How SpaceX Lands Rockets with Astonishing Accuracy

A look at how SpaceX achieves their astonishing landing accuracy with the Falcon 9 rocket.
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Video Attributions:
“ORBCOMM-2 Full Launch Webcast” by SpaceX
“Falcon Heavy Test Flight” by SpaceX
“Making Life Multiplanetary” by SpaceX
“SpaceX Interplanetary Transport System” by SpaceX
“CRS-12 Launch Webcast” by SpaceX
“CRS-8 First Stage Landing on Droneship” by SpaceX
“Grasshopper 325m Test Single Camera (Hexacopter)” by SpaceX
“How Not to Land an Orbital Rocket Booster” by SpaceX
“CRS-10 Falcon 9 First Stage Landing” by SpaceX
“Iridium-8 Mission” by SpaceX
“First-stage landing Onboard camera” by SpaceX
“SpaceX Rocket Tank Production Timelapse” by SpaceX
“Iridium-2 Launch Webcast” by SpaceX
“Koreasat-5A Webcast” by SpaceX
“CRS-11 Landing aerial footage” by SpaceX
“Elon's SpaceX Tour - Engines" by SpaceX
Still Image Attributions:
“Falcon rocket family 3” by Lucabon
“SpaceX ASDS in position prior to Falcon 9 Flight 17 carrying CRS-6” by SpaceX
“Rocket Stove - Poele Dragon v1.3 sortie verticale r002” by Alain Van den Hende
Music by Epidemic Sound
#SpaceX #Rockets #ArtofEngineering

[@ArtofEngineering]

Which SpaceX milestone are you most excited for in 2019? Video corrections: 1) At 2:50, I provide the measurements of the entire Falcon 9 rocket at liftoff, which is misleading. Only the first stage of the rocket returns for landing, which is approximately 43 meters tall and weighs around 22,000 kg empty. 2) At 5:00, I state that the improvement in landing accuracy from 10 km to 10 m is 10,000%. This is incorrect. The increase in landing accuracy is actually a 99.9% improvement.

[@livefire666]

Starship Hopper tests and hopefully the first deployments of Star Link.

[@elliotwooley2630]

Dragon 2 and Starship Hopper Tests

[@Falcon9Block5]

Demo Mission 1

[@terrysullivan1992]

Crewed Dragon to the Space Station. Great PR and big $$$ maker for Space X to back up and finance BFR / Starship development.

[@matgof03]

Bfr

[@PumpernickelBread25]

It just blows my mind every time I see one of those rockets coming back down and landing back on the pad

[@GC16199]

Just like a Mavic Air 2 with RTH, magic! 😎

[@thetwogardens6048]

Would dating Kim Kardashian blow your mind ????

[@harpoon_bakery162]

NASA has always been on the bleeding edge. They show it again here in this compilation of technologies.

[@laos85]

I like how they drop smoothly down.

[@kcirred1029]

Harpoon_Bakery my nigga you watching a space x video

[@dank6617]

Next video, the secrets to getting A+ in every exam: 1) Study Hard every day. 2) Pass the exam.

[@tymmezinni]

Dude, you can't write it like that, there's not 6 minutes' worth of fluff to read before part 1, and step 2 is simplified way too far. You have to spend 5 minutes explaining how you solve the problem and then have to find a pencil to slowly etch a small portion of the graphite into a circular pattern that corresponds to both the correct answer and the originally allocated number for the problem in the exam.

[@noli-timere-crede-tantum]

I think you're missing a step, there... What should happen between studying and passing the exam? Please help!

[@staitz2728]

I actually don't study at all and somehow ace them oh and I don't cheat xd

[@greenm1352]

@@staitz2728 You're not being challenged then.

[@staitz2728]

Green M yeah i’m bored as hell in school smh

[@Chuck59ish]

I'm 67 years old, so I'm a child of space flight, and it's totally amazing what SpaceX has done in less than 10 years. Simply amazing.

