'We have an 18 month backlog for rocket engine testing because we have so much hardware. And it's all because of additive.'

Eliana Fu [EF] and Paul Gradl [PG], of TRUMPF and NASA respectively, have been operating at the intersection of 3D printing and space exploration for years. 

They first connected while Fu was working at Space X, in line with NASA's role to partner with private space organisations and accelerate the innovations that can facilitate space travel and exploration. Increasingly, additive manufacturing is a key element of those collaborations. 

Since then, Fu has gone on to work for Relativity Space - who are trying to 3D print an entire rocket - and now TRUMPF, where she is occupying the role of Industry Manager for Aerospace and Healthcare. Gradl, meanwhile, has remained at NASA in his role as a Principal Engineer. 

In coming on the Additive Insight podcast as part of our Innovators on Innovators series, the pair had much to talk about - including the considerations that are made when implementing additive manufacturing, why space exploration is important, how they suppose the next generation can be inspired, and the value of mentorship. 

Below, we have the full transcript of the pair's exchange. 

EF: Hi, Paul. It's so great to see you. 

PG: You too. Eliana, how are you doing? 

EF: I'm absolutely wonderful today, I'm so glad to be able to have the opportunity to speak with you. And it's always good to see you and get together to talk about some of our favourite topics: additive manufacturing and space exploration. 

PG: Absolutely. I'm really looking forward to it. Great to geek out with a fellow additive enthusiast. 

EF: Well, maybe we should tell the people back home a little bit about who we are and why we're talking today. 

PG: Yeah, sounds great. Do you want to go first on that?  

EF: Yeah, sure. I'm Eliana Fu. I am Industry Manager for aerospace and medical at TRUMPF. I am a titanium metallurgist by training. I got my masters and PhD at Imperial College in UK. But now I live in the US, I recently moved back to my house in Henderson, Nevada. So, I'm working from home for TRUMPF. 

PG: Great. So, I work in a component development group at NASA Marshall Space Flight Centre. And we are responsible for liquid rocket engine components, everything from combustion chambers to injectors, ignition systems, nozzles. And we work the entire lifecycle of components from design, analysis, manufacturing, and hot fire testing, making smoke and fire. We do most of this at NASA Marshall. But we also work with a variety of industry and commercial space and academia counterparts to advance a lot of these various technologies. 

EF: And commercial space is actually how we first met, isn’t it?  

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PG: Yeah, it's been a few years. And I think a lot of the work that we do at NASA, one of our goals is to try to get it out there, do materials development, process advancements, work different component designs, and then the intent is hopefully commercial space to pick that up and run with it. One of our main goals is to see flight in Fusion Applications. And getting that call from you was pretty exciting years back and some of the interests of the work that we were doing, because I think as engineers, we want to see our work used and not just sitting on shelves somewhere, so being able to work with you early on at Relativity and looking at some of the copper alloys as a potential infusion point for some of the applications and looking at other materials and talking processes was a good start to our relationship. I know we've talked a lot since then in various things. 

EF: Yeah, and you mentioned Relativity Space. So, I should tell the viewers back home that I was a senior engineer for additive processes. And I was also part of the materials and processes team at Relativity Space back in the early days. And that's how we got in touch because for people who don't know Relativity Space are actually trying to be the first to launch a fully 3D printed rocket, which is very exciting. And it also meant there are a lot of unknown things about using different additive processes where it makes sense, different materials because they're trying to achieve different things, so different additive processes such as the WAAM process, the wire arc additive process, for the tanks and barrels and large sections. And then 3D printing, let's say, laser AM. So, laser powder bed fusion, or laser metal fusion, as TRUMPF calls it, for some of the maybe more demanding applications like rocket engines, and then even DED processes, which TRUMPF calls LMD, so directed energy deposition, or laser metal deposition, just using blown powder for larger structures, where you can actually print faster. So, looking at a combination of all of those different things, and even things that are still... things like electron beam with wire or laser with wire, all those things are additive processes and stuff that I never even touched, like maybe even binder jet or some of those other things that could help you in the future.

