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Tap into the experiences of NASA’s technical workforce as they develop missions to explore distant worlds—from the Moon to Mars, from Titan to Psyche. Learn how they advance technology to make aviation on Earth faster, quieter and more fuel efficient. Each biweekly episode celebrates program and project managers, engineers, scientists and thought leaders working on multiple fronts to advance aeronautics and space exploration in a bold new era of discovery. New episodes are released bi-weekly on Wednesdays. 

NASA Chief Engineer Ralph Roe discusses engineering best practices.

NASA engineers have a genuine curiosity for how things work and a desire to solve unique problems that no one else in the world has been able to solve. NASA hires 20 different types of engineers, with the most common fields being aerospace, general and computer engineers.

The engineering of NASA systems requires a systematic and disciplined set of processes that are applied recursively and iteratively for the design, development, operation, maintenance and closeout of systems throughout the program or project life cycle. NASA strives to incorporate engineering best practices in the development and implementation of large and small programs and projects.

In this episode of Small Steps, Giant Leaps, you’ll learn about:

  • Expectations set for NASA Chief Engineers
  • Application of engineering safety tenets inherited from the Apollo Program
  • Effectiveness of sharing engineering knowledge through storytelling


Related Resources

Office of the Chief Engineer

NASA Engineering & Safety Center

Technical Authority

NASA Systems Engineering Handbook

NASA Johnson Space Center Oral History: Ralph R. Roe

APPEL Courses:

Human Spaceflight and Mission Design (APPEL-vHSMD)

Manned Mission & System: Design Lab (APPEL-vMMSD)

Requirements Development and Management (APPEL-vREQ)

Space System Verification and Validation (APPEL-vSSVV)


Ralph Roe Credit: NASA

Ralph Roe
Credit: NASA

Ralph Roe serves as NASA Chief Engineer. In this role Roe provides leadership for Engineering Technical Authority and programmatic policy ensuring the technical and programmatic readiness of all NASA programs and projects. He previously served as the first director of the NASA Engineering and Safety Center (NESC). In 2003 Roe developed the concept for NESC, which was formed following the Space Shuttle Columbia accident to provide the agency technical expertise, skills and resources to offer an independent look at NASA’s most difficult problems. He began his career as a Propulsion Systems Test Engineer at NASA’s Kennedy Space Center. Roe served in multiple leadership roles in Space Shuttle Engineering, including Space Shuttle Engineering Director and Manager of the Space Shuttle Vehicle Engineering Office at NASA’s Johnson Space Center. He was Launch Director for four missions, including John Glenn’s return to space and the first International Space Station flight. He has a bachelor’s in mechanical engineering from the University of South Carolina and a master’s in engineering management from the University of Central Florida.


Ralph Roe: The best engineers that I’ve worked with have always sought the best engineers they know to peer review their work.

We’ve seen that when you bring in a diverse team with different backgrounds, you get more robust solutions.

If you can get a project where you’re working in line, hands-on with that project, but yet have engineers from different generations participating and sharing that knowledge, I think that’s the best of both worlds right there.

Deana Nunley (Host): Welcome to Small Steps, Giant Leaps, a NASA APPEL Knowledge Services podcast where we tap into project experiences to share best practices, lessons learned and novel ideas.

I’m Deana Nunley.

From designing powerful rockets for Deep Space exploration to developing cutting-edge technologies to transform the future of aviation, NASA engineers are innovators and visionary problem solvers who make the seemingly impossible possible.

Today, we’re kicking off a multipart series on engineering best practices. And what better way to start than with a conversation with NASA’s Chief Engineer, Ralph Roe.

Ralph, thank you for joining us on the podcast.

Roe: I’m happy to join you. Thanks for having me.

Host: What is most rewarding in your experience as NASA’s chief engineer?

Roe: I think the most rewarding thing I do is I get to interact with most of the programs and projects that this agency’s working. And I would say without exception, the passion and dedication of our folks working those projects is truly inspiring to me. So, really it reinvigorates me to do more, work harder because I see the passion and dedication of our teams. It’s amazing.

Host: Have your approaches and thought processes evolved in this role?

Roe: Oh, absolutely. I’ve been in NASA nearly 40 years and you’re continually learning. And you’re learning from other members of the team, other leaders, people who use different approaches to leading and being a part of a team, new techniques for solving complex problems, better ways to communicate, and listen and learn. We have such great leaders inside of NASA that you can always learn from others when you’re on different teams. So, you’re always continuously learning.

Host: What expectations do you set for yourself and for chief engineers and lead systems engineers across the agency?

