film and computed radiography were 

examined. Computed radiography 

proved to be superior to film in these 

tests.

How Computed Radiography Works

CR uses similar equipment to conventional 

radiography, except that in place of a film to create 

the image, an imaging plate made of photostimulable 

phosphor is used. The plate is housed in a special 

cassette and placed under the body part or object to 

be examined, and the x-ray exposure is made. Then, 

instead of taking an exposed film into a darkroom for 

developing in chemical tanks or an automatic film 

processor, the plate is run through a special laser 

scanner, or CR reader, that reads and digitizes the 

image. CR can then leverage powerful software to 

enhance the digital images through functions such as 

contrast, brightness, filtration, and zoom.

Nondestructive Evaluation

Transitioning from familiar and trusted technology to new, 

more advanced technologies isn’t always a choice; It is 

a necessity. 

For NASA, x-ray film radiography has been the go-to 

inspection method for decades. Right now, NASA is 

using this technique to inspect tube welds on the Orion 

Multi-Purpose Crew Vehicle (MPCV) that will one day take 

astronauts to destinations beyond our Moon. But film 

production is declining, and decisions on what technology 

will take its place must be made before film costs become 

unaffordable or production ceases all together.

During the Orion Tube Weld Digital Radiography Assessment, the NESC evaluated technologies that may soon 

replace film radiography, not just for the Orion MPCV, 

but for the Agency’s nondestructive evaluation (NDE) 

community as a whole.

Film radiography works by finding hidden flaws in materials 

using x-ray photons to capture those flaws on film. “It’s 

very common around the Agency and it’s used for many 

different things, everything from solid rocket booster aft 

skirt welds to small tube welds, tanks, seams, and for part 

certification,” says Eric Burke, Technical Lead for the NESC 

assessment. “It’s the first technique we use to get a quick 

look inside, and it was one of the first techniques added to 

our NASA Standard 5009 (NDE Requirements for Fracture 

Critical Metallic Components). It’s been around for a long 

time.”

Most people are familiar with film radiography’s use in the 

medical community. “It’s exactly the same as a medical 

x-ray,” Mr. Burke says, with a slightly different application. 

While a doctor uses the technology to see through the 

human body, NASA is looking through composites and 

metals. “The medical world and the NDE world are very 

parallel when it comes to using ultrasound and x-rays. 

However, doctors are looking for things that are millimeters 

in size, while we’re looking at things down to the micron 

level,” Mr. Burke says. 

“And typically, higher energy sources are used in NDE 

in order to penetrate denser, thicker materials,” adds

Dr. William Prosser, NASA Technical Fellow for NDE. 

Aside from having to set up a safety zone prior to use, x-ray 

radiography is simple to operate and gives a clear image of 

complex parts, even more so than ultrasonic techniques, 

which can lose focus the farther it penetrates a material. 

“x-rays go straight through,” notes Mr. Burke. 

But the film needed for x-ray radiography is nearing 

extinction. “We don’t consume as much film as the medical 

community, but the medical community has moved to 

digital technology, so film is harder to get,” says Mr. Burke. 

Kodak, one of the primary manufacturers of x-ray film, 

has all but stopped production, leaving only one primary 

supplier left – Fuji. “It’s getting prohibitively expensive to 

get it,” he says. 

Advantages of Digital

The NESC assessment took a closer look at a newer 

technology called computed radiography (CR) (see box 

next page). It has been around for a few years, but only 

recently reached a level to be comparable to, and in many 

ways better than, film. 

The advantages of CR are akin to the benefits digital 

cameras offer over film photography. “To develop x-ray 

film requires chemicals,” says Mr. Burke. “With digital, 

you don’t have to deal with chemicals and their disposal, 

which is a big deal from an environmental and cost aspect. 

Digital gets away from all of that.” And film, which must be 

stored properly and can deteriorate over time, is replaced 

by plates that can be reused.

In addition, time is required to get the processing done, 

adds Dr. Prosser. “You shoot film, process it, and if you 

didn’t get the shot right, you do it again. Today, there’s a 

big driver to reduce costs and get results much quicker.” 

With CR, images can simply be erased and taken again. 

Finding defects is easier with digital as well. “In the past 

you would take x-ray film and put it under a back light while 

using a magnifying glass to find defects,” Mr. Burke states. 

“Now, with CR, images are automatically digitized into the 

Digital Exposure

Shining a light on x-ray film’s successor

X-ray film Computed radiography Digital radiography

Tube weld sample 

specimens, similar 

to that used on the 

Orion MPCV (left), 

were developed with 

deliberate flaws (pores 

and lack of fusion) to 

compare radiography 

techniques. Stainless 

steel, Inconel, and 

titanium tubes were 

used in testing. 

Computed radiography 

image of welded seam 

is shown below.

Detection of a pore 

in a tube weld using 

x-ray film, computed 

radiography, and 

digital radiography. 

NASA is pursuing 

the use of computed 

radiography.
40 41

(ESD). Developing those relationships was really important 

before we could move forward. 

What will independent M&S do for the SLS/Orion MPCV/

GSDO Program? What do we ultimately hope to gain 

from this effort? 

We’re hoping to have an independent simulation, and the 

experts to use it, at the ready. That way, if a technical risk 

comes up within the life span of SLS, Orion MPCV, and 

GSDO, we can corroborate, verify, or mitigate that risk with 

a mature, verified, and validated independent model. Also, 

by working independently, we can look for additional risks 

that may not have been identified or characterized yet. 

That way we can stay ahead of the game. 

Are there key areas where we are focusing our M&S 

efforts? What have we learned?

We’ve developed a nominal, high fidelity simulation

that’s allowed us to provide an independent assessment of 

several key events in the SLS timeline. And we’ve run the 

nominal simulation against the SLS simulation and verified 

those results. 

Building on that, we’ve looked at several clearance events 

on the timeline. We’ve delivered a lift-off proximity analysis 

of SLS and its separation from the GSDO systems, an SLS 

booster separation analysis to determine if the boosters 

would come close to recontacting the core vehicle as 

it ascends, and we also simulated the separation of the 

service module panels to look for potential recontact. 

And we’ve looked at separation of the ICPS, the interim 

cryogenic propulsion stage, from the core, and separation 

of the launch abort system. Those are the events we’ve 

focused on so far, but we’re continually adding events to 

take a closer look at their details. 

We’ve also put together an end-to-end, 3 degree-offreedom capability that allows us to model the entire 

trajectory from SLS lift-off to splashdown of the Orion crew 

module. This lets us find potential efficiencies that we might 

not have found in a piece-meal look. We were able to run 

several trade studies, for example, optimizing the day of 

launch and time of day for best mass performance. As we 

build the capability, we learn more about our framework, 

what it is capable of, and the limits to its flexibility. 

How important is it to see an animated

visual of these simulations? 

We’re using EVE, Exploration Visualization Environment, 

which is critical to getting everyone on the same page. The 

animation makes more sense to the many different people 

working on this program. That animation is critical to my 

understanding, the engineers, and the stakeholders. It’s 

easier to understand where something can go wrong if you 

can see it. 

What’s the next step for the M&S team?

We’ll continue to update the simulation to be current with 

the program’s simulations. Soon we’ll be switching out a 

component of the vehicle as missions change and seeing 

what effects that will have, and doing some additional trade 

studies as we look at Exploration Mission-2 and beyond. 

There’s no shortage of work. 

Because our analysis has been helpful for ESD, they’ve 

continued to ask for more, and we’re so appreciative of 

the easy transfer of data between the programs and the 

NESC. I think the relationship we’ve built is strong and we’ll 

continue to work on that relationship because we all know 

there’s a great return on investment here. 

What will you take away from this assessment?

