How To Start The Massive F-1 Rocket Engine - Explaining "Ignition Sequence Start"

Seconds before the launch of a Saturn V we hear the launch commentator calling out 'Ignition Sequence Start'. The ignition sequence is a complicated series of steps which spin the engine up to speed and light the combustion chamber so that the rocket lifts off rather than explodes.

[@luciusvorenus9445]

"Casual combustion ". As a volunteer firefighter, I'm stealing that for training purposes. "No that's not a backdraft or a flashover. It's just some casual combustion. "

[@nobodynemoq]

and remember to tell your trainees "no need to worry however, it gives hardly any thrust" ;)

[@cosmicraysshotsintothelight]

THEN, one gets a little 'backdraft'. And shortly thereafter one gets 700 tons of downdraft.

[@burroaks7]

The Noosle at the end od the Hoose-- Groundskeeper Willie

[@dgarcia0rivera]

Nothing to see here. Just some casual combustion. These aren’t the turbopumps you’re looking for. Move along.

[@cosmicraysshotsintothelight]

@@dgarcia0rivera Mongo Like beans!

[@frederf3227]

Oh man, I should have watched the video on how to turn off the F-1 first. CAN ANYONE HELP?! IT'S REALLY LOUD!!!

[@tobiasvandermeer584]

Just wait until you are out of feul

[@Rubensgardens.Skogsmuseum]

Try blocking the air intake with a rag.

[@WineScrounger]

Jan M 🤣

[@OMG_No_Way]

Hahahaha

[@mazocco]

Have you tried to pull off the cable?

[@Coastfog]

That's why I love Astronomy and space engineering - it might seem very complicated at first, but when you keep digging deeper and deeper, you'll soon realize that it's even more ´complicated.

[@tommypetraglia4688]

But broken down each system within the system is nothing more than tanks, pipe and pumps Incredible feats of engineering for the incredible feat of the lunar landing. Most of the general public takes if for granted WE PUT MEN ON THE MOON... and brought them home

[@samsunguser3148]

It makes me appreciate the little things

[@waffles9771]

thats why I love it =], its _hard_

[@ThePlaton20]

The genius of engineering is to take a very complex problem and keep breaking it down into smaller parts until the smaller parts are easy problems to solve.

[@tastefulcoder5553]

Yeah I know XD

[@don_mega8727]

My father in law worked for Rocketdyne from the 60’s to 80’s. He was on the design team for the F-1 engine. He worked with Von Braun’s team in Huntsville prior to the Apollo program. He also worked on the Shuttle program too. His most interesting project was the turbine car for Chrysler. He was loaned out to Chrysler from Rocketdyne. The guy is an absolute genius and I hope that gets passed down to my kids. Best FIL a guy could ask for.

[@5Andysalive]

Saturn V launches never get old to watch.

[@dalethelander3781]

I know, right?

[@charlesboyer61]

They never got old to see in person, either.

[@RCAvhstape]

I can never get over the monstrous power of those engines seen from so close in those launchpad camera shots.

[@Ottee2]

I never got to see one blast-off in person, but one year, when I was a kid, my family was on vacation and we visited the Houston Space Center. There was a Saturn V lying on the lawn near the entrance. It was then that I gained an appreciation of the magnitude of this endeavor.

[@RCAvhstape]

@@Ottee2 IIRC that one has been restored and placed indoors now. I plan to visit it, hopefully soon.

[@DanielA-yg3un]

I love your ultra scientific Minecraft fire graphics!

[@cedricdegala184]

That's my favorite

[@ziginox]

I thought Doom, initially.

[@blueberry1c2]

All you need to light a rocket engine is flint and steel

[@Mark-dc1su]

I was almost certain it was from Graal

[@jameswalker199]

Oh that's where I remember it from

[@sergeant_salty]

July 20th, 2019. I saw the Apollo 11 50th anniversary movie and was lucky enough to sit in a seat labeled "F1" by my movie theater. a memory I will keep close forever

[@mycroft16]

The slow motion footage of the exaust gasses flowing out of those engines is always fascinating. The raw power in those engines is just staggering. Also... when your coolant is at 1,000 F. lol

[@vxzrt]

In christ pls what is 1.000 f i dont get it

[@mycroft16]

@@vxzrt 1,000 degrees Fahrenheit. Imperial units. Works out to 537 C.

[@omygod9062]

Those exhaust gasses are ignited

[@richardstoteler1951]

They are not exhaust gasses, the black 'plumes' directly underneath the engine nozzles are unburned supercooled fuel coming from the turbines, thus protecting the skirt of the engine

[@theophrastusbombastus8019]

2:35 Such schematics really makes us appreciate the countless redstone engineers that worked tirelessly to create such a marvel

[@tommypetraglia4688]

Slide rules, mechanical drawings... no computers or models no cad generated prints and schematics Geniuses on and all. Truly Renaissance Men and Women

[@mihirpatil8843]

@@tommypetraglia4688 You missed the joke but ok

[@Not_An_Alien]

@@mihirpatil8843 Problem might be, there was an actual Redstone rocket.