So, basically, that was the beginning of a long conversation on what material makes sense? What process makes sense? What are you trying to achieve in your structure? How many times do you expect this structure to survive? Does it only have to survive like a burst test or a hot fire test? Or does it actually have to be reusable? So, all those questions, we're still trying to find the answers to. I think it's a really interesting place where we are right now. 

PG: Yeah, absolutely. And at NASA, we're really trying to be a central source of information for that. So, we're not focused on a specific alloy or a specific process, we're really trying to investigate all of the different metal AM processes. And you mentioned a handful of them, I think there's somewhere close to a dozen metal AM processes, you talked about powder, bed fusion, and DED, there's a lot of the different solid state processes, cold spray, the additive friction stir deposition, and the ultrasonic AM. And we've been exploring a lot of those, because each one of those results in different microstructure, different properties. And of course you go to vendors, and they're going to tell you information about their process or their properties on that, but we want to gather data and provide data to industry to help with some of those traits.

I'm a firm believer that all those different processes that you mentioned, the different additive processes they're all very complementary to each other, and they all exist for a reason. There's advantages and disadvantages of each of those and I'm sure we're going to talk a lot of that, because that's challenging to demystify some of the different processes and why you trade for one versus the other, and the scale of each of these, and some are better suited for certain alloys versus others on that, but, again, one of our goals at NASA is trying to produce some of that data and disseminate some of that data. So, we've written a lot of papers and presentations to help educate on that. And I think one thing that I usually say, when we talk additive is make sure that you need additive. It's another manufacturing process. And I think there's still a lot of trades that need to be completed before you specifically say, yes, I want to use additive for this part.

I know that you come from a traditional manufacturing background as well, so you have a good understanding of that. And, again, that's something we always emphasise, there's a lot of great manufacturing processes, and additive may not be the best one in some cases, but when when it does make sense certainly we want to apply it methodically and intentionally and make sure that we understand the entire lifecycle of additive manufacturing. 

EF: Yeah, and I think that's really important, like choosing the right process for the right application. And then some of those other limiting factors are, when you speak to somebody, and they kind of don't really understand, 'why can't you just 3D print that?' And the answer could be very complicated. And its simple answer could be straight up there's no material. The material isn't available in the product form that you want it for additive manufacturing.

So, I think people need to actually step back and then ask themselves, is that even the right process for me? Am I actually doing this the right way? One of the things I learned when I worked at the titanium company - I worked for TIMET for eight years. And that's very traditional, billet bar, sheet plate, ingot forgings, castings type of product, mill product, the fastest way that people would know in those days to get a component is just to take a block of titanium and machine it. And that's absolutely the worst thing that you can do, because the material is so expensive. And if you just thought about it in a different way, there's probably a better process or a better way to approach making that part, whether it be forging or casting. Now we've got additive manufacturing, you can add that to the mix too. You can even do hybrid of doing additive on top of a casting or additive on top of a forging or anything like that, or using additive to join two bits of material together that have been made in different ways that's still additive. It's not subtractive. And so that's one of the first things that I learned.

Another thing that I learned when I was actually working at SpaceX was also the language of which you speak is all material science. And it doesn't even matter if it's titanium, which is my preference, but it could be nickel base, it could be copper, it could be stainless steel or refractory material. It's all same material science and metallurgy. So, if you've got the fundamental of that you kind of know what's going on a deeper micro structural level. 

PG: Right, I think when we look at additive, you're totally correct on that, that we evaluate, does it make sense for the application? Is there a traditional manufacturing process or another manufacturing process and additive process, a hybrid process? So, we tend to look at a few things. First thing that I look at is generally part complexity. And most aerospace parts are fairly complex, you're trying to reduce weight, they have internal channels or passages on that, just because we're trying to reduce mass on that. So, there's a lot of cases where additive does make sense from a complexity perspective. But then we also look at the alloy. Again, a lot of aerospace parts, we're using alloys that are very challenging to machine or to process or take a long time, often, you have very long lead times, a forging or casting might take many months, or sometimes, maybe more than a year on that. And then of course, the processing economics. So, looking at the cost and schedule associated with that, if I'm trying to reduce the number of parts, if we have a lot of examples on injectors for liquid rocket engines that were made with 200 parts that we brazed together, and now we're able to print them in a couple pieces. So, I reduce a lot of that processing complexity that goes with that. And of course, there's a lot of cost advantages of that as well. 