Respecting the complexity of this program while figuring out 

how to reduce it to a simpler form for easier understanding 

has been really interesting. It’s a whole new knowledge 

pool that I didn’t have. And there’s always a new challenge, 

and we’re always adding new people to the skill mix and 

growing the expertise across the Agency. That’s been very 

exciting for me. 

Flight Mechanics

For NASA to embark on missions to asteroids, Mars, and 

beyond, three extremely complex systems must work 

together in an exceptionally intricate harmony: the new 

heavy-lift rocket that will launch the astronauts beyond 

Earth’s orbit— the Space Launch System (SLS); the crew 

vehicle that will carry those astronauts— Orion MultiPurpose Crew Vehicle (MPCV); and the infrastructure and 

personnel who will facilitate that launch — Ground Systems 

Development and Operations (GSDO). 

Today, each of these systems is being designed, built, and 

tested individually. But NASA needs to fully understand 

how these three systems will work together once they are 

integrated, long before lift-off from a launch pad. That means 

visualizing how these systems will interact, anticipating any 

potential issues, and finding ways to resolve them. 

To aid in that effort, the NESC put together a multi-Center

team, who since early 2012 has been developing 

independent models and simulations of the Orion 

spacecraft’s end-to-end journey from launch to splashdown, and the critical events that must happen along the 

way. Jill Prince, Manager of the NESC Integration Office, 

has been leading this assessment and explains the work 

required to undertake this modeling and simulation effort 

and what the team has accomplished so far. 

Why is independent modeling and simulation (M&S) so 

important when it comes to integrating complex flight 

systems? 

The key word here is complex. With a complex flight system, 

sometimes you can identify issues, or failure modes, once 

systems are integrated that you wouldn’t necessarily catch 

on a subsystem level or during individual component 

testing. One way to identify those issues is with modeling 

and simulation— putting everything into one simulation to 

find things you wouldn’t find otherwise. There, we look for 

areas of risk and try to reduce or mitigate those risks where 

we can.

What were the major steps the NESC had to take to bring 

all of these independent systems together into one M&S 

tool?

We already had an M&S framework to get started — the 

Program to Optimize Simulated Trajectories (POST), 

which has been used for other flight projects across all 

mission directorates. But because this complex system 

incorporates elements from across the Agency and industry, 

we had to find simulation experts from relevant Centers 

and bring them on board. Modeling and simulation is my 

background, so I knew some great people to get us started. 

But who wasn’t as familiar to me were the experts doing 

the in-line work within Exploration Systems Development 

From Launch to Splashdown

Using modeling and simulation to preview the Orion spacecraft’s journey

EVE combines trajectory data from POST with graphics models in a virtual environment to produce animations, proximity analysis, and 

angle analysis that provide insight into multi-body dynamics.

EVE (Exploration Visualization Environment)

Angle analysis Images and video Proximity analysis

Aerodynamics &

aerothermodynamics

Pad support

SLS mass

properties

Flight software Decelerator models

Earth

atmosphere models

Core engine models

Planet model

(gravity & topography) POST2 trajectory 

simulation results

POST2 Trajectory Analysis

SLS polygonal 

model files

Jill Prince, NESC Integration Office Manager.
42 43

Orbital Debris Model ORDEM 3.0 

ORDEM 3.0 is appropriate for those engineering 

solutions requiring knowledge and estimates of the 

orbital debris environment (debris spatial density, flux, 

etc.) and is primarily used by spacecraft designers to 

understand the long-term risks of debris collisions. 

ORDEM 3.0 can also be used as a benchmark for 

ground-based debris measurements and observations. 

ORDEM 3.0 includes flux estimates for several material 

density classes. It has also been extended to describe 

the orbital debris environment from low Earth orbit past 

geosynchronous orbit (100 to 40,000 km altitude).

A large set of observational data (both in situ and 

ground-based) incorporated into ORDEM 3.0 reflects 

the current debris environment and is NASA’s best 

estimate of the current and near future orbital debris 

environment. These data cover the object size range 

from 10 μm to 1 m. Analytical techniques (such as 

maximum likelihood estimation and Bayesian statistics) 

are employed to determine the orbit populations used 

to calculate population fluxes and their uncertainties. 

ORDEM 3.0 was developed by NASA’s Orbital Debris 

Program Office.

Space Environments

Space Debris

Understanding the risks to NASA spacecraft

Getting to space requires speed. A lot of speed. So, 

for NASA to send an object, like a satellite, into orbit, 

that object must reach velocities of several kilometers per 

second. And if it hits anything while in orbit, like debris, the 

damage can be substantial if not catastrophic. 

This is why NASA has invested much into investigating the 

potential risk of damage to its spaceflight programs from 

orbital debris—those manmade objects in Earth orbit that 

no longer serve a useful purpose, from a derelict satellite 

to a flake of paint. Natural objects like meteoroids are also 

a threat, traveling even faster than orbital debris. Typically 

comprising particles originating from comets or asteroids, 

the vast majority of them are very small micrometeoroids. 

Micrometeoroids and orbital debris (MMOD) is the number 

one risk for NASA’s human spaceflight programs. Many 

orbital debris objects—approximately 20,000—are large 

enough to be tracked and catalogued by the U.S. Space 

Surveillance Network and can be avoided by spacecraft 

maneuvering. But it is the unseen population of MMOD 

that poses the biggest risk to spacecraft: the orbital debris 

large enough to cause damage, but too small to track, and 

the micrometeoroids, which cannot be tracked regardless 

of their size.

To help mitigate the risk of MMOD, NASA uses a variety of 

computer models and applications to perform MMOD risk 

assessments. The primary MMOD risk assessment tool is a 

computer application called Bumper. Bumper helps NASA 

determine the probability of a spacecraft being damaged 

by MMOD during its operational lifetime. Working with 

NASA’s primary MMOD organizations—the Orbital Debris 

Program Office, the Meteoroid Environment Office, and 

the Hypervelocity Impact Technology (HVIT) Office—the 

NESC has performed several assessments in pursuit of 

improving the understanding of MMOD risk, refining the 

risk assessment processes, and reducing the actual risk. 

For example, in 2014, an NESC team compared NASA’s 

newest and most advanced orbital debris model, ORDEM 

3.0, to other orbital debris models to analyze how it models 

the orbital debris population. ORDEM 3.0, key to predicting 

the orbital debris environment, uses the largest database of 

MMOD impact data taken from analyzing damage sites on 

the Space Shuttle after each return to Earth. As a result, 

there is a relatively high level of confidence in the results 

the model gives for the orbital altitude where the Shuttle 

flew. However, no sources of impact data are available 

for higher altitudes, so the model has to make certain 

assumptions on the sources of the debris, which results in 

more uncertainty in orbital debris predictions. The NESC 

review represented the most extensive independent review 

of ORDEM 3.0 since its release. The team concluded that 

ORDEM 3.0 is the best model available and appropriate 

for use in NASA’s MMOD risk assessments, while still 

making several recommendations that may reduce the 

uncertainties and improve the model.

MMOD environment model uncertainty affects the fidelity 

of predictions in MMOD risk assessments. But this is 

not the only source of uncertainty. Damage prediction is 

another area where uncertainties can be introduced into 

risk values. In order to predict the risk from MMOD, a clear 

understanding of the spacecraft’s susceptibility to MMOD is 

needed. This includes looking at each exposed component 

and how it will behave when hit by a hypervelocity particle. 

This is damage prediction. By combining hypervelocity 

impact testing with simulations, ballistic limit equations 

(BLEs) are produced, which define the minimum size of a 

particle that will cause a failure as a function of velocity. 

