Why do cylindrical rockets roll?

Here’s a fun question that not only have I myself asked, but I get asked fairly often, why do we hear a call out like “roger roll” or “roll program complete” at which point we can see the rocket rotate or roll on its X axis…
The best example of this was the Space Shuttle which had a very obvious and dramatic roll program. As soon as it cleared the tower, you can see it making a very impressive and sometimes scary looking roll.
Now a maneuver like this makes sense when a vehicle is asymmetrical like the Space Shuttle, but why do cylindrical rockets like the Saturn V, Titan, Atlas, Delta IV etc etc even bother doing a roll?
Can’t rockets just tip over in whatever direction they need to go? Do a little pitch here, a little yaw there just as long as the pointy end is going the direction it’s intended to go, who cares which side of the rocket is facing the Earth and which side is facing space… right?
So today we’ll first define the pitch, yaw, roll and their corresponding axis on a rocket, then we’re going to dive into why a rocket rolls in the first place, take a look at launch azimuths and their relationships to trajectories and we’ll look at some unique solutions to orientations including some rockets that don’t roll on ascent to align with their trajectory.
Want an article version of this video? Here you go! - everydayastronaut.com/why-do-...
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[@albertbatfinder5240]

We live in a wonderful age. I am not talking about space exploration, but the fact that such a quality science video can be produced by enthusiastic individuals and published for free. 30 years ago it would have taken a full production team and the commitment of an entire broadcast network. Great stuff, sir. (And your helpers)

[@lifter1000]

Yep, today every semi-talented kid can lecture on rocket science

[@awuma]

@@lifter1000 Actually, they have to actually get it right! The fact that Elon and other to people have granted interviews to Tim shows that he is a respected journalist and commentator on space matters. This is a wonderful development, that journalists can win a following and even earn a living without being hired by someboy else and being beholden to an employer (though it's not an ideal situation when the platform owners can decide what videos are worthy of earning money).

[@mrbrianbrush]

@@lifter1000 you upset gil?

[@lifter1000]

Always

[@lifter1000]

The whole article you wrote is related somehow to the subject of this video?

[@BenSullinsOfficial]

I'm sticking with they roll for fun

[@hmm396]

No

[@prohz9129]

Edvin Tabakovic: no you can’t just do it for fun *haha roll go brrrrrr*

[@lucky5853]

Yeah, but first they rock and then they roll.

[@markushahn9123]

Because loopings are not so a good idea, exept the orbital ones.

[@hamburgerhamburger4064]

That must hurt

[@higgydufrane]

The man loves talking about rockets. It makes it so much easier to listen when the speaker is enthusiastic about the topic. Well Done.

[@ioresult]

KSP really comes to life when used as an educative tool. I love it.

[@cjax469]

2:52 engines are in the front, not the back. This bothers me lol.

[@alanmaclaren4118]

Hey give some credit to sfs

[@felsfat4734]

Alan MacLaren SFS is ridiculously unrealistic

[@alanmaclaren4118]

@felsfat because the developers are trying to make the game as simple as possible for players to understand it, plus the game has realistic orbital mechanics

[@beats007]

How to download ksp?

[@liesdamnlies3372]

I kinda love how KSP can be used as a tool to demonstrate so many of the basics of spaceflight.

[@theswagman1263]

So glad I took the time to get vaguely competent at ksp. Gives you a way better understanding of spaceflight. Furthest I've had a manned (kerballed?) landing is only Duna tho

[@martinincze1911]

@@theswagman1263 Build a refueling station on minmus mate. I launch all my craft to minmus where i have a permanent mining operation going with massive fuel tanks. I fuel up there and then on.

[@baflabies]

@@martinincze1911 Thx ama try that:)

[@SpecialEDy]

Yup, In Kerbal Space Program, I learned that separatrons and flea boosters arent enough to separate some larger asparagus boosters. You need to constantly roll to keep the next pair of separating boosters parallel with the horizon

[@SpecialEDy]

@Addison Brendtro the plumbing is very difficult. As far as I know, only the space shuttle and Buran Energia have a retractable fuel coupling like this to an external tank, but they detatch after Main Engine Cutoff

[@solomanwill1]

"Why do cylindrical rockets roll?" Because they rock!!!

[@eliethdiez964]

@Addison Brendtro falcon heavy uses asparagus staging

[@CarlosAM1]

@@eliethdiez964 it doesnt. It was going to but it was decided it would not

[@Thor_the_Doge]

Oh, so I'm not the only one who keeps my rockets stable in ksp by rolling?

