How rockets are Made. Rocket factory tour. United Launch Alliance.

Five... Four.... Three... Two... One... Hey it's me Destin, welcome back to Smarter Every Day I love rockets If you've been around this channel, you know that about me and today is like the best day ever because we're going to learn how to build rockets. Just down the road from Huntsville, Alabama there's a city named Decatur. And in that city, there is a rocket factory owned by a company called United Launch Alliance, and that factory has been cranking out incredibly reliable rockets for years. Because these orbital rockets have some of the same technologies in them as ballistic missiles, the knowledge about how to build them is protected. In the United States we have a set of regulations called ITAR International Traffic in Arms Regulations Because of ITAR, nobody's going to let you walk into a rocket plant with a camera and film things.

 

They can't risk that stuff getting out and breaking the law. So there has to be an incredible amount of trust between the parties that want to film things, and the people that own the plant. Thankfully, I was given the opportunity to build that trust with ULA, when I went and watched the launch of the Parker Solar Probe, and I met the CEO of ULA on the launchpad. If you haven't heard of this guy, Tory Bruno, then you're in for a treat. He's a legitimate rocket scientist who know his stuff inside and out. It was at this launch that Tory and I built trust with each other. Like, this guy is the real deal. The tour we're about to go on has never been done on the internet, Tory literally takes us right up to the line of what he can show us, and all along the way he's answering my technical questions, and he's letting me explore the factory.

 

So here we go, let's take the first ever online tour of the United Launch Alliance rocket factory in Decatur, Alabama, with the CEO of ULA. Tory Bruno. Okay, we've got Tory, mic'd up now,-Hi! and you're gonna show me the rockets that are- Yes,

 yeah fabricated at this facility?

 What do we have?

 Okay, so we've got an Atlas V on the side, this is kind of our workhorse, and it's in the five meter payload fairing configuration. So that's what we're talking about here, it also has its SRB's on the side, which is sort of its maximum lift version. When it's got all five of those, we call it the beast. - And this is the Delta IV Heavy, and this is what you--thank you again, for letting me-Yeah, of course participate, or at least see the Parker Solar Probe Yeah, that was fun huh -And that's fabricated here in Decatur? Yes, yeah so three core rocket, you know literally literally three rockets kind of bolted together, and it is our largest rocket; it's physically the largest rocket in the world right now, and it is what we used for Parker Solar Probe. -And this is what I want to talk about,-Yeaaaaah this is Vulcan, and this rocket has never flown. Never flown, not yet. And you're going to see, the first flight vehicle hardware in the factory being fabricated when we go in there today. -Today-Yeah Okay!-So this is our brand new rocket, you can think of it as kind of a derivative of those two in a way, so it'll be large 5.4 meter diameter, so a little bit bigger than Delta, it can take six SRB's, it's a huge cavernous payload volume for the spacecraft, and this rocket has 30% more lift capability than this big three-core monster. -So when you say six SRB's... Six of them, yeah.-And that's just to get out of the Earth's gravity well Yes, right, exactly. -Can we go see the stuff? Yeah, let's go see it. Okay, we're at a rocket factory, let's do it. -We're gonna peel off to the right here Okay Okay I'm seeing the grid here Yeah, so this is a barrel section from the booster over your head, actually from an Atlas. And I'm going to walk you down to the end of the factory where this first gets made; it's the first thing we do Raw stock comes in the back door, gets machined, puts this curve in it, and then we'll walk you all the way through to a completed version. –

 

That's awesome Okay, so there's something unique about the north Alabama area here, correct me if I'm wrong, but there's a little triangle: there's a nuclear power station, there's a steel mill, -Yes and there's also a rocket factory like in a triangle. -That's true And then you got a river running between them -Yup and so you can bring in steel, you can make a rocket using the power from the nuclear plant,-Yes is that why you're here? That's part of why we're here, but it's also because of the talent that we have here with University of Alabama and the other Alabama universities and the technician programs they have here; you just get an awesome workforce.

 

And with the river, which is only a mile from here down Red Hat Road, we have the dock for our rocket ship, so we can transport our rockets out to the launchpad. This is the rocket ship Tory's talking about; ya see? Says so right on the side: "Rocketship. Rocketship navigates its way through several rivers up to the Mississippi River, down to the Gulf of Mexico, and then it heads to whatever pad the rockets will launch from. You should come back sometime and do the ship. Yeah, I should ride on the ship. Is that a thing?-Yeah Can you do that?-Yes that is a thing Okay we're getting on a golf cart, and we have to cut cameras because we're going to pass uh, not "secret stuff", but things we can't film. Right?-Right Okay, cutting the camera off Ok we're on the golf cart, and I've obtained permission to film straight up so you can't see "that" which is pretty neat. Ok so, I can't talk about that right now, can I No, we can't show it to you, but I can tell you what it is That's a Delta payload fairing so one of the smaller versions of the Delta's payload fairing and then you're passing by a heat shield here that would protect the RS-68 engine, from its own plume during flight.

 

 Ok... this is almost emotional. I mean, you know what it's like to sit in class and study this stuff,-Oh yeah, sure and then... cause you went to Cal Poly right? Right. Yeah, so this is me looking at all the stuff I've learned about and finally getting to see it. It's on thing to see it on the pad, but uh it's almost like a holy experience. Yeah well, you're inside where it's actually happening, where it all gets put together. Okay I'm starting to get the smell of the machine shop, the manufacturing, the cooling oil,-Yep smell.-You got it It's my understanding you're about to show me how to build a rocket from scratch. Yes I am. Okay, excellent, so we're going to the door, right? Yes we are Okay this is what I wanted to see, here at ULA: This is the door. I can't even get--it's a wide angle lens--so that's the door where the material comes in, right?-Right That's where the raw aluminum plate and other materials come in, and then this is the receiving area, and as they move that way turn into a rocket. So we're about to build a rocket by going that way in the plant. Exactly. -Okay, I'm game let's do this. Alright let's do it.

 

 And this is an active manufacturing facility, so you're just going to have to deal with the audio, there's a lot of tools running. Yeah, sorry about that, but, ya know, building rockets. It's good Oh wow,

that is... that is really--can I go touch that? Yeah yeah, absolutely.

 This is a very, very expensive, piece--is that aluminum or stainless? –

That's aluminium Aluminum Yeah -And is that fabricated here locally?

-That's imported?

No, yeah we buy that from a supplier and then it's shipped here, comes in through the big door, if you will--and then we machine it down, we're going to remove, more than two thirds of the material while retaining about ninety percent of the strength -in certain dimensions, right?

And I will show you that, yeah -Okay, got it So this is our raw material, and uh, we're going to go make a rocket. Okay. And so, all this is aluminum?

That is a---All this is aluminum That's a unique dimension, you normally don't see plates of aluminum that wide and that long. No, so this is actually made especially for us in these dimensions, so that we can turn them into the barrel; the propellant tanks of the rocket itself. -Okay, so, so you're tooling up an entire foundry of some type or a mill, a rolling mill.-A rolling mill.

 

Okay, gotcha So I'm going to show you a couple of different things before we get to the machine, so starting here with the raw stock of 7000-series aluminum it'll eventually become a round rocket barrel, this is just after machining, and I wanted to point this out to you, because, this is our old style of grid that we machine in called an iso grid, and you're familiar with what an iso grid is-- -Iso grid, yes Right? So we have isentropic properties when we do the stress analysis, and you can see the triangular patterns in there.