BLEs are generated for particles of different material 

densities (e.g., lighter aluminum will cause less damage 

than heavier steel) and impact angles. The NESC has 

worked with HVIT to conduct testing and simulations to 

refine existing BLEs and to create new ones for advanced 

shield materials and configurations. The NESC/HVIT Team 

also worked together to test and evaluate multifunctional 

shields that would protect from the radiation as well as 

the MMOD environment, and they evaluated self-sealing 

materials for use in pressurized volumes. 

The NESC is also working to gauge how well NASA 

does on assessing MMOD risk overall. The concept is to 

compare MMOD-caused anomalies and failures on active 

satellites to what their predicted risk would be. This work 

is challenging as failure data are not always readily shared 

by satellite operators, and it is often difficult to pinpoint the 

cause of a failure as MMOD. On the other hand, few MMOD 

risk assessments have been performed on robotic satellites 

so predicted risk is, for the majority, unknown. 

The MMOD risk assessment process is time and labor 

intensive and requires a detailed knowledge of the 

configuration, materials, and failure criteria for the 

spacecraft. To achieve a good statistical comparison, the 

NESC is targeting a limited number of satellites for which 

anomaly data and configuration information are available. 

The goal is to determine how close NASA is to accurately 

predicting this top-priority risk and to learn how to improve 

our risk predictions.

Orbital plane

Equatorial 

plane

... it is the unseen population of MMOD 

that poses the biggest risk to spacecraft: 

the orbital debris large enough to cause 

damage, but too small to track

Mission orbital 

parameters

MMOD risk 

assessments

Spacecraft failure 

criteria

Spacecraft finite

element model

Orbital debris

environmental model

ORDEM 3.0

Basic limit 

equations

Micrometeoroid

environment model

MEM

Bumper risk

assessment tool

Spacecraft Risk Assessment Flowchart
44 45

that solutions would lie in how the cells were packaged, 

how vented battery effluents were managed, and how 

the cells were interconnected electrically. So, with the 

addition of the NASA Technical Fellow for Passive Thermal 

and electrochemical specialists, this is where the team 

concentrated its efforts. In particular, they focused on the 

Li-Ion batteries used on the ISS, the extravehicular mobility 

unit batteries in spacesuits, as well as the batteries used in 

hand tools.

“If a satellite has a thermal runaway, the result is catastrophic 

for the satellite, but there’s no human life involved. So we 

focused on human spaceflight, because that’s where it 

matters the most,” Dr. Iannello says.

NASA has never had an issue with its Li-Ion batteries, he 

says. “NASA has had an exceptional track record with no 

in-flight Li-Ion battery incidents, but Boeing’s experience 

made us realize we need to be prepared to manage this 

catastrophic hazard rather than trust it won’t occur based 

on our screens alone. When that one cell goes off, it’s like 

a blow torch; it pops,” he adds, “but if we can ensure that 

blow torch doesn’t impinge on its neighboring cell, we can 

prevent thermal runaway propagation.”

Development of Li-Ion Best Practices

Through the NESC assessment’s extensive analysis and 

tests, Dr. Iannello says that several best practices have 

been identified to help prevent thermal runaway from 

happening. “Managing the effluent and circulation of 

electrical energy within the battery is one,” he says. Should 

a Li-Ion battery cell experience a failure event, managing 

emissions from the cell and the transfer of the heat can 

prevent propagation.

“And when a cell gets hot, you don’t want it touching the 

cell next to it such that all its heat is transferred to the 

neighbor in a localized way. So, interstitial materials can 

be added,” adds Dr. Iannello. Those materials help absorb 

and distribute energy so that it is not localized to a single 

neighbor, which may help to prevent the thermal runaway.

In addition, fusible links help isolate failed cells ensuring 

circulating energy does not exacerbate the problem.

Additional options are being considered for individual 

battery types, including resizing of battery housing and the 

addition of containment bags that are tolerant to flames 

and other effluent released from a failed cell. Results from 

the NESC assessments are guiding the production, and in 

some cases, the redesign of future Li-Ion batteries used at 

NASA. And the NESC assessment team is sharing what 

it has learned with industry users. “We’re publishing our 

results at conferences as we go,” says Dr. Iannello. “In the 

end, we’re making batteries that don’t propagate failures, 

but still remain energy dense – batteries that retain the high 

energy density benefit of Li-Ion, but are safer.”

Electrical Power

Li-Ion batteries perform well in packing a lot of energy 

into a small package. That is why NASA was one of the 

earliest adopters of the Li-Ion battery for use in space, 

where the advantages of smaller batteries with a long 

life expectancy are numerous, from fitting nicely into the 

confines of the International Space Station (ISS) or a space 

suit, to extending the length of a satellite’s mission or an 

astronaut’s walk in space.

Li-Ion Advantages and Drawbacks

“We were some of the first to adopt Li-Ion batteries in our 

vehicles, even before the aircraft and auto industries,” 

says Dr. Christopher Iannello, NASA Technical Fellow for 

Electrical Power. “They have a much better energy density, 

often more than two times greater than other battery 

chemistries, so their run time is much longer.” As a result, 

the Agency was an early adopter of Li-Ion batteries.

But that high energy density has a flip side. Dr. Iannello 

explains that the volatility of the constituents, coupled with 

the flammability and toxicity of typical Li-Ion electrolytes, 

means that at high temperatures the cell becomes thermally 

unstable where exothermic reactions release heat faster 

than heat can be dissipated from the cell. This condition, 

called thermal runaway, often results in the ignition of the 

venting electrolyte in the form of fire, smoke, and high 

temperatures in excess of 600o C. Of further concern is 

that during a single-cell thermal runaway, the high heat of 

the failing cell can propagate to the next neighboring cell, 

causing it to go into thermal runaway as well.

“We knew they had aggressive failure modes,” says

Dr. Iannello, which he likened to a blow torch. “It’s a domino 

effect. If one cell goes, it heats its neighbor, and so on. Then 

it releases all of that energy, which on one of our vehicles 

would be catastrophic.” Hence, NASA’s intense scrutiny 

of Li-Ion batteries. “We’ve spent a lot of time and money 

watching the manufacturing to make sure the chances for 

cell-level defects are driven to a minimum. We do screening 

tests when they come in, and this reduces the likelihood 

that there will ever be a single cell with a problem, much 

less a propagation scenario. 

In the past, the intent had traditionally been to drive the 

likelihood of a single-cell thermal runaway to as low as 

possible, but we gave little consideration to what the 

severity would be if it did occur. Basically, we worked the 

likelihood side of the risk equation hard, but mostly omitted 

the severity side, assuming that if a single cell were to go into 

thermal runaway, propagation was a forgone conclusion.”

But when Boeing experienced thermal runaway on its 787 

Dreamliner aircraft, “we were concerned,” says Dr. Iannello, 

who worked with the NESC’s Electrical Power Technical 

Discipline Team to support Boeing’s investigations into the 

incidents. Ultimately, says Dr. Iannello, Boeing determined 

that manufacturing screens are not a perfect solution, and 

may never be perfect enough to ensure no unscreened 

defects.

Boeing focused on its screening tests and looked hard at 

its battery fleet, but not having solid proximate cause, it 

designed a strong box for its Li-Ion batteries that would 

contain the energy should a thermal runaway happen 

in the future. Dr. Iannello realized NASA could no longer 

depend on screens to protect against potential thermal 

runaway failures and gathered together key battery experts 

at the Agency to figure out how to minimize the risk of 

thermal runaway propagation within NASA spaceflight 

deployments.

Mitigating Risks Through Improved Packaging

Building a box to contain the energy is too heavy a solution 

for Li-Ion battery applications in space. And adding 

additional separation between the individual cells to avoid 

propagation could make the battery too large, eliminating 

the benefits of a compact design. But the TDT concluded 

Li-Ion Batteries

Managing risk to secure reward

Long-life battery: primary 

power for EMU life support, 

communications and data.

