Inside Ursa Major's State-Of-The-Art Rocket Engine Factory!
Hi, it's me, Tim Dodd, the Everyday Astronaut. Welcome to Berthoud, Colorado. We're just a little ways north of Denver amongst the beautiful Rocky Mountains, and I am here to share with you guys a company that I'm really excited about, Ursa Major. Today we're going to check out all the incredible different rocket engines Ursa Major is working on, which is way more than I even knew about. We'll talk to experts who will give us the nitty gritty details that I love.
I'm literally going to be getting my hands on a rocket engine for the first time to help build one. And if all goes well, we might even catch an engine test from a ridiculously close distance. Yes. Now, I do need to warn you, we get really deep into the weeds here with all of the nerdy stuff of rocket engines in this tour, but don't worry, I've got three videos that will help you understand everything we talk about. So if you haven't already, I would consider watching "Why don't rocket engines melt?" "How to power a rocket engine", and "how to start a rocket engine" as precursors to this video, because although this is all extremely exciting stuff, what we talk about in this tour can be pretty hard to follow for those uninitiated. And yes, this is a very long video.
So here's the timestamps for all of the sections that we talk about, and we also have the YouTube timeline broken up as well. Okay. Okay. Let's head on inside and see what they're up to. Joe, how's it going? Good to meet you. Yeah, nice to meet you. Thanks for coming out. Thank you so much for having us.
Yeah, please. Let's check out Ursa Major. I'm so excited to come out here and see-. We're going to see a lot today.
That's what it looks like. It looks like you guys are in the middle of like, I can't even keep up with everything you're working on. So give me an overview of all of the different programs and engines that you're currently working on. Okay. Some of these might be a surprise too.
So Hadley was our first product when six, seven years ago when we started the company, the intent was let's build one engine and hot fire it to show we can, and that was a big proof point because we took the approach of stage combustion for our engines. So higher performance, higher risk. We really thought it was going to be a demonstrator. Now it's a product with three different variants.
You'll see all three today we've got a boost variant, an in space variant, and then a hypersonic variant of Hadley. We built probably 120 of those engines to date. And. Holy crap, what? So when we walk around, you'll get to see a lot of that. You'll see the production line. And Ripley is the big sister of Hadley,
so it's about 10 times the thrust go from 5,000 pounds to 50,000 pounds. So Ripley was intended to take Hadley's architecture, performance, manufacturing, turn it up to 11, but also focus on reliability. So we'll see a lot of that hardware today. And then just last year we announced Arroway. We had for a while done some work on what is the next engine, what is the next product here? And two things really stood out to us.
Russian's invasion of Ukraine meant no more big engines coming into the US from Russia and the industry shift toward methane. While I should let our CTO speak to this, but we are not believers in methane for performance with our architecture kerosene can perform right around where methane does, but it was really important to us that the industry's infrastructure was going toward methane. We were seeing launch pads and tanks and propellant conditioning move toward methane. So airway is our 200,000 pound thrust locks, natural gas, full flow stage combustion engine. And I think you're the first to hear that. We haven't announced that it's full flow. We itemized it as fuel rich initially.
Now it's full flow. Holy crap! Holy crap! Crap. And then two other things you'll see today while we're walking around, we just announced an Air Force program for an engine called Draper that is peroxide kero, small engine for hypersonics. Really exciting there because peroxide's a completely different oxidizer than liquid oxygen on our first three, but we still run closed cycle.
So all of our stage combustion experience goes into Draper as well. Really? Yeah, I think it's the first of its kind. And then lastly, you will see kind of as we're walking around some solid rocket motors. Okay, so four different engines, all different scales and all different capabilities. But all closed cycle.
But all closed cycle. Exactly. I mean, yeah, I don't know of anyone else that's starting there as they're jumping off point. It seems like most people would probably be terrified to try and do close cycle on everything.
We really took to heart. We had to push the industry forward. We didn't want to build another vertically integrated launcher with open cycle engines. So if there's a marketplace for closed cycle engines, I can't wait to see what the next company's going to do. Right. As we walk around, you'll see some hardware that really kind of exemplifies how and why stage combustion. So we had to go develop novel metals from scratch to withstand the environment. And those novel metals using 3D printing, allowed us to create geometries that have never been made in rocket engines before. So we now have rocket engines that can withstand the searing hot,
gaseous oxygen environment, that ones to rust or eat everything in front of them. Yeah. Alright. So you guys are developing a lot of really unique things using 3D printing a lot. I think it's time we head out there and see the hardware. Let's do it. I'm here with Mark. Mark, nice to meet you. Hi, nice to meet you.
Hey, we're going to head in and check out Hadley. Hadley production area. Yep. Awesome. So this is where we build our Hadley engines. Holy crap. Yes it is. That's awesome. Hadley's a roughly 5,000 pound thrust stage combustion engine.
What we're looking at here is a copper chamber vacuum variant. So this would be for an upper stage of a launch vehicle. Wow. It's so small. Yeah. How do you fit so much into that tiny little package? That's incredible. Yeah. Well,
definitely 3D printing plays a pretty big role in being able to get all of that packed in there. So Hadley's about 80, 85%, 3D printed by mass. Oh my gosh. Wow. And it's copper, right? So this chamber is copper.
