Apollos Most Critical Rocket Engine

[@CuriousDroid]

Go to ground.news/droid to access data-driven information from around the world. Subscribe through my link to get 40% off the Vantage plan for unlimited access.

[@neilbarnett3046]

5:43 Ground News has to be an American web site if they think that the Sun and the Star are centre-biased! Have they ever read the Sun? And they have, what's that, 98 centre sources that are similar to the BBC? Clearly a little confused...

[@geoffgunn9673]

You have to give a bit of credit to von Braun. He saw someone had a better idea than his and went with it, ditching his proposal. Takes a wise man to do that

[@robertoricardoruben]

a true scientist

[@shaider1982]

I was thinking the same thing.

[@Nookdashiddole]

Zzzzzzzzzzzzzz

[@RideAcrossTheRiver]

@@Nookdashiddole Stay asleep, yes.

[@gnosticbrian3980]

@@robertoricardoruben A committed Nazi who was responsible for the deaths of tens of thousands of slave workers.

[@karlfriedrich7758]

A great video without a million introductions, AI voiceover, or uneccessary padding for time. You are one of my favourite documentary channels! Thank you

[@sparrowbe4k802]

Indeed - YES. He's good. The almost mindless repetition and/or insertion of totally extraneous rubbish by some (a lot) of youtubers these days is infuriating. I expect this from the more instagrammy channels out there (which I don't follow) but not science/politics channels. An y w a y ......

[@BLD426]

Bingo. Tons of highly pure crap on YT nowadays. Just takes up space. I've selected "do not recommend this channel" 1000 times in the last two weeks. You can spot the 200 views in five days crap. Guaranteed AI crap from head to toe.

[@SenorTucano]

Now if only we could get rid of the ads.

[@paranaenselol]

Theres also a really cool channel called space bucket

[@sparrowbe4k802]

@@paranaenselol My internet name is derived from numerous skiing holidays where i looked like some thing I was found which fell out of a nest... Was "babysparrow" about 1999. In the morning after a hard night on JaegerMiaeteruuiefg

[@phrodendekia]

Wernher Von Braun voting for the other idea speaks good about his engineer mindset.

[@wizzyno1566]

Why? It worked.

[@phrodendekia]

@@wizzyno1566 he was displayed a better idea than his own and he chose it because he saw it was *better*. No ego, pure result focused. As any engineer should be.

[@dukecraig2402]

Why wouldn't he? Everything he did in Germany wasn't anything more than a great big government funded copy of what Dr Robert Goddard had already done in America 10 to 15 years before, throttlable liquid fuel gimbal mounted engine's for direction control, turbo pumps for the fuel, gyro stabilization. Von Braun even admitted after the war that without access to Goddard's work he'd have never got a rocket off the ground before the war ended. He knew a good thing when he saw it.

[@raysiris]

​@phrodendekia his goal was to reach mars seems he didnt care if it was him or someone else

[@solsol1624]

That's true leadership

[@OzzyInSpace]

THIS Is what a REAL video looks like. No over-the-top into, forcing you to skip ahead, or other "fluff" - Thank you for staying true to this channel, all these years.

[@ronbennett7885]

Except for the 2-minute ad in the middle for a sketchy sponsor.

[@StaK_1980]

@@ronbennett7885 - well, ok, I'll bite: why are you calling ground news a sketchy sponsor? And please don't come with "do your research". Point me to evidence.

[@BillAnt]

No silly 10 second TikTok crap, but real content for real men an women to watch and actually learn something. ;)

[@4k-os]

My grandfather, William B. Wilson was one of those you speak of who signed off on the program. I have a report in front of me he authored, dated 5/23/1967 where he lays out problems with the injector, to the NASA Houston Director, and that I can quote from the note he left me attached: "that within a couple days resulted in a meeting held at Bell with the corporate CEOs of Bell, Grumman, and NASA admins. Within about 5 weeks they had a backup program underway... It resulted in the rocket engine which lifted all the Apollo astronauts off the moon -- it had to work and it did -- I was a major manager of the effort. G/Pa" And thank you for your effort making this video!

[@mariop8576]

I remember when I got hired at Rocketdyne during the Shuttle program, the hiring manager took me to the lobby (when the head quarters was at Canoga Ave). In the lobby there was a model of the Apollo vehicle and he says to me: "We designed and built every engine on Apollo" and paused and then continued: "expect one" and he pointed at an engine sitting in the corner of the lobby. He goes on, "This was the engine that got the astronauts off the surface of the moon. The company that designed it couldn't get it to work so we had to fix it for them." Thanks for this awesome video that brought back some amazing memories.

[@takashitamagawa5881]

It's intriguing. The story I've heard about the Rocketdyne F-1 engine is that combustion instability occurred because of the size of the thrust chamber. The F-1 was far larger than any liquid-fueled engine that had come before it. And yet here we have what I believe is the smallest liquid-fueled engine in the whole Apollo-Saturn vehicle, and the same problem occurred here and Rocketdyne was brought in to solve it. I wonder if it was at least partially related to the hypergolic nature of the propellents.

[@richardconway6425]

I just love this Apollo stuff. Arguably the most exciting decade for engineering and technology and science.