[@Trev0r98]

"Why do cylindrical rockets roll?" *Because they rock!!!*

[@The74th]

It's backward innit

[@theEWDSDS]

Ha

[@BillPickle]

Man that 20 minutes flew by so fast, and was still incredibly informative and entertaining. Great video Tim!

[@FlyGuy2000]

Totally! I was like, "Well maybe I'll just watch a few minutes of this" and then it was over.

[@myrobotfish]

Most dads: "Okay are we ready to rock-and-roll?" Tim as a dad: "Okay are we ready to rocket-roll?"

[@panda3d180]

I saw this from the phinese and ferb show thing

[@edmund3504]

ready to rock pitch yaw and roll dad

[@hazgebu]

Are you ready for Rick & Roll? kzbin.info/www/bejne/mYSkoWypd9-DmMU

[@steve1978ger]

It's only rocket roll, but I like it.

[@myrobotfish]

@@steve1978ger Rock-and-roll. Rock-et-roll

[@nettlesoup]

I skipped watching this video the first time it came up in my recommendations because I guessed it wouldn't be that interesting. Boy, was I wrong! This was fascinating from start to finish, and I really enjoyed the way you put it all together and summarized at the end. 🙏🙏

[@dongurudebro4579]

Another great video. At first it seems like a no problem, but you really did a good job explaining why its necessary and how it works. Moreover i really have to thank you for your ever increasing quality standard; nowadays you live up to your name, cause it is literally out of this world! ;-)

[@arghya426]

Agreed😊

[@falafeldurum2095]

great video, but I disagree with Everyday Astronaut that it especially would make sense that asymmetrical rockets roll..

[@micahrandall1344]

he does good job every time

[@chemiegamerpeter1326]

Bist du nen bot oder was? Ich sehe dich echt überall

[@dongurudebro4579]

@@chemiegamerpeter1326 Ich bin Bot Don Versionsnummer 1.55.97.3 beep beep Ich bin gegen Artikel 11 & 13 beepi bup. ;-)

[@AmxCsifier]

First time I see a thumbnail arrow which is actually useful and not spammy

[@mr.boomguy]

And it's not even that eyecatching 😉

[@AmxCsifier]

@@mr.boomguy It doesn't have to be eye catching because I actively look for them in thumbnails 😅

[@ChaseOGLP]

First time writing in English too, I see

[@AmxCsifier]

@@ChaseOGLP English is neither my first nor my second language so my English may not be perfect but I'm always learning and I thank you for providing a correct example. 🤗

[@bfunkt4313]

@@ChaseOGLP You couldn't even take the time to write a complete sentence when complaining about someone else's English?

[@emkasCG]

As someone learning 3d animation, the term "gimbal lock" gives me shivers

[@IDoNotLikeHandlesOnYT]

How does gimbal lock apply in that context? It's been probably 15 years since I've done any 3D animation (just for fun), and I learned about gimbal lock only a few years ago.

[@emkasCG]

@@IDoNotLikeHandlesOnYT basically makes your joints really hard to control and sometimes causes weird movements between keyframes.

[@NHAFFFF]

@@emkasCG good luck with animation :)

[@abizair1832]

I hope there's no more gimbal lock on Artemis & Starship missions.

[@pilsnrimgaard2507]

Wow, the scary part is I actually comprehended almost half of what you just covered. So much to know. I will have to watch all of your videos now that I'm hooked. Great stuff to know! And always remember, Rockets don't fly, they roast the air into submission.

[@KonstaKokC]

In Soviet Яussia launch pad rolls you 🚀

[@kindlin]

This is great, had me lol'ing.

[@mattc.8839]

Nice 👍

[@Ivan_Chesnokov]

В точку!

[@calumaguer0]

Soviet Yahssia

[@NelsonBrown]

lofr - laughing on the floor rolling!

[@jacobsteinebronn2966]

IMU stands for Inertial Measurement Unit not Instrument unit Please upvote so he can see this

[@mattsi-eb4bo]

Hello fellow redditor

[@nicholasboccio]

came to comments to say this as well

[@bennylofgren3208]

@@nicholasboccio Me too.

[@joevignolor4u949]

Correct. The IU is the entire Instrumentation Unit. The Inertial Measurement Unit (IMU) is a major component of the IU that is located inside it.