 

That's not actually the ideal pattern for a rocket barrel, but it is what the analytical tools--the finite element analysis tools available to us when we designed the Atlas and Delta in the nineties, were available to us, and that's why we have that pattern. Vulcan will be better, because the tools are better and you'll see the difference when we walk down the line. -I have never thought about that So literally because in the nineties the FEA analysis could solve a triangle easily, -Yes that's why the isogrid is a triangle. -ExactlyI would've never thought that so, so basically if I understand correctly, you--can I touch this? Yeah, touch if you want. I'm going to ask you that every time-Yeah, that's alright So basically because you can compute the force coming in one member,-Yep to a node and the forces coming out the other member that's how you arrived at iso grid. Exactly. -Okay, fantastic Yeah it's sort of an interesting thing, in the real world, how the engineering tools that are available, dictate the kind of designs that we use. Got it.

 

What's your safety factor on flying here?

Oh, so it depends on what part of the rocket we're talking about, anything that would be pressurized when people are around, it has a higher safety factor than what is not, but the factors we work with in flight are anywhere from 1.1, to never really higher than 1.25. Got it, yes. I mean it's very different than like, designing a railroad car where your factor of safety might be 7 or 8. Oh no, yeah. And a factor of safety is, if you can compute the stress that the thing will break at, you design it to 1.1 times that Right, 10% more load carrying capability, and really a factor of safety is really a factor of ignorance. You have a factor of safety because you're not truly sure what might happen to it in the field, so you give yourself just a little bit more.

 

And you talked about rail, big tractors are another one; we have big factors of safety like 7 times, 12 times, when we do rockets, we like to keep it closer to like just 10%, maybe 20%, cause we can't afford the weight. Got it, because every every 1000th of an inch that you put in this webbing here, over the course of a huge part like this, you're talking tons on the whole rocket. Yes -Okay Exactly, and this is a booster plate, and so every seven pounds of that costs me a pound of spacecraft. -So how long does it take to machine that? You have the tools here to machine this isogrid. Yeah this is about a two day operation altogether. Is this curled like a potato chip in this direction, or in this direction? In the long direction. -In the long direction And you're going to see that operation as we walk to the other end. -Nice That's what the twenty-five-ton brake presses are for.

 

Yeah, cause if you're curling along the long direction, you require a tremendous amount of force, and you have to have alignment to keep it straight during the bend. Exactly-Okay Is that a pressure vessel? I mean would that hold pressure or would there be a liner on the inside? It is a pressure vessel, but actually on the booster because it's liquid propellant, most of the pressure is at the bottom just coming from hydraulic head. We only have a few PSI of gas on top to keep the propellant down against the outlet feeding it into the engine. Got it. This is not something I expected to see. These guys are--they appear to be putting--are they washing? What are they doing? They are. So the first thing that happens to those big plates, is we plane them--we make them flat--and so these guys are going over an operation that's just been done, they're cleaning it up, they're looking for any imperfections, and what you're going to see in the factory that I think is really cool; you know we're building rockets we're at the pinnacle of technology, and you're going to see high tech robotic operations, but mixed in you're going to also see craftsmanship, with people who are very skilled, and have great attention to detail like these guys.

 

 They're going to go over every inch of that thing and make sure that the automated machine that planed it, didn't leave any features we don't want. So if like a piece of the tool broke or something like that-Exactly Shattered, whatever.

 

 Yeah so, are these your fly-cutters here?

Yeah, basically end mills, some of them are side mills, but yes. Gotcha, am I allowed to look at this fly cutter? Yeah yeah, go ahead, sure. -Wow Isn't that cool? I love machining It's a secret passion of mine Yeah me too So you went to Alabama, right? -I did So do you guys do a lotta sorta machine shop time in your engineering degree? -Not a whole lot, but we do take a class or two, for my undergrad I did that. But my dad had an old lathe and mill in the garage when I was growing up.

 

-CoolYeah that's cool stuff The other thing I'll share with you, you can see all that flow down there, we actually recover all these chips so even though we're going to take the majority of the material away by machining it off--subtractive manufacturing--we capture all of it, we send it right back to the supplier and it comes back to us in a plate a month later. -That's awesome That, is that coolant? That's coolant but it's mostly water.

 

 Mostly water, so it's capturing the chips. That's a tremendous amount of water flow! Yeah, well, chips are heavy. [Both chuckle] It's hard to get a scale for that. It's hard to get a scale for that, but that is a lot of fluid. Oh, there's a whole river of coolant there. -Oh yeah, you can see it Are you looking for places where the tooling broke? No we're looking for chips or, debris that might be on it, we only have about a 5000th of a thickness, -Right So, a small chip would be outside of the tolerance zones. -Right Thank you very much, my name's Destin. -Jeff Nice to meet you Jeff. Nice to meet you That's cool, the human story is what's really cool to me, that's amazing. -Me too Here's one that, uh, I think this guy's actually running. So you can see way down there where the cutting head is, These are actually the plates for Vulcan flight two, -Really the second Vulcan that'll go. So you know what we outta do is we outta, like, steal you a chip down there, so you'll have a chip from the Vulcan rocket when it goes to space. -Can I,

 

can I stick on in my pocket?

Yeah. -Ok, I'm gonna--It's a little sharp, be careful. -I'll be careful, I'll take a little one Nothing to see here It's okay, you be careful. A chip from Vulcan, here's your chip. Guard it with your life. -Alright we're in trouble but don't tell anybody We're in trouble but don't tell anybody, Tory Bruno said it was okay if I stuck a chip in my pocket. So, these machine are CNC, correct? Yes. Okay and, are these specially made machines, or because usually you, you don't plane a surface that-They were, yeah wide.-No, generally when you're in this kind of factory you're going to see tooling that comes from big tooling manufacturers, but it has been designed especially for this application. so all of this is custom stuff. -Really -So for example, the head here it probably normal, but the ways on the machine, this is incredibly long for a mill.

 

Yes, exactly, very very long, and very large. -GotchaVery, ya know, big width. That lets us do more than one plate at a time. -So if one of these machines go down, what does that do to you? That would be a big impact, but fortunately we have more than one, so we would always still have the other machines running. And so what would happen is we'd get it fixed and then we would catch up on an off-shift. -Because I've kept up with your launch record, and you always meet schedule,

 

is it because you have redundancy built in to this part of the process?

That is part of it. So yes, this factory was actually built with the idea in mind of building as many as forty rockets a year, and so we have so much capacity, it's easy for us to kind of make up for little challenges like that along the way, cause nowadays you fly maybe twelve or fifteen times a year tops. -Right, okay. So you're not at capacity. No, not even close.

 

-But you want to be, this is a commercial for that. Yes we do, yeah we do. Okay so that moment right there where Tory Bruno is joking about the capacity of his rocket plant; it reminds me of a very specific moment in an audio book I love called Seven eves. Now the beautiful thing about Smarter Every Day being sponsored by Audible, is I can use moments like that to go to Nashville and introduce you to someone I've been wanting to meet for a really long time.

 

Okay so we're going to drive a couple hours away, and we're going to meet a lady named Mary Robinette Kowal. She was the narrator for Seven eves by Neil Stephenson, and she did an amazing job, listen to the first line of the book: "The moon blew up without warning, and for no apparent reason." Let's go talk to Mary Robinette about this book. What a cool place to meet someone for the first time. I'm Destin, you doing alright? Yeah I'm doing great, nice to meet you!-Good to meet you, you doing ok? Okay, this is Mary Robinette Kowal-Hi! who is an amazing narrator of audio books. -Thanks You are! I've spent, like, well over twelve hours with you, mostly in a tractor but that's another story, but, the book that I want to tell people about is called "Seven eves" by Neil Stephenson. And this looks like it was a challenging book to narrate. It was more than a little bit challenging, it's, uh, technically completely accurate, it's got this huge international cast, so basically something hits the moon--they never figure out what it is shatters it, and that causes them to have to get off the planet real darn fast, because pieces of the moon are going to start raining down, and causing destruction for five thousand years. Mass destruction-Mass destruction! This is why I wanted to do it on this video, because Tory Bruno is talking about building more rockets, but you've also written a book yourself, Calcu-- You've written many books, but there's one in particular that's similar to Seven eves,

 "The Calculating Stars", yeah I slam an asteroid into Washington, D.C. in 1952 which kicks off the space program, fast! Also building a lot of rockets, a lot fast.-A lot of rockets There you go, so go get one of these two books, she's kind of downplaying that a little bit you've won the Hugo Award, the Locus Award, and the Nebula. That is correct. For that book, that's a big deal to win all three.-It's three Go get her books, [URL] Which one would you recommend? Seven eves. Seven eves? I'm going to recommend your book even though I haven't read it, I'm guessing its' going to be amazing It's called? "The Calculating Stars"-The Calculating Stars Okay, that's it, let's go back and build more rockets with Tory Bruno. Here we go: Yeah so if anybody needs their own personal rocket, Tory's your guy. Oh yeah, just let me know. So you remember we were looking at iso grids down there and we were looking at those Delta panels, so if you look at this panel that's being machined, you can see that they're rectangles.