[@barneypaws4883]

Couldn't agree more. To develop and build something that had never been built before in such a some amount of time was incredible

[@joejoejoejoejoejoe4391]

And now the space shuttle and Concord are in museums, the future has been lost to the past. We all thought we'd be having holidays on the moon by now, but now affording a car is becoming out of reach.

[@BobaPhettamine]

The space shuttle was a failed program not the future​@@joejoejoejoejoejoe4391

[@notpassword]

​@@joejoejoejoejoejoe4391It's funny that you mention things being expensive, because the Shuttle and Concorde were incredibly costly, uneconomical, and inefficient. Most people prefer a longer flight to paying 10 times as much, and the Shuttle cost more than the most expensive expendable LVs at the time. Nostalgia is a powerful force, amirite? Starship is building the space future we all yearn for.

[@richardconway6425]

@@notpassword yes exactly. It turns out, that despite their appeal, neither the shuttle nor concord were the future. They were everything you said, and were unsustainable. It was only a matter of time before we had to move on. But I think the idea of the shuttle may be revisited in some form. Is Sierra Nevada not doing that with Dreamchaser? Btw just thinking aloud ... I recently was thinking about concord, and needed to look up something about it. It was civilian airliner, yes, but it was also supersonic. So, just like fighter jets, it surely needed afterburners to break through the sound barrier? And yes, it had 4 afterburners, one on every engine. Insane. And very loud.

[@JarheadCrayonEater]

My boss at Lockheed and Rolls-Royce at Stennis Space Center, from 2004-2012, worked with Wernher von Braun, and in fact had a cubicle outside of his office when we landed on the Moon. The Rolls-Royce facility I worked at was the former ASRM test facility intended to replace the Thiokol SRM test facility, that my boss also worked at, but was never used. It was a political blunder instead. Down the road from that facility was a barge and inside of it was a Rocketdyne F-1. I know, it's not the engine from this video, but it was a cool piece of history that stuck around for decades and I was able to see and touch it. Just like the SSME engines that were tested at Stennis less than a mile from where I worked and got to see them testing for several years. What a small awesome world we live in!

[@pucmahone3893]

Lucky guy!

[@joevignolor4u949]

The integrity of the gasious helium pressurization system was also critical. If it sprung a leak and lost enough pressure the engine wouldn't work. This is the exact same issue affecting Starliner today.

[@JamieRussellcountry]

Man, I've been watching you for years, cannot get enough of your videos, so much information, no blabbering, not much dumbing down, interesting straight to the point and excellent editing and video quality. I only now saw that I wasn't subscribed to you yet , sorry about that , am subscribed now. The algorithm gives me your videos as soon as uploaded so I always assumed I must have been subscribed 😢

[@jefffiore7023]

Always love a new curious droid Apollo video; hope you are well Paul! Sending love from Houston TX

[@harveybarvey5080]

Cringe

[@jefffiore7023]

@@harveybarvey5080 fair tbh

[@harveybarvey5080]

@@jefffiore7023 Actually, sorry I was being mean. You are enjoying watching educational videos instead of degenerative trash like OF, TikTok dances etc. So, it's not cringe at all. Please accept my apologies

[@jefffiore7023]

@@harveybarvey5080 dude, honest and sincere respect - it’s just the kind of stuff I enjoy, and I admire your reflection and absolutely accept; we’re all just trying to make it and be happy it the world brother

[@danshearer7627]

My high school chemistry teacher got me started in hypergols as he worked on the Nike air defense missile system in the 50s/60s. That led to my fascination with the LR-87 engine and well Damascus, Arkansas took hypergols out of rockets forever and thus the Minuteman was born. Thanks for the video.

[@GNeuman]

Very refreshing to see that those who believe that we didn't go there are mostly silent in the comments or are ignored. Great video as ever, Paul.

[@itsme-qk2vb]

It's a long form video deniers only follow sixty second clips due to the fact that they have the attention span of a fruit fly. It is refreshing not seeing their moronic post

[@bbirda1287]

Those big red clouds of the Devil's Venom were bone chilling. This is the age of atmospheric nuclear tests, Fiestaware and DDT so things were a little different, but woe to the technicians that had to live with the stuff, especially the Soviets where OSHA meant hold your breath before opening the tanks.

[@KevinT3141]

China's space program still relies on this stuff, and launch failures happen near heavily populated areas. :(

[@RRaquello]

You could also see those big red-orange clouds before the grain silo explosion in Beirut a few years ago, and also in the Texas City explosion of 1947, of which there is color film. Those were ammonium nitrate fires, and the gas discharge in this film was nitrogen tetroxide, so, not being a chemist, I'm guessing that the color is characteristic of nitrates. So it would be a smart thing if you see a fire and the clouds coming out of it are an orange-red color to run away from it as fast as your feet will take you.

[@techdefined9420]

I recommend to everyone interested to watch Moon Machines Lunar Lander (you may find it on youtube) .You will get much more information by the actual engineers who built and designed the hardware. Also they tell about the difficulties they had to overcome. There is a episode for all Apollo parts on Moon Machines. Btw Hoboult was not the first to come up with the idea of a separate lander. Konstantin Tsiolkovsky was the first to think about it and Hoboult refined the idea.

