On February 21st, 1969, the Soviet Union set a record for the
world's most powerful rocket to fly, a title that they would
hold onto for over 50 years. But on April 20th, 2023, that record would finally be broken by
SpaceX's Starship and its Super Heavy booster. People have been quick to point out the
similarities between these two rockets, most notably the ridiculous amount of
engines on the first stage of each rocket. The N1 featured 30, NK-15
engines on its first stage, while Starship's Super Heavy
booster sports, 33 Raptor 2 engines. But the similarities
don't end there. In fact, the first integrated launch of Starship
proved the rocket to be even more similar to the N1 than most would be
comfortable with considering the N1 flew four times, but never made it all
the way through the first stage burn. And this has brought up
an all important question. Has SpaceX fallen into a similarly
flawed design that plagued the N1? Why did they choose so many engines? Will it continue to suffer a similar
fate over and over like the N1, or is there something inherently
different? My name's Tim Dodd, the Everyday Astronaut, and today we're going to answer these
questions and compare the most powerful rockets ever made from completely
different sides of the world and totally different eras to figure out how they're
similar and perhaps more importantly, how they're different. And like always.
Here's the timestamps for this video. The YouTube timeline is
broken up into these sections, and we have an article version of this
video up everydayastronaut.com for links and sources. Okay, N1 versus
star shift. Let's get started. 3, 2, 1. Okay. Let's start off by comparing
these two vehicles side by side. I've talked about each of these vehicles
pretty extensively in previous videos such as Starship versus Falcon 9, and my entire history of
Soviet Rocket engines video, but I've never actually directly
compared them before the N1 was a Soviet union's attempt at a moon rocket, a rocket that would nearly match the
capabilities of the United States's incredible Saturn V rocket.
It was massive at the base. It was a ridiculous 17 meters wide, and it tapered up to a point with the
upper stages that were about six meters in width. It stood an impressive
105 meters tall and fully fueled. It weighed a total of 2,735 metric tons. SpaceX's Starship, on the other
hand, is even more of a skyscraper. It's nine meters wide on
both stages and comes in at 120 meters tall.
But where Starship's numbers get shocking is with its weight when it's fully fueled, it's about 5,000 metric tons, so almost twice as heavy as the N1. The N1 was capable of putting
95 tons into low worth orbit, while Starship is designed to be able
to take up to 150 tons into low Earth orbit, and it does so
while being fully reusable. But what's even more ridiculous is they
can put around 300 metric tons into orbit if it's not fully reused. This puts both rockets squarely
in the super heavy lift category. With Starship being the most
capable rocket ever built, each rocket utilized
different propellants. The
N1 was powered by carlock, specifically RG1 and liquid oxygen.
Starship, on the other hand, uses methylox, so liquid
methane and liquid oxygen. The N1 had a lot of stages. The
rocket had a minimum of three stages, but when sending a payload to the moon, it would've utilized up to five stages
in a similar fashion to the Saturn V with the Apollo service module and
the lander stages, and of course, the entire rocket was expended.