Li-Ion rechargeable 

EVA battery: 

Glove heaters, lights, 

camera, etc.

Li-Ion pistol 

grip tool

EVA Batteries

Trigger 

Cell

EMU batteries are composed of numerous, 

individual Li-Ion cells, packaged in a brick 

fashion (inset). 

Early “picket fence” model 

to investigate propagation of 

heat due to thermal runaway 

of a trigger cell (far left).
46 47

Software

Applying Model-Based Development to Flight Software

Implementing autocoded GNC algorithms

The Orion Multi-Purpose Crew Exploration Vehicle 

(MPCV) Guidance, Navigation, and Control (GNC) 

design and analysis team is developing the onboard 

GNC flight software (FSW) algorithms using the Matlab/

Simulink tool suite as a model-based approach to FSW 

development. This approach uses the Matlab/Simulink tool 

suite for developing the architecture, design, and modeling 

the GNC executive and its algorithmic computer software 

unit components. The methods supported unit-level and 

closed-loop testing simulation, test environments, and the 

test and verification of the auto-generated code products.

Past GNC flight software development processes on NASA’s 

human-rated spacecraft have been more traditional in nature, 

whereby the GNC design and analysis team is chartered 

to develop and validate subsystem level requirements and 

document the lower-level functional subsystem software 

requirements (FSSR) in a form of pseudocode within that 

documentation. In this paradigm, the GNC team is “handsoff” of the actual flight software implementation. The FSSR 

documentation is delivered by the GNC design team to the 

FSW team for implementation, and it then becomes the 

GNC team’s task to interpret the written word and manually 

translate it into handwritten executable code, which 

becomes the onboard FSW. The Space Shuttle GNC FSW 

followed this development process. For the International 

Space Station (ISS), the development process increased 

the amount of autogenerated code (known as autocode). 

The ISS GNC FSW was a mix of handwritten code and 

from the graphical-based tool MATRIXx. The current Orion 

MPCV GNC FSW development process intends to use the 

Matlab/Simulink modeling tools to auto-generate 100% of 

the GNC algorithmic FSW as C++ code. This approach will 

involve the GNC design and analysis team working side-byside with the FSW team in the production of the software 

artifacts that will lead directly to the onboard flight code.

GNC Algorithm and FSW Development Cycle

GNC team algorithm development Flight software build process

Initial prototyping 

and testing of 

algorithms

Algorithms Autocoded CSUs

Design 

loop

Production

loop

Run and analyze autocoded 

algorithms

Build Simulink 

models

Run integrated FSW and analyze 

behavior in a software-only 

environment

Integrated GNC partition and 

verification by test

Integrate GNC code

into the FSW

partition framework

GNC analyze and 

verification

Analyze and 

preliminary design 

selections

Run and analyze modeled 

algorithms

Run integrated FSW and analyze 

behavior in hardware/software 

test rig

Design 

documentation

Autocode

A hybrid particle-finite element hydrocode, developed by the 

University of Texas, simulating the hypervelocity impact of a steel 

particle against a multilayer spacecraft shield. (See page 42)
48 49

Erik G. Merilo

In recognition of engineering 

excellence for innovative analysis of 

Frangible Joint behavior giving NASA 

outstanding new evaluation tools

Craig L. Streett

In recognition of engineering excellence 

for computational fluid dynamics 

support to the NASA Engineering and 

Safety Center critical to mitigating 

aircraft damage risk during NASA 

Vehicle Integrated Propulsion Research 

III testing

Erik J. Takacs

In recognition of engineering 

excellence in support of the NASA 

Engineering and Safety Center 

during the assessment of anomalies 

experienced during the processing 

of the Orion Exploration Flight Test-1 

heatshield

James M. Womack

In recognition of engineering excellence 

for statistical analysis support to the 

NASA Engineering and Safety Center 

Orion Avcoat Team leading to the 

identification of causes of critical 

issues experienced during Exploration 

Flight Test-1 heatshield production

NESC Administrative 

Excellence Award

Teresa B. Derby

In recognition of over 10 years of 

dedicated, sustained, and superior 

contributions to the success of the 

NASA Engineering and Safety Center 

(NESC) assessment teams and the 

NESC mission

Alfreda D. Hampton

In recognition of administrative 

excellence in supporting the NASA 

Engineering and Safety Center

Anna H. Jackson

In recognition of outstanding executive 

resources support to the NASA 

Engineering and Safety Center

Pamela A. Sparks

In recognition of over 10 years of 

dedicated, sustained, and superior 

contributions to the success of 

NASA Engineering and Safety Center 

(NESC) assessment teams and the 

NESC mission

NESC Group

Achievement Award

Composite Overwrapped Pressure 

Vessel Liner Inspection Capability 

Development and Assessment 

Nondestructive Evaluation Team

In recognition of outstanding 

contributions in the field of 

Nondestructive Evaluation for the 

NASA Engineering and Safety Center 

Composite Overwrapped Pressure 

Vessel Liner Inspection Capability 

Development and Assessment 

Exploration Flight Test-1 Remote 

Imagery Team

In recognition of conceiving, 

planning, acquiring and processing 

unprecedented NASA Engineering 

and Safety Center quantitative thermal 

imaging data on the Orion spacecraft 

during Exploration Flight Test-1 

hypersonic entry 

Exploration Systems Development 

Integrated Hazard Development 

Process Assessment Team

In recognition of innovative NASA 

Engineering and Safety Center 

recommendations for improving the 

Exploration Systems Development 

integrated hazard identification and 

mitigation process 

Ground Operations Human Factors 

Task Analysis Team

In recognition of successful 

demonstration of a robust NASA 

Engineering and Safety Center task 

design and analysis methodology for 

Exploration Systems ground operations

Independent Modeling and Simulation 

for Commercial Crew Program Entry, 

Descent, and Landing

In recognition of the development and 

continuous improvement of NASA 

Engineering and Safety Center entry, 

descent, and landing 3- and 6-degreeof-freedom simulation capability for 

commercial crew vehicles and the 

conduct of independent entry, descent, 

and landing analyses 

Multi-Purpose Crew Vehicle Avcoat 

Testing and Analysis Support Team

In recognition of exceptional support 

to the NASA Engineering and Safety 

Center Orion Avcoat Team leading 

to identification of causes of critical 

Avcoat issues experienced during 

production of the Exploration Flight 

Test-1 heatshield 

NASA Standard for Fracture 

Control 5019A Team

In recognition of outstanding 

diligence and dedication to the 

NASA Engineering and Safety Center 

team demonstrated in the revision 

of NASA Standard 5019 “Fracture 

Control Requirements for Spaceflight 

Hardware” 

NASA Standard 5017A Team

In recognition of outstanding work 

performed by the NASA Engineering 

and Safety Center team charged 

with revising NASA Standard 

5017A “Design and Development 

Requirements for Mechanisms” 