[@franciochoa1892]

Agree. that's totally amazing.... and the competition with Boeing OMG..... a few team with less money thatn Boeing and they can do that beautiful rocket!!! Elon is a genius but he have a genius team and a very young people in his team. That's great for the generations to come.

[@avikashnadan]

Even though the company has many smart people its actually only Elon.

[@stumpedii8639]

i hope we both make it to see a mars landing. good luck!

[@TwstedTV]

scientist has said this before many times. "Currently, humanity are at least 25 years behind evolution" humanity has engulfed itself into other things such as hatred & other nonsense, that humanity lost their way in evolving. Humanity are more involved in world wars and killing each other, than evolving ourselves... And we ALL lost out way. We are suppose to be 25 years ahead of our current time in evolution, but for some reason humans got really fucking slow in evolution, and now we are 25 years behind and its increasing rapidly. Can you imagine ALL the things we are missing because we have slowed down so much in our evolution...?? Think about that for a second.........

[@Chuck59ish]

@@TwstedTV I'm 68 now, and I hope to be around when they land on Mars, but humanity will always be trying to wipe each other off the face of the earth, they've been doing it since the dawn of time, and if the beings that planted life on this piece of dirt ever come back, I hope they're well armed because fleas on this ball will try to wipe them out too.

[@chesterjordan817]

The engineers must be really proud of their engineering to launch and land rockets bravo..

[@pahu47]

Brava, also, as there are many female engineers working on this feat

[@jamiejones8424]

Waste of money

[@masterlesstheband]

@@jamiejones8424 what's a waste of money ? Reusable rockets save loads of money. Like 90% of the cost. Research that goes on in orbit will probably save your life one day and if we access the resources found off planet as Musk intends to man's energy requirements for the foreseeable future will easily be met. There's also the possibility for clean development of advanced technologies in orbit without harm to those on the surface but we still get all the rewards. Big picture thinking. So again, where's this waste of money you refer to?

[@jamiejones8424]

tristan hann your deluded unfortunately theres lives that could be saved now! today! with all the money they waste!! Can you name me something useful that they have discovered up or out there in the dark void they call space ? 😂

[@masterlesstheband]

@@jamiejones8424 yes I can name loads ball bag. Sadly whilst you can lead a horse to water you can't make it drink.

[@Barnacules]

Rapidly unscheduled disassembly, I love it ♥

[@sora3121]

Who are you?

[@dellpacker7657]

guy

[@hrsh042]

This guy from blue origin

[@ZeitGeist_TV]

It's how Elon says it was he did recently with SN8.

[@jacobbauer9812]

this guy used to hunt for his food

[@Daniel-qp8fj]

wait, so the whole landing is automated by a computer? I thought it was Elon playing with a joystick the whole time.

[@gmdtanker6211]

Good one

[@Beerbottles123]

It's either that, or Elon's high score on 'Lunar Lander' must be insane.

[@andrew_slayer8966]

no its called the "probe core" its an auto landing for reuseble tech

[@WarpOverload]

@@Beerbottles123 You remember Atari Lunar Lander? Wow.

[@markmontagna7637]

This thread is gold

[@chastion3689]

I am obsessed with the grid fins. Whoever thought of that system must be incredibly proud, it looks simple yet is so impactful, simply brilliant.

[@SeanONeillUS]

Most excellent engineering has those traits, simple and effective.

[@dr4d1s]

The Soviets back in the 60s.

[@walkingmanvideo9455]

Hands down the most impressive technology seen in a while.

[@ElSelcho77]

I remember watching the live stream of the first landing and crying tears of pure joy as humanity stepped into a new era. still get goose bumps and sweaty eyes when I see those scenes. ah, nice :) I liked this video, thank you!

[@jamesahern9864]

How about today? May 2020

[@christheother9088]

Here's the key. SpaceX really wants to go to Mars. Boeing (and others) really want to make money.

[@Cwg.]