EF: Labour, overheads, all that kind of stuff, even people making manufacturing errors and quality issues, you can eliminate a lot of those flaws that way as well.  

PG: Yeah, absolutely. So, we we look at all of those when we're trying to trade. And again, I think it's trying to break through some of the hype of additive. It's a mainstream word now, which is fantastic that you can ask almost anybody and they know generally what 3D printing is, but trying to break through some of that hype again, and make it real and have people apply intentionally and understanding why they're using it. I think that's one of the things that we've been emphasising that you mentioned earlier is about the process selection, you said that usually the alloy is one of the first criteria for selecting a process and I agree with that, because certain processes, some of the processes where you're melting material may not be the best option compared to a solid state process. So, yes, each of the processes, DED, powder bed fusion, the solid state processes, there's different alloys that are used for different processes.

Then, we also look at the overall size is one of the other early criteria on that. Powder bed fusion, you can make very complex parts, but you're going to be limited in the overall size. I know there's machines out there now that are a metre by a metre or so but some of our parts we're looking are several metres in diameter and several metres in height. So that's where we tend to look at some of the DED processes. But then we also need to trade part complexity, there's certain processes that I'm using as a forging or a casting replacement. So, I have lower complexity in that, and I'm just trying to deposit a lot of material in that, some of the processes like additive friction or deposition, and some of the WAAM processes, you can do 20, 30, 40, 50 pounds per hour on that were powder bed fusion, you're 0.1, 0.2 pounds per hour on that. So, deposition rate, but with that, I think there's an inverse of complexity. Deposition rate, I can do really high deposition rate, but really, I'm starting to lose the complexity on that. 

EF: Yeah bad surface finish or something like that, yeah.  

PG: Yeah, feature resolution. And then there's a lot of other things that we consider like you mentioned, the alloy selection. So, looking at feedstock, like, can I get the feedstock parameters, and then, of course, all the post processing, as well. So, again, I think, having people understand why they're selecting certain processes, and not just selecting a process, because it's readily available, or they have it in their shop, it may not be the best and most economical one.

Then you mentioned microstructure too, which is something that can be overlooked sometimes that every one of the processes, results in a different microstructure, a solid state process has more refined grain structure in it where some of the melting processes, I may get enlarged grains on that, which results in different properties. And I think one of the things that we're trying to push through and educate on is, again, to have people understand the microstructure a lot better of additive processes and the resulting properties from that. So, just because I have properties for laser powder bed fusion doesn't mean that I can use the same properties for laser powder DED, or blown powder DED on that, each one is very unique. 

EF: Yeah, and also I was thinking about, you said something about the feedstock as well, because in this time that we're living where we have like supply chain issues, and constraints [around] supply chain, I mean, I'm even thinking, I have been thinking for a long time now, about even the scarcity of the materials, where they have to come from, do they have to be shipped from overseas? I mean, that's something, obviously, when I worked at the titanium company, we had lots of issues with, but also we had to worry about things like piracy, people committing acts of piracy on the high seas, and things like that. And we've got all kinds of things going on right now. I mean, in the titanium days, we had to actually get certificates to sign off to say that our materials do not contain any conflict minerals. So, a lot of people in additive these days, don't even think about those things because the thought's never crossed their mind, until suddenly they can't get the material and it's like, oh, you went down a road where you chose material that only comes from one region, which is now in some kind of conflict zone. And that's potentially bad, it's disastrous, in fact, for everybody involved.

So, it's kind of an interesting topic that I think also bears some consideration when trying to make those design decisions as well, where does the material come from? Who are my suppliers? Can I go and visit my suppliers and do quality audits, make sure the materials consistent and that I'm not going to get any interruptions in my supply chain that will affect my lead time? Because that is all going to affect my launch window. 