And then it appears to be, yeah, this is the vacuum. Right. So would've nozzle extension on top of that? Yes, exactly. And that's made out of...? That's a nickel alloy. Nickel. Okay. Okay.
It's film cooled. It is film cooled. Okay. So is there a little bit of a manifold right here then? Yes, yes. You can see that the cooling manifold. Okay.
This is the cooling circuit. Cooling circuit right there. Yep. Okay.
And this has kind an interface ring stub, skirt there for testing on the stand, not the full nozzle on it. Cause it'd be too high of expansion ratio. Exactly. Yeah. You'd have flow separation and structural issues with the full one at sea level pressures.
And then you might not have much of an engine left. Potentially. Exactly. So let's see, if you wouldn't mind, I love nothing more than trying to dissect these guys and see if we can figure out what exactly is going on here. So your engines are oxygen rich, correct? Stage combustion? Yes. So that means that the turbine is going to be the top, the very bottom here on top of the chamber will be the turbine.
Yes. So this is kind of vertically stacked. So the turbo pump sits on top. So it's inline with your thrust. And then it just shoots right down into the main chamber. So it's also a structural... the turbo pump assembly... The thrust goes through the whole turbo pump
assembly. I. I love that. And is that even what those ribs are for kind between the pump structure? Part of it is to provide that structural support to keep everything in good kind of physical location. You've got high speed turbine machinery in the inside of that that's spinning around at a very high speed with very tight clearances.
You want to get the type of the clearances, the better the efficiencies are on the turbine machinery. And so you want to keep all of that stuff kind of in the right position. Right. That means that if it's oxygen rich, that means this is probably the ox pump, then... This is the preburner. Oh, that's the preburner. It's got its own little separate preburner.
So here's the discharge of the ox pump is coming right out there and going into the preburner. And the preburner comes back around and goes into the turbine inlet. So this is kind of what Arianespace or whoever makes the Viking engine has a separate gas generator basically, or preburner in this case. And then it goes through a tube into the turbines you have. This is all pretty tightly packaged in there. So it's right there and it just takes a little turn, goes through the turbine then and then into the combustion chamber.
So the oxygen pump is there. So it's kind of the lower of the two pumps. So here's the oxygen inlet that comes down and feeds into the ox pump. And then over here is the fuel inlet that feeds into the fuel pump that sits on the top. Look at how tiny that all is. It's incredible! And this can produce 5,000 pounds of thrust.
So that'd be like, what is that you guys know in kilonewtons? Is that around 20 kilonewtons of thrust? I don't remember that number off the top of my head. Let's get a conversion. I always struggle with tons, kilonewtons, pounds. You have to first go to kilogram, which would be 2200, 2300 and then divided by 9.8 or whatever, and then something that's stupid. 23 kilos?! At least I wasn't an order magnitude off. Okay. So yeah,
that's an incredible amount of thrust coming out of such a small little thing here. And just as a reminder, so it's RP-1 one liquid oxygen, but ox rich stage combustion cycle. And all copper, there's no minor... Correct. Yeah, so the chamber is monolithic printed copper. And this is for us a fairly recent development. We've been working on getting the printed copper chamber into our engines here.
We're getting into 340 second ISP range on the test stand with its engine. So it's quite good performance, especially for a small package like that. So the flow of activity here is on this side of the production floor. We've got a basically sub-assembly stations here. So we'll put together, you can see some valve components, you can see turbo pumps being assembled over here, and on this side is the kind final engine integration. So each engine gets built in a specific stand, bring the chamber over, bring the turbo pump over and start to build out the whole engine. And then you can see they kind get stacked up for shipping or testing down the tail end here.
So when they're this small, how heavy does this thing end up? How heavy are these units when they're assembled like this? They are, at this stage they're like 80 pounds, 84 pounds. Oh really? So you could in theory just pick one up? Yeah, you could pick one up. Wow. Definitely flight weight is important, important aspect of the overall performance of the engine.
Yeah, that's awesome. Well, should we go check it out on the test stand? Yep. All right. What's up? Hey, I'm Tim. Bill. Bill, awesome. I'm going to hand you this mic here.
Let's take that here in your collar. So where are we? What are we looking at here? What all is this? So this is our test facility. We've got three test stands in a row right here. We're going to look at both stands, A and C, which we've got two Hadleys on ready to test right now. So we can go take a look at both of those.
But these were built a commission in 2017 and commissioned last year just to really hit Hadley test rate, both development and production. Awesome.Yeah, let's check it out here. So right up here, these on the testing now, so you got three different cells. Yep. So cells are relatively configurable to different variants of the engine. What you've got on a test cell, generally speaking is a thrust structure that you can bolt Hadley up to. You can get really close to it. We'll actually keep walking over to C.