Yeah but elon is a genius

[@cpufreak101]

@@Cwg. he also really wants to live on mars

[@jacoblawson5243]

What about NASA? They have been in Space tech for much longer.

[@harikumarv4658]

@@jacoblawson5243 Well, for NASA reusability was never a concern as they get billions in funding for every mission, whereas the entire point of SpaceX is reusability to make space less expensive for humanity.

[@jesud1012]

@@harikumarv4658 they tried with the space shuttle program though

[@constantdarkfog49]

When I first saw a SpaceX rocket completing a vertical landing, I thought it was an aminination, but no it was the real deal. This landing menuvior is a real game changer. I never thought this was possible.

[@GodAdministrator]

You were right. First several times IT WAS animation. CGI

[@geoffdearth7360]

Menuvior? No.

[@stargazer7644]

Game changer? I seem to recall NASA landing some vehicles under rocket power on land in the 60s. I think one was called the LEM, and it managed to land, and takeoff again on the Moon.

[@stargazer7644]

@@AP-qs2zf Probably because it isn't as novel as you think it is, nor is it as big of a deal. The space shuttle was reusable, including the first stage. Yes it was expensive. It was also far more capable. Soyuz has been using rockets for the final capsule ground touchdown for 50 years (on Earth). You young folks seem to think Spaceflight began with Elon. They have no concept of all the technologies that hadn't even been created for the Apollo program to be successful. Falcon nine's magic comes courtesy of computers that Elon simply buys off the shelf and uses development tools that someone else wrote. NASA had to invent the first IC based portable computer - the Apollo Guidance Computer. Nothing ran an operating system, it was all custom. The software for the Apollo Guidance Computers in the command module and LEM were hand woven bit by bit by running wires through magnetic cores. A software update meant reweaving all the cores. The designs for the hardware and the calculations for the orbits on the ground were done primarily by hand by people, not by computers in the early days. The astronauts had to know how to do navigation with sliderules and sextants in case the computers failed. THOSE were game changers. They invented spaceflight out of nothing.

[@hairfall7681]

@@stargazer7644 stfu kid.. crawl back to your mum's basement..

[@aylean3628]

It looks so unreal and yet so fascinating when you see the Falcon booster decending to the landing pad, man I love SpaceX.

[@elettrofans]

As a programmer i appreciate this way more than the normal viewer.. knowing the undefinable amount of complexity that goes into this...damn

[@SeattlePioneer]

Now think about the piloting skills that allowed the moon landings half a century before the advent of Elon Musk!

[@djarvils]

It's a huge talent to speak 10min and still having no answer - explanation!

[@vmbharathiraja]

Most of the YT videos... same story...

[@MrSkylightOffical]

Doesn't matter, you clicked.

[@AffordBindEquipment]

how much more detail do you want? Schematics? Detailed drawings? computer program printouts? how long would you be willing to watch?

[@freeagent.87]

the answers were in the video, it just went over your head..

[@anzelmasmatutis2500]

@Arvils Zeipins Did you saw numbers 1,2,3,4,5,6?

[@berttheace]

As an engineer I can repeat : That's really the 'ART of ENGINEERING ' Congratulations to Elon Musk !

[@GabstheGamerYT]

and the other great minds at spacex!

[@mnorth1351]

It's so beautiful. I could watch those boosters land all day.

[@haydena9998]

Agreed. In the future, you very well might be seeing boosters land constantly.

[@SeattlePioneer]

[@iamachine]

I will never get over the ridiculous complexity of the engineering required to pull these landings off. I watch these landings in awe and amazement, it never gets old!

[@111utoobmetoob111]

That's what they count on, simpleton.

[@sailorman8668]

@@111utoobmetoob111 Hey BOOB, you showing your infinite ignorance on this thread too? Way to go bud!!!

[@111utoobmetoob111]

@@sailorman8668 Why did you put a question mark on a statement? Infinite ignorance?