[@jocax188723]

It's okay Tory Bruno beat us to it twitter.com/torybruno/status/1141298274491613184

[@PeterArnold1969]

Another amazing explanation of what can be a complicated subject. Always remember, going to space is HARD! Thanks for putting the time in to make this.

[@prjndigo]

You forgot centripetal distribution of fuel / slosh dampening.

[@integralmath]

Plus there's moisture in the air that gets it wet. 'Roll program' and 'rolling about its x-axis' is just a highfalutin way of talking about putting it on spin cycle.

[@kvltizt]

It helps prevent resonant waves forming in fuel, I suppose?

[@facuigua12]

The quality of this channel is simply breathtaking.

[@Davide_sd]

Another great video, thanks Everyday Astronaut. One thing I'm not entirely sure about is the 20% increase of payload capacity of the Space Shuttle (that would be insane!!!!). A few months back I followed the entire open course "Engineering the Space Shuttle" at EdX, and the question "why the SS perfomed the roll maneuver" came up a few times. The engineers doing the talks gave 2 reasons: 1. They were re-using old Apollo launch pad, therefore they were subjected to their limitation and needed to be able to place the vehicle at the right attitude (with the roll maneuver). 2. The aerodynamic engineers figured it out that there was less stress on the orbiter when it was sitting underneath the main tank during the max Q phase (maximum areodynamic pressure), this was because (as you mentioned) the thrust was directed throught the center of the mass of the entire system, therefore the orbiter was somewhat skewed with respect to the flight path. Funny story (I don't know if it's actually true, but it was stated on the aformentioned course): when Soviet launched their first and only Buran, they too did the roll maneuver. They didn't have to, because their launch pad was capable of giving the right attitude to the vehicles. So american engineers (after the collapse of the soviet union) asked russian engineers: why did you do that roll maneuver??? They replied: "Because you did it" :)

[@eigenvalue9358]

I'm no rocket engineer by any means, but the payload increase seems quite logical to me. As stated in the video the engines of the space shuttle had to gimble outward in order to compensate for the far stronger thrust of the booster. If now the space shuttle is aligned so the booster is "outside" of the flight curve and the shuttle "inside" of that curve there is less need for compensation. I can just guess that this way less gimble has to be used on the engines, which would sound more efficient to me. In case I'm wrong please someone smarter correct me.

[@kindlin]

There are a number of reasons that make having the the heavy, lopsided thing orient earthwards makes sense, not least of which what Eigen Value discussed. With less stress on the vehicle, the vehicle can now handle more weight within. With this being the case, the critical limit state must have been the structural integrity of the shuttle/booster at max-Q. I would have thought it would have to do with how much fuel you can fit into the tanks, but maybe the tanks aren't always full, and, actually, they only have as much as they need?

[@matejlieskovsky9625]

If the improved aerodynamic saved a few percent of fuel and the decreased engine gimbal saved a few percent of fuel and the reduced stress allowed for a little more fuel on board and a little lighter shuttle... Yeah, I can imagine that made a 20% payload difference. Don't forget, that would be a change of roughly 5 tonnes to LEO on a 2000 tonne system.

[@kpatelPub]

Tim mentions that the increase was from the shuttle being in the wake of the tank, presumably indicating aerodynamic benefits. I also wonder if it might have benefited from the fact that, with engines always gimbaled outward, situating the shuttle underneath automatically orients its engines' thrust vectors so as to have a stronger upward component to them throughout the fight path than they would in the opposite position. Apologies if this idea is foolishness. I, neither, am a rocket engineer. :D

[@matejlieskovsky9625]

@@kpatelPub Rockets don't care about upward thrust - most of their energy goes into moving sideways. You really just want forward thrust and the rocket mostly just pitches over to point where it needs to. The whole SSME gimbal vs SRB offset and gimbal thing is getting more complicated the longer I look at it. :-(

[@jacksagrafsky4936]

"Stick the pointy end" in the direction you want to go?? I have to go now this highly technical talk is way over my head.

[@a64738]

That actually work if you have enough fuel and power... I successfully managed to go to the moon in Kerbal Space Program using that method but it is ineffective.