Starship, on the other hand, is only a two-stage rocket. And
again, perhaps most importantly, both the massive Super Heavy booster
stage and the Starship upper stage are designed to be fully and rapidly reusable. But perhaps the biggest thing these
rockets each share is the ludicrous amount of engines. Like we
talked about in the intro, the N1 had 30 NK-15 engines
on its Block A first stage eight NK-15 Vs on its
Block B second stage, four NK-19s on the Block V third stage, one NK-21 on the Block G fourth stage, and an RD-58 on the Block D descent stage. There's 33 Raptor 2 engines on the Super
Heavy booster and three more sea level Raptor 2 and three vacuum optimized
Raptor 2 on the Starship upper stage. But these numbers are all
subject to change as Starship
is still in development. The NK-15 on the block, a booster of the N1 utilize
the oxygen-rich closed cycle, which those of you who have watched my
deep dive on Soviet rocket engines may know this is something that the
Soviets mastered in the early sixties. The engines were impressive, capable of 1,526 kilonewtons of thrust and 297 seconds of specific
impulse at sea level, and it had a mass of
about 1,250 kilograms. Raptor 2 on the other hand
produces 2,255 kilos of thrust and 327 seconds of specific impulse at
sea level while having a mass of only 1600 kilograms. This means the Raptor has approximately
a 144 to one thrust weight ratio while the NK-15 had a thrust
to weight ratio of about 125 to one. So not only is the Raptor
2 much more efficient, it also produces more thrust kilogram
for kilogram, which is important. Now, we should mention that of course,
in typical SpaceX fashion, they're still upgrading Raptor,
and in the relatively near future, they'll be utilizing Raptor 3, which is already producing some
even more impressive numbers. So this is all subject to
change, but even with Raptor 2, we can see how advanced this engine
is already. So as you can see, the rockets quite
different from each other, but they do share a couple similarities
like being super heavy lift rockets and utilizing several smaller engines
rather than a few bigger ones, but they actually share more in
common than just their hardware. So let's dive into some core
philosophies that they share, including the pros and cons
of utilizing so many engines, why they both believe
in testing by flying, and heavily leaning on
the iterative process. So let's start off with the
biggest question people have. Why do these rockets have so many engines? Doesn't more engines mean more potential
points of failure and ultimately, a more complicated system? Well, many less powerful engines have a few
advantages over fewer more powerful engines. Most obviously is that a loss of an engine
has less of an impact on total thrust levels with many smaller engines
versus fewer larger engines. Let's look at the N1 versus the Saturn V. The N1 had 30 engines producing
45 meganewtons of thrust, whereas the Saturn V had 35 meganewtons
of thrust from just five engines. So if you were to lose one
engine on your Saturn V, you'd lose 20% of your thrust, which if early on in flight would've
certainly led to a loss in mission. Whereas if you lost just
one of your 30 engines, you only lose about 3% of your thrust, which is well within the margins
to continue on in pretty much any situation.
But as far as reliability goes, more engines also has the
potential for more failure points, more moving parts, more chances of
for failure, more complications, and more chances that one engine's failure
could affect its neighbor and cause a cascading failure scenario. So there's a little bit of a bell curve
here and definitely an engineering trade between having fewer engines
because it's simpler, but it's more susceptible when there
is a failure. On the other hand, more engines is more
likely to have a failure, but it can be more robust when an engine
does fail and it's hopefully not as catastrophic. SpaceX's Falcon 9 Rocket actually already
utilizes this approach by having nine smaller engines instead of one large
engine like their biggest competitor historically, ULA's Atlas five rocket, which only has a single RD-180 engine. So how has that been going for SpaceX?
Well, for the Falcon nine in total, two Merlin engines have shut
down on ascent, and to date, none of their failures have ever
caused a loss in mission. Now, there have been two other
losses of engines which
cause the failure of a Falcon 9 to land, but that's not
mission critical. So overall, a larger number of engines have helped
make the Falcon 9 become one of the most reliable rockets ever made. In fact, even the landing of the Falcon 9 has
become more reliable than almost any other launch of a rocket in general
with over 115 consecutive landings in a row. So SpaceX's landing of a rocket success
streak is better than pretty much every rocket's launch success streak. Think about that, and SpaceX has already taken this approach
up threefold with their Falcon Heavy rocket, which uses 27 Merlin
1D engines at liftoff. And to date that rocket has had a
flawless track record for mission success. Now, there's a few things you can do to
help many smaller engines be even more reliable, including having each engine
inside its own blast containment shield. This way, if the engine does
experience a catastrophic failure, it won't affect its neighboring engines. This is something that SpaceX has already
improved upon between the first Super Heavy booster that flew, which
is Booster 7 and boosters after, which have a much more robust blast
containment shield on each engine, but beyond the actual
operation of a rocket, many smaller engines have a few huge
advantages over fewer larger engines. First off cost the R&D and
tooling cost can be depreciated through each engine much quicker.