[@mihirpatil8843]

@@Not_An_Alien That's probably not what OP was talking about

[@theophrastusbombastus8019]

@@Not_An_Alien a minute of silence for all the creeper died to farm the TNT to lift it off

[@wojtek4p4]

Okay Scott, you can't just casually mention the pogo suppression system without at least roughly explaining what it ts. I'd love a video (or at least a segment of a video) explaining what it is and how it works 😋

[@heatshield]

pogo suspension system is so easy. Its just a spring in a tube. You jump up and down.

[@thomasfholland]

heatshield 👍

[@GlanderBrondurg]

Pogo in this case was a problem identified early in the development of the Saturn V. As fuel gets burned in the engine it produces thrust and acceleration. That acceleration increases the tank pressure thus also increases the amount of fuel burning to cause the turbopump to spin faster in a positive feedback loop. Some valves try to slow down the fuel flow so it doesn't destroy the engine, but that causes acceleration to drop and a reduction of pressure, so the fuel valves open up to compensate. Unfortunately the opening and closing of the fuel lines aren't instantaneous, so that creates an oscillation of high and low acceleration. In other words, pogo. It causes the whole spacecraft including the astronauts to shake violently potentially killing astronauts and destroying the spacecraft too. Trying to keep that under control is why rocket scientist get paid the big bucks.

[@KayoMichiels]

Vintage already has a video explaining what it is: kzbin.info/www/bejne/poCyo4uNgbGtl5I

[@eugenecbell]

GlanderBrondurg, thank you for the POGO explanation. Do you know at what cyclic rate this POGO oscillates?

[@davidpreneta3805]

...how...HOW? can anyone not be absolutely amazed at this engineering. This is such a complex process and it's not all computer driven...mostly just mechanical. All these sequences and all these component designs have to work perfectly. Not to mention all the coordination among these engineers working on the designs and components and having them all fit together and work together. And this is just the main engine...let along the other engines, computer ring, lunar module, command module, the rocket itself, etc. I just shake my head in disbelief that this was possible. Engineering at it's best...!

[@davidelliott5843]

Before we had email and CAD, people had to talk to reach other. I think this is a big problem today. Everyone makes their nut or bolt someone else puts it together someone else again makes it work. Maybe.

[@tma2001]

Just re-reading Chaikin's 'A Man on the Moon': Charles Lindbergh the day before the launch of Apollo 8, asked how much fuel the Saturn V would consume on ascent - 20 tons per second they said. "In the first second of your flight tomorrow, you'll burn ten times more fuel than I did from New York to Paris".

[@adamwishneusky]

omg my F-1s have been sitting around idle because I didn't know how to start them. Thanks! 😜 -- srsly tho, thanks for another awesome video!

[@WineScrounger]

Lol. I hope you have understanding neighbours over half a mile away.

[@KiranAlokkan]

Hope you didn't attempt to start it. Else you would have burned down the whole town.

[@user-nu2pj2ch7t]

Karen haircut 🤣

[@zhiqiandu3110]

You have a serious gas bill to pay

[@MAGGOT_VOMIT]

@@user-nu2pj2ch7t _2 sugarbloods attacked him an alley. One held him down, the other did his Hair._

[@gmpsandw]

Even mow 50 years later it still gives me goose bumps to see that thing go up. Amazing.

[@Big.Ron1]

Yes, me too.

[@thisnicklldo]

Me too.

[@trashmail8]

Absolutely, me too! If you haven't seen it yet, try to go and watch the most recent Apollo 11 documentary in a Cinema. Seeing Saturn V launch on a huge screen filled with beautifully restored 70mm film was jaw dropping. Not trying to offend anyone, but it was almost a religious experience. My heart was definitely beating faster than that of the astronauts simply watching this happen.

[@Tiisiphone]

yep, major case of goosebumps!

[@danielthesantos]

It just gives me geese, lots of them. Of course, I live next to a duck pond and they leave me every spring.

[@Crunk99ify]

So on the igniter, there is a little "aspirin" tablet that then lights a solid fuel components that looks kinda like a dynamite stick. After numerous successful test, they suddenly started having catastrophic engine failures. They sent the engines over to the vibration and acoustics labs at Marshall in Huntsville. After running numerous test, they couldn't figure out what was wrong or different, until the head shock and vibe engineer (one of the best in the world) noticed a previous good vibration test set that didn't have such a "shocky" graph pattern so early in ignition. Comparing the two test, he realized whatever was going wrong was happening during the igniter start up. He went to the purchasing guy and asked "did you change where you bought these little "aspirin" tablets?" the purchasing guy said "yes, a salesman came in about two months ago and showed these burn much hotter and fit the same spec." After switching back to the old "tablets", the engines went through another successful test...apparently, the hotter igniter tablets were breaking the solid fuel components apart and causing uneven burning that then causes basically a mini-explosion because you started mixing the remaining solid fuel and LOX. So that's how a 80 cent item almost shut down the Apollo fights.