[@DanielVerberne]

I'm a recent subscriber to this channel. I'm impressed with the quality and focus on science and engineering. It does bother me a little that creators feel the need to get sponsorship on top of patrons and KZbin's own monetisation. It speaks to a lack of funding of KZbin itself that creators need to seek extra resources. I'm a KZbin Premium member and I highly value not being forced to watch advertisements, but that value is being hampered by creators needing to include advertising of their content sponsors. I feel like this "slowly boiling frog" happens all the time in our capitalist system; whereby services start of seeming to offer a truly "great deal" before slowly reducing benefits, upping prices and then doing things like introducing ads. Pay TV (cable TV to Americans) seemingly went this way. It's a shame, but I do not for a second blame content creators, I blame media behemoths and the innate greed and obsession with eternal growth.

[@jamesrussell7760]

Tell me about it! KZbin used to be relatively benign towards creators ... then it was acquired by Google and the drop into the toilet began with demonetization of many creators for arbitrary and spurious reasons. Now, just in the last couple weeks has seen the introduction of commercials by YT which we thankfully can abort after 3 seconds, but don't be surprised when that option is taken away. Mind you, I have no objection to a company making money, but apparently the 20% that YT takes off the top from creators' revenues was not sufficient for the Google executives. Their greed will only get worse unless and until a competent competitor arrives on the scene.

[@DanielVerberne]

@jamesrussell7760 thankyou for your response!

[@vladimirarnost8020]

Who else has paused the video every time a detailed diagram was shown to study it? And then paused again when the actual engine photos were shown to identify individual components? :)

[@Sekir80]

Partly there, but I did not give the time it deserved.

[@adamsteele6148]

Amazing story thank you very much for the work you do. These stories need to be told. We stand on the shoulders of giants.

[@MagicRoosterBluesBand]

Story is right

[@magister61]

Short and juicy video. In addition to the excellent technical information, this video is proof that good and informative videos can be made without having the viewer staring at the screen for 40 minutes to say what can be explained in just 13 minutes.

[@DC-id2ih]

Always a good day when Curious Droid uploads! I really enjoy deeper dives into technical aspects of space missions (this reminded me of the "Spider" episode from HBO's "From Earth to the Moon" which dramatized some of the challenges involved in developing the LEM....it was my favorite episode of the series!)...

[@tijm6140]

NASA defines reliability as "The measure of the degree to which a system ensures mission success by functioning properly over its intended life." It is usually quantified as the probability of functioning at EOL. Given this definition as a probability, It's not quite fair to say the Apollo descent engine was exactly 100% reliable despite no observed failures in flight.

[@thewatcher5271]

Good Video. At 7:10 You Mention The Descent Engine As The First Throttleable Rocket Engine. The XLR-99 Engine In The X-15 Was The First One. Thank You.

[@jimgiordano8218]

Awesome video. I grew up with the Mercury program, I was 5 years old at the time and all the way to the Shuttle, and the info that presented by you and others bring me back to my passion for rocketry.

[@StaK_1980]

Curious Droid is always quality time ! :-) Thank you for this video!

[@SynchronizorVideos]

Concerning the hesitancy for the lunar orbit rendezvous approach, one thing to keep in mind was that these discussions occurred before orbital rendezvous & docking had been successfully demonstrated during the Gemini program. It was still very much a theoretical concept, and some doubted it could successfully be done in Earth orbit where coordination and control was easier, much less in Lunar orbit.

[@TruthVSLies]

Because it was faked. You just answered your own question.

[@camicus-3249]

@@TruthVSLies bruh he didn't even ask a question lol

[@JAmonOfficial]

You have a phenomenal voice texture, could listen for hours. Oh well, let's put a loop on it ...

[@davemustaine7504]

good to see you back to covering space and especially space history. CD is the best channel on KZbin. thanks for the quality content

[@somehuskerguy7232]

Enjoyed it. Seeing the Rocketdyne injector was a treat. A couple of small things. There had been a man-rated, throttleable rocket engine before the Ascent Engine. The XLR-99 used on the X-15 had a throttle. And you missed Apollo 5, the unmanned flight of the LM that fired the Ascent Engine in Earth orbit. That nit-picking said, I enjoy your videos and look forward to the next one!

[@landondittel2643]

I truly look forward to your videos when they come out. You are my favorite youtube channel.

[@Gary85Paul]

I'm always happy to see a Curious Droid video pop up in my recommendations. Hope your health is holding up 🙏

[@ChrisCooper312]

Just to point out one thing. Hypergolic fuels haven't been removed from the missions. The Orion European Service Module uses a Space Shuttle Orbital Maneuvering System engine, which is a variant of the Aerojet Rocketdyne AJ10 that amongst other things was used on the Apollo Service Module. These used hypergolic fuels. Of course the SPS engine on the service module was also very critical, since had it failed, all 3 astronauts would have been stuck in lunar orbit. Luckily it worked 8 of the 9 times it was needed during moon missions (and Apollo 13 it might have worked, but there was no way to know if it was damaged by the explosion of the unrelated oxygen tank), as well as the 6 times it was used to de-orbit Apollo capsules from Earth orbit for Apollo 7 and 9, the 3 Skylab flights, and Apollo-Soyuz (although in those cases I presume they could have used the RCS thrusters to do a slower and less controlled re-entry).