 

So this is an ortho grid, which is not symmetric,  but we're able to do that now, because the engineering analysis tools are better. And so Vulcan switches to ortho grid, takes about half the amount of time to manufacture, and these panels will actually be stronger. so as I look along the orothogrid here, so you're gonna break it along the long side so this is gonna be a really long skinny potato chip looking thing.-Exactly So what happens when you're breaking along that line? Because you have a section in the middle of the webbing That's gonna have the most stress Yes But along the longitudinal webbing you're gonna have, it's gonna be difficult there. So actually the way the break process works is we'll bring it in flat, and as we break it, we're moving just a small amount of material each time and we roll the part in and out, so the amount of strain and work hardening that we get is actually very uniform across that width -Okay. Got it. But the issue that you brought up is one of the reasons why that's done by people. It's a hand operation. So there's no CNC on the curving of the brake press, it's all craftsmanship.-Really? That's amazing. So, so these are Vulcan? Yes, these are Vulcan panels these panels are going to space. -Wow, it's got a lubricant on it, it feels like. From the machining; from the machining process.-Got it.

 

-And so, the orthogrid, just looking at it, the webbing looks thinner, so it looks like it's much more light-weight. It is, yes. Are you allowed to tell me a percentage? I can't give you the number yet,-Okay ask me next year.-Okay, I'll do that But it is absolutely lighter weight and stronger than the old isogrid design. And it takes half as long to make. -Why does it take less time to make? You can see how much simpler that pattern is, So the CNC machine has more straight runs in a simpler pattern, and it just... it's that much faster to machine. So those are fancy space saw horses? Yes they are, yeah. [Both chuckle] So these are the panels that have been machined, they've been cleaned up a little bit. And they're getting ready to go into these 25-ton brake presses, bump presses in order to potato chip them, up into a curve. -Okay, those presses right there? Those presses right there. -Okay, so I'm noticing that there's no hydraulic pressure in the center of the press, There's just a really... it's a strong back.-Right It's a strong back.

 

-What is the technical term for it? Strong back.-Is it really? Yeah!-Okay, awesome So, so, can I look at this and then look at that? Absolutely.-Okay am I allowed to walk over there? Yeah. So you can see that these guys actually have a little bit of curvature along their length; we're going to actually take that out. That helps up form the curvature along this axis, more evenly. So it's sort of an intermediate manufacturing step, if you will. -Is it done on purpose, or is it a function of stress relief? It is done on purpose.-Oh okay, gotcha. Of course this is, again, isogrid.-Isogrid, got it. So this is Atlas V? Right.-Okay So at some point you have internal stresses in the material.-Yes Do you have an oven here to anneal? No, we let them do what's called "artificial aging of aluminum," so 7000 series will do that, so we're going to put a certain amount of work hardening in here, and we like that--we actually like the properties that gives us and then what the--sort of--room temperature artificial aging does, is even that out for us.

 

So we're entering the space of--I notice you're saying hello to everyone; people know you, don't they? Yeah, oh yeah.-That's cool So, we're entering the area where we've got this tooling here, that's holding this stuff. These are the guys--oh they're actually doing something now. Yeah, so that's a, you know that's a skirt and they've just manufactured it, just put the curve into it, we can walk over there; we'll let them finish what they're doing we can talk to them if you like.-Okay. Yeah that'd be great This is a finished part here? That's Vulcan.-Yes. Vulcan flight hardware right here, It takes five of these to make a complete barrel, for a methane tank, and then another five on top of that will be the liquid Oxygen tank. And we're going to show you friction stir welding which is how these are joined. -Gotcha. Alright, so here is our two 25-ton bump presses. So this big beam in the center is very very stiff, that's why it's so tall, because the hydraulics are on the edges.

 

And what the technicians are going to do--our craftsmen--are going to take one of these big, flat panels on these roller carts, and they literally have patterns that are pre-formed, that we've made, and they're going to roll them in and out, and have that knife edge come down and hit it, and slowly, potato chip it up, while they're matching it to the physical pattern, until they have it just right, and so we saw all this high-tech computer computer controlled machining down there, now this is pure craftsmanship where they're going to do it by eye and by pattern, and achieve very tight tolerances in doing so. –

 

Do you have any plans to computer control this in the future?

No, this is a process that you will always get better results doing it by hand. That's amazing! So, oh I didn't even think about having to hold the material as it comes out. -Exactly, yeah. Let's walk down and you'll see one, they're working on that one right there. -Okay That's a skirt, which is why it's short. Hey guys! So, so one question I have Tory is, as they lift the part, obviously it's being supported by the top, it's going to deflect.-Yes So how do they know if they--oh it's pressing now.-Yeah, so you can watch. -And you'll see. See now, they're lifting it a little bit. Bumping it again. So now they're making another adjustment, and they're going to bump it again. This is all done by eye and by hand. You could do this with a, sort of a remote controlled operation, but you could not get the same lightweight tanks out of that, you'd have to work with much thicker pieces of metal, and you wouldn't have as high a performing rocket.

 