Roe: I really like to set the example for listening to our experts and asking the right questions so we can make the best possible decisions. And I think by being as engaged as possible with each of our programs and projects, I can set that example for our chief engineers and lead systems engineers by showing that level of engagement, asking questions, listening to the experts, and helping to make the best decisions that we can.

Host: On this podcast, we’ve had the opportunity to talk with a lot of engineers and project managers across the agency about the challenges of figuring out first-time-through issues and never-before-solved problems. From your perspective, what is it that drives and equips NASA’s workforce to find elegant solutions to so many unique problems and challenges?

Roe: Yeah, I’ve seen this quite often in our agency. When the problems are the most difficult or complex, we’re able to break down any barriers between our centers or even with our industry partners and leverage the diverse experience to get the best experts possible, both inside and outside the agency, to focus on whatever that problem is. And we’ve seen that when you bring in a diverse team with different backgrounds, you get more robust solutions by leveraging those diverse backgrounds. Especially when things are most challenging, we make that happen. Our challenge seems to be on a day-to-day basis, how do we keep that up? But I know when things are at its worst, we’re able to do that. So I think that’s really what helps us is leveraging those diverse backgrounds.

Host: When you’re in those situations where people are trying to work through these problems, what do you see as far as the back-and-forth conversation that they’re having when you’ve got these people with such expertise talking about a really hard problem?

Roe: Yeah, it’s really amazing to watch when say two experts in a particular area get together to help solve a problem. That bond that’s almost created when they realize they’re speaking with someone with the same expertise or near the same level of expertise and they almost feed off of one another and go back and forth and help us get to a more robust solution by leveraging their different backgrounds, I think is just amazing to see. And the results are usually what we’re hoping for. So, it’s great to watch when you can bring together a team with different backgrounds, maybe from different geographical locations, maybe some that are in the government, some that are in industry. And when you see the light go on, when the team really bonds and begins to work together well, that’s just an amazing process to see. So I think leveraging those diverse backgrounds is what gets us the best solutions possible.

Host: And as we think about engineering best practices, three safety tenets inherited from the Apollo Program come to mind. And we’ve like to hear your thoughts, first on the importance of strong inline checks and balances.

Roe: Yeah, the environment we work in exploring space is really unforgiving. So, the test and analysis that we do is critical and deserves peer review. The best engineers that I’ve worked with have always sought the best engineers they know to peer review their work. And that’s really, that individual check and balance, is really what we’re looking for and are really the backbone of our success. So, I like to make sure that when the analysis is so critical, or the test is so critical, that we get an opportunity to peer review that work to make sure we’ve done everything possible to make it successful.

Host: Healthy tension between responsible organizations is another safety tenet that we’d like to discuss. How does that work at NASA?

Roe: Yeah, traditionally at NASA now there are three organizations — Engineering, Safety, Health and Medical — that are separate organizations but on equal footing with our programs and projects. And those Technical Authorities — Engineering, Safety, and Health and Medical — can push back if the program or project is not following the requirements that are established by those Technical Authorities. This pushback is really the healthy tension that allows decision makers to hear different perspectives on whatever the issue is that we’re working and keep our programs and projects safe and successful.

Host: A third safety tenet that we’d like to cover is value-added, independent assessment. How would you define this and explain the benefits of independent assessment?

Roe: So, value-added was a term I borrowed from Bryan O’Conner, a former Chief Safety and Mission Assurance Officer at NASA and a former astronaut. It really means that when the test or analysis is so critical or complex, it deserves bringing in the best experts available, not just the best experts in NASA or in a particular program, but wherever they are inside or outside the agency, to come in and do a peer review of the work. And value-added means they have the expertise to penetrate that test or analysis.

Host: NASA places a lot of emphasis on knowledge sharing and lessons learned. Over the years, what have you seen and experienced in terms of the effectiveness of stories, or storytelling, as a method to share lessons learned?

Roe: First, I’d say hands-on experience tends to be the best teacher. But when you’re able to bring in different generations of engineers on one project, I’ve seen this firsthand where the sharing of knowledge across those different generations on that project really seems to increase the level of learning in both directions really where maybe the younger engineers involved in that project have learned new tools and techniques, where maybe the older engineers on that project have experience from past programs or projects that they can share with the younger engineers. And I think if you can get a project where you’re working inline, hands-on with that project, but yet have engineers from different generations participating and sharing that knowledge, I think that’s the best of both worlds right there.

Host: Are there any stories that you’ve heard told over the years that just kind of have resonated with you, they’ve stuck with you and it’s like, that story helps to guide your thought processes, or your responses to different things, or your decision making?