[@small_SHOT]

in ksp my abominations usually commit explosion

[@fancy4663]

This conversation is too high iq for me

[@achtsekundenfurz7876]

[@theEWDSDS]

Ha ha very funny

[@ericcsuf]

This could have been a terminally boring video esp. for someone who never even considered why rockets roll. It wasn't...boring, that is. I didn't even realize I had just watched a 20 minute video until someone in the comments mentioned it. Very entertaining and informative. You're a talented teacher.

[@bluered3228]

Thanks. We all really appreciate the obvious time and effort you put into your videos.

[@zymosan99]

i cant tell if this is sarcastic or not

[@bluered3228]

@@zymosan99 it's not. Perhaps if it was about his live streams, we'd have something to be sarcastic about...

[@zymosan99]

@@bluered3228 ok

[@borgman151]

Wow Tim! Even an idiot like me can now understand azimuth, pitch, yaw and roll in rockets. You are brilliant sir.

[@thunderbird1921]

Remarkable so, why did the space shuttle not roll after a few moments? Did the wings stabilize the whole launch stack during flight?

[@yodaandthebike5839]

This was an awesome video. I watched someone else trying to explain roll a few days ago and came away with more questions than when I started. Brilliantly explained and the summary at the end was perfect.

[@marco_plebani]

I've developed a mild addiction to your videos recently. They make me marvel at the many unexpected challenges of space exploration and at the spectacular engineering ingenuity that overcome them.

[@jebediahkerman3826]

Other world: *turns a rocket to its flight asimuth* Soviets: *turn a launchpad to rocket's flight asimuth*

[@oremooremo5075]

Jedediah Kerman Other world pours millions of litres of water to reduce sound levels during launch. Soviets build a deeper trench

[@TarsoFranchis]

Another world: build rockets horizontally, like a production line, USA: They build the most difficult, vertically, needs a costly VAB and large tugs for the pad. xD

[@nikolatasev4948]

In Soviet Russia launchpad rotates you.

[@notmenotme614]

@@TarsoFranchis How fragile the payload is determines is it can be fitted horizontally or vertically. Because the payload is designed for less gravitational forces and can’t withstand the weight bearing on Earth in certain directions

[@obsidianop9802]

The soviets were pretty genius in terms of spaceflight Yes, more genius that the US

[@AthanImmortal]

Tim, I really appreciate that you asked a question on twitter that turned into a whole video. You're one of the best examples of not being afraid to ask what you don't know, especially with some of the idiotic replies you got. The video is fantastic, well produced, great narrated. Thanks again!

[@kenfreeman8888]

You helped clarify a lot for me. Thank you.

[@craigdeandean4036]

Great job Tim I really enjoy your episodes I grew up in the time of Apollo and ever since have been mesmerized by space! Thank you

[@rowde8203]

10:50 "It's nice to keep it simple" while literally talking about ROCKET SCIENCE

[@TheGreatDrAsian]

That's the best part! :D

[@TheBrandoGR]

It's actually exactly why they need to keep it simple. Any added complexity can increase the risk of failure by a substantial amount.

[@AdrianoCasemiro]

Simpler will do.

[@Sciguy95]

I have a shirt that says, Aerospace engineering: It's not rocket science, Oh wait, yes it is.

[@Theraot]

@@Sciguy95 So, you like to signal that you think engineering and science are the same thing

[@Gibson99]

Tim: Hey Elon, why was there a big roll in the launch from Vandenberg today? Elon: That's how I roll...

[@MrJaiimez]

Although like others have said, it's highly unlikely they didnt have a reason, but I would be crying with laughter if he did it just to mess with Tim, it would be beautiful. Let's face it his speed in responding to the raptor video I wouldn't be surprised if he was a patreon and was able to see bits of the video before release.

[@drpeejay54]

Robert Slackware That’s what I’ve been saying all along😏

[@zhongxina9420]

@Robert Slackware *insert angry essay here* Just kidding you don't desrve attention

[@rickskrovan2477]

I don't know how you don't have more subscribers on this channel. Your videos are always so informational! Soon as my kids are old enough to comprehend what you are talking about, they will be watching your channel. Keep up the awesome work!

[@dukecity7688]

Finding this at my late age is just thrilling. Let me be clear. I played this three times and i am years away from understanding but i don't care because i love watching and you are a great teacher - You are great and i feel lucky to have found your site. First go up really fast - then sideways really,really fast. Funny Thank You

[@nathanwahl9224]

You got it! Just add "And point it in the right direction, too." Methinks you understand a lot more than you let on to, and a LOT more than most folks in the general population do!!! I'm "at that age," do understand most of it; now, that is anyway. And have wondered about these whys for six decades! It IS rocket science: If you liked it, you're doing great! Cool!