PG: No, I totally agree. And I think that's one of the advantages and disadvantages of additive sometimes is the feedstock, is we are able to get feedstock quicker in many cases, powder or a wire form on that, but also developing custom alloys has been a challenge for us in trying to set up those supply chains and making sure that they're meeting our requirements and we have the quality associated with that because ultimately all of that is going into your end part on that.

I think one example is the GR Cop alloys that NASA developed which is a copper chrome niobium material that we use for combustion chambers, high heat flux, you need high strength on those high conductivity is, for many years, it really wasn't accessible because of supply chain, there weren't companies that were printing it commercially, it was very difficult to get the powders, very expensive to get the powder. And again, that was something that in our NASA role that we had to work with the supply chain to set up powder atomisation on that, working with a variety of vendors to make sure that they could, again, produce it to our specs and making sure that oxygen content was low, and that we weren't having challenges with the atomisation nozzles, causing trace elements in there. Because again, anything that's part of your feedstock is going to go into your part. And one thing that we always talk about from the certification perspective, is the roles have shifted quite a bit so before we would get a certificate of conformance from the titanium plant, or the forging of the casting vendor saying that we produced this material per theses specs, and it meets that. Well, now we get a feedstock, and now you're producing the material or melting the material, consolidating the material in place, and now we're responsible for all those material properties on that.

So, the supply chain, and how we approach that has has shifted quite a bit as well. And, again, we're responsible for ensuring that the feedstock is really meeting the quality requirements, because any impurities and any issues with that, it just gets amplified when you go to print it in your part. And we've had our fair share of print failures, and even challenges on the test stand where we've seen defects or other issues that propagate through from the supply chain, such as the raw feedstock on that. 

Hopefully we can inspire the next generation to develop complex designs and new materials, as long as they understand the process and apply it methodically and intentionally.

EF: Yeah, so in order to understand all these things, all these issues, you're not just being a material scientist, but you're also being an additive technologist. And you're also being a supplier quality engineer. So, you have to do all of those jobs as it were in one because... and you also have to look at the economics of the supply as well. So, somebody is doing a cost analysis on whether it was cheaper to make this part by forging or a casting? Or should I just machine it from a block or just print the thing? Can you even do that? Where can you do that? Where can you get it heat treated? What are the logistics of shipping it all over the country to get it heat treated, and so on. And so when you look at that, you really then have to ask yourself, okay, I really need to choose the right process for this part for this job. And then all of that adds up into whether you're going to make your stated flight date on time.

So, I was thinking about that the other day, because I saw an update on the Artemis programme and I was like, wow, this is going to fly pretty soon, like, sooner than we expected. So, I was thinking, how did we get to this point? Where did actually, maybe you can tell me, Paul, where did your interest in space actually start? 

PG: So, I started my career back at NASA Glenn Research Centre back in early 2000s, as an intern, and I was working on the fluids and Combustion Facility, which is one of the racks that is flying on International Space Station. And I remember going to Glenn and putting on one of the bunny suits in the White Room and cleanroom and going in and looking at the hardware. And I think you're just in awe of this is going to be flying in space soon. And this is when we're still building out a lot of the different research facilities and International Space Station, thinking this can be flying in space, and there's going to be groundbreaking research that will be conducted on some of this.

So, I think that latched me pretty early in terms of where I wanted to go with my career, but of course, I think we all have our stories as a child and I remember watching space shuttle launches and those were just definitely inspirational to our generation. And I remember watching the Challenger and the accident at the time, and I was six at the time that that happened, but still like that memory is very vivid to me. I think as a nation and as a species, the whole planet, spaceflight is one of those things that people seem to come together on. And to me, that is really exciting. So, for me, the job that I do now is, of course, a career but also a hobby, in a sense. I love rocket engines, I love spaceflight, but I love manufacturing.