Roe: Yeah, well, I think really the most important stories are from our catastrophic accidents — Apollo 1, Challenger and Columbia — and the lessons learned from each of those accidents is very similar, right? Where perhaps we weren’t communicating as well as we could up and down the chain of command in each of those instances. And we weren’t listening to the experts in each of those instances when we were making decisions. So, I think those hard, tragic lessons really are the ones that have been imprinted on my brain the most and I think about almost on a daily basis for things that I’m doing each and every day, right? So, remembering those lessons I think is just critical and important to carry on. And even for folks that weren’t there for those accidents, communicating those lessons to them and getting them to learn from those same lessons.

Host: Ralph, how do you think engineering has changed over the past decade?

Roe: Oh, the tools have definitely improved over the years, even in the last decade, right? The things that we’re able to do, the things that we’re able to model and analyze as compared to having to maybe develop a complex test for is just incredible. I think back to when I first started at the Kennedy Space Center. The work that I did as a young engineer now is really done by anyone’s laptop. I used to plot data from the space shuttle during processing, and now any laptop could easily do what I was doing. So I think the tools make the job much easier, I think it gives us a greater ability to improve our designs. So I think things will continue to improve I think, as our tools get better and better, and our computing capability gets better and better.

Host: Have you seen other changes in addition to the tools and the computing capabilities?

Roe: I think even like, even with the pandemic here and the way we’re able to communicate with each other, even across all of NASA’s 10 centers using today’s tools, like this podcast, for example, or we do a lot of video conferencing now that we didn’t do in the past. And I think it allows us to communicate with folks across all 10 centers much more easily than we were in the past. And I think the more we can communicate, the better.

Host: In spite of the pandemic, 2021 was an amazing year for NASA missions. If you take a moment to reflect on the engineering challenges that had to be overcome to achieve mission success, which ones especially stand out?

Roe: Yeah, I agree. 2021 was an incredible year, especially in the middle of a pandemic. But the highlights to me in 2021 included landing Perseverance on Mars. I think that was our ninth successful landing on Mars. We had our first flight on another planet with Ingenuity. We completed the test and verification of JWST, which is an incredibly complex spacecraft and instrument and telescope, and all that culminated in a successful launch at the end of the year. All in the meantime, we had Crew-2 and Crew-3 missions to ISS. We’re launching our crews from the U.S. again and we completed stacking of SLS and Orion in the VAB down at the Kennedy Space Center in preparation for Artemis I this year. So, it really was an amazing year.

Host: What are the 2022 mission priorities and engineering challenges that are getting your attention?

Roe: Right now, our top priority is Artemis One, right? The whole team is at KSC testing the SLS rocket and Orion stacked on top. And I think about the fact how long it’s been since we’ve flown shuttle, a decade. And so we’ve got a generation of engineers that haven’t launched and flown rockets really. So this is their opportunity to gain experience launching and flying missions with our rocket. And so really a lot of eyes will be watching as we fly Artemis One, hopefully here in the spring. And then on top of that, we’ve got to help our industry partner Boeing get their crew module flying, CST-100. And so we hope to have a re-flight of their test flight late spring, early summer, and then get them flying crew by the end of the year I hope. So, 2022 is full of exciting missions.

Host: What advice would you offer to young professionals who are embarking on an engineering career?

Roe: Yeah, back to what I was talking about before, find a project that gives you hands-on experience and allows you to get as involved with every aspect from design, development, test, verification and operations as possible. And I think if you can find a project like that, that you can get engaged with, that experience will be invaluable to you throughout your career.

Host: What do you see as the future of engineering?

Roe: Oh, the possibilities in front of us are incredible. We’ve got plans for Moon and Mars. And what we’ll learn from those missions, what we’ll learn from a mission like JWST, can change everything about what we’re doing here on Earth. And so I think just the excitement of being involved in those missions that are going to occur over the next decade or two decades, just incredible for anybody to be a part of.

Host: Well, Ralph, it’s been a genuine pleasure getting to talk with you today. Thank you so much for being on the podcast.

Roe: Thank you for having me. It’s been my pleasure to talk to you.

Host: Do you have any closing thoughts?

Roe: I think we’ve got so much exciting work about to happen returning to the Moon, building the Gateway, exploring Mars, James Webb Telescope. I think anybody in space has to be excited about the future that we have right in front of us.

Host: You’ll find links to topics we discussed as well as related APPEL courses, Ralph’s bio and a show transcript at

In the next segment of our engineering best practices series, we’ll chat with NASA Aeronautics Research Mission Directorate Chief Engineer Steve Hirshorn. That episode is set to drop March 9, and we’ll look forward to connecting with you then.

If you enjoy the podcast, please follow us on your favorite podcast platform and share the episode with your friends and colleagues.

As always, thanks for listening to Small Steps, Giant Leaps.