[@Ricky40369]

Perfectly explained. Typical, though.

[@rearspeaker6364]

wonder what they did with the unused tablets?? or the aspirin tablets that lit your head up!

[@NPCNPCB]

Quality Control has entered the chat

[@rearspeaker6364]

@@NPCNPCB 1960's style!!

[@BrianMorrison]

Interesting that the spec wasn't adequate to keep the "super-aspirin" tablet out of the system. I bet someone revised it after this was discovered.

[@Ender240sxS13]

I can never get enough of close up shots of the F1 firing, there's just so much raw power there and thinking of the engineering feats that enable it is just mind boggling and inspiring for an aerospace engineer in training

[@twistedyogert]

Yet mankind's talents are wasted on trivial things like war.

[@Esteb86]

@@twistedyogert Indeed. A damn tragedy. Humankind could do so much, if we stopped spending funding and brain power on killing each other.

[@Jacksonflax]

@@twistedyogert Previous wartime development is what made this technology possible

[@mrman5517]

alternatively: just press spacebar. then watch in awe as flames & smoke billow from one end of your rocket, and parachutes deploy from the other!

[@eisenklad]

or worse... watch the thing drop when you put the clamp staging first

[@beanlegion8529]

mr man or watch it completely split in half because you staged it wrong.

[@MrChilliconqueezo]

First rule of ksp is of course more boosters and struts. But the second is.. Check staging. Tho according to my launch history the second rule is rarely enforced

[@seanbaskett5506]

don't forget to hit T and Z first

[@thefuzzman]

No, space bar is pause, enter is start lol

[@tonywharton5220]

2 tonnes of fuel per second? And I thought my kia was bad.

[@-danR]

What amazes me is that that stuff is being driven through by turbine disks only a foot and change in diameter.

[@TheErilaz]

The fuel pump delivered 15,471 US gallons (58,560 litres) of RP-1 per minute while the oxidizer pump delivered 24,811 US gal (93,920 l) of liquid oxygen per minute. Thats for one engine.

[@jimbarino2]

@@TheErilaz The fuel pump on 1 F-1 used about 50,000 horsepower...

[@Calilasseia]

It's actually a little more than that. Total propellant consumption rate at full throttle for all 5 engines together, is frequently quoted as 13 tons per second. However, this ferocious rate of propellant consumption has an advantage - the booster stage becomes lighter by the same amount. So, by the time the propellant is running low, the entire Apollo stack has shed, wait for it, some *two thousand tons* of mass. By this time, the booster stage has done its job, lifted the stack to an altitude of about 38 miles, and the second stage takes over. Two thirds of the mass of the Apollo stack has effectively vanished by the time the second stage fires up.

[@adamkendall997]

Kia is a vastly superior machine..

[@hoorayimhelping3978]

Great editing Scott! Loved that you explained everything, then showed a couple of shots of the startup sequence. I was totally able to follow along with the whole process you just explained. Awesome!

[@davidpoynter6546]

Scott, I want just to tell you since I was a young child I have always been interested in rockets and space. I watched every Apollo launch and everything thing I could see on Apollo 11, and the moon. I have learn so much from your videos, I just wanted to say thank you.

[@davidpoynter6546]

I believe that we should have never stopped going to the moon and at this point in time we should have had a fully functional moon base that would have been in operation for years. This should has happened before the ISS was even started.

[@davidfountain6607]

People should also remember that there were four launches of Apollo in 1969. Apollo 9 in earth orbit, testing the Lunar lander for the first time, Apollo 10 which was a full up dress rehearsal of the lunar landing, Apollo 11 and Apollo 12, both of which landed on the moon. So it's a 50th anniversary for all those crews!

[@Andrew-13579]

Yes! Apollo 9, 10, 11 & 12 were all Saturn V boosters, too...March, May, July & November of '69. Did we ever launch 4 Space Shuttles in one year? It looks like Apollo 10 still holds the world's record for fastest manned craft (Earth ref) at 24,791 mph. 50-year-old speed record!

[@Andrew-13579]

Including Apollo 8 in Dec '68, that was 5 manned Saturn V boosters inside of 12 months...with 4 of them sending Apollo to the Moon. Will we ever see such a thing again? Doubtful SLS-Orion ever will. Come on, Starship!!

[@charlesshreeve319]

I was 12 in 1969. It was a great time to be a kid!

[@slpybeartxtx3006]

@@Andrew-13579 Yes, we launched 6 times in the period from 2/3/1984 - 1/24/1985 and then we launched 10 times from 1/24/1985 - 1/12/1986. I think SpaceX will beat these frequencies though.