[@windmillstudio]

Speaking of rocket azimuths... In 2017 Russian "Fregat" booster has failed to deliver some communication sats to the orbit. The launch was happening on the new "Vostochny" cosmodrome, which has a starting azimuth of 168°. Target azimuth for lower stage was 354°. So the lower stage has decided prior to launch: "I need to rotate from 168 to 354, the fastest way is to rotate left by 174 degrees". Target azimuth after separation for upper stage, however, was 344°. So the upper stage has decided before launch: "I'm gonna rotate right by 170 degrees, it's the fastest way". Then after launch when the first stage completed the roll succesfully to the left, the upper stage calculated correctly that it is only 10° to the right from it's target direction, but it already decided on the ground that the fastest way to roll is to roll right... So it started to roll full 350° to the right, but didn't make it before second stage ignition and has gone to the wrong unstable orbit, ditching to the Atlantic Ocean shortly after. The problem was in the code of booster's navigation system, but it always worked just fine before, because there was never such an unfortunate combination of azimuths.

[@chmeee9562]

thanks for sharing that!

[@janiss2926]

yikes! - that's an oopsie! :)

[@kvltizt]

That is a painful way to figure that out.

[@gramulho1]

Loved your channel buddy! When my son learns enough english, he will love it it. Mean while I translate everything to him! Cheers man! Keep up the science!

[@QRSTUVWXYZ123ify]

Hats off, wonderful presentation!!! Thx to anyone helping produce these and to your patrons.

[@MisterLiftoff]

This was exactly the question, what I wanted to be andwered since a very long time! Thank you very much for your great explanation!

[@oliverdots]

Not only is this well explained, it's answered a question I have asked myself for many years. Great Video

[@faceplants2]

Out of clever comments for the day but gotta show love and keep the engagement up for Tim's channel!

[@davidsymalla]

I was really impressed with your knowledge!. I am so happy I stumbled onto your page. I absolutely enjoyed this video. Thank you. You just filled my head with knowledge. I had no idea. I knew that rockets rolled and now, I know why.You don’t know what you don’t know.

[@Migs3]

Excellent video. Thanks for taking the time to film and edit it and of course for positing it for our benefit. Keep up the good work! -Migs

[@grovermatic]

Wow, you managed to keep my A.D.D. butt in the chair until 20:24. Well done! (This is legit a compliment, in case it sounds smartassy)

[@mas13ish1]

I have to agree the ADD is strong with me too, but I finished it.

[@jazz21977]

Oh hello! Me here?... *eh focus dude*... oh yeah.. I actually made it to the end too.. LOL

[@machy8515]

Michael Siemon same

[@shehulsuratwala2684]

This is what a quality video should look like. Amazing explanation and knowledge rich content. Seriously man, Hats off to your work. You have improved your videos quite a lot.

[@esecallum]

DONT YOU FIND IT BORING?

[@fruitella196]

Ese Callum no?

[@shehulsuratwala2684]

@@esecallum It is definitely more interesting than reading your useless comment and replying to it. From which angle you think it is boring? I am an engineer and I know how much time they have invested in development of these rockets and the math behind it. For me it is very interesting. You please enjoy your cats and dogs videos.

[@shehulsuratwala2684]

@@fruitella196 English please.

[@fruitella196]

Shehul Suratwala what are you on about? It was English

[@aoiattentiononinvention8031]

First time watching your videos! Don't think I've ever subscribed to a channel without watching more than one video, but I did here. It's obvious you put a lot of effort in your research. Love it!! While rocket science is fascinating I just never put much energy towards it because of the other things I am interested. I'm making "space" in my free time for this channel. Thank you, for the spark of Interest. 👍👍👌

[@reda.woodcock]

Amazing video, man. So much info and so clear (nice gfx, they really help) and answered a head-scratcher for me. Thanks!

[@mikekocziban]

I love rocket-roll, so put another dime in the soyuz baby!

[@djdm2603]

When you forgot to add sepatrons to your SRBs and dont wanna blow up when staging.