If you're making, let's say, five times more of something, there's economies of scale that work
really well here with smaller engines when you're cranking them out
almost once a day. In fact, SpaceX is already making the Raptor 2
engines for under a million dollars now, and they're continually pushing
to make them even less expensive. Compare that to the F-1 engines
that were on the Saturn V, which cost about 115 million
per engine in today's dollar. So even though that engine
produced 3.5 times more thrust, it was about 30 times more expensive
on a dollar per kilonewton of thrust measurement. And don't even get me started on the
RS-25 from the space shuttle and SLS. That thing is also ridiculously expensive
and has even less thrust than the Raptor engine. Our numbers for the price
came from a recent OYG report here, and they're actually kind of conservative, and the report even says it's likely
much higher than that. So the RS-25 just really is not great from a
dollar to thrust perspective. Smaller engines also don't suffer the
same problems of combustion instability like larger ones do. This is where
the combustion chamber is so big. Different areas of the chamber
can experience slightly
different pressures and temperatures, and it can
lead to oscillations. These small instability can lead to big
problems and it's combustion instability that almost grounded the Saturn
V because its gargantuan. F1 engines were plagued with
combustion instability issues. The US figured it out, but the Soviet Union never really
figured out how to solve combustion instability on large engines. Instead, it was most common for the Soviet
Union to take one engine and split his combustion chamber up into two or four
smaller chambers as a way to avoid combustion instability. When
designing the N1 lead engineer, Sergei Korolev reached out
to a new engine designer, the Coots Netsov Design
Bureau, or OKB-276, and wanted smaller engines to
avoid combustion instability.
Another advantage of smaller engines is they're just
easier to handle, test, install, and move around, in general. We see SpaceX moving
raptors around all the time, like it's nothing down at
Starbase and at McGregor, Being smaller and easier to handle ends
up being an efficiency in time and labor hours. It's easy to imagine that it's a lot
easier to install an engine like Raptor that can be installed in hours
versus an entire F-1 engine on the Saturn V, which would've taken
days and huge machinery to install. But high production rates also help find
flaws and design and production much quicker. If you have, let's say, five times more engines than another
design that has fewer engines, that's five times more
opportunities to find flaws or make improvements in manufacturing.
This also applies to testing. If each engine goes through
a similar testing phase, you'll rack up five times more
testing and time in total with several smaller engines, which will lead to a better understanding
of the system and a more reliable engine in the long run. This means five times more
startups and shutdown sequences. It means there's more time to
really hone in what works and what doesn't work. Stokes Space CEO, Andy Lapsa brought this concept up to
me when talking about their unique test engine that has 15 combustion chambers
drilling in the advantage of testing so many combustion chambers. Every single test we're doing tests 15
of these systems at once we're racking up. Like if you rack up chamber test time, we rack that up 15 times times
faster than a normal program, and that couldn't be seen
as a totally bad thing. But at the end of the day, it might be-. The end of the day, it's gotta work,
right? Yeah, like a little at Starship, it's got a gazillion engines, right? And if you beat the crap
outta these things enough, then you work all the bugs
out and they're reliable. Now, of course, it might be easy to point to the first
flight of Starship in 2023 and say, well, it doesn't look like those Raptors
weren't all that reliable, after all, were they? But let's not forget, those were literally some of the
first Raptor 2 engines ever made. As of the making of this video, SpaceX now has produced over 300
Raptor engines and have developed a much more robust testing
regime for each engine, which will hopefully lead
to outstanding reliability. I don't think it'll be nearly as much of
an issue on later Super Heavy rockets, but at the end of the day, SpaceX still decided to fly
Booster 7 despite knowing it had a relatively low chance of success. Why? Why did they do that? And why did the
Soviets do something similar with the N1? Well, here's the thing, the Soviet Union didn't actually have
much of a choice in the matter other than to just fly the N1. The N1, not only couldn't static fire test
the whole Block A first stage on a stand or at the launchpad, but they couldn't even
test fire each engine. The N1s that flew all
utilized the NK-15 engine, one flaw it had was it relied
on pyrotechnics to open valves. This means they were single use and
required a massive overhaul to fire again. So instead, the Soviets decided to test just one
in every six engines that came off the manufacturing line to try and test
for general errors and production. Now, as you can imagine, this means the engines flown on these
flights weren't actually test fired before being lit for liftoff. So yeah, this means the only way to actually test