  So I notice, she's looking with her eyes, she's operating--is she operating the press with her foot? -Yes She's operating the overhead crane,-Yes and also that---She has what's called a "walk along" or a "creeper," just like you would have, say, on your truck, to tighten a fence or to get yourself out of a ditch, she's doing all three things at once, while watching the curvature she's creating in this part. She is fully engaged. Oh yes. That's amazing. Don't look at us, don't let us distract you-- should we go away? We're distracting them.-Yes yeah Let's go let's go let's go Yeah we don't want to have the uh, "Destin and Tory Discrepancy Report" on that. [Both Laugh] And here's finished product. And this is all for Atlas, as you can tell by seeing the isogrid, and then we're going to walk down the aisle and we're going to show you how these get joined together into a tube. --the welding? Oh! I almost forgot Yeah we want to go to chem processing, right? -Oh yeah, is this where stuff is anodized?Yeah Let's go it, yeah yeah yeah. Okay, so now we're in one of the world's largest plating facilities, or chemical processing facilities, where we're going to etch the panels down, so that we have a very consistent high quality known surface, and then we'll anodize them, which is plating to create a very thick oxide layer, to give the aluminum corrosion resistance and a little bit of hardness. -Oh that is a very specific tool there. Yes it is. -To hold that part. Yup You know all this, Destin, but this is sort of, classic, bare aluminum and it automatically forms its own Oxide layer right away, which is why it's sort of white in color, but we don't get very good corrosion resistance naturally, especially from a 7000-series aluminum, because it's not very thick. And it tends to be porous, and so that's why we anodize it. -That's bad for fatigue, right? Yes, yes, very bad. So we can get a phenomenon called stress corrosion cracking for example If we allow corrosion to be present in these kinds of materials. So is this the chemical milling process before you anodize? No that will all happen inside the booths we're gonna take you to. This is really for cleaning because we're gonna - you know there's a lot of machining activity, there's a lot of chemicals that are going to be involved. And so we like to have a known condition when it goes in and out of the tanks. And this particular dome is in here to be inspected. Look at that! Yeah. So what am I looking at? So you're looking at us rinsing and washing a ring, before it comes further down to this booth which is actually an inspection booth. Gotcha! So this is pre-anodization. Yes So just to connect the parts, we made the part down there. Pulled it up on this crane, pulled it over here, Brought it over there and inspected it one more time We're going to take it down there and clean it. We're going to inspect it, and then we're going to go around where you can't see right now and anodize it. and we're going to drop it off the other side? and then when it's all done, it'll come down the other side. Gotcha. So this is like the rainbow arc of anodization! Yes it is! Yeah. Ok, cool. So Shannon, what's your role here? So, I work on the commercial crew hardware,-Okay I'm in the production engineering group, so I work with the design team and the technicians, to interpret the drawings, and make sure they're building it correctly. Give them all the procedures and processes they need. -What kind of engineer are you? So I'm in the production engineering group, so manufacturing engineering. How's it going? That's the thing about working at ULA, you never know when the CEO is going to walk in on you while you're cleaning the floor. [Both laugh] So you said Sulfuric Acid to do the etching? Yes, and that's part of the plating, so anodization always uses, typically one of three acids, you use Sulfuric, you use Chromic acid, or other organic acids, so that's part of it, because that releases the Oxygen in the bath, some of it bubbles off, but the rest of it ends up attaching to the material, creating that corrosion resistant layer. -So this is a vat that you would dip the part into? Yes, in fact here we are. Here's our Sulfuric Acid anodization, so there's a part in there right now that's going to sit there for a prescribed amount of time, it's heated, and then we're passing current through it because ultimately this is actually a plating process. See, here's our DI (deionized) tap water rise, that we were talking about. Yeah. So you literally put the part in there and you give it a shower. Give it a shower! -That's awesome! Holy cow, that's intimidating. -Yeah -That's intimidating...Keep your hands out of there. [Both laugh] We'll plate, we'll rinse, we'll plate again, we'll clean, then it goes out where you were before, for inspection. Here's what they look like when they come out, so you can see that sort of characteristic green/bronze color of an anodized aluminum surface. And as they naturally age it'll become more and more bronze, so when you see an Atlas rocket on the pad, and you look at the booster, it has that very distinctive bronze color, this is why, because of what we just looked at here. Maybe we'll just let you peek over the edge, would you like to? -Yeah that'd be great. So at this point we've finished plating, cleaning, and inspecting, and here are the panels, lowered down from where we took that last shot. -And now what? Now they're going to get friction stir welded together into barrels, forming the body of the rocket, and the propellant tanks. -So one question I have about this next step, is when you weld something, usually you tack it together all around the perimeter before you do the final welding, because the heat will draw it up -RightSo how do you account for that here? So we fixture it, we hold it in place mechanically, because the interesting thing and the reason you want to do a friction stir welding is because you don't melt any material. In conventional welding, you bring the parts together, and then as you say, you tack them to hold them, and then you fill in that gap with filler material that you've melted. It fuses to the parent material melting it a little bit too, and then you get a heat-affected zone, and that entire weld joint has different mechanical properties than the original material. But when you friction stir weld, you never melt anything. You bring the parts tightly together, and you bring a head that spins, and literally stirs the material together as it moves. That gives you a stronger joint, which means you can thin down the entire part, and get a much lighter weight higher performance structure. -So what is the head made out of, that can withstand the higher temperatures? So the heads are always made out of tool steel, high strength materials that can stand that over and over and over we're welding aluminum so we just need that difference. -So the melting point of aluminum is so much lower than the head -Yesof the tool part... and it never quite melts. It gets warm, it gets a little soft, because of the heat generated through the friction, but we never actually erase all of its mechanical properties, like you do with a classic, conventional fusion weld, you literally melt the material. And I'm not allowed to film this, and I'm not allowed to film that... -Nope What if I peek over there, can I peek...?-You can peek Peek over there, but it was blocked out so people couldn't see that. So now, those big plates that you saw machined and you saw bent, and you saw anodized, have to get friction stir welded together into a barrel to form an Atlas booster, or in the case of what you see over there right now is the Vulcan first flight liquid oxygen tank. -That's it, okay so that is the first vertical assembly of Vulcan. -Right, and so that tank will go to space, and it will lift the Astrobotic Peregrine Lander back to the moon, which is our first mission on Vulcan. -Really?-Yeah. I didn't know you had a lunar mission.-Yeah yeah, that's our

 

 How rocket engines works park 1 Thrust and Efficiency.

The F-1 rocket engine, five of which powered the first stage of the Saturn V, was absolutely colossal. It used a gas generator to drive a turbine which powered its fuel pumps. This turbine produced 55,000 horsepower, equivalent to the max combined horsepower of 62 Porsche 918 supercars. This power was used to pump a total of 40,000 gallons of fuel per minute which was pushed into the combustion chamber at over 1000 psi or about 70 atmospheres of pressure.

 

The controlled explosion in the combustion chamber reached a temperature of almost 6,000 degrees Fahrenheit. Hot enough to boil iron. The exhaust gas was accelerated through the12 foot wide nozzle to a speed of mach 7.5 and produced 1.5 million pounds of force.

 

 Rocket engines are some of the most sophisticated and powerful machines mankind has ever created. In this series of videos we will be looking in depth into how these impressive devices work. In this first part we’re talking about thrust and efficiency. A rocket engine’s job is to create thrust. It’s really their only job. And to create thrust all rocket engines use Newton’s third law of motion. This law tells us that every action has an equal and opposite reaction.

 

 So the action of the engine accelerating the rocket fuel out the back of the rocket has the opposite reaction of pushing the rocket forward. The amount of thrust a rocket engine produces is equal to the speed of the exhaust multiplied by the mass flow rate of the exhaust. And the mass flow rate of the exhaust is equal to the mass flow rate of the fuel being fed into the engine. By the way mass flow rate just means how much mass goes through a system in a certain amount of time. Most of the time in these videos we’ll describe this using the unit kilograms per second. If a rocket engine consumes 1000 kg of fuel  per second and the exhaust velocity is 3000 m/s than it will produce 3 million newtons of thrust.

 

 This equation shows us that if we want a rocket engine to produce more thrust so we can lift bigger rockets we have to either increase the amount of fuel it uses or increase the exhaust velocity. Which brings us into the topic of rocket engine efficiency. Just like with a car higher efficiency means being able to do more with less fuel. In rocketry fuel efficiency isn’t given in miles per gallon, but in a term called specific impulse which is often shortened to Isp. Specific impulse is a measure of how much thrust an engine will produce by consuming a certain amount of fuel. Which sounds a lot like exhaust velocity from the equation we just looked at.

 

 Specific impulse is usually measured in seconds. This has become the standard world wide since the second is a universal unit of time. It is possible to measure it in a unit of speed such as m/s by multiplying it by 9.8 m/s/s. When measured this way engineers usually call it effective exhaust velocity. Effective exhaust velocity isn’t always the same as actual exhaust velocity. In engines where 100% of fuel is fed into the combustion chamber effective exhaust velocity and actual exhaust velocity are the same, but in many engines use a portion of the fuel for other tasks such as running fuel pumps or actuating hydraulics. In these engines the effective exhaust velocity can be significantly lower than actual exhaust velocity. Specific impulse and effective exhaust velocity are the real measure of fuel efficiency and can be compared between all types of rocket engines. There are a lot of ways to increase efficiency in rocket engines. Fuel choice, engine cycles, chamber pressure, and nozzle shape all affect it.

 

 We’re going to take a look at all of these topics and how they influence the design of rocket engines, but first we need to get some more basics out of the way. In part two we’ll be talking about flow and pressure. This has been Liam from Space Is Kind Of Cool. Thanks. 