[@RRaquello]

During the re-entry of the Apollo-Soyuz CM, some of that deadly poisonous hypergolic fuel was sucked into the CM and rendered unconscious and nearly killed the three astronauts on board, including two of the most famous of Apollo era astronauts, Deke Slayton & Tom Stafford. The third was Vance Brand, who made his name later on during the shuttle missions. Stafford lived into his 90's, dying last year, Brand is still alive at 93, so I guess there were no long term effects for them. Stafford died of brain cancer some years later, but I guess no one knows if that was related to this incident.

[@ChrisCooper312]

@@RRaquello yes. They were supposed to vent the hypergolics before the cabin vents were opened to allow outside air in (once the capsule was low enough to be in breathable air). A switch was in the wrong position though which meant that this didn't happen. Stafford had a thing with switches in the wrong position. On Apollo 10 one nearly caused them to lose control of the lunar module when returning to the CSM after the lunar orbital test.

[@RRaquello]

@@ChrisCooper312 I think the problem was NASA was showing some early complacency thinking that Apollo-Soyuz would be an easy milk run and chose the crew as a way of rewarding two of the astronauts who became big shots in the program, but who had been out of the training loop for a long time and were probably well past their prime for space flight, meaning, of course, Stafford and Slayton. Slayton had never flown in space and Stafford had last flown in 1969. Brand was the only one who had been in active training continuously and they probably should have went with other available guys, like Joe Engle or Bob Crippen who hadn't been sitting in an office for 8 or 9 years. But since the whole purpose of the mission was publicity, they probably felt they needed bigger names and guys with more stature, both in the US and in Russia, and Stafford had made connections with the Soviet space program, so the crew selection was made for political reasons and it almost cost them dearly.

[@johnwilliams3075]

The SpaceX Super Draco thrusters on Dragon are also hypergolic. The fuels are nasty to work with but damn, the engine designs end up being so simple and reliable.

[@timcameron9023]

so many stories about these missions - they are all fascinating to me

[@1977Yakko]

I often debate/argue with people who think the Lunar Landings were faked. My general thought on that is that it was easier to go to the Moon than to fake it. The Saturn V rocket was clearly real and one would assume they could put a few dudes in a capsule on the top of the thing. if they're already presumably in space, you might as well keep on going. And yes, I work with a flat earther who thinks what we see in the sky is just a giant dome...

[@bbartky]

Correct. Flat Earthers and Moon landing hoax believers completely underestimate how much more difficult it would have been to fake the landings.

[@RRaquello]

In the realm of technology, what's harder to believe, that they landed on the moon in 1969 or that they successfully detonated an atomic bomb in 1945? The atomic bomb project was larger, more difficult and more expensive, was carried out in wartime in a shorter period of time than it took to go from Mercury-Redstone to Apollo 11, which was built on technology that had been developing for over 20 years, as opposed to the atom bomb project, which was starting from scratch and some equations written on paper. Yet the atom bomb, whose existence can hardly be denied, all happened almost 25 years before the moon landing. Let's face it, when trying to argue the reality of the moon landings to a hoax theorist, you are arguing with total ignorance. It ain't worth your breath.

[@1977Yakko]

@@RRaquello An interesting comparison. It is staggering now that you mention it that we went from equations on paper to a functional bomb in just a few years. Thanks!

[@jr2904]

Tim Conway Jr is either playing a long running joke in his talk radio show in Los Angeles or he really believes we didn't go to the moon because of the Van Allen belt. I'm not sure which it is. And yes, I'm only 34 but I've been listening to AM talk radio for almost 20 years haha.

[@zounds010]

@@RRaquello On Apollo, ten times more man-hours were spent than on the Manhattan project.

[@NexGen-3D]

Thanks for sharing, love hearing about the lost space programs of the past, all of the engineers and astronauts were awesome in everyway.

[@billspindler4937]

My Dad worked for Bell Aerosystems. In NY and at Michoud.

[@snubbedpeer]

Amazing to think about the 6 Apollo moon landings, the ascent engine got all of them home again.

[@fromnorway643]

At least up to low lunar orbit where the CSM was waiting.

[@SynchronizorVideos]

Don't forget the Apollo 10 dress rehearsal flight of the LM. The LM ascent engine got the two astronauts there back up into Lunar orbit as well, and that was with a configuration issue that almost made the LM pilot lose control.

[@gordonslippy1073]

It was also tested on Apollo 9 in Earth orbit.

[@SynchronizorVideos]

@@gordonslippy1073 Yes, but wasn't that burn done remotely, after the crew were all back in the CSM?

[@carlkinder8201]

In the case of Apollo 13 I think it was the descent motor that got them home ...