the N1 at all was to just launch it. And this is exactly what the Soviet
Union did all four times, and again, never getting all the way
through the first stage burn, just send it is the common philosophy
that both the Soviets and SpaceX have adopted. So why did SpaceX choose a
similar philosophy and just fly Starship? Isn't it different with SpaceX who does
test every single engine and they even performed a handful of static fire tests
with the booster and Starship upper stage? Well, SpaceX still believes the best way to
gather data and to get to the next step is to test, even if the test fails,
there's still a lot to learn. So instead of trying to completely
solve the complex problem of flying, landing, and reusing the
world's largest rocket, just start by trying it and
seeing what goes wrong and what goes right. The goal of the first Starship integrated
flight test was to clear the launch pad and not blow it up. Now, although
the rocket cleared the launch pad, a large amount of concrete was violently
ejected from below the pad and tore up a good amount of the area. But I think that's just gonna
be a small blip in history. And two years after the
making of this video, no one's gonna be thinking much about
the concrete ejection problem from the first launch. But the first test
flight did validate many things. The rocket made it through the point of
maximum aerodynamic pressure or Max Q. They put the heat shield tiles through
some pretty strong high velocity airflow. It validated aerodynamic models
and guidance and control. It also proved the launchpad and systems,
including the tank farm, the pumps, the coolers, the quick disconnects, and the launch clamps
all worked as designed. They got real world experience
from flying. So overall, SpaceX validated many things and even
learned the rocket was maybe perhaps a bit too robust and maybe had too small of
a flight termination system since the flight termination system failed to
immediately destroy the rocket when it was activated.
And in my opinion, the fact that the flight termination
system didn't immediately destroy the rocket was by far the biggest failure of
the first flight test. Everything else, including the concrete tornado, actually went better than expected and
was still largely considered a success. But this still all raises the question
of why did SpaceX and the Soviet Union do this iterative design process
instead of just doing it, "right?" And you know, just engineer and test every part until
it's pretty much perfect and you have a high degree of success for
that first flight. Well, let's take a look at NASA's S SLS rocket. It took 12 years to go from
signed legislation to flight, but SLS had to work perfectly or
else it was at risk of cancellation. So things were tested, engineered, and worked out to a high degree
of likelihood of success, which it nailed.
Now granted, it cost billions of dollars per launch
vehicle and has cost over 30 billion to get to the first
launch of SLS and Orion. But it does just go to show how important
it was that it all worked flawlessly on that first launch. Now,
Starship, on the other hand, began engine development in
2016, and around that same time, it became a legitimate project. So it took seven years before
the first integrated flight test, and it didn't complete all the milestones. And the rocket is still
far from being operational. But we can imagine where the
program will be in five years, likely by then it will
be more operational, at least to the point of flying some
tankers and payloads like Starlink and hopefully even NASA's HLS Moon
Lander variant. And from there, the rapid production rate and the
evolution of the rocket means it'll only continue to become more capable
and more reliable. And again, we're already seeing some details
about an upcoming Raptor 3 engine. So everything we've talked about is
likely to be outdated sooner rather than later. And I expect that the 10th Starship that
will fly will look quite different and will be a lot higher quality
than anything we've seen to date, which is something that is harder for
SLS to do because it doesn't have the freedom of failing or rapidly
making changes in design. So SpaceX is following in the footsteps
of the Soviet Union by build fast, test, break stuff, iterate, fly, blow
stuff up, learn from it, repeat. But will Starship ultimately suffer
a similar fate as the N1? Well, now it's time for my final thoughts on
whether or not I think Starship might repeat history. So why did the N1 fail? And is
Starship doomed to do the same thing? Is there just simply such a thing as
too big, too powerful, too many engines, and engineering too fast? I think the biggest misconception is that
the N1 failed simply because it had so many engines. While in some ways, of
course it was a contributing factor. It's not really the full story. The main reason the engines on the
N1 failed wasn't because of quantity, but quality. The NK-15s flown on
the N1 were extremely primitive, and as we know, they were still relatively
untested and quite failure prone. Couple of these relatively new
engines that couldn't be tested, a full first stage that couldn't
be tested without flying it, and then a primitive computer called
cord that was in charge of managing that many engines. It was a recipe for disaster.