But this engine, we will get off test here in about 30 minutes. Behind the test cells, we have run tanks, which we fill with propellant so that we can actually run the engines at a higher propellant pressure and condition the propellant to the temperatures and pressures we want. And so here we have Hadley up on mounted to stand C. Like I said, we will basically change the engine on the stand on whatever basis we want to. Right now we're doing a lot of development testing on this engine and what it's bolted to is a thrust structure so that we can very accurately measure thrust. And behind that we have flow meters so that we can accurately get flow rates for both liquid oxygen and kerosene. And beyond that,
we can get about 1% error in calculating ISP. Can you explain the regen a little bit? Yeah, so the regen cycle, and let me see. Okay. I see the weird cone vein things coming off of the throat there. So basically this is the regen inlet on the engine main fuel valve right ahead of it. And then the regen flows into this manifold and down to the aft end of the nozzle and then back up to the injector. It almost looks like because of these weird vein things, is it going outside and then on the inside? Yes.
Interesting. So it's a pass down on the outside of the chamber and then internal passages going up. So it's up and down. Some go parallel to each other. This is almost like on the outside inside.
And it was really there to minimize the pressure drop getting down to the bottom of the nozzle. But yeah, and what's great about this variant is that we don't have any other film cooling additions inside the chamber itself with a copper variant. Really. This is three printed at our facility in Youngstown, Ohio, and we did a lot of the alloy development ourselves and have successfully been able to manufacture a lot of copper chambers up at that facility. And it's pure copper? It's GRcop42, is that right, Joe? Yeah, a NASA proprietary copper, but there was not an industry standard for 3D printing that copper alloy. It's just a really nice alloy. So we developed the printing process in-house. Yeah, but there, there's no structural jacket on the outside of it.
It's all copper. So this is all copper. There's no structural jacket. This is essentially the lower pressure version of our station combustion technology on Ripley.
We'll see a structural jacket on the outside of the chamber. So this is a lot lower combustion chamber pressure compared to Ripley? Compared to Ripley, yes. Okay. But yeah, still pretty sporty for the engine size we're at. And then back here you can see it's a bit of a mess, but I can point out a few things.
What was interesting about the architecture is that our customers have been pretty happy with the form factor of it, and we've left where it is, which makes it really easy from a gas flow perspective to flow gas from the turbine right into the main chamber. Right. Yeah. Wow. That is a slick little package. So the turbo machinery has been completely ground up developed by Ursa, all the blading and design of the turbo pump. It's been something we've developed since day one as a company. How fast is a little tiny turbine, like this spin? I feel like when it's that small, it's got to be screaming.
So at about 60,000 RPMs. 60,000! Down to the small form factor really gets RPMs up and yeah, that's about what the pump runs. And another couple cool features of the engine. We've got a in-house developed TVC system that also locks out on its own. So we have multiple customers for the engine,
the boost version of the engine, a hypersonic variant, and an in-space variant. So the engine actually is used in both a horizontal and vertical configuration. Cool. And one of the tricks here, we're using a kerosene for the TVC, so it's the same hydraulic fluid as a appellant and then a lockout system that allows it to unlock under pressure and then re-lock afterwards. So the engine returns to a center neutral locked out state for hypersonic emissions.
Oh, that's cool. So you're using the RP1 as the hydraulic fluid? Correct. Okay. Yep. Yeah, packages really well, especially for kerosene engines, you really want to just stick with what you've got on board and there's no need for another hydraulic fluid. The viscosity is lower than a typical hydraulic fluid, sometimes by a factor of 10, but it really doesn't pose too many challenges.
Right. And what is the gimbal range? Gimbal range is about seven degrees. Seven degrees. Wow. Yep. Wow. And when the nozzle extension is on here, how much bigger does the ascension get? So this'll be an expansion ratio of 110 to 1. 110 To 1. Okay. So that's up to pretty far.
That's about about here ish if I were to gauge it. Wow. Yeah. That's incredible. Wow. Yeah. Is there anything else? Oh yeah,
I guess one thing I was going to ask, you mentioned recharging and using the relighting multiple times. What do you guys actually use for an ignition system then? So ignition system is a hydrogen gas ignition system. Hydrogen gas ignition system.
The bottles are on this side of the engine. So right now we're utilizing hydrogen. We've built many different ignition systems in the past for Hadley, it's been a long product history, but we're also developing methane and we've used kerosene as well. And then we have a start bottle for oxygen and yeah. What?! So does that go into some kind of torch igniter then? It's a torch system.
A torch system. Okay. Wow. I've never heard of using a little bit of hydrogen gas like that for... It's nice because if you look at it wrong, it lights hydrogen's pretty easy. Well, especially in gassiest form as well. I mean, it's-.
One part of our mission profile, especially with our hypersonic flight, is that we don't get a chance to retry an ignition, so it has to light the first time. And we really wanted to minimize risk on the system. Like I said, we've tried every propellant, we're still developing multiple types of ignition systems for all of our engines, but right now our current version is a hydrogen ignition system and we found a lot of success with that. I might as well ask on camera knowing, I might not get the answer to it, but what kind of injectors are you using in there? That is a little on the ITAR side too.