[@theoilpainter]

@@111utoobmetoob111 its amazing how many times he's watched the landing and still didn't figure out that its fake, just look at it, they cut to the smoke after, looked like the take off in reverse...so funny

[@bdmora8208]

Billybob You’re one of the biggest idiots I’ve seen on this video.

[@TheTrueKailash]

i still think the film is just played in reverse when i see that thing land :D incredible !!

[@fernleystephens2436]

If the landing is just the launch played backwards where is the gantry etc?

[@Impulse_28]

@@fernleystephens2436 whooshh

[@AhmedRw]

@@fernleystephens2436 r/woooosh

[@kalok4419]

I believe the film is played in reverse

[@storiestellr]

Thank you for this great video - lots of things explained that i had been wondering about

[@charlessmith6412]

Highly recommend that anyone who is really interested in how SpaceX does this, that they read the rather lengthy but greatly informative comment by David Ogawa. Thank you sir.

[@truman42746]

Could you please post a link to this?

[@masonkanterbury3007]

Every time I see one of those things land upright, it reminds me of science fiction movies from the 50s, when they showed rockets landing exactly the same way on alien worlds. It's absolutely amazing to see it in real life.

[@karltite128]

Operative word " fiction"

[@fromagefrizzbizz9377]

@@karltite128 Fiction helps you imagine what sometimes is possible. There are videos of rocket amateurs doing upright landings on KZbin. Nothing at all fictional about them.

[@TheGamingMotionTGM]

That projection of reality could mean one thing, that we're late for about 60-70 years when counted from the 1950s.

[@SeattlePioneer]

[@carenspencer-smith2921]

I watched this launch and landing with my family from Cocoa Beach near the Wakulla - it was fantastic! Having grown up with regular Apollo launches, followed years later by the Space Shuttle, this event marked a welcome next generation of US space flight from KSC. In addition, since the launch engines are so much more efficient (and quieter) now, the sonic booms of the booster landing are a visceral reminder of the older launches.

[@sneprojectssync316]

Your description was the most thorough and accurate description of any SpaceX process I have seen to date, and I've watched them all, some multiple times. Adding you to my bookmark, please keep it up. And feel free to use my comments. Thanks.

[@halonothing1]

No matter how many times I see it, watching those boosters land vertically like something out of a 1950's sci-fi movie somehow looks fake or CG. I'm not saying it is fake, I'm just saying it looks so incredible that my brain can scarcely believe what it's seeing.

[@caffewaffe]

So bad cgi omg i can’t believe people believe this shit

[@gmckenzie175]

When you look at the comments you can tell they deleted the ones that don't believe this Bs. I'm not unimaginative or proud of this accomplishment but can't help but see the edit prior to landing. All shots do this. Reason why is it's in reverse then cgi. Hope that helps the science explanation. Peace

[@halonothing1]

@Scott Carter Wow calling me a dick head instead of making an actual point makes your side of it sooo much more convincincing.

[@halonothing1]

​@Scott Carter Brilliant retort. You only make yoruself look like more of a simple minded fool by your juvenile name calling rather than provided actual evidence in support of your claim.It's sad really becaue it tells me you're either a troll or you have no actual cogent arguments for it. Either way it doesn't bode well for your side of the debate.

[@halonothing1]

@Scott Carter Obviously not. Otherwise you'd be able to do more than just call me names like a 12 year old with no real point to back up what he's saying. Rather than explaining your point view in a mature and respectful way like an adult would. But you seem utterly incapable of something that simple. Much less understanding it. All you seem capable of is coming up with lame insults that nobody finds amusing other than you. While to everybody else you just look like a child.

[@clavo3352]

Great summary explanation for laypersons to understand. Well done video. it's too bad we are running out of well educated and disciplined people.

[@kanva4]

*_RIDICULOUSLY WELL-ENGINEERED ROCKETS_*

[@Angry.General1461]

How do they not burn up in the atmosphere during re-entry?