And this goes back to even in high school, I worked in a plastic injection moulding plant and I was doing CAD drawings for them, computer aided design. I didn't have my driver's licence at the time, I think I was 15 or so. So, my mom would drive me to work and I loved being in the factory and smelling shop oil and seeing parts made. I've always had this strong interest in manufacturing. So, being able to marry manufacturing, with spaceflight and rocket engines, really is a passion for me and, of course, it's gotten better too, in a sense, with additive manufacturing because now we're able to make parts very quickly and get them on the test stand.

One of the examples that I love to give was early in my career. So, again, back in the early 2000s, when I started at NASA Marshall is we would run a handful of test programmes a year, we might be running three or five programmes, and we were always limited by hardware, it would take six months, 12 months, 18 months to make some of this hardware with traditional manufacturing processes. And that's always where you have your challenges, right, the design goes easy, you get to manufacture it, and oops, things don't meet the drawings, or we had this issue, or we have repairs on it. So, we were very limited in the number of programmes we run. Well, now, we run 15 or 20 programmes a year. And we have an 18 month backlog for rocket engine testing because we have so much hardware and it's all because of additive. A lot of our programmes, we will make two, three, four combustion chambers as backups or injectors on this and we're just not able to keep up with with all the testing. So, that's exciting.

I think that is one of the proofs of additive in itself is we're able to go through these design, fail, fix cycles very quickly and make design changes and prove things out very quickly. And I think we started some of this conversation out talking commercial space. And I love the time that we're in right now, because I think there's a lot of commercial space companies that exist or are able to accelerate their development because of additive manufacturing. Now, it may not be the final solution, like they might do some of the early development work using an additive part and then ultimately going into production, it might make more sense to use the traditional process where you're making dozens or hundreds of something, but again, you can get on the test stand a lot quicker. And I guess that goes back to some of my reason for coming to NASA and some of the inspiration is being able to see rocket engines test and then ultimately seeing yes, this is going to go into space, we're going to launch these payloads and do this groundbreaking research that is exciting. And that definitely motivates me every day. 

EF: Yeah, I remember when people didn't really know the term additive manufacturing, but they call it rapid prototyping, but actually it's the same thing. You are doing a rapid prototype. It's just the method in which you're using is like a laser AM method or electron beam or plasma or whatever it is. But you can see I'm on the bridge of the Rosinante from The Expanse, that's one of my favourites [Editor's note: This is a reference to Eliana's Zoom background].

Like you, I was also very much a fan of watching NASA back when I was a kid. But I was also inspired by Star Trek and Star Wars and Babylon Five and that kind of thing. So, I was always interested in it but I grew up in UK so there wasn't like a big space programme in UK. Years later, I moved to the US and then finally I got my US passport. And then I was able to work very freely at SpaceX with no issues, and I couldn't believe it. I mean, it is like a dream come true for so many people that grew up thinking, well, I don't know if I'll ever get to work on a space programme, but with the commercial space like Virgin SpaceX, Relativity, Blue Origin, everybody, there's a chance for kids, especially young people, to achieve their dreams of working on a product that will go to space. And I think that, like you said, this is a really exciting time that we live in, because who would have imagined it, like I could not have imagined 20 years ago that I would be working in this industry and working on products that go to space, or that will one day go to space, or working on the development of things that fly and things that are going to help the next generation of space explorers, or help humanity become a multi-planetary species.

I want to tell you a really funny story that I had - it's very personal as well, so if you don't mind me sharing some personal detail - when I first moved to LA to work at SpaceX, I went on a like a match.com date with this one guy who was, like, not my type. And he was kind of like a surfer dude. He was asking me what I did for my job. I said, 'Oh, I work at SpaceX.' And then he asked me what that entailed and I told him some basic detail, I didn't tell him everything, but I just sort of told him a basic outline. And then he was like, silenced. And then he was like, he looked at me like he was really fascinated, he goes, 'that's incredible. I've never been on a date with anybody like you.' And then he suddenly turned, he goes, 'I think we should not be exploring other planets, we should be solving our problems on Earth first!' and I was really taken aback [Laughs]. So, I was like, 'oh, cheque please.'  

PG: [Laughs].