That's what I was thinking. Unfortunately, I would love to tell you off camera. I can tell you everything about it. But yeah, I mean,
one thing I can mark or say is that the engine is over 80% 3D And that's one of the greatest things about being able to print and design one printed by mass. of theses small engines so that the injector being fully 3D printed allows us to create some really, really complex geometry in a single print. Now we started doing that back in 2016, 2015 when we started to develop the engine. And I think it's become quite the standard starting point for many engines and the small to medium class. So it was interesting to pioneer developing a 3D printed injector and get it to work. And there's a lot of tailored manufacturing approach to getting injectors to repeatedly print and perform based on the specifications you designed them to.
There's been a unique challenge, but what's great about having a 3D printed injector is that it goes from one of the most expensive parts on the engine to one of the cheapest. Right, right. Well, should we go check out Ripley up there? Yeah. All right. Hey, I'm Tim. Hey, I'm Melissa.
Melissa, nice to meet you. Yeah, stick that right there in your top of your shirt collar. Nailed it. Exactly. And I'm Tim. Hey Brad.
Brad, nice to meet you. I'll have you do the same thing, just kind of stick this right up. We will walk over to the front where we have Ripley Block 1 development engine installed right now.
Cool. Get to take a look at it. So why don't we come on back, you guys, the first thing you're going to see is this is the lock space. This is of course the run tank for pressing LOx to pump in let pressures essentially the storage tanks.
We kind of walk past already many thousands of gallons that gets transferred here to actually run the tests. So we have a LOx bay isolation valves press system mirrored over there for the RP1 system. Got it. So we're going to walk back here to the back of the test cell. Actually,
we can follow Melissa out front. The first thing you're going to notice here is we have a lot of passive sound suppression going on. When you look at rocket test stands, some of the fundamental different types are of course vertical or horizontal or an angle, and then what kind of flame diverter system, cooling system sound suppression system are involved. So as far as the passive sound suppression systems, you're looking at, of course an array of engineered dirt berms. We actually did acoustic modeling of the whole area in order to reflect back the sound waves as much as possible from the surrounding area.
And it goes for these concrete walls back here as well. So let's go take a look at Ripley. Oh, look at that. So this is a 50,000 pound thrust ox rich stage combustion engine. It is the highest pressure kerosene rocket engine that the United States has ever hot fired that. Wow. We have Melissa here was our lead for development.
We did about a two year sprint where this block variant of Ripley started as a clean sheet back in early 2021. And we went through all that rapid, the usual PDR design phase, early procurement, all of that culminated in our hot fire activation campaign this past February. So roughly 24 months from actually Melissa's sketches of engine cycle diagrams, turning that into real thermodynamic models and requirements for the component designers. And now here we are with,
this is actually still the serial number one engine that's been rebuilt since its first campaign and it's back on the stand for more aggressive engine development testing, longer duration tests, a lot of startup sequence investigation. I think you had some discussions with Bill and Joe earlier a little bit about how there are all kinds of unique technical challenges when you get to stage combustion engines. And the ones that get talked about a lot are the pressures, material compatibility and all those things, the complex turbine machinery, all those things are certainly challenges. But the one that I would say honestly to the development engineer of the stage combustion engine that we spend the most time with is the startup sequence. Oh yeah. If you think about it, you've got the preburner and the main chamber, or if it's full flow stage combustion, multiple preburners.
Of course you have these combustors in series and they're on different sides of the turbine. And when you do that, you have fractions of a second to get right of a window between when you have a viable startup when you might stall out or when you might actually run away. Yes.
So in order to do that, you have lots of requirements for propellant control valves that you don't see on some other engine cycles, open cycles, that sort of thing. So one of the things that Melissa worked on in particular was how we dial in multiple fuel valves that have tailored profiles that inside of a quarter second have to do certain maneuvers to deliver the propellants to certain combustors at the right timing. There are additional auxiliary start systems. Obviously we have ignition systems.
We'll use TEATEB right now for this Ripley campaign. So I'm sure the viewers are very familiar with that. We have multiple ignition systems here at Ursa.
We saw hydrogen down there. I've never seen a gas hydrogen ignition system before. That was cool. That was the first for me. I wish I made a video about how to start a rocket engine and I never included gaseous hydrogen as an option. I mean, that is something really cool. Yeah, that's a great one. We like that for our vacuum engine where it really maximizes the ignitable range for multiple relies, you really increase reliability by having a really high flammable set of gases basically for development.
And obviously the TEATEB is an operational vehicles and could be operationalized all the way through flight for development though, especially we really like it because it takes out the guesswork of it. Is this combustion chamber going to light or not? Yeah, I mean the truth is if you get some kind of dribble of TEATEB in there, you're probably just going to be fine. Yeah. So we'll go to the back of the test stand here shortly. But while we're here,
I was thinking, Melissa, would you like to kind of give a tour of the propellant systems? Yeah, sure thing. And actually right when we get started, I want you to give me first an overview of your baby here, but I love trying to figure out an engine too. So if you won't mind letting me guess around and try to figure out, and then you correct me and help me figure out what I got and got wrong. But give me the overview first and then I'll dive in and see what we can figure out. Okay, sure thing. So this is Ripley. It's our 50,000 pound force LOx kerosene engine, also ox rich stage combustion.