[@WhyPee24]

@@Angry.General1461 That's what the "re-entry burn" is for(duh), things only burn up during re-entry if they're going very fast, and the re-entry burn slows down the rocket to prevent that.

[@Angry.General1461]

@@WhyPee24 you would think the temperature of the re-entry burn would make the fuel inside the rockets explode.

[@briannewton3535]

@@WhyPee24 I dont think we needed the (duh) but the rest of your explanation was informative cheers :o) I was hoping to see your knowledgeable response to The Angry General when asking about exploding fuel, is the slow re-entry not at all hot then?

[@briannewton3535]

@Miguel Jeffrey Ah, cool, never even considered that.. Who would have thought rocket science could be so hard 😋

[@wavydavy9816]

Great video. Informative, well narrated and smashing editing. Top work all round. Thanks for answering all of the questions that I had, and many that I hadn't thought even of yet 🤗

[@S_K_J]

Who is here after falcon 9 dragon capsule launch

[@LiteLotus]

I take it you mean the manned launch

[@thegunnysgaming421]

Me

[@raven085]

Me

[@blueslsd]

me

[@loboestepario-cl]

[@More-Space-In-Ear]

It’s an exciting time for anything space...great video too 👍🏼😊

[@macbryan1559]

Whos here after Bob and Doug launched off in 2020 ? Ive never been soo confident about anything Go SPACEX Go ELON

[@JoelEverettComposer]

I was so thankful the lift off went well, but when I saw that booster rocket land... I was blown away.

[@Mqablehgaming]

Yes ..hhhhhh..actually I came here because I have been surprised from the landing mechanism,,

[@zhiyan_ykb]

Pacific Landing brought me here.

[@shardanorman]

Ooooh my family and I watched it in awe..... amazing indeed!!!

[@sheildstrike1845]

Space flight has changed in my life time ; marking a new era of reliable space travel. To the stars and beyond 💫

[@aphovasse]

Great presentation, well structured, clear and simple, thanks for your hard work.

[@rabaham]

Glad that do many commentators are well knowledgeable about the subject, but for us the novice, great video and hopefully will be followed by a more detailed videos from you the experts. Thank you

[@rileymannion5301]

That video in the beginning is straight up history I get goosebumps watching it

[@thirdworldrussia3900]

SpaceX has been nailing it. perfect landings and deliveries to the ISS. December 16, 2019

[@jamesahern9864]

And again today, May 30-31, 2020

[@jeffreylebowski4927]

5minutes 30seconds into the video, you still have not adressed, how they land the rockets so accuratly. Also saying, they do with with well engineered rockets, is saying nothing about how they do it... How did humans go to the moon? - with good engineering. - oh ok, great thx.

[@ArtofEngineering]

I don't think it's fair to criticize the video if you only watched the first half. The first half provides an introduction and context, while the second half covers the design elements that make the landings possible.

[@jeffreylebowski4927]

@@ArtofEngineering Ok sorry, i allways feel bad, when i criticise people on youtube and they actually respond. I dont know how much work it was and you are right, in the 2nd half you do explain how they land the rockets, with nice explainations and video. Thank you for that! Still i watched the whole video and i think you could make your introduction a bit shorter with less, but more relevant information, OR change the titel of the video, so people know, its not entirely about landing accuracy, but the entire history of spaceX landings etc. - i think thats a youtube/modern age thing, that people want quick and well packaged information, and dont want to sit through loads of time and information they arent interested in, to get to the relevant part, even if its only 5.5 minutes - as far as youtube videos go, thats alot of watch time. At least thats how i felt (i knew everything about the history already), and ive seen some other comments, that went along those lines - so maybe you can take it as constructive criticism. Also i think my point still stands, that saying someone achieved something, by doing it "well", is not a meaningfull analysis. Ofc the rockets would be well engineered (by definition, because they achieved their objective). - That doesnt explain how its done. Maybe if you said: "by equipping the rocket with several means, to guide and correct its descend" - or something like that, you would at least add the notion, that it is a guided and corrected process or so, and it wouldnt be as trivial as "by having well engineered rockets". I dont want to be a smartass, im sure you know much more about engineering, than i do, and also about making youtube videos. Still i hope u can take something positive from my comments, and make your videos even better. I will subscribe too! Take care.