[@reubenmitchell5269]

@@slpybeartxtx3006 they certainly did unmanned but maybe wont manage 5 manned in one year

[@therichieboy]

I've known for a long time a rocket engine is far more complex than just a chamber that burns fuel and oxidiser but this blew my mind as to the true engineering magic that goes into them. Beautifully explained Mr Manley! Thanks.

[@vxzrt]

The f1 engine is EXTREMELY complicate to made in this day the only thing What can help the nowdays enginers are the blueprints but they are in a secret place somewhere in nasa facilities Almost 60 years later there is no enginer Who can totaly dominate the f1 engine even the best of the best today

[@jimmysparks315]

I've looked at Saturn V engines roaring away about 100 times... i never get sick of looking at them. I was at the Cape in '85 to see shuttle STS-62 night time launch... WOW.. .. You hear people talk about the crackle, and just how loud the crackle is... God it sounded good.

[@Esteb86]

I always love watching the side view of engine start. Watching that plum of smoke and flame get sucked back down through the launch stand is amazing.

[@alexhatfield2987]

When Jack King NASA PAO announced "ignition sequence start", his voice charged with adrenalin, my 8 yr old imagination lit up like those F1's, my heart raced like the clappers, and my mouth dropped open. What a ride Apollo. There's never been a Global adventure quite like it since...

[@trespire]

When engineers are set a task, and let loose to get it gone.

[@tommypetraglia4688]

I was 9 in 69 and today I'm there again but now with some knowing of how great it really was.

[@gasdive]

I was 6, and I'm as excited today as I was then.

[@Zoidberg227]

Ever listen to the GO/NO-GO poll for the landing? One of the controllers (Guidance) was definitely feeling that excitement.

[@miketype1each]

He was so charged up that he said, "All engine r-unning". He noted later that he said it that way. Apollo 11 was the big one. I was 7 at the time, and everyone was excited about it.

[@adbell3364]

Excellent! Simply superb! Eight minutes and change, and I learned more about the Saturn V launch than I have in the last 50 years. Thank you, Scott!

[@PTuffduty]

that’s my point. the most important information and I know it now.

[@mwolfod]

Brilliant explanation of a stunning triumph of engineering.

[@SirChickenMacNugget]

I was really curious about the "blips" in the thrust profiles for engines 2-5 when you showed the graph. So glad you explained it! Great video as always

[@SupremeRuleroftheWorld]

can you explain how the gimbal works? putting 700 tons on a strut and making it move at the same time seems quite the engneering challenge

[@tippyc2]

That's probably the simplest part of all of this. Imagine big hydraulic rams like you might see on construction equipment. That's basically what they use to move the engine. The engine thrust is in line with the pivot, so the thrust doesn't try to pivot the engine. That's important because it means the rams (called actuators in a rocket engine) only have to push a small fraction of the thrust force. The control system is just a feedback loop which controls the hydraulic valves. It's the kind of thing you could do yourself with an arduino these days, but I believe the Saturn V used some sort of analogue system to control the engine gimbals. The bps.space channel has several videos of amateur rockets with gimbal capability, and he explains how he does it if you're still curious.

[@athr_blu]

Nice idea, tweet it to him

[@PatrickKQ4HBD]

SECOND!

[@manlymcmanface9932]

Great idea, I keep wondering about this, too! On these technical drawings I always look at the upper narrow parts of the engine (where I suppose much of the upward force applies) and wonder how the hell does it stay in one piece? Especially with gimballing going on. The forces have to be humongous! Also, isn’t it a lot more than 700 tons in case of Saturn V?

[@joevignolor4u949]

There is a large X shaped universal joint on top of the engine that is rated to carry the 1.5 million pound thrust load imposed on it by the engine. That lets the thrust chamber and engine bell move back and forth in two axis. The engines have two mechanical arms that are welded to the thrust chamber 90 degrees apart. The arms are several feet long. There are two hydraulic cylinders connected between the ends of the two mechanical arms up to the rocket's structure. As the hydraulic cylinders extend or contract they move the engine back and forth. By moving the two cylinders together in tandem the engine can be pointed in any direction up to the limits of the cylinders. The hydraulic fluid used to move the cylinders is actually pressurized rocket fuel coming from the fuel pump. The fluid is controlled by a flow control valve to move the cylinders in and out to move the engine back and forth. The control valve is in turn controlled by the flight control computer up in the Instrumentation Unit (IU) sitting on top of the third stage. The IU has a gyro stabilized platform that moves on 3 gimbals to give the computer attitude information and it carries 3 accelerometers to provide the computer with acceleration information. This allows the computer to gimbal the engines and keep the rocket pointed in the intended direction and following the correct trajectory.

[@seanbaskett5506]

It's always fun to listen to Jack King say "Ignition sequence staaht!"

[@glenchapman3899]

"All engines running....Lift off........we have a lift off 32 minutes past the hour" Still gives me goosebumps

[@rohil3023]

Ikr!!!