EF: But you're gonna run into people like that, you are going to meet people who think that we have no business exploring our inner solar system, let alone going to other worlds and other solar systems. So, what do you say to people like that? 

PG: So, I think at NASA, we're always challenged with that, and again, one of our goals is to help inspire current generations, future generations of dreamers, and I think as a species, that is one of the things that we need to hold on tight. Because we don't know what's out there. And as humans, I think we want to explore and understand better where we came from, and what else is in our universe, on that, and I think NASA does a great job at doing that and really, space agencies around the world, again, have come together and allow us to put humans on orbit for six months and 12 months. I mean, that's fascinating, the research and all the nations coming together on International Space Station is really a fantastic project, going back to the moon and setting up permanent habitats there and then ultimately going to Mars. 

I think that's something that every young child is inspired by and, again, I think that is part of our role is to keep those dreams alive and let people wonder and imagine like, okay, I can be the next astronaut, and I can go explore other planets. And I think with that, we see all kinds of new technology developed. And that is something else that I get excited about working at NASA is you have problems that you have to go solve and we need a new alloy for a harsh environment or we have to go develop some certain process and we develop those processes and use it for launch vehicles. But then several years later, a decade later, they use that technology in something completely different in medical or a different field. And I love seeing the growth and the infusion of that technology. So, I believe by being explorers and developing those technologies that we are bringing those technologies back to Earth and helping to solve problems on Earth. So, I disagree with the surfer dude on your date, and I think that.. 

EF: I disagreed with him too, which is why I exited right pretty quickly. But yeah, you're right, we should be working to inspire the next generation. All these things do teach us about our environment, like, we can use satellite probes to study how glaciers melt, or how the sea levels rise and fall, as climate change occurs and things like that. So, it is telling us something, and we are learning things, and we're learning things about ourselves, too. But I think I like the aspect of being able to inspire people because I think that inherently, the human species is a curious one, we do want to find out what's out there, we do want to leave our homes and our safety and security and we we do want to push our limits, and see what we're made of. And then whatever we learn bring that back to hopefully make the world a better place. Seriously, but I do think that there's lots of things that people are doing, that maybe aren't being celebrated as much as they should be. And so they should be in the conversation more. 

How do you think that we can inspire more of the next generation, especially in STEM fields? One of the things that we did when I was at Relativity was work a lot with the sort of middle school kids, and that age where they can be inspired, and then realise that this is a career option for you. Especially for me, middle school girls of colour, which at a certain age, they don't go down an engineering or technical path, and they choose some other path, because they don't even know that these routes are open to them. So, what would you say to try to capture that kind of potential that might go away? 

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PG: Right. Education, STEM is definitely high on our list at NASA. We want to inspire that next generation of explorers, but we also want to train the next workforce that's going to be building upon all of our work. And we try to do as much as we can, to get information out there, whether it be middle schools, high schools, we get involved in a lot of science competitions, and robotics and student launch initiatives. We're heavily involved with academia, college level, that NASA sponsors, a lot of research projects, and I work with probably 20 or 30 PhD students at various universities and invest in mentorship with them. And it's interesting, because we have a lot of regular meetings, and I don't treat those meetings any different than I do internal NASA meetings - I want students to understand the process flows and the economic side of it, because in engineering school seemed like we're taught a lot of the technical aspects of things. And sometimes we're not always taught well, you need to look at the economic side and the programmatic side and the risk side of things.

So, educating a lot of that, and I think additive in particular, it's really easy for students to get excited about, middle school, high school students, because they can go make a design, and a lot of high schools now have plastic printers, so they can hold their part in their hand. And I think that is definitely inspiring in itself. For colleges, and universities, they're doing a lot of development with metal additive manufacturing. And again, we're sponsoring a lot of that through through various grants and contracts but those are going to be the next generation that's working at NASA and going to be our colleagues on that.