And we hot fired it for the first time this year. So do you want to try and figure out what things are? Okay. So we would know the turbine's up here. It makes it a bend into the injector into the top of the combustion chamber. So the turbine there, ox rich turbine, did you say ox rich combustion chamber too? Well, it's stage combustion or preburners ox rich. Okay. But your main OF is obviously fuel rich. Right. Okay. I was going to say,
I've never heard of anyone doing ox rich is making a combustion chamber, but today could have been the day. Okay. So if it's ox rich, then this must be the oxygen line here, so it feeds right into the turbine. So this means this is your fuel pump down here. Let's see here. What else?
So this... It goes regen cooling right out here into the manifold up there. Is that correct? So this is our fuel pump and you can see that this bigger line is what goes to our main combustion chamber region. And what's really exciting about Ripley is we also have this kick pump.
So we have a smaller pump on top of our pump that's pumping the pressure up just to the preburner. So they want to walk around over here. So this gets it up to the-. You can see the small amount taps off and goes to there.
And then this line is the one that runs it to our preburner. So this is all the size that feeds the, and that's at a, because it has to be higher pressure since, has to be high enough pressure to feed the preburner has to be high enough pressure to feed the main oxygen or the main combustion chamber. Yeah, that's exactly right. And so you don't really need to pump up all of the fuel to that higher pressure. You just need a small amount of fuel that's being directed to the preburner.
That's awesome. So that really saved us from having a two-stage fuel pump. Right, right. So it's just this little bitty guy is its own little boost pump. Yep. Yeah, exactly. Okay, that's cool. It's funny because hardly ever actually seen it in real life to understand how in my head I don't have a sense of scale of how much fuel is actually getting boosted up to these higher pressures. Right. Okay. So keep going here.
I'm seeing something that I... Yeah, so from our ox pump, it taps off over here and then we have our main oxygen valve here, which is a pneumatic valve all designed in house. This is tapped off so that we can chill in our pump ahead of going into our start sequence. Got it. So that's upstream of the MOV. You have your MOV that runs to your preburner. So this is all of our preburner. And you can see the fuel,
it comes from the kick pump down here around the backside. So this is the preburner valve, and then we have another valve on top of the preburner head in, but it comes in from the top for the fuel. So you have an off chamber, a separate preburner that it's going to feed your hot gaseous oxygen.
It's not... Okay. Yeah. So all of the ox comes in here, the fuel comes in there and then it's combusted in this main combustion chamber here. And from here on is hot gaseous oxygen.
Yep, that's exactly right. So then that goes in and drives our turbine, which is then fed through the hot gas duct and into the main combustion chamber through the injector. The other part of the fuel circuit, the main portion is tapped off here and it's a little hard to see, but it's tapped in here.
So it goes into the region and then it's a single bypass. And then we have our main fuel valve here, which taps off and then is going in through the main injector over there. Main injector up top. Yeah. Wow. That's a tight package. I mean it's impressive to think that you have to be able to get access to everything to be able to install or do all the things you have to do to it, but also then make it tight enough to fit on a vehicle for space.
Exactly. And with Hadley too, we have our whole TPA is stacked on top of a thrush chamber, but with this, our TPA was so big that we couldn't fit it there. So packaging is very tightly in this way. And then also just all of the routing within that too is really important for the packaging. So that's something we had to consider a lot with our layout and our design of the engine.
And so it looks like you're doing a similar thing here. We just have a temporary nozzle extension. So is this going to be a vacuum version? We have both versions. This chamber specifically was the vacuum variant. So this expansion ratio is in line with that.
So we are working on another combustion chamber design that would be for the sea level variant, but it's mainly all the same engine components aside from the nozzle extension. Okay. And it looks like it's a similar, it's copper on the inside, but you do have a structural jacket on the outside for this because it's higher pressure.
Exactly, exactly. So we have that inconel shell to provide some of the structure for that, but then the copper is better for some of the heat transfer. And is it 3D printed for the main cooling chambers and everything? All the channels and everything are still 3D printed copper, like the technology that you guys have developed in house.
And then you have buy metallics though to be able to keep it all. So it's actually printed in four different sections and then we weld 'em together and braise 'em together. So it is quite a long process, but seems to be working out well for us. And the copper, we print ourselves at an Ohio facility, so we've really done a lot of parameter development using a well-known NASA copper powder alloy. But we've done a lot of process development to tune in both the sort of laser printer settings, but also the post-processing and that sort of thing. When you look at the engine, it's sometimes more useful to talk about what's not printed than what it is because generally everything that's, that doesn't lend itself to more of a sheet sheet metal type construction.