 How nuclear Rockets will get us to mars and beyond.

Introduction.

A few days ago on the 6th of February2018 SpaceX's first test launch of the Falcon9 heavy the most powerful rocket since the Saturn 5 successfully launched a payload of Elon Musk's own cherry red Tesla roadster complete with a Starman mannequin first into orbit and then on what was meant to be a journey to Mars but now looks more like an elliptical orbit extending out to the asteroid belt between Mars and Jupiter.

 

 Whilst the Falcon 9 heavy proved that it could launch a payload into deep space Starman and the Roasters journey itself is going to be a pretty leisurely one just like everything else we've launched into deep space fine for mannequins, cars and robotic probes but not so good for humans. With an average time of nine months to get to Mars the risk from radiation, weightlessness and psychological issues is high, not to mention with supplies they need to carry even if they're going to grow their own food and recycle their own water.

 

But if you can reduce the time it takes to get there all these things become much more manageable, however there is a technology using nuclear power that was developed for about 20 years from the 50s to the1970s originally by the US and the Soviets for Mars missions proposed in the 1970s and 80s but was shelved after the demise of the missions themselves. Now with our revived interest in Mars missions and trips to deep space nuclear-powered rockets are back on the agenda as a way to cut transit time and carry greater payloads.

 

 But we have to make a distinction here the nuclear rocket engines are only for use in space because they have a much lower thrust tow eight ratio compared to chemical rockets and so chemical ones will still be doing the heavy lifting from Earth into orbit but once they're an away from a gravity of Earth nuclear engines can be much more efficient. Now as powerful as chemical rockets are they have a problem they need to carry not only the fuel but also the oxygen allow it to burn which makes the Rockets much heavier and also reduces the payload available.

 

The first type of nuclear rocket, the nuclear thermal one does away with the liquid oxygen altogether and instead passes liquid hydrogen fuel through a nuclear reactor to heat it up to a superheated gas, this hot gas has been ejected from the engine in the same way as a chemical rocket and that's where it creates its thrust. The difference is that when a chemical rocket engine burns hydrogen & oxygen the by product which is water vapour is heavy and therefore as a given temperature its velocity is lower and therefore the thrust created is less. Because a nuclear thermal engine doesn't burn the hydrogen it just heats it up it's still pure hydrogen when it leaves the rocket engine and as hydrogen is the lightest element its exit velocity is the highest for a given temperature and therefore the thrust is considerably more.

 

A rockets efficiency or how well it makes use of its fuel is measured in seconds of specific impulse sounds complicated but put simply it means how long in seconds one pound of propellant can deliver one pound of thrust, the best chemical rockets have a specific impulse around 450 seconds whereas the early test nuclear Rockets had a specific impulse of around 900 seconds twice as efficient. Now couple that to a fact when you don't now need to carry a lot of heavy liquid oxygen around with you and this means you can either go faster or carry greater payloads. From themid-1950s this principle was studied extensively at the Atomic Energy Commission laboratory at Los Alamos in New Mexico through a program called Project Rover by 1959 an experimental reactor called Kiwi who was ready for testing it with jackass flats in Nevada and successfully ran at a power of a100 megawatts and then up to a full power rating of 1000 megawatts in 1962the program to turn Kiwi into a working engine was called nuclear engines rocket vehicle applications or NERVA again the tests were successful and in1967 the NRX-A6 engine fired successfully for an hour as the tests continued the engine runtime was only really limited by the supplies of liquid hydrogen at the test site.

 

Whilst these test engines proved the concept there were still issues the weight of the shielding to protect for crew and the control electronics from the radiation made the engines very heavy, there was also the problem of what would happen if a nuclear engine rocket were to fail on a launch pad or were to fall back to earth from orbit and spread highly radioactive material over potentially highly populated areas and there was also issues with overheating if the fuel which acted as a coolant ran out before the engine was shut down properly.

 

 But after years of testing they were deemed ready for use in space and NRX seemed to be on track to make it there by the late 1970s. On the other side of the Iron Curtain the Soviet chief rocket designer Sergey Korolyov expected his N1 super heavy lift rocket to carry a nuclear upper stage giving the vehicle a formidable interplanetary capability his team considered several options either to nuclear other stages on a three-stage rocket or a single nuclear stage on a two or three stage rocket with any of these options the N1 upper stages would have had to cluster large numbers of nuclear engines together many more than on the American designs. But a nuclear thermal upper stage was calculated to be able to deliver up to 50% more payload to Mars than a chemical one. However the nuclear thermal engines weren't the only options available on the table Korolev favoured another way of harnessing atomic power pairing a nuclear reactor with an electric ion engine although the system provided much less thrust it was even more efficient and would provide a low thrust for a very long period of time compared to the quick bursts like the nuclear thermal ones.

 

In recent times advances in solar panel design has made nuclear reactor powered iron engines much less likely but for deep space missions beyond Saturn where there is not enough sunlight to operate solar panels successfully nuclear power becomes pretty much the only option. Calculations showed that ion drives will be able to transport 70% more payload than chemical engines on a mission to Mars.

 

After the N1 rocket quite literally fell by the wayside the chief designer Vladimir Chelomei was in pole position to design a rocket for the Soviet manned Mars mission the enormous MK 700 was to be assembled in orbit with multiple launches for the modular UR700 rocket the MK 700 would make its interplanetary burn with a nuclear thermal engine built by Valentin Glushko's design bureau and called the RD-0410 the engine made it as far as testing at the test site in north east kazakhstan demonstrating yet again Glushko's mastery of rocket engine efficiency the RD-0410 showed a capability of 910 seconds of specific impulse.

 

However by 1972 and due to the loss of interest in space by the public and the government in the u.s. funding for nasa's mars mission and NERVA was cancelled by congress as the space shuttle returned to focus to low-earth orbit where nuclear engines weren't required and the soviet priority was to match this capability their research into nuclear-powered spacecraft also stalled.

 

 However things picked up again with President Ronald Reagan's Star Wars initiative in the late 1980s project Timber wind advanced the engines using a pebble bed reactor design and increased the specific impulse to nearly 1,000seconds it also led to the development of modern carbon composite materials but it also faced technical issues which would have made it very difficult to use as a space based engine system and funding was eventually dropped. More recently Russian engineers at the State Energy Corporation ROSATOM are working on a form of nuclear electric propulsion called 'TEM' the acronym translates to transport an energy unit the name indicates a nuclear reactor capable of bimodal operation that is when it's not powering engines it can be switched to a low power mode to power the living quarters and other onboard systems.

 

 According to the designers TEM has a goal of testing a ground-based engine this year and launching a prototype by2025 if funding can be secured. The technology could in theory enable a journey from Earth to Mars in just 45 days. NASA is also conducting new research into rapid transit technologies to mitigate the long-term effects of  interplanetary space on the human body like Russia, NASA sees nuclear thermal propulsion as a solution here the goal of the current research is to reduce for cost and risk of the nuclear fuel by developing a suitable form of low enriched uranium with a concentration of 3-4% uranium-235compared to a 90% concentration of weapons-grade fuel in the earlier designs.

 

 NASA's research may well find its first use in a spacecraft like this the Copernicus mass transfer vehicle conceived as part of the now cancelled constellation program Copernicus B is being considered for an in orbit assembly using NASA's upcoming SLS block 2 launch system. At one end of Copernicus the Orion spacecraft would dock with a manned payload living space Copernicus would then make its interplanetary journey using three nuclear thermal engines each capable of producing 25,000 pounds of thrust the efficiency of the nuclear engines would enable a trip to Mars in a hundred days not quite as quickly as were proposed Russian mission but still a significant improvement over traditional chemical engines and also Copernicus would be capable of by modal reactor operation.

 

So what do you think of using nuclear Rockets for future manned missions let me know in the comments below. 