So, we're trying to provide as much education as we can through journal articles and papers and presentations. We teach a lot of classes, undergrad and graduate classes where we'll do one or two sessions for a course and talk about here's why we're doing additive, here's the applications of it. And I think students can start to make the connection saying, well, I'm making these tensile specimens all day long and now I understand and why it's important because you're showing me rocket engines and the importance of microstructure material properties that go into that. So, we tried to do those types of things as well. And we actually just completed about a three year effort writing a textbook, and this will be in print, it's in print, now, it should come out in mid August. And again, the objective of the textbook was to help educate students to apply additive manufacturing, methodically and intentionally. And also allow industry to use this as well. So, we're all talking the same language on some of this because I think with a lot of the processes, there's still different names for some of them. And people have different concepts of what additive is, and I think even you and I probably do, when I say additive, you're probably thinking a certain process.

But I think we want to, again, educate and show people that it's a generic term, and there's a lot to additive. And that's probably one of my focus areas too when we talk about additive and education, a lot of people focus on the process itself, right, I go build a part. And that is the process, but I think to be successful in additive and train the next generation workforce, and even some of the current workforce on this is understanding that entire process. And that includes the design and the pre processing, the feedstock, which we talked earlier, the processing parameters are really important. And then post processing, I think, is one of the most critical aspects of additive manufacturing, you can't be successful without post processing on this. And then of course, understanding how your part goes into service. So, understanding that entire lifecycle, and you're not going to get additive right without making sure that each of those steps are completed in a certain sequence, and that I'm understanding the physics of each one of those steps. And I have to design for it early in my conceptual design. And a lot of the lessons that we put in the book, were hard lessons learned, because we failed a lot of parts, we would go make this complex part, and we would build it, and we'd remove the powder, and then we'd bring it to our machinist. And he'd say, I don't know how to machine this thing. There's no way to hold on to this part. Or we would design a part and take it to one of the machines and we we build it and then our engineer would say, I don't know how to get the powder out of this, you didn't include the proper powder removal ports on that. So, again, all of it has to be designed very early in that process. And you'd have to think about each one of those steps. And it kind of goes back in what you were saying earlier that the roles, some of the traditional roles in engineering, have merged together in additive manufacturing.

So, I think with students, we're not just teaching them to be a design engineer or a manufacturing engineer, a quality engineer or a metallurgist, additive has sort of morphed all of those together. And there's a lot of nuances in the process. So, for instance, we want our designers to understand, when I have a thick section and a thin section on my part, the microstructure might vary there, and I might get different properties. From that. And again, they need to understand machining, how am I going to hold this part? How am I going to get the powder out? How am I going to do inspections? That's a definitely a key area in Aerospace, we need to make sure that the parts meet the geometry and the microstructure and the quality that we need for aerospace parts. Because I think first first and foremost, we have to keep our astronauts safe. That is number one goal with all of our missions. So, I need to make sure that I'm applying the additive process properly. And you know that I can inspect parts and understand that what I think I'm building is what I'm actually getting, we often say that complexity is the inverse of inspectability, because I can make these really complex parts and then our non destructive evaluation engineers or inspector are like we don't know how to inspect these, because there's so many features in here. It's going to be really challenging on that.

So, I think all of this is definitely an area that we're trying to educate, and we find a lot of different opportunities, whether it be teaching classes, publishing books, providing courses, or we bring in Tour de NASA occasionally. And just having middle school students or high school students or university students get their hands on parts. I think that is something that's really inspiring as well.

EF: Yeah. And I also like what you said about the education of the current workforce, because there's so much potential in people who have traditional skills that actually don't even know that there are jobs available for them in additive, and with a little bit of education, and maybe some certifications and things like that, some of its on the job training as well, but I think being open minded to the idea, you can learn something else as well. I mean, and people say, 'Well, I'm a bit too old to learn that', actually, you're not, you can carry on learning throughout your career, because something new is always happening. So, if you keep yourself open to that possibility, the rewards could be amazing. Could be immense there. Yeah.