[@FiiZzioN]

This has to be one of my favorite videos you've produced... Simply stunning!

[@JohnBoyDeere]

Great job explaining the basics of the S-V rocket start up. Thanks!

[@104thDIVTimberwolf]

This is your best since I found your channel, Scott, and that says one hell of a lot.

[@Cby0530]

It's much better than looking at an in-depth literal description of the sequence in an Haynes manual for the Saturn 5.

[@OldBenOne]

Cby 0530 So the next video is going to be the brake booster on a 1988 Doge Caravan?

[@Cby0530]

@@OldBenOne lol.

[@drw1926]

"Haynes manual" LMAO!!

[@mikefrerichs8860]

@@drw1926 There is one. Look it up on Amazon. "NASA Saturn V 1967-1973 (Apollo 4 to Apollo 17 & Skylab) Owners' Workshop Manual" Unfortunately a Saturn V won't fit in my workshop. Guess I'll have to work on it in my driveway. Hope the neighbors don't mind.

[@AlexAltair]

This is the perfect amount of detail for me. I would love to see a similar video for other engines!

[@reubenmitchell5269]

watch everydayastronauts video on the various types of rocket engine

[@Kujeful]

Wonderful breakdown of the startup sequence, thank you! I love the punchline at the end.

[@yumazster]

That was tightly packed 8 minutes 😊. Great work!

[@GianniBarberi]

Simply wonderful, I was 7 50 yrs ago and always wanted to know more about the missions

[@tritop]

I was 8 and wish my father would have take me there to whitness the start

[@Tiisiphone]

Exciting! I'm glad you're here to tell us these things Scott!

[@nickmudd]

It's crazy to think that less than 100 years before the Saturn V, we humans were still walking or riding horses

[@entangledmindcells9359]

There were still folks in the rural US that still did not have indoor plumbing at the time of the Moon Landing.

[@likhiiiii]

Need a video completely dedicated to Pogo suppression systems!!! Great video tho!!🤩

[@StreuB1]

Acceleration induces increased head pressure in the tank which increases injector pressure which increases Pc which increases thrust, increase in thrust increases acceleration which increases head pressure in the tank, and on and on and you get this positive feedback loop with a period equal to the latency time between head pressure rise and the vehicle responding to the increase in thrust. The higher the hysteresis, the worse the feedback loop can be. On small vehicles, it can be mitigated purely by the fact that the system cannot respond fast enough to induce the oscillation. So, the systems acts like a pogo stick oscillating up and down as pressure, thrust and acceleration chase each other.

[@likhiiiii]

theretep64 Jus thought of doing it!! First time!! So I was a bit excited!!😶😶

[@likhiiiii]

Darius Kang 😂😂

[@alfo6085]

On holiday. Enjoying a dram. Just learned how a Saturn V engine works. Surreal.... And wonderfully more enjoyable than watching TV! Scott, you're doing a grand job. Thanks 👍

[@ntcrwler]

Truly fascinating! thank you! I can now watch the footage of the launches with a new understanding and appreciation!

[@Dakakeisalie]

How to turn on a rocket engine. Press Z, then Spacebar

[@Atlessa]

'Y' on german keyboard layouts.

[@jorgeaugusto1867]

My sequence is T, Z, spacebar

[@pegasusted2504]

i found it was mostly "forget" to ramp up the engines then press z.

[@coffeecup1196]

@@jorgeaugusto1867 Z, Space, Revert to launch, T, Z, Space is mine

[@jimbutke]

Little known fact is that the Saturn V originally had four engines but due to the fact of the astronauts huge balls they had to add a fifth engine

[@BackToSpace]

Great video Scott! No matter how much I learn about the Saturn V and the rest of the Apollo hardware, there are always more details under the details.

[@stevenhull4425]

Awesome Scott! The F1 is by far my favorite piece of flight hardware of the Saturn V! An awesome engineering feat!

[@Random12231]

It's even more impressive when you think about the relatively limited computer aid available to the engineers at the time. Marvelous engineering that still fascinates me to this day. Thanks for the great video 👍

[@-danR]

You can appreciate why Bob Truax went with dirt-simple pressure-feed with the Sea Dragon concept.

[@reubenmitchell5269]

shame it was never built, but it would have been too slow IIRC it would have staged at only 50km?

[@duelette]

Thanks for the very clear explanation! I have always wondered about that and didn't realize how complicated it was.

[@davidranlet5019]

Scott, incredible video. I spent 10 years working on AE2100-D3 engines for the USAF and consider myself an expert on them. The science here makes me feel like an idiot. Thank you so much for doing the research on this and presenting it in such an awesome way. I could watch this over and over.

[@catfish552]

That's very helpful, I can never get mine to start right!

[@MrHichammohsen1]

Amazing as usual. Waiting for the episode with CuriousMarc channel :)

[@ancliuin2459]

Super informative! How often have I watched slow-motion videos of Saturn V launches... now I know what is happening. Many thanks!