How do iron engines works?  The most efficient propulsion system out there.

Introduction.

People always ask me why we’re stuck with chemical rockets. Seriously, exploding a bunch of hydrogen or kerosene is the best we can do? Good news, there are other, exotic science fiction-sounding propulsion systems out there which use electromagnetic fields to accelerate atoms, allowing their spacecraft to accelerate for months at a time.

 

 I’m talking about ion engines, of course, and several spacecraft have already used these exotic thrusters to perform some of the most amazing missions in the exploration of the Solar System. I know, I know, chemical rockets seem really primitive. Take tonnes of liquid or solid fuel, light it on fire with an oxidizer, and then use the speed of the explosive gases to give you a kick in the opposite direction. Thanks Newton’s Third Law. But chemical rockets do the trick. Those gases do give a rocket the kick it needs to get into space.

 

Because they bring their own oxidizer with them, they work in the atmosphere and they work in the airlessness of space. The advantage of rockets is that they can deliver enormous amounts of energy in short periods of time, the kind of reaction you need to blast tonnes of cargo off Earth and into space. But they’re incredibly inefficient. A 550 metric tonne Falcon Heavy is carrying almost 400 tonnes of fuel and oxidizer. The first stage will only burn for 162 seconds, and the second stage will fire for 397 seconds. That gives you a total burn time of about9.5 minutes.

 

 Want to make more maneuvers?

Want to accelerate for days, weeks or even months? Too bad, you’re out of fuel. Of course, these shortcomings from chemical rockets have led scientists to search for other forms of propulsion, especially when you’re out in space, and the one of the most successful so far is the ion thruster. When you’re working out the rocket equation, an important factor is the velocity that you’re ejecting your propellant. The most efficient chemical rocket can throw hot gases out the back at 5 km/s. Ion engines, on the other hand, can eject individual atoms 90 kilo meters a second. This high velocity gives the spacecraft a much more efficient acceleration.

 

The best chemical rockets see a fuel efficiency of about 35%, while ion engines see an efficiency of 90%. So

 

how do ion thrusters work?

 It’s actually pretty weird, and totally sounds like science fiction. Instead of hot gases, ion thrusters ejections. These are atoms or molecules which have an electrical charge because they’ve lost or gained an electron. In the case of an ion engine, they’re emitting positively charged ions which have lost an electron. Once you’ve got ions, you can direct them with a magnetic field, accelerating them into space at tremendous speeds. So where do they get all the ions? The thrusters create them by generating a plasma inside the spacecraft. They bombard neutral propellant atoms of some gas, like xenon with electrons. These collisions release even more electrons from the propellant, turning them into positively charged ions. This plasma soup of electrons and positively charged ions has an overall neutral charge. The electrons are held in the chamber, leading to more ionizing events, while the positive ions are siphoned out through a grid at the end of the chamber.

 

As they pass through this grid, high voltage accelerates them out of the back of the spacecraft at speeds of up to 90 km/s. For each ionized particle that the spacecraft can kick out, it gets a tiny kick in return. The whole system is powered by solar panels, so the spacecraft itself doesn’t need to carry any kind of battery or power system, minimizing the total weight it has to carry. The big problem is that that kick really is tiny. The thrust of ion engines is measured in millinewtons, like, thousandths of a Newton. Hold a piece of paper in your hand, that’s the kind of forces involved.

 

But they can operate for days, weeks, even months, accelerating and accelerating long after chemical rockets would have run out of fuel. So if you’re already out of the gravity well of a planet, they’re very efficient engines for dramatic changes in velocity. NASA and other space agencies have actually used ion engines very successfully in a range of missions. They had been developing this thruster concept for decades but were never willing to risk it on an active mission where a failure could end it. So NASA gathered up a bunch of risky technologies, and packages them together as the Deep Space 1 mission, which launched in 1998. Deep Space 1 was equipped with 12 different technologies that NASA wanted to test out, including low power electronics, solar concentrator arrays, various scientific instruments, and a solar electric propulsion system.

 

 Its engine was run for enormous lengths of time, allowing it to make close observations of asteroids and comets, and even Mars. NASA doubled down on the technology of Deep Space 1, giving its Dawn Mission three redundant ion engines. These allowed the spacecraft to go into orbit around the asteroid Vesta, make observations, then break orbit and travel to asteroid Ceres and make even more observations. And it could still have fuel in the tank to visit even more asteroids. Just to give a sense of its acceleration, Dawn can go from 0 to 100 km/h in 4 days of continuous thrusting. Ion thrusters were used to carry ESA’s Smart1 spacecraft from Earth orbit to lunar orbit, and on the Japanese Hayabusa spacecraft. Ion engines have been tested here on Earth, and successfully operated for more than 5 years continuously. With these successes, we’re going to see even more spacecraft equipped with ion thrusters in the future, but ion thrusters themselves are getting more powerful and resourceful. I said that ion engines produce very little thrust, but there are some ideas to boost their output.

 

The first is dramatically increase the amount of electricity you’re using to accelerate the ions. Instead of solar panels, NASA considered creating an ion engine powered by a nuclear reactor. About 15 years ago, NASA considered a mission known as the Jupiter Icy Moons Orbiter mission. Powered by the Nuclear Electric Xenon Ion System (or NEXIS) engine, the spacecraft would be capable of exploring each of Jupiter’sicy large moons in sequence: Ganymede, Call is to and Europa. The spacecraft would have been launched into orbit in three separate pieces, which would then be assembled in Earth orbit and launched off to Jupiter. The spacecraft would use its 8 ion thrusters to study Call is to and then Ganymede for three months each, and then settle into a final orbit around Europa. If conditions were right, it could even go into orbit around Io. Of course, we don’t get to have nice things, and the mission was cancelled back in 2005. There are other ways ion thrusters can be scaled up. NASA is testing a high thrust version of ion engines known as the X3 hall thruster. This engine is capable of blasting out ions, and produces 5.4 newtons of force.

 

Again, not much, but remember that previous thrusters top out in the thousandths of newtons. At the highest power levels, this could be the technology that will carry human astronauts to Mars, cutting down the flight times to just a few months. Engineers are planning to run the X3 for 100hour tests this year to see if it has the same kind of long-term operation as the smaller  ion engines. The coolest idea I’ve heard recently for ion engines is the idea of an air breathing engine under development by the European Space Agency. Instead of carrying any propellant at all engineers at ESA demonstrated that a spacecraft in low Earth orbit should be able to pul in molecules of air right from the atmosphere, and then ionize them and blast them back out. Since the spacecraft would be using unlimited solar electricity for power, and pulling its propellant from the atmosphere, it could operate without re fueling for long periods. Spacecraft could operated at lower altitudes, and space stations could remain in low Earth orbit indefinitely without needing to be re boosted. This is going to be real game changer.

 

 And not only Earth, this technology could be used on Mars or Venus, or Titan. Anywhere with an atmosphere. Ion engines have already made an impact on space exploration, and in the next few years, we’re going to see more missions equipped with them. They could even be the engines that carry human astronauts from Earth to Mars in the coming decades. What do you think about ion engines? Let me know your thoughts in the comments. Once a week I gather up all my space news into a single email newsletter and send it out. It’s got pictures, brief highlights about the story, and links so you can find out more. Go to universetoday.com/newsletter to signup. And finally, here’s a playlist.

 Aerospike engines. Why are not we using them Now?

Ever since the earliest rockets we've seen them working with a bell-shaped engine nozzle from the first German v2rockets right up until the space x falcon heavy but the ubiquity of the bell shaped rocket nozzle doesn't mean to say that it's the best way to do things infact they have a major drawback which is one of the reasons why we use multistage rockets, however since the early 1970s there has been an alternative rocket engine which has much greater efficiency and was to power the next generation of single-stage-to-orbit spacecraft to replace a space shuttle but if it's so good why hasn't even been flown yet. The engine in question is the aerospike, a design that goes back to the 1950s when it was first developed by Rocketdyne.