Space Launch System Booster 

Interface Loads Assessment Team

In recognition of compelling 

advancement of the state-of-theart in launch vehicle buffet and 

aeroacoustic environment prediction, 

evaluation, and reduction 

Standard Check-Cases for SixDegree-of-Freedom Flight Vehicle 

Simulations Assessment Team

In recognition of the development of 

standard check cases to significantly 

improve the ability to verify flight 

simulation tools and reduce risk for 

numerous NASA and industry flight 

projects 

NESC Honor Awards

NESC Directors Award

Brian V. Rochon

In recognition of the tenacity and 

personal accountability demonstrated 

in the defense of his alternate opinion 

on the Orion Ascent Abort two test 

flight content reduction

NESC Leadership

Award

Gregory J. Brauckmann

In recognition of outstanding technical 

leadership of the NASA Engineering 

and Safety Center Booster Interface 

Loads Team charged with predicting 

and reducing aerodynamic buffet 

environments on the Space Launch 

System

Ralph E. Lucero

In recognition of outstanding 

technical leadership in the field of 

Nondestructive Evaluation for the 

NASA Engineering and Safety Center 

Composite Overwrapped Pressure 

Vessel Liner Inspection Capability 

Development and Assessment 

Dax Luis Rios

In recognition of outstanding technical 

leadership of NASA Engineering and 

Safety Center frangible joint testing

Regor L. Saulsberry

In recognition of outstanding 

technical leadership in the field of 

Nondestructive Evaluation for the 

NASA Engineering and Safety Center 

Composite Overwrapped Pressure 

Vessel Liner Inspection Capability 

Development and Assessment

Richard J. Schwartz

In recognition of outstanding 

leadership in planning and executing 

mission control coordination during 

the Exploration Flight Test-1 NASA 

Engineering and Safety Center remote 

thermal imaging campaign

Jeremy D. Shidner

In recognition of technical leadership 

and outstanding contributions to the 

NASA Engineering and Safety Center 

Exploration Systems Independent 

Modeling and Simulation Assessment

Joel W. Sills

In recognition of outstanding technical 

and management leadership key to the 

successful completion of the NASA 

Engineering and Safety Center Space 

Launch System and Orion Modal Test, 

Development Flight Instrumentation, 

and Dynamic Model Correlation Plan 

Peer Review

Steven J. Tack

In recognition of outstanding 

leadership in planning, rehearsing 

and acquiring NASA Engineering and 

Safety Center thermal imaging data of 

the Orion spacecraft during the entry 

phase of Exploration Flight Test-1

NESC Engineering

Excellence Award

Robert J. Christie

In recognition of engineering 

excellence in the development and 

correlation of NASA Engineering and 

Safety Center thermal mathematical 

models to improve the understanding 

of the thermal runaway phenomena in 

lithium-ion batteries

Sotiris Kellas

In recognition of engineering 

excellence leading to advancements 

in testing and analysis of Orion 

heatshield Avcoat material in support 

of the NASA Engineering and Safety 

Center Avcoat Team

Christopher P. Kostyk

In recognition of engineering 

excellence for a state-of-the-art 

instrumentation suite for the NASA 

Engineering and Safety Center 

Frangible Joint Assessment Data Team

Left to right, Tim Wilson (NESC Director/presenter); Bohdan Bejmuk (Independent Consultant); Christopher Kostyk (AFRC); Richard Schwartz 

(AMA); Pamela Sparks (AMA); Michael Kirsch (NESC Deputy Director/presenter); Damon Stambolian (KSC); Carlie Zumwalt (LaRC); Teresa 

Derby (AMA); Jeremy Shidner (AMA); Regor Saulsberry (WSTF); Sotiris Kellas (LaRC); Richard Russell (KSC); Robert Christie (GRC); Erik Takacs 

(Textron Systems); Ralph Lucero (MEI Technologies); Erik Merilo (SRI International); James Womack (Aerospace Corp.); Stephen Alter (LaRC); 

Brian Rochon (JSC); Michael Madden (LaRC); Gregory Brauckmann (LaRC); Brandan Robertson (JSC); Craig Streett (LaRC); Joel Sills (JSC); 

Pat Forrester (NESC Chief Astronaut/presenter). Not pictured: Alfreda Hampton (ManTech International Corp.); Anna Jackson (Valador, Inc.);

Dax Rios (WSTF); and Steven Tack (Navy DoD).
NESC ALUMNI

50 51

NESC Alumni

Frank H. Bauer

NESC Discipline Expert for 

Guidance Navigation and 

Control (2003-04)

J. Larry Crawford

NESC Deputy Director for 

Safety (2003-04) 

Dr. Charles J. Camarda

NESC Deputy Director for 

Advanced Projects (2006-09) 

Kenneth D. Cameron

NESC Deputy Director for 

Safety (2005-08) 

Steven F. Cash

NESC Chief Engineer at 

Marshall Space Flight Center 

(2005) 

Derrick J. Cheston

NESC Chief Engineer at Glenn 

Research Center (2003-07) 

Mitchell L. Davis

NASA Technical Fellow for 

Avionics (2007-09) 

Dennis B. Dillman

NESC Chief Engineer 

at NASA Headquarters 

(2005 -08) 

Freddie Douglas, III

NESC Chief Engineer at 

Stennis Space Center 

(2007-08) 

Patricia L. Dunnington

Manager, Management and 

Technical Support Office 

(2006-08)

Dawn C. Emerson

NESC Chief Engineer at Glenn 

Research Center

(2011-14)

Walter C. Engelund

NESC Chief Engineer at 

Langley Research Center 

(2009-13)

Wayne R. Frazier

Senior SMA Integration 

Manager (2005-12)

Dr. Michael S. Freeman

NESC Chief Engineer at Ames 

Research Center (2003-04)

T. Randy Galloway

NESC Chief Engineer at 

Stennis Space Center 

(2003-04)

Roberto Garcia

NASA Technical Fellow for 

Propulsion (2007-13)

Dr. Edward R. Generazio

NESC Discipline Expert for 

Nondestructive Evaluation 

(2003-05)

Dr. Richard J. Gilbrech

NESC Deputy Director 

(2003-05) 

Michael Hagopian

NESC Chief Engineer at 

Goddard Space Flight Center 

(2003-07)

David A. Hamilton

NESC Chief Engineer at 

Johnson Space Center 

(2003-07) 

Dr. Charles E. Harris

NESC Principal Engineer 

(2003-06)

Dr. Steven A. Hawley

NESC Chief Astronaut 

(2003-04)

Marc S. Hollander

Manager, Management and 

Technical Support Office 

(2005-06)

George D. Hopson

NASA Technical Fellow for 

Propulsion (2003-07)

Keith L. Hudkins

NASA Headquarters Office 

of the Chief Engineer 

Representative (2003-07) 

Danny D. Johnston

NESC Chief Engineer at 

Marshall Space Flight Center 

(2003-04) 

Michael W. Kehoe

NESC Chief Engineer at 

Dryden Flight Research 

Center (2003-05) 

Denney J. Keys

NASA Technical Fellow for 

Electrical Power (2009-12)

Robert A. Kichak

NESC Discipline Expert 

for Power and Avionics 

(2003-07) 

Dr. Dean A. Kontinos

NESC Chief Engineer at Ames 

Research Center (2006-07) 

Julie A. Kramer White

NESC Discipline Expert 

for Mechanical Analysis 

(2003-06) 

Steven G. Labbe

NESC Discipline Expert for 

Flight Sciences (2003-06) 

Matthew R. Landano

NESC Chief Engineer at 

Jet Propulsion Laboratory 

(2003-04) 

Dr. David S. Leckrone

NESC Chief Scientist 

(2003-06) 

Richard T. Manella

NESC Chief Engineer at Glenn 

Research Center (2009-10) 

John P. McManamen

NASA Technical Fellow 

for Mechanical Systems 

(2003-07) 

Brian K. Muirhead

NESC Chief Engineer at 

Jet Propulsion Laboratory 

(2005-07) 

Dr. Paul M. Munafo

NESC Deputy Director 

(2003-04) 

Stan C. Newberry

Manager, Management and 

Technical Support Office 

(2003-04) 

Dr. Tina L. Panontin

NESC Chief Engineer at Ames 

Research Center (2008-09)

Joseph W. Pellicciotti

NASA Technical Fellow for 

Mechanical Systems (2008 - 

13) and NESC Chief Engineer 

at Goddard Space Flight 

Center (2013-15)

Dr. Shamim A. Rahman

NESC Chief Engineer at 

Stennis Space Center 

(2005-06) 

Ralph R. Roe, Jr.