[@JFrazer4303]

Still nothing about guidance. GPS is the sole outside contact the entire Booster has during launch and fly-back? No radar altimetry, no IR frequency beacons to tell it anything?

[@benjaminchung991]

@@JFrazer4303 If you're interested in the detail of how the guidance system works, look at the following paper by Lars Blackmore, one of the GNC leads at SpaceX. "Autonomous Precision Landing of Space Rockets." Lars Blackmore. National Academy of Engineering 'The Bridge on Frontiers of Engineering', Volume 4, Number 46, pages 15-20 (2016).

[@benjaminchung991]

@@hanznathanpo GNC is a bit funny, in that it's both simple in some respects (specifically, the dynamics of the system tend to be rather on the simplistic side) while the way you solve them is tricky. I'd suggest starting with some of Lars Blackmore's earlier work then moving on to some publications by Michael Szmuk. I'd suggest reading www.larsblackmore.com/AcikmeseAAS08.pdf arc.aiaa.org/doi/10.2514/6.2016-0378 arxiv.org/abs/1802.03827 Don't get too intimidated, I learned how most of it works by writing code and seeing how it failed miserably.

[@pkos91]

Video title: "How do rockets land with accuracy" Video content: "It performs a landing burn to reduce its velocity to zero" -_- There are comments under this video with more research in them than the content itself.

[@andricode]

Yes basicallt at the middle of the video i found a comment explaining everything and i didnt continue seeing the video animore

[@TONYPARAMOTOR]

abit like MAGIC= TEC

[@GntlTch]

Right. Kos: I got the velocity down to zero at landing just perfect. Unfortunately, I was a mile away from the droneship... Too bad you don't have the smarts to think in two dimensions let alone three.

[@markheller197]

Fantastic. Comprehensive, educational, and gives you an appreciation of the engineering.

[@davanamsrinivasulusetty6353]

Unbelievable technology, hats off to people who achived this feat

[@douglasfurtek7637]

Marvelous engineering and programming! I would like to see profiles of the brilliant scientists and programmers behind all of this.

[@proventure307]

Unbelievable what SpaceX made possible till today. Starship first landing etc. What a time we live in.

[@stargazer7644]

Yeah, Apollo and the Moon landing was nothing, right?

[@thecyanadon]

@@stargazer7644 Lot easier to land on the moon then on Earth. Also this is major stuff in terms of the space industry.

[@stargazer7644]

@@thecyanadon Before I ban you for being utterly clueless, i’ll point out that Apollo landed on both the Moon and Earth. I’ll also point out if it is so easy to land on the Moon, why hasn’t spacex done it already?

[@thecyanadon]

@@stargazer7644 When did you say any of that??? All you said was that Apollo was harder than making a reusable rocket. If it was then NASA would have reusable rockets but they don't.

[@stargazer7644]

@@thecyanadon When did I say any of what? What I just said? I just said it. See, the way this works, is you say something stupid, and then you get called out for it. You act like SpaceX managing to land a rocket on its tail on their 20th attempt is somehow anywhere near as difficult or as big a deal as building an entire space program for the first time from nothing and putting a man on the moon 50+ years ago. You have no clue.

[@Eyecytubes]

The quality of the video footage presented is astounding! Space X has developed its own peculiar cinematheque genre.

[@chrislong3938]

I was truly agape when I first saw one land for the first time! ... and then doubly so when two did it simultaneously! 'Astonishing' is a massive understatement!!!

[@joewright9879]

Excellent video. I am a boomer and well remember Mercury, Gemini, Apollo.. I am as excited about the potential of SpaceX as I was about NASA in the 1960s. Well done!