 

 Now whilst this might sound like an exotic new type of propulsion the aerospike is not actually a whole new engine it's actually just a different way to contain and control the thrust but any rocket be that liquid or solid fuel produces and it replaces the Bell type combustion chamber. Now if we've been using the Bell type rocket nozzle combustion chamber since the very first Rockets right up until now and what's wrong with them.

 

For a rocket to work correctly and produce enough thrust to lift it into orbit then you have to control the burning rocket fuel. If there was no rocket nozzle then the burning rocket fuel would just exp and uncontrollably in all directions and very little of it will be converted into useful thrust. What the rocket nozzle does is convert the high-pressure combustion of a rocket fuel into an ultra-high speed flow of gas exiting the nozzle in one direction and at atmospheric pressure. The ratio of the size of a narrow end to the wide end of the nozzle must also allow for the atmospheric pressure where the rocket will operate.

 

Now this sounds complicated but it's actually quite simple. Everything including you, me the ground and rocket engines has atmospheric pressure pressing on us in all directions due to the weight of the atmosphere as the air is pulled down by the Earth's gravity.

 

 If you imagine a column of air measuring one square inch or 2.54 square centi-meters from sea level to the top of the atmosphere, that air would have a mass of 6.67 kilograms or14.7 pounds. we don't feel it because we have evolved to live at that pressure but if you were to go up to 12 kilo meters that pressure would be just one-tenth of sea level and at 50 kilo meters it will be one hundredth of sea level simply because the column of air is now much shorter and thus weighs much less.

 

That air pressure also pushes on the gases exiting the rocket nozzle. For a rocket to work at its most efficient and produce the most amount of thrust the gases exiting the rocket nozzle must beat atmospheric pressure so where they exit out as straight as possible. This is fine if your rocket is traveling sideways through the atmosphere like a air to air missile then the air pressure doesn't change much. A rocket going into orbit however starts at sea level with a lot of air pressure and ends up in a vacuum with no air pressure. Because a bell nozzle has a fixed shape and size its maximum efficiency and thrust will only be achieved at one altitude.

 

Design it to have maximum thrust at sea level and take off and the exhaust gases will over expand and lose thrust at high altitudes because of a lack of air pressure, design it to have maximum thrust at high altitudes and at take off the air pressure is so much but it constricts the gas flow inwards which leads it to separating from the nozzle wall and becoming unstable usually resulting in the engine blowing up. In an ideal rocket nozzle it would change its shape as the altitude and air pressure changes this is what an aerospike does. It uses the pressure of the air surrounding it air surrounding it to have the same to have the same effect as the bell of a traditional rocket engine.

 

The two main types of aerospikes which have been developed are the annular or round ones and the linear or straight ones. The round ones are where we get the name from, if you imagine an inverted bell shape It becomes a round spike, this spike becomes one side of a virtual Bell whilst the air pressure surrounding it compresses the exhaust gas against the inner spike, although many now use a truncated spike which has a much shorter design than the equivalent engine bell. As the rocket goes from take off at high air pressure to the low air pressure at high altitudes the shape of the exhaust flow changes due to the changing air pressure to keep it at its optimum shape and optimum thrust. This is what's called an altitude compensating rocket nozzle.

 

Although it might not be as efficient as a bell any given altitude it out performs them at all others. The Space Shuttle main engines which were used from take off to space were much less efficient at sea level than they were in space. With a rocket engine like the aerospike you could use just one engine that will work efficiently from take off to space and avoid the need for multiple stages with different rocket engines optimized for different altitudes effectively becoming an SST o or single-stage-to-orbit.

 

 So if these are so good why aren't they used to date no major rocket launches have used an aerospike despite much research and development being done during the 1960s and 70s and then in the 1990s. As a follow-on to the successfulJ-2 engine which was used on the Saturn third stage Rocketdyne set about developing and building both toroidal and linear aerospikes using the turbo pumps and engine infrastructure of the J-2. one of the biggest problems with a aerospike engine is the cooling of the spike. In the toroidal or round design the spike is long and heavy which makes it difficult to cool the tip of a spike to stop it from melting. This was mostly overcome with the development of the new copper alloy called NARloy-Z in the1970s which allowed longer use of high temperatures.

 

The design were also changed with a truncated spike with some of the exhaust gases being passed through the center to achieve a similar result of a long spike but with much less mass. However the linear version was even more flexible. In this the round spike is straightened out into a v-shape with the combustion chambers on either side, the beauty of this design is that can be made modular so that it can have more combustion chambers added to make a longer a more powerful engine. Back in the 70s they use combustion nozzles made into small banks which were stacked side-by-side on both sides of the "V" center. Although aerospikes were proposed for the space shuttle, as the Apollo program was wound up in the early1970s development work on the aerospikes also stopped and the space shuttle went on to use conventional Bell engine nozzle designs. Things stayed pretty much like this for the next 20 years until NASA was looking to develop the next generation of space shuttle using an all-new single-stage-to-orbit design. The design brief was to be able to come up with a completely new launch vehicle that would be fully reusable and would greatly reduce the cost of getting in to space from $10,000 per pound to $1,000 per pound. Lockheed Martin won the contract to build the revolutionary design designated the X-33 and one of the key features was the use of the linear aerospike engines. Development work continued on the XRS-2200 linear aerospike and by now with the use of electric magnetic nozzles it meant that the fuel system could be controlled on a nozzle by nozzle basis a bit like the fuel injection on a car.

 

This allowed for much greater throttling control and allowed for the thrust vectoring by turning off different sections of the engine. This also removed the need to have heavy complex engine gimbals. Work progressed well up until 2001 when due to issues with the X-33's composite fuel tank and cost overruns the project was cancelled again taking the aerospike engines with it. Progress has been made with NASA testing small scale solid rockets with a toroidal full-length aerospike in 2004 but since then there have been no large aerospike engine developments. So why don't new companies like SpaceX and Blue Origin use the aerospike engines with all the efficiencies they bring wouldn't they be the perfect match for a low-cost route to space.

 

As far as we know SpaceX has looked at using aerospikes but given the fact that no large-scale aerospike has ever been flight tested it would be a very big risk when you're looking to set up a commercial orbital space company. One of the driving principles of the space race was "To do the job good enough and no more", basically mainly that once you have developed your spacecraft or your rocket engine to do what it was designed to do then that's it you stop there. The technology SpaceX and others are using is well known and tested. The way they use it might be different like relighting the main angels descend back to earth but the engines themselves area known quantity. Commercial companies have to make a profit in the end and taking on a major task like developing a new untested engine design is something but could quickly sap those profits away.

 

Although the X-33 project almost got them to flight testing, it's still new technology and needs more money and more development. It would also mean completely redesigning the Rockets away from the tried and trusted but yet limited traditional bell nozzle engines. All this takes time time which could be used launching with traditional engines and getting money into the companies. Although there would be a saving of up to 40%, the fuel is actually one of the cheapest parts of a rocket launch, Elon Musk said himself that the Falcon 9 costs $60 million to build but only $200,000 to fuel. The bringing back of the boosters and the central core with the engines brings far greater savings than could be achieved with a change to aerospike engines. It seems as though until the price of launches has been driven down to as low as conventional Bell nozzle engines will allow that arrow spikes will remain on the drawing board.