Anything besides that would be printed. So the entire thrust chamber except for the nozzle extension here, which as you said is an early development fill in, the entire turbo pump preburner system all printed. And what's really notable is when we talk about materials. So if you go through the materials list on this engine, you're going to see a lot of the normal ones, your inconels, your titaniums aluminums, that sort of thing. And then obviously copper on the combustion chamber liner. But what's interesting is of course, so preburner ducting through the whole turbine housing and what we call that turnaround duct that Melissa was pointing to you where that turbine exhaust feeds into the main chamber. All of that is where you have high pressure,
high temperature, nearly pure oxygen. And of course that is where your normal engine alloys are not going to cut it. They'll have a tendency towards ignition and combustion propagation. So that's where SS developed our own alloys, our own printable alloys, tweaking composition chemistries and other process parameters, and also doing a lot of lab scale testing to prove that out in high pressure environments.
And so what you're seeing there is when you look at this engine is a lot of the materials you're used to and a lot of all, they all look the same, but a lot of alloys that are special to Ursa. Okay. Wow. What do you think was the when first, very, the very first meeting saying this is what we're going to aim for. Where do you start with an engine like this when you're designing it? The first thing are you at, are you hitting and trying to hit a target number and then you have to walk backwards of like, okay, if we're trying to get this ISP or this thrust level, we know this, is that your variable and you've designed backwards from there? How does that actually work? A lot of it starts in the main combustion chamber and then you work your way back through the system. So you start with what sort of thrust and ISP you want there and your chamber pressure. And then from there you have to have all of the systems that can support that.
So you have to have pumps that are able to produce that much pressure. So you kind of start from the main combustion chamber and work your way back. And then we use a rockets model as our transient and steady state analysis, but it has all of the resistance in there. It has pump maps,
so you can tell what performance you're going to get with those pumps as well as all of the rest of components on the engine. So is there anything else we want to be seeing here? Let's do a quick look in the back. Yeah, so this thrust takeout rated a 50,000 pounds thrust, which Ripley will be making good use of. It's got a whole set of load cells to measure that with high accuracy.
You're seeing here a dual set of coriolis flow meters, which are more or less for this scale of flow rate, the most accurate that you can get. And so we all like to talk about ISP, it's ISP and thrust, it's actually one of the hardest numbers to really pin down inside of one or two percent uncertainty. And so we go through a lot of effort here on the ground support equipment side to install the right instruments, also the right data acquisition system because in all that conversion on the backend you can add sort of hidden uncertainties. And so when we want to go to our customers with a certain thrust and ISP estimate, especially for upper stages where uncertainty margin really draws away from real performance capability of the vehicle, we really try to drive that sub 1% uncertainty on ISP and thrust. So this is sort of the flow meters and load cells, that's really where it all counts. Yep. Yep. Great. So one of the things we wanted to do next, Tim,
is we really have you help build the next Ripley. So we have the dev engine on the stand and the next one ready to go here about halfway point of the build. So this is the Ripley build area. Over here we have the engine that Alex, our lead technician is working on. Nice. Alex, this is Tim.
Hey, how's it going? So Alex is preparing a few extra parts to go on the engine coming up next. We have a lot of the Preburner hot gas section as well as some of the region fuel ducting. So if you have some time, we wouldn't mind a little help installing one of those pieces.
Yeah, I would love that. Okay, cool. Just to orient you, right, so we talked about how the Ripley flow path and cycle works. And so the fuel pump discharge is here, we have to get it over to the main chamber to start the region cooling process. And so there's going to be a duct that goes from here to here. Yep.
We call it the saxophone. Saxophone. Alex has it over there. Here. I see why it's called the saxophone. Yeah. So yeah, you want to install it? Yeah, I would love to.
Alright, let's get some gloves on and. So we've got torque specs there. Yeah, we got some torque specs. We got part numbers so we know what we're installing. And with this in combination with the model will help us kind of install the whole thing. Okay. So like I was saying,
we are still in dev processing so we don't have everything super refined, but we have enough information for us to install it. So that's where we're at. And the torque specs, is that plus or within 19 pound feet, is that like-. Yeah, that's like a range, right? Plus or minus right here. And we will set that on the torque wrench and I'll show you how in a sec. And that is a range of that. Gotcha. Sweet.
Basically, so we know we have the fasteners here. That's the part number. We already got all that set up for you. I already verified that and the seals are ready.
These are the seal part numbers, so we'll go from there. Sick. Alright, so part of the process is we want to document it as much as we can.
So we'd like to take a lot of photos because photos help if you want to go back and check if you have an issue, if a leak happens or anything like that, you want to take photos and you could kind of revert back to that. So you want to grab that camera for me? Yeah, yeah. So we're mostly just checking to make sure there's no burrs or any like0. Yeah, so any negative material, any dings, it happens when you handle parts and you get scratches. So stuff like that could cause some leaks in the wrong places. And we're going to do the same on the engine side.
So come over here with that camera. There you go. Got photo skills. I can start with that and I'll run these through. This is actually pretty heavy, heavier than I thought. Yeah. Look at that. All right. Okay. All right, so I'm going to get in there, get this started. How's that looking? It looks flush and straight on.
Beauty. Alright. I'm going to have you grab a fastener from down here and then get the bottom one in the bottom. You got the saxophone? Yeah, I got the saxophone. Get the top one over there. See if you can get that.
Top one up in there. Yeah, make sure we kind of. Yeah, I have another anchor point. Yeah, exactly.