NESC Director (2003-14)

Jerry L. Ross

NESC Chief Astronaut 

(2004-06) 

Dr. Charles F. Schafer

NESC Chief Engineer at 

Marshall Space Flight Center 

(2006-10)

Dawn M. Schaible

Manager, Systems 

Engineering Office (2003-14)

Steven S. Scott

NESC Discipline Expert for 

Software (2003 - 05) and 

NESC Chief Engineer at 

Goddard Space Flight

Center (2008-09) 

Bryan K. Smith

NESC Chief Engineer at Glenn 

Research Center (2008-10) 

Dr. James F. Stewart

NESC Chief Engineer at 

Armstrong Flight Research 

Center (2005-14)

Daniel J. Tenney

Manager, Management and 

Technical Support Office 

(2009-13)

John E. Tinsley

NASA Headquarters Senior 

Safety and Mission Assurance 

Manager for NESC (2003-04) 

Timothy G. Trenkle

NESC Chief Engineer at 

Goddard Space Flight Center 

(2009-13)

Clayton P. Turner

NESC Chief Engineer at 

Langley Research Center 

(2008-09)

Nans Kunz, NESC Chief Engineer at 

Ames Research Center, passed away 

in February 2016. As a valued member 

of our team, he made numerous significant contributions to the NESC, Ames 

Research Center, and NASA. He was 

extremely proud of his contributions to 

the Stratospheric Observatory for Infrared Astronomy 

(SOFIA) Project, which he was involved in for over 20 

years. Our colleague and friend will be greatly missed.

NESC Leadership Team

Michael L. 

Aguilar

Software

Dr. Thomas 

M. Brown

Propulsion

Dr. Michael J. 

Dube

Mechanical

Systems

Cornelius J.

Dennehy

GNC

Clinton H. 

Cragg

Dr. Nancy J. 

Currie-Gregg

Dr. Michael G. 

Gilbert

Michael D. 

Squire

Patrick A. Martin

NASA HQ Senior 

S&MA Integration 

Manager

Timmy R. 

Wilson

Director

Michael P. 

Blythe

Deputy Director

for Safety

Patrick G.

Forrester

Chief

Astronaut

Dr. Daniel

Winterhalter 

Chief Scientist

Michael T.

Kirsch

Deputy

Director

Steven J. 

Gentz

MSFC

Robert S.

Jankovsky

GRC

R. Lloyd 

Keith

JPL

Nans

Kunz

ARC

Dr. W. Lance 

Richards

AFRC

Jill L. Prince

Manager,

NESC Integration 

Office

Stephen A. 

Minute 

KSC

George L.

Jackson

GSFC

Dr. David M.

Schuster

Aerosciences

Henry A.

Rotter

Life Support/

Active Thermal 

Steven L. 

Rickman

Passive 

Thermal

T. Scott 

West

JSC

Michael D. 

Smiles

SSC

Dr. William H.

Prosser

NDE

Dr. Robert S. 

Piascik

Materials

Dr. Cynthia

H. Null

Human

Factors

Dr. Ivatury S. 

Raju

Structures

Oscar

Gonzalez

Avionics

Dr. Curtis E. 

Larsen

Loads & 

Dynamics

Daniel G. 

Murri

Flight

Mechanics

Dr. Joseph I.

Minow 

Space

Environments

Dr. Christopher

J. Iannello

Electrical

Power

Jon B.

Holladay

Systems

Engineering

NESC Principal Engineers NASA Technical Fellows

NESC Chief Engineers

See nesc.nasa.gov for full bios
52 53

NESC Scholarly Papers, Conference Proceedings,

and Technical Presentations

 1. Bauer, F. H. and Dennehy, C. J.: Looking Back and Looking Forward: 

Reprising The Promise and Predicting the Future of Formation Flying and 

Spaceborne GPS Navigation Systems, 38th Annual Guidance and Control 

Conference, January 30-February 4, 2015, Breckenridge, CO, AAS-15-042. 

 2. Dennehy, C. J.; Brady, T.; and Greenbaum, A.: Identifying Trends in 

Spacecraft GNC Components: The Development and Application of an 

Open-Source GNC Component Database, 8th ESA Workshop on Avionics, 

Data, Control and Software Systems, October 27-29, 2014, Noordwijk, 

Netherlands. 

 3. Dennehy, C. J.: Guidance, Navigation & Control (GNC) Lessons 

Learned from Spacecraft Relative Motion Missions, European Control 

Conference 2015, July 15-17, 2015, Linz, Austria. 

 4. Gilbert, M. G.: The Max Launch Abort System - Concept, Flight Test, 

and Evolution, 7th IAASS Conference, October 20-22, 2014, Friedrichshafen, 

Germany. 

 5. Greenbaum, A.; Brady, T.; Dennehy, C. J.; Airey, S. P.; Roelke, E.; and 

Judd, S. B.: Understanding International GNC Hardware Trends, 2015 IEEE 

Aerospace Conference, March 7-13, 2015, Big Sky, MT. 

 6. Karpenko, M.; Ross, M.; Stoneking, E. T.; Lebsock, K.; and Dennehy, C. 

J.: A Micro-Slew Concept for Precision Pointing of the Kepler Spacecraft, 

2015 AAS/AIAA Astrodynamics Specialist Conference, August 9-13, 2015, 

Vail, CO. 

 7. Kolaini, Ali, Moderator, and Larsen, Curtis E., Panelist: Panel 

Discussion: Extreme Peak, Spacecraft and Launch Vehicle Dynamic 

Environments Workshop, June 2-4, 2015, El Segundo, CA.

 8. Larsen, C. E.: A Perspective on Loads and Dynamics in NASA 

Programs and Engineering, Spacecraft and Launch Vehicle Dynamic 

Environments Workshop, June 2-4, 2015, El Segundo, CA. 

 9. Larsen, C. E.: 86th Shock and Vibration Symposium NASA Status and 

Perspectives, 86th Shock and Vibration Symposium, October 5-8, 2015, 

Orlando, FL. 

10. Larsen, C. E. and Irvine, T.: A Review of Spectral Methods for Variable 

Amplitude Fatigue Prediction and New Results, 3rd International

Conference on Material and Component Performance under Variable 

Amplitude Loading (VAL 2015), Procedia Engineering, Vol. 101, pp. 243-250. 

11. Larsen, C. E. and Irvine, T.: A Review of Spectral Methods for Variable 

Amplitude Fatigue Prediction and New Results, 3rd International Conference 

on Material and Component Performance Under Variable Amplitude Loading 

(VAL 2015), March 23-26, 2015, Prague, Czech Republic. 

12. Larsen, C. E. and Irvine, T.: A Review and Comparison of Cycle 

Identification Methods for Fatigue and Fracture Analysis, International 

Conference on Engineering Vibration, September 7-10, 2015, Ljublijana, 

Slovenia. 

13. Marti, H. D.; Mazzuchi, T. A.; Sarkani, S.; and Larsen, C. E.: Integrating 

Expert Judgement and Bayesian Analysis, 4th Symposium on Games and 

Decisions in Reliability and Risk, June 17-19, 2015, Istanbul, Turkey. 

14. Mendenhall, M. R.; Lesieutre, D. J.; and Kelly, M. J.: Trailing VortexInduced Loads During Close Encounters in Cruise, AIAA Aviation 2015, June 

22-26, 2015, Dallas, TX. 

15. Minow, J. I.: Chandra Space Weather Vulnerabilities and Needs Update, 

7th Space Weather & NASA Robotic Mission Ops Workshop, September 

29-30, 2015, GSFC, Greenbelt, MD.