[@mitchgordon8199]

I've seen grid fins used on guided bombs way bsck, still cool.

[@calbackk]

Very informative. Thank you from Sweden.

[@rocketmanfossel1174]

I just love the space X command center. All skilled people giving their best on computers inside glass room and all fans just jumping with joy outside the glass room

[@hyperqx]

I love the video. Thanks for the explanation.. I'll always thought this is so well engineered. And the first time I saw a landing of the rocket I was amazed. I'm no engineer. Don't have a degree or something. I love technic. And landing a rocket vertically I know is just so hard coz of the weight. Almost impossible. But it's not. Just amazing for that reason. Love it.

[@craigparrish9677]

Your video had nice production and for an overview of the development program was fine. Thank you. When you do the Part II video one of the interesting facts you may want to cover is the payload penalty of having the reusable first stage. To get the heaviest customer payloads into orbit they will use Falcon 9 boosters without the recovery system.

[@penguin44ca]

For a heavy launch yes, although now the recent FH can expend a centre core and reuse the boosters for most if not all payloads. They just did a 9 ton launch to gto

[@MouseGoat]

Its insane what level of skilled work has gone into make this, and the forces we humans a playing with. It really gives me hope for a future of space colonies and interplanetary travel.

[@jetsons101]

I just took a tour of SpaceX, what a great place. My son works there. Thanks for posting.....

[@teefkay2]

Overall, this was an outstanding video. A great example of what the Internet could and should be. A couple of small errors: At 7:40 The cold gas thrusters operate when the booster is empty. When the booster is empty, the center of gravity is much, much lower than you’ve shown it. It is no where near the vertical center of the rocket. The vast majority of the mass of the rocket is contained in the engines which are at the very bottom of the booster. I’ve heard a SpaceX engineer describe the system as “a brick glued to the bottom of an empty soda can”. This mass distribution gives the booster its stability when reentering the atmosphere & during (and after) landing. @8:30, _“if the computer detects any deviation from the flight path, it instructs the rocket to adjust its orientation and velocity as necessary.“_ Orientation, yes. Velocity, no. The grid fins change orientation to keep the rocket on the correct flight path. The only two times the velocity is adjusted by the rocket is when the rocket is firing, i.e., during the reentry burn & the landing road. The rest of the time, velocity is determined by Isaac Newton.

[@marsag3118]

teefkay2 teefkay2 well, strictly speaking fins change attitude, which change aerodynamic forces, which change acceleration of the vehicle, which integrated changes its velocity. So, what is said in the video on that is somehow true.

[@teefkay2]

mar sag Nope. The key word is “control”. Yes, in aerodynamics, lots of variables interact. But you’ve only got 2 control inputs: the fin pair that controls yaw, and the fin pair that controls pitch of the booster. Yaw is used to control lateral deviation from the trajectory (i.e., landing left or landing right of the target). Pitch is used to control the range deviations (i.e., landing short or landing long of the target). In principle, the engineers COULD have used the pitch to control the velocity. But then you would have lost control of the range, which is a very, very bad thing. You really, Really, REALLY want the rocket coming down at the right location. To go a little deeper into “control systems theory“ ... I’ve seen control systems that attempt to control two outputs (in this case, range & velocity) with one input (pitch). It’s a prescription for disaster (i.e., instability) as the control system bounces back & forth between “range control state” & “velocity control state”. If you want to have a reliably stable control system (which is a very, very, very good thing), you use one control input to control one output. In this case the pitch fins control range. And you let the other outputs (e.g., velocity) “relax” to whatever the external variables decide it should be. Note also that the velocity merely has to stay “below a maximum value (at some air density) that will cause overheating damage to the rocket engine components”. “Getting below a max value“ is a fairly easy engineering task. The reentry burn sets an initial velocity condition outside the atmosphere. And then “grabbity”, the atmosphere’s air density profile & drag coefficients (all well predictable) determines the velocity (& heating) from that point to the ground.