You guys are working some tight quarters here, huh? Yeah. Most engines are pretty much the same. You want a nice tight package, right? So you get in these situations where you have tools, issue tooling, clearance issues, and just throw.
Lower one in here. Yeah. Get a couple in there. You guys want to hire me? Sure.
I was gonna say we definitely could. This is the interview process. Yeah. This is how all interviews actually are. It's like, okay, we're going to pretend that you have a YouTube channel and then. Come in here. You do need wrenching experience on cars in the past. Yeah, this is the downpipe of the 16G Turbo or not doing too much different.
That flange you're working on is probably worst case on this engine, but I've definitely worked on car engines for worse. I know. Yeah, me too. I mean turbos are a pain in the butt. Yeah, turbo manifolds, all of it is just, it's similar to this only it's normally you're working on it right after you ran, so you're like, oh, something broke and everything's searing hot.
You're like, but I don't want to wait three hours. So this is actually nice air conditioning. I'm not on my back sweating and in dirt. This is great. Have you ever had your hands on an engine before? Not like this. I mean I've physically touched an engine a few times but never got wrench on it at all, which I'm so stoked on. Sweet. I've literally,
I've debated a handful of times just being like, you know what, I'm just going to take a, I just don't know if anyone would hire me for an internship, just do a summer thing. It's pretty sick though to realize what I'm bolting and what I'm clamping down on is going to have thousands of just insane pressure and insane. It's many, many thousand PSI. If it leaks on the stand, you'll be the first to know. Yeah. Yeah. I hope I'm in the worksheet here of person responsible and-.
I'm going to make you buy it off. Yeah. Hey, if this one doesn't quite work out that well, let me buy the parts off it. I'll hang it up in my office. Yeah, a half charred one. Yeah. I'll drive these ones. If you want to start wrenching, just make sure you're,
yep. Not tight, but snug enough to get ready for a torque. A torque. Just seat it. Yeah, exactly. So you know a little bit about a star pattern. Yeah. You want me to go over yet out crisscross? We don't need to do that now, but definitely on the torque. Yeah. When you're going to do that, do you go just every binging, bing, bing,
bing. Pretty much? Or do you do a 90-. Small flange like this works in 90 because kind of go 90 and then you rotate. Okay, then rotate. Yep. Okay. Helps like a drum head.
Yeah, if you want, you could grab that torque wrench right over there and set. I think the torque might be set to that. I will double check on...
Which will be 3 78, right? Yes sir. Cool. Alright, so you got the power now. Oh god. All right. We need the... Which one do you want? You have a combination of-.
Can I do this one that has, that's not rounded? Yeah. Typically you don't do the rounded end because it doesn't have that much contact points, so I end up stripping. Yep. So just try to avoid that. Be as square as we can? Exactly. All right. Is it going to click at me or is it just...? It's going to get up to a green point and you can stop right when it beeps and gets to green. There you go.
Cool. I've never used a fancy one like this! Right? This is sick. Yeah.
While we're looking at this here, this is a really good shot of a gimbal mount here. You can see the bearings. So this allows the engine to swivel on two axis. So you can imagine it's swinging here on this pivot point this way and on this pivot point this way. And you can see too, they have flexible bellows here. These are to help allow, because obviously this is going to be rigid up here.
Rigid, rigid and all this moves. So these bellows have to be able to take up either compress or give some slack to be able to manage when the engine is moving around. It's pretty cool. That's a sexy looking mount there. Gimbal mount, we have learned that this is a separate structural jacket on the outside and it's still copper lined on the inside. So 3d printed copper on the inside, but structural metal jacket, it looks like they're able to weld a few of these different places together to help manufacturing. So you can kind of stack these things,
get the thrust chamber, the inside of it in there, stack and weld the outside of it together. And obviously you have some biometallics you have to work with to be able to meld the two together, the inside and the outside. And while we're pointing things out here, maybe we should, so this, let's see, this is the regen manifold here. This is the injector inlet or am I backwards? You're correct. So basically what you just installed is fuel pump discharge-.
Into the regen inlet. What we have is a single pass down here coming through here. It actually, the regen exit is here and the tube that's not here, but you can see where it's going to jump between. Is that your main fuel valve? Exactly. So the main fuel valve, which performs two functions. One, it's a shutoff valve for fuel, so you obviously need that. And two,
it adjusts the mixture ratio of the fuel. Yes. So if you want to burn more or less fuel relative to LOx, you kind of just trim that valve pretty slowly during burn, although it has a role to play during the startup sequence as well, but correct. So we enter here now, this is the manifold. This is the main injector and it'll distribute to hundreds of elements.
And then this is throat film cooling manifold. And this you said was just the outlet side of that. Got it. That's awesome. Thank you so much for showing me you're on the engine. That is super fun. Good luck and can't wait to see that thing fire up. I'll keep you posted. Yeah, I'm genuinely curious.
I want to know if the engine I actually physically worked on-. We'll post the video. If you see a leak squirting out into the distance, maybe you'll start getting nervous.