Not to mention the N1 also steered via a pretty advanced mode of steering,
known as thrust differential. Thrust differential is where you
throttle engines to provide pitch or yaw. So increase thrust on side and decrease
the thrust on the engines on the opposite side, and it will
pitch or yaw the vehicle over. This means the engines need to handle
precise throttle commands and they spend more time in transients as
they throttle up and down. This is a fairly advanced task even
for today's rockets with modern computers. A major downside to relying on thrust
differential is that if an engine shuts down, the cord computer had to shut down the
engine opposite of it so as to maintain equal thrust. The N1 could fly
nominally with four engines shut down, but that actually means they could only
lose two engines since each engine that would shut down would require the
shutdown of its opposite engine. So there wasn't actually much room for error. Starships Super Heavy
booster on the other hand, primarily steers via the center
13 engines that all gimbal. Now gimbling is where the engine itself
can swivel and provide pitch and yaw, and assuming there's at least two engines, they can even provide
roll control that way too. The Raptor 2 has an astonishing
gimbal range of 15 degrees. This is the most gimbal range of any
main engine, at least that I know of. And they can do so at extremely ridiculous
rates with the new electromechanical servo thrust vector control system
that will be on all Raptor 2s after the inaugural launch. And that's actually something that was
different about the first flight test of Starship. The older Raptor 2 s were hydraulically
driven for their thrust vector control system for the gimbals, and those also had to rely on some
hydraulic power units or HPUs, and those failed on that flight test.
But now with the electromechanical thrust vector control system system, they
won't have to worry about that at all. But having engines that gimbal also
means that Starship doesn't need to shut down opposite pairs to maintain control. The rocket can simply use the gimbals to
correct for any offset and thrust if an engine does fail. We actually saw this in action on the
first flight test with Starship where the rocket lost many engines, but it maintained control via gimbling
and it didn't need to shut down opposing pairs. Now, personally, I honestly have no doubt that had
the N1 been able to continue flying, they would've easily figured it out and
likely within the next flight or two, and especially because the next
N1 called the N1F would've had much upgraded and much more
reliable NK-33 engines. Another thing to remember is that Starship
has had over 50 years of computer and aerospace advancements to lean on, which I don't think I need to really
even begin to explain how much computers and aerospace has advanced in 50 years.