16. Minow, J. I.: DMSP and ISS Auroral Charging Events, March 17-18, 

2013, GEM-CEDAR Storm, GEM Mini-Workshop, December 13, 2015, San 

Francisco, CA.

17. Minow, J. I. and Willis, E. M.: Ionospheric Drivers of ISS Charging, 

Abstract SA41C-02, AGU 2015 Fall Meeting, December 14-18, 2015, San 

Francisco, CA. 

18. Null, C. H.: Designing for Human Reliability: Human Factors at NASA, 

4th Human Dependability Workshop (HUDEP) 2015, October 6-7, 2015, 

Darmstadt, Germany. 

19. Prosser, W. H.: NASA Experiences in Structural Health Monitoring, 

Deep Space Deep Ocean, April 7-8, 2015, Houston, TX. 

20. Prosser, W. H.: The NASA Engineering and Safety Center 

Nondestructive Evaluation Technical Discipline Team, 14th International 

Symposium on Nondestructive Characterization of Materials, June 22-26, 

2015, Marina Del Rey, CA. 

21. Raju, I. S.: Structures, Failures, and Lessons, Invited Lecture at Vidya 

Jyothi Institute of Technology and Anurag College of Engineering, February 

6-9, 2015, Hyderabad, India. 

22. Raju, I. S.: Observed Trends in Finite Element Structural and Damage 

Tolerance Analyses, NAVAIR Presentation at Pax River, October 27, 2015, 

Patuxent, MD. 

23. Raju, I. S.; Knight, N. F.; and Shivakumar, K. N.: Some Observations On 

The Current Status of Performing Finite Element Analyses, SCITECH 2015, 

January 5-9, 2015, Kissimmee, FL. 

24. Raju, I. S. and Knight, N. F.: Observations and Comments on the 

Current Status of Practice of Finite Element Analyses, NAFEMS Seminar 

on Engineering Analysis & Simulation in the Aerospace Industry, October 6, 

2015, Montreal, Canada. 

25. Reiff, P.; Sazykin, S.; Bala, R.; Coffey, V.; Chandler, M. O.; Minow, J.; 

Anderson, B. J.; Wolf, R.; Huba, J.; Baker, D.; Mauk, B.; and Russell, C. 

T.: Investigating Storm-Time Magnetospheric Electrodynamics: MultiSpacecraft Observations of the June 22, 2015, Magnetic Storm, Abstract 

SM41C-2498, 2015 AGU Fall Meeting, December 14-18, 2015, San 

Francisco, CA.

26. Rickman, S. L.: Form Factors, Grey Bodies and Radiation 

Conductances (Radks), Thermal and Fluids Analysis Workshop (TFAWS) 

2015, August 3-7, 2015, Silver Spring, MD. 

27. Rickman, S. L.: Overview of the NASA Engineering and Safety Center 

(NESC), Thermal and Fluids Analysis Workshop (TFAWS) 2015, August 3-7, 

2015, Silver Spring, MD. 

28. Rickman, S. L.: Status of NESC Wire Thermal Analysis, Science and 

Technology Electrical Systems and Wiring Inter-Agency Meeting, December 

9, 2015, Houston, TX. 

29. Sazykin, S.; Coffey, V.; Reiff, P.; Chandler, M. O.; Minow, J.; Huba, J.; 

Anderson, B.; Wolf, R.: Magnetosphere-Ionosphere Coupling during the 

June 22-24, 2015, Magnetic Storm, Abstract SA44A-07, 2015 AGU Fall 

Meeting, December 14-18, 2015, San Francisco, CA.

30. Schuster, D. M.: MAX Launch Abort System Flight Test, Seminar at the 

University of Cincinnati, October 31, 2014, Cincinnati, OH. 

31. Schuster, D. M.: Recent Progress in Prediction of Buffet and 

Aeroacoustic Environments at NASA, International Forum on Aeroelasticity 

and Structural Dynamics, June 30, 2015, Saint Petersburg, Russia.

3. Wilder, M. C.; Bogdanoff, D. W.; and Saunders, D. A.: 

Heat Transfer Measurements on the Afterbody of Spheres 

in Hypersonic Free-Flight in Air and Carbon Dioxide, AIAA 

2015-2966, 45th AIAA Thermophysics Conference, June 

22-26, 2015, Dallas, TX.

4. Wilder, M. C. and Bogdanoff, D. W.: Heat-Transfer 

Measurement Capabilities in the NASA Ames Hypervelocity 

Free Flight Aerodynamic Facility, TFAWS15-AE-03, Thermal 

& Fluids Analysis Workshop (TFAWS), August 3-7, 2015, 

Silver Spring, MD.

Publications

NESC Technical Discipline Team Member Scholarly Papers,

Conference Proceedings, and Technical Presentations

Avionics 

1. Ladbury, Raymond L.; Lauenstein, Jean-Marie; and 

Hayes, Kathryn P.: Use of Proton SEE Data as a Proxy for 

Bounding Heavy-Ion SEE Susceptibility, Nuclear and Space 

Radiation Effects Conference, July 2015, Boston, MA.

2. Ladbury, Raymond L.; Lauenstein, Jean-Marie; and 

Hayes, Kathryn P.: Use of Proton SEE Data as a Proxy for 

Bounding Heavy-Ion SEE Susceptibility, IEEE Transactions 

on Nuclear Science, Vol. 62, Issue 6, December 2015, pp. 

2505-2510.

Guidance, Navigation, and Control

1. Orr, J. S.: A Critical Analysis of the X-15 3-65 Accident 

Part I: Aircraft Systems and Flight Control, Aerospace 

Control and Guidance Systems Committee Meeting #114, 

October 14, 2014, Cleveland, OH. 

Loads and Dynamics 

1. Chen, Bing-Chung; Ortiz, Gary; and Peng, Chia-Yen: 

Modeling of Crawler Transport for Prediction of Rollout 

Forcing Functions, Spacecraft and Launch Vehicle Dynamic 

Environments Workshop, El Segundo, CA, June 2-4, 2015. 

2. Irvine, T.: Using a Random Vibration Test Specification 

to Cover a Shock Requirement via a Pseudo Velocity 

Fatigue Damage Spectrum, 3rd International Conference 

on Material and Component Performance under Variable 

Amplitude Loading, VAL2015, Procedia Engineering, Vol. 

101, pp. 211-218. 

3. Irvine, T.: Seismic Analysis and Testing of Launch 

Vehicles and Equipment using Historical Strong Motion Data 

Scaled to Satisfy Shock Response Spectra Specifications, 

Spacecraft and Launch Vehicle Dynamic Environments 

Workshop, June 2-4, 2015, El Sugundo, CA. 

4. Irvine, T.: Derivation of Equivalent Power Spectral 

Density Specifications for Swept Sine-On-Random 

Environments Via Fatigue Damage Spectra, International 

Conference on Engineering Vibration, September 7-10, 

2015, Ljublijana, Slovenia. 

5. Irvine, T.: Pyrotechnic Shock Distance & Joint 

Attenuation via Wave Propagation Analysis, 86th Shock 

and Vibration Symposium, October 5-8, 2015, Orlando, FL. 

Mechanical Systems 

1. Hernandez, A. and Hess, D. P.: Use of Anaerobic 

Adhesive for Prevailing Torque Locking Feature in Threaded 

Fasteners, Journal of Failure Analysis and Prevention, 2015, 

Vol. 15, pp. 633-640.

2. DellaCorte, C.; and Howard, S. A.: Superelastic Ball 

Bearings: Materials and Design to Avoid Mounting and 

Dismounting Brinell Damage in an Inaccessible Pressfit Application-Part I Design Approach, ASTM Journal 

of Materials Performance and Characterization, Vol. 4, 

Number 1, 2015. Presented at the 2015 ASTM Rolling 

Element Bearing Symposium, Anaheim, CA, April 2015.