[@radioactive9861]

And THAT folks, is why they call it 'rocket science'. The concept is simple to understand: chemicals combine and burn and you get thrust, but dam if the actual engineering isn't hard as hell. Glad Scott Manley gave a rather simple diagram for non-rocket scientists like myself to understand. Keep up the good work, Scott Manley.

[@TastingwithTonyShow]

Hi Scott, Great video as always. Another detail you didn’t mention was that when full thrust was detected and normal engine performance confirmed the hold downs would release; but they did so in a fashion that was almost instantaneous so a means was needed to transfer the thrust to the vehicle over a (short) period of time. This was achieved with a set of tapered pins and corresponding dies through which the pins were pulled. These were called Controlled Release Mechanisms. On the sides of each hold down arm structure were secured the tapered pins. Special dies were very firmly secured to the lower rim of the launch vehicle such that when the hold down arms released, the dies had to pull the tapered (and larger) pins through them. The physical design and metallurgy of the components meant that transfer of full thrust to the vehicle occurred not instantly, but was spread over the first few inches of upward travel thus ensuring that dynamic loads at liftoff didn’t exceed vehicle tolerances. www.capcomespace.net/dossiers/espace_US/apollo/ksc/LUT/LUT%20HDA%20TSM.jpg

[@alpurl]

This is neat info. Very cool. THANKS for sharing!

[@maxfan1591]

Five of those babies firing would drain our swimming pool in under 4 seconds.

[@StonyRC]

Thanks Scott, that was succinct, clear and very well presented. Answered all of my questions about the F1 startup.

[@alanmcrae8594]

Excellent presentation! Very clear explanations of the entire start sequence. Just what we're used to seeing from Scott Manley.

[@drtidrow]

Did anybody else notice all the thermal insulation on the engines at the end of the video? All the engines had insulation around them, to protect them from exhaust backflow during flight... something that you generally don't see on engines displayed at museums.

[@NoNameAtAll2]

Asbestos Not safe for a museum

[@drtidrow]

@@NoNameAtAll2 Not all of it was asbestos. Not many people know what they looked like on the actual launch vehicles... would be nice if at least one location had two engines next to each other, one 'naked' and one 'dressed' for launch.

[@RtB68]

People just don't realise what a monumental achievement the Apollo program was. It ranks among the greatest - if not THE greatest - engineering achievements of mankind.

[@dannywest903]

And, all calculations were done with a slide rule.

[@rearspeaker6364]

@@dannywest903 that is the most amazing part! today's "calculated"designs are too close to failure 95% of the time.

[@beeble2003]

Wuh? Do people really not realize how amazing Apollo was? _Really?_

[@flaplaya]

Wow for the first time I wrapped my head around this whole thing.. Amazing! One thing I noticed here was the Turbopump exhaust being dumped into the wall (outer layer) of the plume.. Makes the first ten feet or so out of the bell look black (7:08). Love your shows Mr Scott Manley! Thanks!

[@karljesaitis3656]

I’m 50 years old I’ve been interested in this for 35 years thank you for the explanation

[@KennyRusso77]

The more I learn about the Saturn rocket program -and particularly F1 rocket engine development and engineering, the more stunningly brilliant I find that the NASA scientists were (are?)! Their acute understanding of how these F1 engines worked (and what physically needed to take place within them to make them work well), combined with the sheer simplicity of their design, stuns me. I am simply AWESTRUCK by what they accomplished (working essentially from scratch) in just a matter of a few short years, using what would be considered by today's standards rudimentary engineering tools, is amazing. It’s no wonder why today we refer to someone of incredible intelligence “…a rocket scientist”!!!! These folks set the bell curve long ago!!!

[@kumoyuki]

given that they had no CAD, no fluid dynamics simulations, mostly slipsticks & trial & error and dedicated intuition - the F1 engine is an absolute marvel of engineering. And then to go from 0-100% thrust in 9 secs? I can't even get my car started that fast ...

[@jdrok5026]

@Alan Tang a lot of the design required hands on work tho. Even today cad is not the end all be all of your design process.

[@paulmichaelfreedman8334]

@Alan Tang Productive graphic CAD design with capable computer mainframes was instigated by the design of the space shuttle, which was mostly designed in graphic CAD, starting in 1968. Thanks to the shuttle graphic CAD design made huge leaps forward in the 1970's. It was necessary due to the complex shape of the shuttle. During the mercury era and gemini era, CAD was non existent. For Apollo, CAD was limited to parameter-fed algorithm number crunching, no graphics and no complex designs.

[@Yazidn]

A brilliant piece of engineering! Thanks, Scott!

[@MattVileta]

Those close up shots in slow mo of the thrust coming out of the rockets is intense. It's like.... you're looking at raw power, on ridiculous scales.