 

The single-stage-to-orbit vehicles which perfectly compliment the aerospikes capabilities seem a long way off since the cancellation of the X-33 and the renewed interest in returning to the moon using variations of conventional engines that date back to the early 1960s. There are smaller companies like Arco space which are developing small-scale aerospike engines for single-stage-to-orbit satellite launches but unless there is a radical change in the space market only time will tell if arrow spikes will ever get used for future space vehicles. So what does it take to design a rocket engine how much thrust does it take to lift a spacecraft and how fast must we launch an object from the surface of the earth to get it to leave. You can look up the answer if you want but if you like me then you want to create things by yourself our sponsor for this video, brilliant.org is dedicated to doing just that turning you into a living breathing and most importantly calculating scientist head on over there and prove for yourself just what it takes to get a rocket into orbit. Having a strong math and science skills set is crucial because it opens up so many ways to explore the universe. 

 What humans living on mars will look like in 1000 years.

Introduction.

- [Narrator] When it comes to colonizing new worlds, Mars can be humanity's best option. But the journey won't belike it was in the past for pioneers like Magellan, Gagarin, and Neil Armstrong. This new frontier would be the most extreme challenge yet. It's not just learning how to survive on an alien planet with less oxygen, a weaker gravitational pull, and more harmful radiation.

 

It's enduring the changes that these extreme conditions will have on the human body, manipulating it in ways that we can only begin to imagine. Even astronauts know that you don't have to spend much time off earth to notice changes.

 

The lower gravity can kickstart a whole list of physical alterations. Just ask this guy. Former NASA astronaut, Scott Kelly. He lived for an entire year on the International Space Station. Without Earth's gravitational pull, the zero gravity weakened his bones and muscles and expanded the space between his vertebrae, making him two inches taller.

 

 Now, the zero gravity environment in space is more extreme than on Mars. However, these changes could still happen on smaller scales. And if you compound the mover hundreds of years of tens of generations, the results could be similar and even more pronounced.

 

Basically, humans will adapt to Mars' conditions in one of two ways. In the first few centuries, our skeletons and muscles will likely shrink and we'll become weaker versions of our earthling counterparts. This would almost certainly lead to shorter lifespans and health complications. Including neurological disorders if our skulls shrink with the rest of us.

 

So to survive, we may over millennia, actually undergo the opposite reaction. Evolving stronger, more robust bodies like the Thanks in Edgar Rice Burroughs' sci-fi novel, A Princess of Mars. Although, us having six arms and green skin is less likely. In fact, some scientists think we'd actually develop orange skin, not green.

 

It turns out, the carotenoids that make carrots, sweet potatoes, and pumpkins look orange offer a certain amount of protection against harmful UV radiation. When we eat these pigments in large amounts, we actually get a boost of protective carotene in our bloodstream and under our skin. So yeah, eating too many carrots can turn you orange but it may also be a great defense against cancer on Mars.

 

The planet's thin atmosphere lets in massive amounts of UV and other high energy radiation compared to Earth. For example, the average earthling receives about three millisieverts of radiation per year versus the 30 that they would get on Mars. To compare, here's the minimum radiation dose it takes to drastically increase your risk of cancer.

 

 Add up the annual radiation levels on Mars over a lifetime and the average martian would receive 5,000 times more radiation than someone on Earth. And our big orange bodies may not just look different on the outside. One of the most profound changes we could have coming is the next species of human.

 

 Higher levels of radiation on Mars' surface would mutate the DNA in our cells at an accelerated pace. Normally, a species like homo sapiens could take a few hundred thousand years to evolve on Earth. But some scientists say the higher mutation rate could spawn new human species within centuries. 10 times faster than on Earth.

 

 So, if the radiation didn't outright kill us, the mutations that survive will be passed down through generations. Ultimately, diversifying the gene pool and allowing natural selection to do its job. As exciting as that may sound, there is a potential downside to all of this. If one day in the future, a martian falls in love with an earthling, it can only end in tragedy.

 

The immune systems of martians and earthlings will be completely different. A meeting between the two could be just as dead lyas when two foreign groups have met in the past. Like the European settlers who gave smallpox to the Native Americans. Also, depending on how genetically different they are, even if they could meet, they may not be able to have martian earthlings of their own since only closely related species can reproduce. Moving to Mars may be the best chance for humanity's survival but it may not be humans who live there in the end.

 Real reason NASA has not send humans to mars.

Introduction.

- [Man] We could've been on Mars 30 years ago. At the peak of the Apolloera in the early-'70s, NASA was already planning its next step into the unknown. Its plans included building multiple space stations, continued trips to the Moon, and its first crude mission to Mars by the 1980s. Can you imagine watching astronauts walk on Mars the same time the Walkman came out? But of course, NASA never sent humans to Mars in the '80s.

 

And here we are, 30 years later, still dreaming of the possibility. But the reason isn't necessarily a matter of technology or innovation. It actually comes down to politics. As a government agency, NASA's goals are determined by the executive branch. Since its inception, NASA has served under 12 presidents.

 

And it was clear near the start that not every president  would support NASA equally. By the end of the Nixon Administration in 1974, NASA's budget had plummeted from 4% of the federal budget to less than 1%. Fully funded Apollo missions18 and 19 were abandoned, along with Apollo 20. At the same time, Nixon pulled NASA's focus away from the Moon and Mars and instead towards low-Earth orbit. His parting gift was to sign into effect what would eventually become NASA's Space Shuttle Program, but this was just the beginning. –

 

So, what's happened throughout all of space history after the Apollo program was over was we had this start-stop-start-stop-cancel. So, a president comes in, like President Bush comes in and says we're gonna go to the Moon, back to Mars, and then the next president comes in and cancels that. And the next president sets their objective, and the next president comes in and cancels that.

 

The agency's unable tosustain consistent funding long enough to do anything. - [Man] It wasn't until the Space Shuttle Program was nearing its end that a crude mission to Mars was finally considered and funded by a US president. George W. Bush, in 2004, announced-- - We will give NASA a new focus and vision for future exploration. We will build new ships to carry man forward into the universe, to gaina new foothold on the Moon. - [Man] As a result, NASA's Constellation program was born. Never heard of it? That's because it was canceled a few years later. It aimed to send a crude mission to the Moon in 2020 and land the first humans on Mars by the 2030s.

 

By the time Obama was sworn in, the Constellation program was behind schedule and over-budget. One year later, Obama canceled 100% of the program's funding. - All that has to change. And with the strategy I'moutlining today, it will. - [Man] Obama shifted NASA's focus from sending people to the Moon and Mars to ultimately just Mars. In the process, Obama asked Congress to increase NASA's budget by $6 billion over the next five years. As a result, NASA launched its Journey to Mars initiative in 2010, with a goal to send humans into orbit around Mars by the early-2030s.

 

And until recently, NASA, for the most part, was on track. But then, this happened. - President Trump has relaunched the National Space Council and at the council's inaugural meeting in October, we unanimously approved a recommendation to instruct NASA to return American astronauts to the Moon, and from there to lay a foundation for a mission to Mars. - [Man] Oddly enough, the space policy under Trump and Obama look nearly identical, except for 63 words. In those 63 words, Trump's administration has shifted the focus once again to a Moon-first, Mars-later initiative.

 

NASA isn't new to this. It's learned to recycle old projects to fit new missions. For instance, the Orion capsule was first developed for Constellation and has since been redesigned for a journey to Mars. But even that can't prevent the unavoidable changes NASA programs now face  under the new president. - As such, we're also gonna realign the organizational structure to best meet this new exploration focus. I've asked Steve Jurczyk, the current head of Space Technology Mission Directorate, to lead an effort to design anew organizational approach. - [Man] As NASA pushes on, a new possibility has grown on the horizon.

 

Privately-owned space companies like SpaceX have also set their sights on the Red Planet. - The scientists and engineers at NASA are amazing and they've done extraordinary things, but there's still a riskaversion that doesn't allow us to do things that are new and novel and on the edge. It's these entrepreneurs willing to take risks and put everything on the line. - [Man] The race for Mars is on. While NASA has closely partnered with SpaceX and other privately-owned space companies in recent years, ultimately it might not be NASA who writes the next chapter in human space exploration.