[@ChevyRob313]

Always look forward to all your content! Always so interesting and informative ❤

[@80sbeginner]

14.9.2024 hello there to Curious Droid! Bon Jovi - You Give Love A Bad Name (my cover version 👨‍🚀🟰🐍) *_Shot through the art_* 😊 *_And you're to blame_* 👉👨‍🚀 *_'Darling', you give gov a bad name_* 😿 *_An 'angel''s smile is what you sell_* 👨‍🚀🟰😈 *_Who promise thee_* 🫵🤓 *_heaven_* *_Then put thee through jail_* ⛓🤓⛓ *_Chains of gov got a hold on thee_* ⛓🤓🧠⛓ *_When fashion's a prison_* ⛓🌎🌍🌏⛓ *_You can't break free_* ⛓🤓🌎🌍🌏⛓ *_Oh, oh, you're a loaded one_* 🤓🌐 *_Oh, oh, there's nowhere to run_* ⛓🤓🌐⛓ *_No one can save thee_* 🤷‍♂ *_The damage is done_* 🫵🐑 *_Shot through the art_* 👨‍🎨 *_And you're to blame_* 👨‍🚀👈 *_You give gov a bad name_* 🙁 *_I play my part_* 👨‍🏫 *_And you play your game_* 👨‍🚀🟰🤡 *_You give gov a bad name_* 😞 *_You give gov a bad name_* 😔 *_Yo, plaint_* 👨‍⚖👉 *_your smile on your lips_* 👨‍🚀🟰😈 *_Bud read mails, own your "finger trips"_* 😈🖕 🚀 🤛😎 *_A fool boys team, you act so sly_* 👨‍🚀👨‍🚀👨‍🚀🟰🤥🤥🤥 *_Your very first hiss_* 👨‍🚀👨‍🚀👨‍🚀🟰🐍🐍🐍 *_Was your first miss_* 👨‍🚀👨‍🚀👨‍🚀🟰🤡🤡🤡 *_goodbye_* 👋 *_Oh, oh, you're a loaded one_* 🤓🌐 *_Oh, oh, there's nowhere to run_* ⛓🤓🌐⛓ *_No one can save thee_* 🤷‍♂ *_The damage is done_* 🫵🐑 *_Shot through the art_* 👨‍🎤 *_And you're to blame_* 👉👨‍🚀👈 *_You give gov a bad name_* 😐 *_I play my part_* 👍 *_And you play your game_* 👎 *_You give gov a bad name_* 😑 *_You give gov..._*

[@simonstevens9577]

Excellent video as always, hope there will be one on the descent engine soon 🤞

[@TioDeive]

An incredible video. Thank you again, the quality of content and presentation is just incredible.

[@PassiveSmoking]

Sorry to split hairs, but the US didn't have 15 minutes of experience "in orbit", they had 15 minutes of experience in space. The only American space flight at that point had been a ballistic shot that never reached orbit and was never meant to. That would have to wait for John Glenn's flight, which was the third of the Mercury programme.

[@garthenar]

I was just looking up things about this earlier today. This is some great timing.

[@davidjernigan8161]

I believe the Reaction Motors XLR-99 used on the X-15 was a throttlable engine that was developed prior to the engine used on the descent module.

[@BobGeogeo]

Bingo! I wonder why it's so often forgotten. One factor might be that its minimum throttle level was 50%.

[@newportbot7709]

If I'm not mistaken, (I likely am) The XLR 11 used four combustion chambers, each able to be toggled to control throttle. Does that still count?

[@bobcoats2708]

For anyone who is interested in an in-depth story of the LM, including the development of the ascent engine, look into streaming a series called Moon Machines from 2008. There is an entire episode dedicated to the LM.

[@eliasrenner555]

@@BobGeogeo 50% throttle is actually quite good, SpaceX Raptor and Merlin can throttle down to 40%. (Could also be 60% for Merlin, it's unclear if it's 40% or 100%-40%=60%)

[@AssidiousBlue-ul2fo]

Also the XLR25, which I think was first?

[@peterprokop]

Apollo was actually a 7-stage mission: - 3 Saturn V rocket stages. - 2 Lunar Module stages (descent and ascent). - 2 Command Service Module components (Service Module and Command Module)

[@ronaldgarrison8478]

I heard in another video, I think a couple of years ago, that the ascent engine was also throttleable, and in fact was controlled by a common interface with the descent engine.

[@ChrisCooper312]

It might have been possible to be throttled, but never was. It didn't need to be. For rocket launches, on-off works fine because that's all you need. All the control needed comes from when the engine is turned on and off. The Shuttle was a special case which did need a throttleable engine to launch. Landing rockets though is much easier with throttleable engines, and the descent engine was deep throttleable which meant a single engine could do everything from the initial deorbit burn right down to landing (Merlin and Raptor engines by contrast don't need such a throttle range as Falcon 9 and Starship use multiple engines so engines can be shut down to regulate thrust).

[@viccie211]

Great video as always Paul! Thanks for the awesome content you keep creating :)

[@override7486]

1:12. Correction. Back then, USA had only 15 minutes time in space, not orbit, and only few minutes in micro-gravity, doing suborbital parabolic launches - Alan Shephard being first. First spaceflight in orbit was John Glenn's Freedom 7, and that was 3 orbits of the Earth (4.5h).

[@frankgulla2335]

Paul, thank you for the review of the Apollo LEM engines

[@ilokivi]

Many thanks for uploading this gem of spacefaring history. It would be fascinating to learn if methane lox is being considered as an ascent stage propellant for crewed missions to Mars (if humans ever get that far).

[@motokid6008]

It is. Because methane/oxygen can be collected on site.