[@Xavier-zm8wv]

hi! Idea for a future video : what is the internal sturcture of a rocket, the structure that makes it stay as it is, and which preserves its integrity when the mass opposes the thrust? Which part of the engine supports all that mass?

[@sk8punk318]

This whole time I thought someone with a BBQ lighter just lit the bottom and ran. Who would of thought it was more complicated lol wow

[@samarvora7185]

"It must be damp."

[@johnstreet819]

that's the way the Soviets did it for years

[@RedLP5000S]

You lost me at "Hello", but I watched the entire episode in gleeful admiration.

[@buckhorncortez]

I am so glad I've found this video...I was having one heck of time getting my F-1 started...I think you've helped clear up the problem..

[@valuedhumanoid6574]

There's a video on why we can't make these engines today. I think it's made my Curious Droid. You would think that with our level of technology today we could not only make them again, but make them better. Not even close. Much of the work was done by engineers who were making changes on the fly. The main design would be considered version 1.0. The engines on the actual Apollo were using version 4.5 (a rough analogy) all those changes/updates/mods were kept in each engineers notebooks, which we don't have. And a lot of it was in their heads, which we don't have (lol) And much of the machine tooling, like the massive presses, punches and brakes are gone. It's a fascinating video to watch. I don't mean to talk about another's video, but I think it dovetails nicely with this video. Well made and researched. Liked and subbed.

[@donnebes9421]

00UncommonSense00 if that’s true there’s no better example of lost technology. Which makes you think about some of the things on earth that nobody can figure out how they were done.

[@KingdaToro]

We couldn't recreate the exact flight engines used on Apollo, no. But we can absolutely improve on it. Look into the F-1B proposal. It eliminates the gas generator exhaust manifold (replacing it with a straight pipe) and the nozzle extension, and replaces the brazed tubes of the thrust chamber with a milled channel wall nozzle like the Merlin. That would have meant a part count of about 100, compared to 5000 for the F-1. It would have been throttleable, too. But ultimately there wound up being no need for it.

[@RoelfPringle]

Great, but now I need a video on the POGO suppression

[@xureality]

It's basically water pressure regulation, but on rocket fuel. - Fuel/Ox burns and produces thrust, causing pressure to rise in the system because F=ma - More pressure causes turbine to spin faster causes a positive feedback loop - Too much pressure means fuel lines burst means you don't go to space today (or if you were on the rocket, possibly ever again) - Engineers built a regulator valve, it stops fuel lines from bursting alright, but it can only open and close so fast - Oscillation ensues, manifesting itself in the form of rocket thrust going up and down And that's pogo, which is a no go. And so engineers come up with a question: rocket fuel is incompressible, what if we have something compressible to "surge" into to dampen the pressure oscilations? In principle, this is exactly just like a shock absorber on your car, and for once, in practice, it is a shock absorber grafted onto the pipeline. Yes, literally a tube with some gases (spring loaded piston in gemini, later on in apollo they use helium), Modern rockets still does this, but they actually are calculated to eliminate pogo entirely instead of being a mitigation strategy.

[@cowboybob7093]

Look through a copy of _On The Shoulders Of Titans_ - NASA has it in HTML and you can find it in PDF and even book form. There's several pages dedicated to POGO and how it nearly sank Gemini as we know it.

[@Mp57navy]

I went out on a date, With a girl, a bit late, She had so many friends, Gliding through many hands. I brought my pogo stick, Just to show her a trick, She had so many friends, Gliding through many hands. Jump pogo, Bounce pogo, Down, up Jump, bounce, up, down

[@MrJackHackney]

Apollo 6 videos talk about the Pogo issue

[@chris-hayes]

Videos about water hammer suppression will be very similar to POGO suppression and there's much more of them

[@johnahrens]

Thanks for making the complex easy to understand.

[@JEBavido]

I loved the footage you put together! In admiring your knowledge I sometimes forget your KZbin skills.

[@stevefick3919]

Hat's off to the men and women who thought up this stuff. Amazing engineering! And that's just the engines!

[@zegreatpumpkinani9161]

2:45 accurate diagram of how Minecraft Galacticraft rockets work

[@eisenklad]

Hold space to slow down

[@cowcannon8883]

I'M PRESSING SPACE IT'S NOT WORKING *crashes

[@ThijsWasTaken]

@@cowcannon8883 I miss those days

[@SweetBerryWine3000]

This is a beautiful explanation of a gob-smackingly incredible feat of engineering. 👏🏼

[@pyrodoll2422]

Brilliant as always Scott, thanks for doing what you do xx

[@neilbarnett3046]

Engine fires in the sequence 1-3-4-2, just like a Morris Minor!

[@stevenmoody4531]

Much easier than figuring out the remote for the tv. 🤣

[@backsideofblue3163]

Absolutely amazing stuff. I love the F1 engine even more than before. Keep up the great work!