PG: Yeah. And I think as we grow in our careers too that you find the value of mentorship, and being able to provide somebody the tools and maybe get them headed in the right direction and see them do amazing things is extremely rewarding in itself. I've found myself in that stage, you gave a personal example, I know that we work with a lot of universities, and one of the universities that we've been working with doing a lot of additive development has been UTEP. And there was a masters student that I mentored for a couple years, did fantastic work, and graduated, is looking for jobs. And we knew he was going to fall in a really fantastic role in additive, and he did, and sent me a personal note and said I was, the first person in my family to get a degree, went on to get a master's degree, and now I believe is going to be one of the experts in the field on additive. And that itself is extremely rewarding on a personal level, professional, to be able to see these people, these students go and do amazing things, in additive. And definitely, I think mentorship is something that every engineer should be involved in at some point in their career, because you'll learn a lot about yourself. But again, you're also training people to go do great things.

EF: Yeah, and I think another good point that you made about mentorship is, you can even be mentored by someone who is on a similar level to you, you don't have to be mentored by somebody from up high, it doesn't have to be like a manager level, you can still grow and develop as a person from somebody who's alongside you. So, for example, I'm helping someone right now, who I would say, I'm definitely not their manager, but I'm helping them. And the change that I've seen in just the couple of months that we've been working on this one thing together and I'm encouraging them, it's astonishing. And they didn't even know, I wouldn't say, they didn't even know they had it in them, but they, they weren't aware that all these things were open to them. And then now they're looking at things with a new vision or different eyes or something, because somebody else has just come along to provide some extra commentary about things or avenues or things that they want to achieve or accomplish or ways to look at things or ways to get things done or whatever it is. And I mean, the subject matter is additive, but the way that you approach it is human to human. And so I think that that's a really cool thing to have seen and be a part of, so I'm pretty happy on that respect as well.

PG: I completely agree on that. And I learned stuff from our interns that come in all the time and they…

EF: Exactly, Relatively Space was actually also started by two people who were interns. So, one interned at SpaceX and one interned at Blue Origin. So, interns these days are amazing people, they don't just push bits of paper around, they actually do real meaningful work, and they are going to be the leaders, and, CEOs, and leaders and business owners and entrepreneurs that are going to lead us into this next sort of wave of, well, they already are leading us in this next wave of, let's say, commercial, and also governmental cooperation, I'd say, in space exploration.

PG: Yeah, and I think that to bring it back, I think additive has helped enable some of that creativity too, if you've been designing rocket engines for a long time, there's certain rules that we might apply, or maybe we have certain biases that it has to be manufactured like this, and we get some of our interns come in and say, 'Well, why can't you do this?' and sometimes my brain will go well, because we could never manufacture that. But now we can manufacture some of this stuff, or we can use some of that complexity. So, there's new designs and new performance that we can get out of that. And sometimes it's intern or Co Op ideas, just trying to shift you out of your thinking on that. And I think that again, the, the current and next generation workforce is going to come up with these new ideas for designs, and we're seeing that with some of the topology optimisation and the generative design with additive is adding in this complexity and applying certain constraints to come up with these organic structures.

EF: Yeah or even algorithmic designs or designs that are inspired by machine learning and AI. Yeah, it's incredible. It's really incredible.

PG: So, I think that that's a huge opportunity for growth in additive. And I think the other one that I sort of mentioned a little bit earlier with the GR Cop alloys is just the opportunity for a lot of new materials.

EF: Now you’re talking my language!

PG: [Laughs].

EF: That’s something that I'm really excited about. It's like a bee in my bonnet that I have about 'why are we using materials that were developed 70 years ago?' They just happen to be able to be melted and solidified by a laser so that's a massive advantage that we have and we already have thousands of data points on how to make those parts traditionally with those materials, but the new materials, that's what I'm talking about, like those things are to me as a material scientist really exciting. But I'm sure that that will go hand in hand with the process development. I mean, it has to, it has to. Oh my gosh, Paul, that we've spoken for, like almost an hour. This is incredible.

PG: It's fun, again, to geek out on additive, and I'm sure we could talk all day about this, there's a lot of aspects of it, a lot of nuances. Hopefully again, we can inspire the next generation to develop complex designs and new materials, as long as they understand the process and apply it methodically and intentionally.

EF: Yeah, where it makes sense.