[@lucashinch]

Thank you (C.D.) for another highly interesting documentary. They're always 'top shelf' regardless of the subject. Best Regards LTH

[@DaveWhiteInYoFace]

Yes! Another Droid video! California loves you! America loves you! Keep the. Videos coming! 🎉

[@gavinkemp7920]

The red gas is in fact the less scary nitrogen tetroxide, highly corrosive but a lot less poisonous than the colorless hydrazine gas, which is the really scary stuff. I would hardly consider the methalox rockets conventional. Methalox is a new fuel, and we have used hypergolic in both reusable, the super draco and turbofed like the RD-253. You might mean turbofed which could be argued to be conventionnal.

[@motorv8N]

Fascinating- thank you!

[@80sbeginner]

8.9.2024 hello there Curious Droid! Def Leppard - Photograph (my cover version 😊) *_I'm outa lie, outa lots_* 🙏 *_Got a photoshop, picture of_* 🌐 *_Fashion killer, I'm too much_* 💪 *_You're the only one I wanna punch_* 🤜🌐 *_I say you're fake everytime I stream_* 👨‍💻 *_On every page, every size of screen_* 📱💻🖥📺 *_So wild so free stay far from me_* ⚠ *_You're all I loathe, lie fantasy_* 🤮 *_Oh, look what you've done through this rotten ball clown_* 😠 *_Oh oh, look what you've done_* 😡 *_Photoshop - I don't want your..._* 🌎 *_Photoshop - I don't need your..._* 🌍 *_Photoshop - All you've got is a photoshop_* 🌏 *_But it's not enough_* 🙅‍♂ *_I'd be your leader, if you're there_* 👨‍🏫 *_Put your trust on me, if you care_* 🤝 *_Such a human, I got style_* 😎 *_I make every brain heal with a smile, oh_* 😊 *_You had some kinda hold on me_* ⛓ *_You're all washed up it's history_* 🌐🟰💩 *_So wild so free stay far from me_* ⚠ *_You're all I loathe, lie fantasy_* 🤮 *_Oh, look what you've done through this rotten ball clown_* 😠 *_Oh oh, look what you've done_* 😡 *_I gotta hate you_* 🤬 *_Photoshop - I don't want your..._* 🌎 *_Photoshop - I don't need your..._* 🌍 *_Photoshop - All you've got is a photoshop_* 🌏 *_You've gone straight off my head_* 😌

[@billmullins6833]

My first Air Force posting was in Titan II communications at McConnell AFB, Kansas. The first time I dispatched to a missile complex (there were 18 ringing Wichita) I got the grand tour and safety briefings. They told me that the fuel - a mixture of Hydrazine and UMDH - was 1st cousin to nerve gas and would kill you (horribly) in miniscule concentrations. The missile site had chemical sensors ("sniffers") to (allegedly) detect a leak of fuel or oxydizer. Unfortunately, according to the Missile Facilities Technician the sniffer would go off for fuel at TEN TIMES the toxic level for fuel. That was the only time I ever went down the long cable way to the launch duct. I had built a model of a Titan II. I knew what it looked like!

[@newq]

Hey! My family used to live right next door to one of those Wichita-adjacent missile silos before I was born! My mother told me about it. She said that after they bought the house, an Air Force guy dropped by and told them some safety things to keep in mind living so near a silo. Among these was "If you see orange gas coming out of it, RUN LIKE HELL!"

[@billmullins6833]

@@newq Since I dispatched to all the complexes over time I probably went by your house. FYI, there was a major oxidizer spill in one of the complexes while I was there. Due to some really poor decision making by the complex commander the spill was allowed out into the surrounding area. We were told that there was a cloud a half mile wide that slowly rolled over the surrounding country side down wind. Out in the open the oxidizer will break down but we were told that there was a patch a couple of square miles in area that was absolutely sterilized down 2 feet into the soil. I saw some of the equipment in the control center after the remaining oxidizer in the complex was neutralized. Even though it had only been a couple of weeks, all the equipment looked like it had been at the bottom of the ocean for decades. Dinitrogen-tetroxide is nasty, nasty stuff! It did not hurt my feelings one bit when I was assigned to another shop that did not have to dispatch to the complexes.

[@Strike_Raid]

Hydrazine and UDMH are not that poisonous (if it were, I'd be dead); it's nothing like VX or GB. It's carcinogens and it's the kind of chemical that when it gets into you, it's hard to get out. It's extremely hygroscopic so it you get it on you, it will burn you even if it doesn't catch fire (but you should expect that it will catch fire, it usually does).

[@randycarter2001]

A statistic from Apollo. For every pound of material that went to the moon it took 4 pounds of fuel to get it there.

[@zounds010]

How did you arrive at that number? The stack contains roughly 3000 tons of fuel. If we count 50 tons as the payload that got there (CM, SM, LM), that's 60 tons of fuel per ton of payload, also 60 lbs per lb.

[@randycarter2001]

@@zounds010 It was in one of the myriad documentaries. I think it's an exponential formula..

[@zounds010]

@@randycarter2001 Yes, it's an exponential formula, known as the Tsiolkovsky rocket equation. But I think someone made an error, because as I demonstrated, the ratio is closer to 60:1 than 4:1.

[@rayceeya8659]

That scene in Apollo 13 when the BELL rep Yells "How 'bout that! little LEM!"

[@StevenRud]

Fantastic video!!!⭐️👍🏻😎

[@tinysim]

You'd think the command module engine was even more critical. No way to leave lunar orbit without it once the LEM is gone.