[@MrFlarespeed]

When u added sepatrons but they don't work well enough to not boom your kerbals

[@valorkaizen]

@@MrFlarespeed when you use those small solid thrusters to launch your Rocket

[@tylisirn]

You don't need sepatrons 99% of the time if you attach your SRBs correctly. Instead of putting the decoupler in the middle, put the decoupler high, and then use the translate tool to move the SRB down, so that the decoupler attaches to the nose of the SRB. (Optionally, attach a strut on the bottom of the SRB to keep it rigidly connected to the rocket). This way when you decouple, the decoupler kicks the SRB such that it starts to rotate *away* from your rocket, rather than towards it like it does when the decoupler is in the "default" middle position.

[@franklinz8098]

separate them one second early so the shoot out instead of hitting the rocket

[@ebigunso]

@@franklinz8098 And by chance they shoot into your rocket instead of outwards. If you ensure that doesn't happen, you now don't have to separate early.

[@jimmyday3984]

Great vid, great content! You're the real deal, man. Keep up the amazing quality :)

[@thomasdillon7761]

Thank you for answering a question that I have had since the 1960s,

[@RaitisGrandovskis]

@9:48 IMU stands for Inertial measurement unit- basicly combination of multiaxial Gyro/Accel/Magnetometer , every modern phone has IMU chip inside.

[@stevee8884]

MEMS-IMU : en.wikipedia.org/wiki/Vibrating_structure_gyroscope#MEMS_gyroscopes

[@stevee8884]

All flying drones have a MEMS IMU

[@AbsoluteDespotism]

en.wikipedia.org/wiki/Saturn_V_instrument_unit

[@kindlin]

I always wondered how our phones could do so many marvelous things, it's all because of that one chip.

[@JesseMcCall]

Came here to clarify. Thanks for beating me to it!

[@secularmonk5176]

10:47 Stannis Baratheon has entered the chat: "Fewer"

[@nathanwahl9224]

Absolutely answers questions I've had for six decades!!!! Thank you!!!

[@joncapps3338]

Just wanted to say thanks, I've always been a space nerd but don't have the math skills to understand engineering speak. You hit the perfect balance of common sense layman terminology but still giving a really precise and comprehensive explanation. Great job and I've learned so much.

[@toxichaos21]

Thanks for the explanation 👍 it was thorough and we'll explained

[@bryandraughn9830]

Excellent work man! You and your team are going places! Far away places! Wink wink;) Congrats on your trip and I can't think of a more deserving recipient. Peace

[@laurin4405]

😉Indeed💌🌛

[@Prestomeco202]

Brilliant, insightful analysis. I used to build spacecraft and didn't know most of this stuff. Thanks so much Tim!

[@fcbrants]

Great video, thank you!! I especially appreciated the summary the end.

[@Fish_InChips]

Only through the intro and can already tell this is going to be a good video.

[@LordOstrik]

As someone from that area of Iowa... I feel special lol.

[@grlldfsh123]

I ALSO am from Iowa, felt good to be youtube recognized on a quality video

[@JeremiahCecil]

Hear, hear!

[@TheSaheasy]

It’s weird hearing someone online talking about a town I’m am used to.

[@curtislowe4577]

Oddly Rocket Man overlooked that the streets in the downtown Houston are also oriented 45° to the compass points.

[@HohmanDesign]

So good. Right in the sweet spot of overview with enough detail for curious minds.

[@keithbrown2458]

This is probably my third or fourth time to watch this film because I forgot all the reasons why the rotation you’re the first one to actually explain most all of them if not all of them indeed, Thank you sir for keeping me well educated, love your stuff man!

[@Airguardian]

Wonderful, WONDERFUL video! Well done! :D

[@KRGruner]

Man, you are killing it once again. Excellent in all respect. Keep the videos coming!

[@pushing2throttles]

I like rewatching this every now and then to keep my knowledge base sharp. What a great presentation.

[@markstover984]

That was the best explanation I’ve ever heard for the roll maneuver. Great video!

[@theanonymous393]

Great Video, really appreciate your work. :)

[@jamesbarisitz4794]

Loving the dig deep you do on all things rocket. The animations were outstanding. Super clear and beautifully presented. Oh , and top notch editing. 👍

[@marekszirdzins]

This is informative, inspiring and just pure joy to watch!

[@danieljakubik3428]

Thanks for posting! The first useful explanations of why rockets roll I have encountered.

[@bobcousins4810]

I always wondered about this too. The V2 was literally pointed in the desired direction by rotating the launch platform, I guess before the days of electronics it only had a primitive pitch control.