This is an accidental flame thrower. You'll know who to blame, I guess. Right? Oh man. Sweet. Where to now? Well, thanks a lot Tim. Yeah, we can go head out and continue the tour outside. Yeah, I'll follow you. Great. So we're about to see an engine test here. What are we going to see? So we're actually going to light two engines at the same time on both stand A and C next to each other.
Wait, you're lighting both engines? Yeah. Yeah. Sometimes it's actually easier from an operations perspective, but yeah, we have the capability to do that so. What?! So wait, so I saw the one cool down thing on the left cell, but you're also chilling the right one down too. Yep. They're both chilled in and ready to light.
No way. Yeah, so the engine on the left stand C is going to light for its 50th test and it's current build configuration and it'll be three, it's a 3000 seconds on that engine right now and about 330 tests on the stand. And the engine on the right is about half as many tests in its current build. And that stand has had about 1300 tests since it was commissioned back in 2017. No way. This is a pretty unique viewing area for a test.
We're basically as close as you can get to an engine of this class and they're facing us. Oh, you're right. Be ready. Going to be crazy. Yeah, I've been parallel to them off to one side, but I don't think I've ever been down range of one. [Engine noises] Yes, that might be. I think that's the best engine test I've ever seen! Holy crap! Definitely unique. Yeah.
Oh my god. Want to do it again this afternoon? Yeah, you can fire them up again this afternoon? Oh yeah. Oh my god, yes. No way. The interference of the two is so interesting when the second one started. Oh my god, it felt like it more than doubled. It was, yeah, that's what it felt like. Yeah. Oh my god, that was intense.
So we were in that little gravel area right there. Yeah, exactly. And that's what...? It's a hundred meters away, basically. A hundred meters away. And I think that's got to be as close as I've been to any engine.
But the crazy thing is that we're almost downstream of it, so it feels... It's exactly where that pole is. Where we were standing is as close as the NASA safety spec to an engine this size. No way. We were literally as close as you can get per NASA safety. Well, you could feel it, and especially when by the time the second one lit up, I don't know if it was just some kind of resonance or some kind of. Interference? Interference something, it went more than like you'd expect double the engine.
Not even, you'd think just a mild increase. It felt like it at least doubled. Oh, I felt it hit me. And I felt like all of a sudden I felt the heat too. You can actually feel and it's so bright.
And it's not a normal test for us to run both at the same time. So you definitely caught a good day. That was perfect! As you heard on the radio, both tests were full duration, so we were testing this in-space variant, a hypersonic variant side by side and got all the data we needed. Oh my gosh. And you were doing V C and everything. Yeah. Yeah. Got see some TVC motions, which on an engine like this,
it's very close coupled. TVC can be tricky, so you want to make sure it's really dialed in. That was incredible. I know people watching are probably like, oh, Tim's excited about a rocket test he's faking.
It still catches me off guard. I still am sitting there going, this is so loud. Louder than I expect. Brighter kerosene. So bright and I know it is hilarious. The first I've waited nine years or whatever to watch SLS fly the first words. I've never really seen big SRBs like that, especially at night. The first...
I was expecting to have some glorious and here goes the future of humanities, return to the something beautiful I had to kind of sculpted in my mind. Instead, I'm like, it's so bright. That was Oh, cool, Tim, great commentary. I'm sure everyone's excited about my insight on that. Very per the script. Yeah, exactly Oh my! It's so bright! Yeah, we probably blew up 15 Hadleys, 20 Hadleys in the early days. Just catastrophic, dramatic explosions when we're trying something new.
And actually the very first Ripley explosion, I think the team immediately was kind of sad and I went around slapping people on the back because you have to push it hard. You have to turn it up to 11 and see what it does. Do you have footage of that? Absolutely. Absolutely. Can we share it? Sure.
You heard it. If we're cutting to that explosion footage right now, it's all thanks to Joe. [Engine exploding] You guys are working on some awesome things. Thank you. We're really glad you could come see it.
Yeah, I mean, seeing everything today, getting hands-on with an engine, being able to actually see these things fire. I am not nervous about my build on Ripley, but I am very curious about how that's going to go. If I was hand assembling engines at like 22, you'll be fine. You'll be all right. It's true.
I am excited to see I'll be paying very close attention to that test campaign. Awesome. So that'll be very fun. Yeah. Well, we'll have you out for Ripley some time and then down the road to airway. Oh, now that will be awesome. Yeah. Thank you so much for your time. Really appreciate it. It was really amazing. So glad we could do it. Thank you. Had a great time.
Thanks so much to everyone at Ursa Major for having us out and for showing us all the amazing things you're working on. Be sure and keep up with Ursa Major on social media so you don't miss out when they have some exciting updates and content to share. I also owe a huge Thank You to my Patreon supporters, YouTube members, and X subscribers for helping me make content like this. If you enjoyed this video, consider showing your support through one of those platforms or maybe consider dropping us a super thanks. All of it really makes this stuff possible. And while you're online, don't forget to check out our incredible merge store for things like our 1:100 Scale Metal Falcon 9 models or our heat shield, color changing mug, or lots of other fun stuff everydayastronaut.com/shop. Thanks everybody. That's going to do it for me. I'm Tim Dodd,
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