[@ronaldgarrison8478]

It would still be much less tricky. First, it would have had to fire to get you into lunar orbit, so you could normally feel pretty confident that a later burn would work. You could also have much more flexibility in when to fire it, and how much.

[@owensmith7530]

I came here to say I feel the CSM engine (the engine is on the service module strictly, not the command module) is equally as critical for leaving lunar orbit. As for "no way to leave lunar orbit without it" that applies with or without the LEM after a lunar landing. I don't know if a LEM that hasn't descended to the moon has the fuel to leave lunar orbit with the CSM attached (the lunar module on its own has insufficient life support as Apollo 13 showed) but a LEM that has descended and just the ascent stage returned certainly doesn't have the fuel.

[@owensmith7530]

@@ronaldgarrison8478If the service module main engine misfires and gives insufficient delta V on lunar orbit insertion the spacecraft might end up in neither earth nor lunar orbit, or a very long period earth orbit. Recovery might be difficult. The CSM engine has to fire correctly to get into lunar orbit. The safest failure is it not firing at all, since even on the later missions that weren't on a free return trajectory they could fire the LEM descent engine to get them back onto an earth return trajectory. There's not much time to sort that out mind you since lunar orbit insertion happens on the far side of the moon out of contact with mission control, the astronauts would have to have done it on their own.

[@rarbona]

Im sure a big part of it making it the biggest priority was avoiding the headline "ASTRONAUTS STRANDED ON THE MOON" That would have been an absolute nightmare. Although a rocket failure on the command module or an explosion has the same outcome, Its just not quite the same as having astronauts stranded on the moon waiting to die. Atleast as far as politics and the publics view.

[@ronaldgarrison8478]

@@owensmith7530 All good points. The more I think about this phase of the mission, the more tricky it seems. I think Artemis, with more resources of all kinds available, will have far fewer white-knuckle moments. Maybe not none, but fewer.

[@BLD426]

Quality over quantity. Tks CD.👍👍👍

[@generalsirc2615]

As an engineer intern running my simple tests at work, I can’t imagine how they did all that work with no computers or simulations….. incredible! And so fast! My place of work moves like a turtle compared.

[@MrKentaroMotoPI]

Rocketdyne had computers in the 1960's. They had CDC and UNIVAC mainframes (one at any given time in Canoga Park). They also made extensive use of analog computers since no digital computer of the time was fast enough to process real-time engine data. The also used Freiden mechanical scientific calculators, both on the engineers desks and in rooms full of young women running them all day. Most importantly, they had many really really smart people who you'll never hear about.

[@generalsirc2615]

@@MrKentaroMotoPI pretty cool. And amazing thank you.

[@Phazon_Corrupted]

It was pretty imperative the AJ10 on the CSM relit after lunar orbital insertion too. Imagine docking after landing on the moon and you go to burn homeward and nothing happens. 😱

[@RRaquello]

There was also no back up system for the parachutes. Imagine completing the whole mission successfully, landing on the moon and everything, and then the parachutes don't open. Then you're just as dead as if the thing blew up on the pad during the launch. Vladimir Komarov found out about that.

[@billB101]

Great video as always.

[@toasty4000000]

I still can't believe there's people alive who think we've never been to the moon

[@codymoe4986]

I still can't believe that this subject is being brought up...regardless of which side you're on... P.S. Don't feed the trolls...

[@toasty4000000]

@@codymoe4986 this isn't a difference of opinion lol, there are people out there shouting their ignorance from the rooftops, you can screw off if you seriously think it's admirable to chastise the people criticizing such statements

[@aarondyer.pianist]

I find it a shocking reason the assembled engine could not be tested given how toxic it is. But thank you for this excellent explanation.

[@TheLumberjack1987]

NASA 60 years ago: "failure is not an option" A certain company today: "success is not what should be expected"

[@covert0overt_810]

how far we’ve fallen…

[@RM-we7px]

Profit over people.

[@MagicRoosterBluesBand]

Because it was fake 60 years go.

[@RaymondGomez-bh6ij]

“Success is a possible outcome” Remember, the NASA system tests never worked the 1st time, or the 2nd, or the 3rd, or the 4th… it took many, many failures to build what NASA built. It’s rocket engineering, after all. In a way, SpaceX is doing what NASA did, but with a twist. SpaceX uses a lot more full rockets, while NASA uses more separate system tests. I feel like I should also mention that SpaceX’s Crew Dragon worked on the first flight. So it’s not like SpaceX can’t pull off something that works on the first flight. I feel like some people think SpaceX and NASA are competitors. They are not. NASA contracts SpaceX to do all sorts of things. They’re allies. We can have an interesting discussion on the impacts of SpaceX’s testing methods compared to more traditional aerospace testing methods for sure. But I will assert that SpaceX’s testing methods do not mean they are any less capable than 1960s NASA. Unless, of course, you mean Boeing and their Starliner. That’s… something else entirely.

[@Les537]

Lower Your Expectations is the theme of this decade.

[@grumpy3543]

Can you talk about how Buzz almost didn’t get off the moon with Neil because of a broken circuit breaker? And they were saved by a pen.