[@allangibson8494]

The V-2 had a rather complex programmed pitch routine hard coded into the guidance system. The gyro’s have pitch limits due to the gyro gimbals which can lockup if over rotated. All the rockets until the shuttle had mechanical gyro’s and thus gimbal lock was a problem.

[@johndododoe1411]

@@allangibson8494 Modern gyros are still mechanical, Just smaller.

[@johndododoe1411]

The turned launch mount makes a lot of sense once you know that the USSR classified it's rocket program as part of the artillery. Artillery officers are used to rotating their cannon on the ground to point towards the target. Same with the V1 and V2.

[@allangibson8494]

@@johndododoe1411 The Russian R-11 Scud was a direct A-4 (V-2) descendant with a duplicate of the A-4 guidance system and engine just like the American Redstone but with even fewer changes.

[@allangibson8494]

@@johndododoe1411 Modern guidance systems are solid state using silicon accelerometers (like what’s in your phone) and laser ring “gyroscopes”. No spinning masses at all. That has been state of the art since the 1980’s. Reaction wheel gyroscopes are actually much larger than traditional guidance gyroscopes - because they actually move the entire flight vehicle on their own.

[@maglax]

Great video as always. I did want to point out that IMU typically stands for inertial measurement unit, and consists of Accelerometers and Gyroscopes. You'll find em in a whole lot of thing (including in a good percentage of boards in any modern car). They can be pretty small too. But yeah a little nit-picky.

[@paulwalsh2344]

Man, you're so smart and your videos are so informative and yet still accessible to us ordinary ground dwellers !

[@jamesf6315]

Fascinating! Thanks for digging in and figuring it out!

[@topiastanhuala5146]

🎵They see me rolling, they hatin'...🎵

[@Bacongamer13789]

🎵 Patrolling and tryna catch me gravity turning 🎵

[@MrJdsenior]

TIM, you could most likely NEVER figure out all the reasons for the roll program, and CERTAINLY not all the decisions that went into augmenting it. As an engineer, I can tell you that many decisions that are made are never voiced, not even in "lowly" (functionally) design reviews, and certainly never committed to "paper", and most all of them stem from a plethora of competing, often directly contrary, requirements. Payload wants the rocket to weigh nothing, structural want some "factor of safety", aero wants NOTHING anyone else wants, etc. and all with good reasons. I like that the SpaceX guys were "griefing" you on some of it, shows they are interested. With a bit of research, you could find plenty to playfully pick back, I can guarantee you....but with your little "stunt" in the space suit...maybe NOT. Keep up the good work, nice to have someone explaining this stuff to the interested layman with due diligence toward accuracy and reasonable completeness. Here's a fun one for you. My boss and I were walking out of the building one day, and the group in front of us was trying to figure out where their cars were parked, and started one way, then turned around and went the other. I made a snarky comment, and one of them said something to the effect of "the worst of it is we are the G&C (guidance and control) group". We got a great laugh out of that one. Back to the original point, I can GUARANTEE you I've made many design choices, hopefully the right ones for good reason at the time, that I will never remember again. ;-) As I often say, old age sucks

[@Artemis-ko4ug]

Hey Tim thank u very much🙏, took a while to understand the science behind rolling of rockets, had to rewind and watch it again a few times, now that I understand it I feel extra smart. Great video man👌, keep up the good work👍.

[@joekresan8990]

This was quality content worth every minute. Thank you. Well done!

[@xnandox]

watched the video 4 times... still haven't got it yet... gonna re watch it 5 more times... i'll keep you post.

[@xnandox]

I just kind of got it. For real I watched 12 times. I'm a huge nerd, and an all time weirdo, but this video clarified me a bunch of my weird theories. for instance: 1.- That "Boring Company" doing high speed tunnels... that might be 1st stage development for: Rail gun orbital objects, and so forth. 2.- within that cannon you can test all the "early life theories" 3.- I'm kind of high and Iost my point

[@rhijermem9300]

ok

[@dfdgfdgf0000]

🚀 they see me rollin' They hatin'...

[@edwardmunye]

lol, good one

[@nethascotx24]

Patrolling and tryna catch me ridin dirty

[@spaceguy9025]

Lmao

[@janstankiewicz9816]

Elon, why?! That's how I roll!