[@jeffreylindsey1757]

A very articulate and informative video Scott! Thanks

[@jeffreykreft5442]

Just totally amazing just how complex these systems are. Of course breaking them down to their basic components helps to understand, there is so much more going on that it just is almost impossible to comprehend . The F1 engine is by far the most complex piece of machinery every created by the hand of man, complexity to the point where it cannot be replicated today, even with all modern technology, it can’t be done!

[@oliverlemley9343]

Ohh, thanks man i have one of these sitting in my drive way and couldn't figure out for the life of me how to get it to turn on.

[@doapin6240]

Everybody gangsta until somebody starts launching the sea dragon

[@vincentvoncarnap2473]

Breaking news: crime rates rise to 100% forever

[@carbo73]

Amazing and very informative. Many thanks Scott. Keep up the good work!

[@tropifiori]

I was a kid during Apollo and Gemini and it was a huge thrill to see a rocket launch on black and white TV. Nice video Frank

[@ShinVega]

Note: The turbopumps that delivered the kerosene and LOX were 75,000 horsepower....

[@beru58]

USS Nimitz at full throttle developes 260 000 horsepower. 5 F1 engines combined developed 15000 more horsepower. And that's just the turbopumps.

[@DarkSim77]

@@beru58 What if you strapped 5 F1 engines to the Nimitz..how fast could it go?

[@archstanton1628]

I so want to see that now, stick the Nimitz on hydrofoils and light those F1 engines 😁

[@ichich3978]

With the fuel, the turbopump runs, (some 400kg/min) the Concorde was at mach 2.2. The power of the Concorde just to pump fuel. :-)

[@rearspeaker6364]

@@DarkSim77 new york-Hudson to london-the Thames in 65 minutes--tsunami warnings everywhere!!

[@bobkurbel4306]

Very interesting explanation of ignition sequence start Scott, thanks for posting. I agree that an idea for a future video might be to explain POGO Suppression The F-1 engines performed flawlessly on all Apollo flights, but I wonder if they ever had problems during static tests ?

[@merlyworm]

iirc, there were several tests that had alot of problems with pogo oscillation on apollo 6. Look it up for more info. Just imagine how many people worked on these masterpieces. Hand crafted by experts with slide rulers.

[@joevignolor4u949]

They had lots and lots of problems during static tests. One issue was something caused combustion instability. This problem caused several test engines to blow up on the test stand. However, the extensive testing eventually led to an understanding and fix for the combustion instability problem, which is why no F-1 engine ever went unstable or otherwise failed during flight.

[@bobkurbel4306]

Merlyworm Thanks for the reply. I remember taking my college physics exams using a slide rule. They are quite accurate if you take your time. There is a video out regarding the 1201 alarm and the onboard “computer “ they used, truly amazing that they were successful on the first try with landing.

[@bobkurbel4306]

Joe Vignolo Thanks

[@nerdzy8454]

Fascinating! I love to learn about all of these fine details. Next you gotta explain the second stage ignition.

[@TheLandormaxim]

Very well explained Scott. Being an Engineer myself I thought that your explanation had all the necessary components but delivered so that non Engineers could understand.

[@AmusedWalrus]

Petition to bring back the X-Wing intro back!

[@alextrilby4566]

You're the manliest Scott I know

[@odom2142]

Most of that went over my head, but I appreciated watching it. Thank you

[@mikldude9376]

Great explanation of the rocket workings , thank you .

[@tengoindiamike]

7,000,000 + POUNDS of thrust - how insanely awesome is that?!?

[@SimonBuchanNz]

Well... 7 million Newtons, which is about 1.5 million pounds. Still a delightfuly ludicrous amount though.

[@SvenSchumacher]

In Fakt 7000kN (one F1-engine) are 1,573,662 lbf ... And there are 5 engines with that 7000kN. So that are 7.9 million lbf together. That's insane!

[@SimonBuchanNz]

@@SvenSchumacher my mistake! Correction welcome!

[@Anvilshock]

@@SvenSchumacher 35 MN are a lot less insane than 7.9 million idiot units.

[@SvenSchumacher]

lol, good point ;)

[@eugenecbell]

Great video, now do the POGO Suppression system. By the way what is the POGO Suppression system?

[@charlesboyer61]

Pogo is oscillation the booster system that is essentially a feedback loop. It is up and down vibration (like a pogo stick) in liquid-propellant rocket engines caused by combustion instability. There were severe problems with this in the AS-502 / Apollo 6 test flight -- the launch that very nearly failed. NASA and its contractors worked to correct these problems, but did not conduct another test flight -- the next launch of the Saturn V was Apollo 8.

[@salamanca1954]

@@charlesboyer61 I was going to explain that, but you nailed it.

[@SquillyMon]

Excellent video and explanation... I have wondered about these exact details for years, nice to have it all in one place now.

[@flwi]

Great video that explained this complex process in a way that easy to understand! Thanks a lot! Fly safe!