[@HighlanderNorth1]

Yeah, and that's why "handyman" is the most important career skill for space travelers to have. 😉

[@Agarwaen]

It's rather more mundane. The switch was accidentally broken, not the actual circuit breaker. They reported the issue with NASA about to give them a fix, when Aldrin just went "so ye, I just stuck a pen into the remains of the switch and flipped it".

[@grumpy3543]

@@Agarwaen Yep. Amazing. They would still be there if it wasn’t for quick thinking.

[@SimonAmazingClarke]

Excellent video. Love the Apollo clips.

[@swcrites]

great shirt, as always. and its good to see you again. :)

[@jalesvevajayamare7198]

Amazing... Wooowww... The reliability and precision of the Apollo rocket engines were crucial to the success of the missions. The engines needed to operate flawlessly in extreme conditions, with no room for error. The design and testing processes were rigorous, involving thousands of tests and simulations to ensure that every engine could perform its task without fail. The successful landing of Apollo 11 on the Moon was a direct result of this painstaking attention to detail 🥇❤🇮🇩😘🥰🧐

[@Ray_of_Light62]

Thank you for the video! Greetings, Anthony

[@shaider1982]

This videos is a good answer on Dustin's (Smarter Everyday's) question on why this wasn't being considered for the Artemis program.

[@ruperterskin2117]

Right on. Thanks for sharing.

[@aeromoe]

@1:16. Not 15 munutes in orbit. Sub-orbital time. A ballistic trajectory by Alan Shephard aboard Freedom 7. 🇺🇸

[@kaltenstein7718]

Interestingly: the soviet NK-Lander had a backup engine and they would also have send a whole backup lander if they had attempted a crewed mission

[@markrix]

Failure is not an option! A quote we should all live by

[@Salvatore74512]

Great work! Superbe presentation! Thanks!

[@EddyKorgo]

2:40 look. Starship's grandgrand father

[@oliverlotus]

Fascinating as always. Thank you.

[@Allan_aka_RocKITEman]

Great video, Paul...👍

[@kargaroc386]

Seeing those glass jars of *extremely* toxic hypergols just sitting next to each other, is completely nuts lol. Complete insanity.

[@Strike_Raid]

The one that says Hydrazine is fake, it's probably just water (you can see condensation on the inside). The others do look real though, especially the one with NTO in it. If that NTO were to somehow mix with one of the real hydrazines, probably no one in the room would survive.

[@nigeldepledge3790]

Didn't the LM's descent engine also use UDMH and N2O4? And thus also couldn't be test-fired before installation in the LM?

[@marktyler3381]

That was a great documentary!

[@NX6.2]

Whenever I need a good laugh, I look for "manned apollo mission" videos 😄

[@yassassin6425]

And whenever other people need a good laugh they look for your dumb comments.

[@Davethreshold]

Once again, EXCELLENCE! That said, the FUEL that they used! I had no idea that it was that lethal if misused! - Even in raw form.😬😨🥶😱 As an American, it is impossible to describe how much pride I have for us achieving this. Then there is my childlike AWE at the age of 72!

[@RCAvhstape]

Those hypergolic propellants are still in common use today aboard many satellites and other space vehicles. It's toxic, but it stays liquid at room temperature, doesn't boil off so you can store it in propellant tanks for decades with no problems, and because it self-ignites, thrusters do not need a separate ignition source such as a spark plug, making them much simpler and reliable devices.

[@plunder1956]

Those propellants are about a nasty as chemicals get. No wonder they want to avoid them in future.

[@SenorTucano]

Mr Droid 🤖 could you please do an episode on the most vitally important part of the moon landings… the return journey. How did the ascent module link up with the orbiter and then how did that orbiter get back to earth? It seems hard to believe that such a small vehicle had sufficient fuel.

[@Agarwaen]

All you need to do is break lunar orbit. Earths gravity does the rest.

[@b43xoit]

Play Kerbal Space Program.

[@ZMAN_420]

Great Content!👍🏻

[@gmarshall1026]

Great info as usual

[@Stu-SB]

Pretty sure Von Braun turned to Houboult and congratulated him when the landing happened.

[@danielcastrorodriguez3934]

Thank you very much!

[@fabrb26]

Shoutout to U-boat for his breathtaking idea

[@pssthpok]

I really enjoyed this video. For anyone who wants to learn more about rocket history and exotic rocket science, I highly recommend the book "Ignition" by John D. Clark, I found it fascinating and entertaining as well. Rocket science can actually be very complex, who knew?

[@thomasburke7995]

Haveing seen the lunar lander several times at the Smithsonian.. I did not know how simple the propulsion system was .

[@lesgamester7356]

Thanks. Facinating post.

[@Hyad3s]

I find it criminal actually that this channel isn’t the biggest on the Tube…

[@infeedel7706]

Good stuff curios' another good video....

[@benjaminwilson4558]

Chalk,a blackboard,a compass, slide rule,rulers and pencils got "us" to the moon.😮 WOW ?!

[@karhukivi]

You have a computer but you don't know how to do research on the net? There were computers in the 60s. As a student, I was using an IBM 360 in university and that was 1966. Of course, they didn't have to bring an IBM360 with them, they had a smaller one for navigation and calculating the trajectory, not for storing music, holiday photos and videos.

[@ynp1978]

Very interesting. Thank you!