In fact, thanks to modern computers, the engines can be less prone
to catastrophic failures
because the engines can sense when things are off nominal and
they can quickly shut things down before they get worse. But in the end, I think one of the biggest reasons the
N1 failed altogether and never got those additional flights is the untimely
and the unfortunate death of lead engineer Sergei Korolev, who died right in the middle
of development in 1966. And unfortunately for the program, Korolev was the main advocate of the
program while his contemporaries Valentin Glushko and Mikhail Yangel had
other plans and they just weren't supportive of the N1. Not to mention the
program was underfunded to begin with, and after Korolev's death, and then of course with the Soviet Union
being defeated by the United States's Apollo program to the Moon, the N1 was canceled before it ever got
a chance to really mature and live out its ultimate goal of sending
humans to the Moon. Now, isn't SpaceX still susceptible
to running out of money? Or what if there is an
untimely death of Elon Musk, or what if they just end up canceling
Starship altogether? Now, in my opinion, at this point, I genuinely don't
see much risk of that happening. Not only has NASA invested billions of
dollars into Starship because they're going to be using Starship as the
lunar lander for the Artemis program, but SpaceX has a solid revenue stream
by not only being one of the most prolific launch providers
by a huge margin, they also are likely operating at the
highest profit margins by reusing their Falcon 9 boosters and fairings. But they are also quickly becoming
one of the largest internet providers. SpaceX is investing billions of dollars
into making Starship happen and not just make it happen once, but they're
literally mass producing Starship. Although the N1 was set up in a similar
fashion with a production rate of up to one N1 a month, and they had engines coming out once
every 1.5 days or so. There really hasn't ever been a rocket
engine built like Raptor, which is being built so
inexpensively and so often, and they're still pushing that envelope. SpaceX is currently building multiple
facilities to build starships at scale. Now they're baking in efficiencies
to maximize economies of scale. The iterative design process. And of course this is after all every
usable launch vehicle that once it's proven, it will be beyond
disruptive, it'll be transformative. Much of what I just said can be backed
up by the fact that there's already several vehicles mostly finished
just waiting to fly. Now granted, they currently don't have a launchpad
to launch on as of the making of this video, but I think SpaceX can get
that part figured out, no problem. Now I know it's easy to write me off as
just a SpaceX fanboy that's gonna think that Starship is gonna work out no matter
what and not fall to the same fate as the N1. But don't forget, over and over SpaceX is proven to
be able to do what was once thought impossible. And every time the impossible
becomes routine in about a year. I mean, just look at the Falcon 9 first, just launching was considered
impossible. Then they did it. You know, getting to the International Space
Station was something they would never be able to do. They did that no problem. Then they started working on landing
the rocket and people said that was impossible. Well, they did. And then
people were like, okay, cool party trick, but you're never gonna be able to reuse
that thing they did. And they're like, okay, sure. Maybe you'll reuse it
once or twice, but you'll never like, you know, reuse these things over and
over. It'll never be financially worth it. Now they are up to like 15
reuses on most of their fleet. Their fleet is just getting so
ridiculous. They're so used. It's really rare to see one that's new
or it's really rare to see one expended or one that doesn't land. I mean, that's
just almost unheard of these days. What about fairings? Those were supposed to be impossible
and not worth it to reuse. And now it's rare to see a new
set of fairings and humans. Let's not forget about humans. People thought there's no way
SpaceX would get humans into orbit. They just thought it was something
that would never happen. Of course, as we know now, they're the most prolific
provider of getting humans into orbit. Um, you know, not only for NASA getting
to the International Space Station, but also private individuals doing
free flights and things. I mean, it's, it's just incredible. And all of these things have had
people the whole time saying, this is impossible. It'll never happen. And now so many of these things are
completely routine. Now, of course, it's really hard to predict when Starship
will go from completely impossible and experimental to completely
ordinary and routine and mundane, Do you think Starship will
suffer a similar fate like N1? Do you think we'll ever see a completed
first stage burn and a full clean stage separation? Do you think we'll see it get to orbit
or do all the other things it's supposed to do and become operational? Will it
take a year, two years, five years, 10 years? Never? Let me know your
thoughts and the comments below, and don't hesitate to ask
any additional questions. I'll get to as many of them as I can. I owe a huge thank you to my Patreon
supporters and my YouTube members for helping make all of this stuff possible. If you wanna join our amazing community, get access to some exclusive live
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Thanks everybody. That's gonna do it for me. I'm Tim Dodd, the Everyday stronaut bringing space
down to earth for everyday people.