3. Howard, S. A.; and DellaCorte, C.: Superelastic Ball 

Bearings: Materials and Design to Avoid Mounting and 

Dismounting Brinell Damage in an Inaccessible Press-fit 

Application-Part II Detailed Analysis, 2015 ASTM Journal 

of Materials Performance and Characterization, Vol. 4, 

Number 1, 2015. Presented at the 2015 ASTM Rolling 

Element Bearing Symposium, Anaheim, CA, April 2015. 

4. Krantz, T. L. and Handschuh, R. F.: Gear Tooth Root 

Stresses of a Very Heavily Loaded Gear Pair – Case 

Study: Orbiter Body Flap Actuator Pinion and Ring Gear, 

DETC2015-046274, Proceedings of the ASME IDETC 2015, 

Boston, MA, August 2015.

5. Whittaker, J. T. and Hess, D. P.: Ductility of Titanium 

Alloy and Stainless Steel Aerospace Fasteners, Journal of 

Failure Analysis and Prevention, 2015, Vol. 15, pp. 571-575.

Nondestructive Evaluation 

1. Brust, F. W.; Punch, E. F.; and Kurth-Twombly, E.: Weld 

Residual Stress (WRS) Modeling of Layered Pressure 

Vessels (LPV) and Fracture Assessment, ASME 2015 

Pressure Vessels & Piping Division Conference, July 19-23, 

2015, Boston, MA, PVP2015-45784. 

2. Koshti, Ajay M.: Considerations for Ultrasonic Testing 

Application for On-Orbit NDE, SPIE Smart Structures/NDE 

Conference, March 8-12, 2015, San Diego, CA.

3. Koshti, Ajay M.: Ultrasonic Measurement and Monitoring 

of Loads in Bolts Used in Structural Joints, SPIE Smart 

Structures/NDE Conference, March 8-12, 2015, San Diego, 

CA.

4. Koshti, Ajay M.: Simulating the X-Ray Image Contrast 

to Set-Up Techniques with Desired Flaw Detectability, SPIE 

Smart Structures/NDE Conference, March 8-12, 2015, San 

Diego, CA.

5. Youngquist, Robert C.; Nurge, Mark A.; Skow, Miles: A 

Comparison of Three Methods for Measuring Distortion in 

Optical Windows, NASA/TM-2015-218822, April 2015.

6. Youngquist, Robert C.; Skow, Miles; and Nurge, Mark 

A.: Optical Distortion Evaluation in Large Area Windows 

using Interferometry, 14th International Symposium on 

Nondestructive Characterization of Materials (NDCM 2015), 

June 22-26, 2015, Marina Del Rey, CA.

Passive Thermal 

1. Bogdanoff, D. W. and Wilder, M. C.: Afterbody Heat 

Flux Measurements in the NASA Ames HFFAF Ballistic 

Range, 65th Meeting of the Aeroballistic Range Association, 

October 19-24, 2014, Arcachon, France.

2. Ku, J. and Robinson, F.: Testing of a Helium Loop Heat 

Pipe for Large Area Cryocooling, 2015 NASA Thermal Fluid 

Analysis Workshop, August 3-7, 2015, Silver Spring, MD.

Continued next page
54

Publications

NASA Technical Memorandums

 1. A Comprehensive Analysis of the X-15 Flight 3-65 Accident

NASA/TM-2014-218538

 2. NASA Workshop on Hybrid (Mixed-Actuator) Spacecraft Attitude

Control NASA/TM-2014-218539

 3. Maximum Expected Wall Heat Flux and Maximum Pressure after

Sudden Loss of Vacuum Insulation on the Stratospheric Observatory

for Infrared Astronomy (SOFIA) Liquid Helium (LHe) Dewars

NASA/TM-2014-218540

 4. James Webb Space Telescope’s (JWST) Near-Infrared Spectrograph

(NIRSpec) Micro Shutter Subsystem (MSS) Alternate Materials and

Coatings NASA/TM-2014-218541/Volume I

 5. James Webb Space Telescope’s (JWST) Near-Infrared Spectrograph

(NIRSpec) Micro Shutter Subsystem (MSS) Alternate Materials and

Coatings Appendices NASA/TM-2014-218541/Volume II

 6. International Space Station (ISS) External Thermal Control System

(ETCS) Loop A Pump Module (PM) Jettison Options Assessment

NASA/TM-2014-218542

 7. Alternative Software Programming for Human Spaceflight

NASA/TM-2014-218546

 8. NASA Engineering and Safety Center (NESC) Independent Review and

Support of the International Space Station (ISS) Extravehicular Activity

(EVA) Water Anomaly and EVA Recovery Team (ERT) Failure

Investigation NASA/TM-2014-218547

 9. The Growth of Small Corrosion Fatigue Cracks in Alloy 7075

NASA/TM-2015-218672

10. Spin Forming Aluminum Crew Module (CM) Metallic Aft Pressure

Vessel Bulkhead (APVBH) - Phase II NASA/TP-2015-218674

11. Check-Cases for Verification of 6-Degree-of-Freedom Flight Vehicle

Simulations NASA/TM-2015-218675/Volume I

12. Check-Cases for Verification of 6-Degree-of-Freedom Flight Vehicle

Simulations Appendices NASA/TM-2015-218675/Volume II

13. Review of Exploration Systems Development (ESD) Integrated Hazard

Development Process NASA/TM-2015-218676/Volume I

14. Review of Exploration Systems Development (ESD) Integrated Hazard

Development Process Appendices NASA/TM-2015-218676/Volume II

15. Multi-Purpose Crew Vehicle (MPCV) Alternate Heatshield Carrier 

Structure NASA/TM-2015-218683\Volume I

16. Multi-Purpose Crew Vehicle (MPCV) Alternate Heatshield Carrier

Structure Appendices NASA/TM-2015-218683\Volume II

17. Payload Performance Analysis for a Reusable Two-Stage-to-Orbit

SA/TM-2015-218760

18. Advancing the State-of-the-Practice for Liquid Rocket Engine (LRE)

Combustion Stability Assessment NASA/TM-2015-218771/Volume I

19. Advancing the State-of-the-Practice for Liquid Rocket Engine (LRE)

Combustion Stability Assessment Appendices

NASA/TM-2015-218771/Volume II

20. Joint Polar Satellite System (JPSS) Micrometeoroid and Orbital Debris

(MMOD) Assessment NASA/TM-2015-218780

21. Empirical Model Development for Predicting Shock Response on

Composite Materials Subjected to Pyroshock Loading

NASA/TM-2015-218781/Volume I

22. Empirical Model Development for Predicting Shock Response on

Composite Materials Subjected to Pyroshock Loading Appendices 

NASA/TM-2015-218781/Volume II/Part 1

23. Empirical Model Development for Predicting Shock Response on

Composite Materials Subjected to Pyroshock Loading Appendices 

NASA/TM-2015-218781/Volume II/Part 2

24. Empirical Model Development for Predicting Shock Response on

Composite Materials Subjected to Pyroshock Loading Appendices 

NASA/TM-2015-218781/Volume II/Part 3

25. Glenn Extreme Environments Rig (GEER) Independent Review 

NASA/TM-2015-218809

26. Simplified Methodology to Estimate the Maximum Liquid Helium (LHe)

Cryostat Pressure from a Vacuum Jacket Failure

NASA/TM-2015-218810

27. International Space Station (ISS) Anomalies Trending Study

NASA/TM-2015-218991 Volume I

28. International Space Station (ISS) Anomalies Trending

Study Appendices NASA/TM-2015-218991/Volume II
56

National Aeronautics and Space Administration

Langley Research Center

Hampton, VA 23681

NP-2016-03-694-LaRC