[@LibertyDankmeme]

africans don't go to space - let's keep the cow-hide drum banging outta space too plz

[@tracycapilot2002]

Hey Tim, I grew up watching the Apollo flights and always heard that 'roger roll' callout and just figured that it (the reason) was too technical for us space fans to comprehend. THANK YOU for the explanation! Others might have 'fire hosed' us with too much info but you keep it simple. Your 'friend' Elon just toys with us simpletons (fun) but it's helpful to know why a thing does what it does. My 3 year old granddaughter is at that stage where she asks "but why?" and it occurs to me that we all ask "but why?" all our lifetimes and it's great to be taught and understand. Thank you again Sir!

[@tpstrat14]

that Chris Hadfield masterclass ad is the only ad I have ever watched all the way through on youtube. And I've watched it 3 times now!

[@wallymcguire2033]

Timothy Stratton Lol, I took a screenshot of it and made a Facebook post that I actually watched a KZbin ad to the end for the first time ever 😂 Good job Chris, you kept me interested!

[@jimmyb998]

20:40 You forgot one: sometimes, they just roll for fun ;)

[@ashishganguli4660]

i still didn't understand, i am so dumb

[@frankv7068]

You’re smarter than you think if you click on rocket science content 😉👍🏽

[@user-px1wj2uv3r]

This is one of those videos I can return to every few months. Love it.

[@philmoore71]

i better watch this a few times again to comprehend this intriguing topic - really good. tks

[@REDACT3D]

extra points for KSP custom flag - I learned somthin ^.^

[@BeechSportBill]

How Air Force Missileers understood the guidance system... The missile knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the missile from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't. In the event that the position that it is in is not the position that it wasn't, the system has acquired a variation, the variation being the difference between where the missile is, and where it wasn't. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the missile must also know where it was. The missile guidance computer scenario works as follows. Because a variation has modified some of the information the missile has obtained, it is not sure just where it is. However, it is sure where it isn't, within reason, and it knows where it was. It now subtracts where it should be from where it wasn't, or vice-versa, and by differentiating this from the algebraic sum of where it shouldn't be, and where it was, it is able to obtain the deviation and its variation, which is called error.

[@TheNevawuz]

Like dribbling a ball with your eyes closed.

[@chrisneale7453]

The best space channel at the best time in human space history. Thank you for your hard work

[@deepblueuniverse]

Very helpful my dude! Loving these new videos.

[@edwardstrassberger2024]

Roll to azimuth could be 180 degrees around. Alignment was to make the astronauts sink into seat rather than fly up, restrained by safety belts. Other way would be like going over the top of a roller coaster or an outside loop. It also keeps the breakfast down!

[@night_aviation]

Gotta love how Tim explains it with KSP

[@jesstheheathen]

Just happened on this video as a recommended one. Love that you use KSP for your breakdown here man.

[@Enemji]

With the amount of reasearch you do, you could and should be awarded a honorary degree in Rocket Science.

[@MrMattie725]

"A nice simple zero" you say, that is, until somewhere someone forgets an exeption and the computer tries to divide by zero :D

[@DerKiesch]

15:30 - I think flying parallel to the horizon should give you an additional small amount of lift allowing for a less fuel consuming ascent profile. Since the drag should be roughly the same in perpendicular or parallel configuration, this might be the main reason. From KSP (with ferram) I personally noticed that the rocket seems to also be more stable if you fly parallel.

[@forloop7713]

Good point

[@Gauseltown]

@Everyday Astronaut....Tim, what can I say? It is always a great pleasure to take some time and look and enjoy your videos. So much great information and footage. Thank you so much. You bring space and space technology to us with your fantastic enthusiasm. Hope you are doing good in these special times. Stay safe. Cheers from Germany.

[@frisk151]

Excellent video! My brother and my kids (and both of us too!) watch all of your content. My uncle retired from NASA (in Clear Lake, TX = Houston) a decade and a half ago but we got entrance to Mission Control (guest viewing area) a few times in the 80's to watch Shuttle launches, but he only talked "rocket science" to us, which to kids is essentially static... The way you explain things is easy for even the layman to understand! Thanks!!!

[@beaudanner]

That was so interesting and being so in depth helped me understand this a lot. I've seen this explained before but your video might help me actually commit this to memory. I would love a video on azmeuth and inclination and the sperical trig you mentioned. I'm crazy interested in how we pinpoint precise orbits. To the weeds! :)

[@PinataOblongata]

With mechjeb ;)

[@bobbob123ful]

11:31 My boi out here on the Macintosh