[@rohitbhandari5460]

Yeah you're good at physics man. You can make good meme.

[@jimlarsen6782]

Thanks, I was wondering how its done. For years I repaired an inertial nav system for the Air Force and others. I think the addition of gps makes a big difference. Grid fins also.

[@hammerheadcorvette4]

I came hear specifically looking for an explanation on the grid fins, Learned a hell of a lot more !

[@depressedknight369]

your channel ..got into my favourite youtube channels list.. all your videos are great keep it up and thanks

[@kevin7151]

Excellent video. Very informative and insightful. Thank you for sharing.

[@farthercashew851]

This video received a lot of hate, but it was interesting and well written. Keep up the good work!

[@ArtofEngineering]

Thank You!

[@briannewton3535]

Yup Me too, I found the landing trajectory surprising :o)

[@Yezpahr]

Agreed, too much hatred in the comments. People should just learn to use 1.5x speed setting, it's very useful with 80% of the video's, saves loads of time. This vid was still great confirmation of information. And it never gets old seeing that thing land successfully (and the failed attempts are fun too since no human lives were lost).

[@slehar]

Wow! Rough commentators! Tough crowd tonight! I thought it was AWESOME! I learned a lot I didn't know. Well done! Thank you.

[@anatollegros3454]

We all read the comment of david ogawa in wich he gives like 100× more details than the vid...realising that it was a loss of time

[@anatollegros3454]

But yea, people are overly mad at the author

[@briannolan7818]

That was a great video. Thanks for making it so I could understand.

[@Nvrgofulretrd]

amazing! absolutely amazing! even more exciting than the launch.

[@briannewton3535]

a really enjoyable and informative video. I am an engineer, and I liked the level of info. I'm not a rocket engineer though :o)

[@josvah]

Poor guy, you're playing to a tough crowd. They are critical AF. Great work on your videos, they look good and they're made in such a way to pull in the viewer.

[@spaceflightnerd]

Actually, no. You're falling for this shit. I'm gonna be real, most of his shit was obvious, and everyone has the RIGHTS to say whatever the fuck they want. And here, they are properly criticising his video.

[@emmanuellim155]

Don’t worry you’re not alone

[@nullnada1707]

I've always been curious on the tech involved for such a feature that only exist with SpaceX. Thanks!

[@twist7799]

Amazing Space-X, Well Done.

[@cllau110]

Remind me of the scene in the JAMES Bond movie You Only Lived Twice in which a rocket was seen descending vertically and landed inside a hollowed out volcano It take 50 years to achieve this manoeuvre ! Terrylau

[@majorgeeks]

Played Lunar Lander as a kid, thought that was a good idea? ;)

[@Mark1Mach2]

Amazing video, very entertaining with right video clips, commentary and audio. Subbed.

[@richardashton9425]

Thanks, good video.

[@TheBluemanBenny]

You know, people are always caught up with ridiculous specs and this incessive need to prove they know better. I really enjoyed the video for the information and how you delivered it. Thanks for the great work! If others think they can do better, let them actually prove it!

[@ReneAltena]

Sorry, but the only thing everybody asks is to answer the question in the title of the video.

[@michaeldeierhoi4096]

@@ReneAltena The title of the video was clearly answered as recognised by myself and dozens of other commenters. You may have to watch the video a few timesb but is all there just not wrapped up in a simple little package like probably wanted. Gosh and whoever thought rocket science wasn't simple?!

[@whitedovetail]

Art of Engineering You must always walk before you can run. This is an excellent video and the information is also excellent. Do not listen to the hate comments. You will be chasing your tail from now to the end of space. You did good. Keep them coming. And remember, you have walk before you can run! Love this!

[@djosearth3618]

i agree, no doubts here! ;] your comment reminded me to sub too.

[@cybervigilante]

Well, I subscribed. Seemed like a fair analysis. Much more tech-detail and it would have been too long and there is only so much KZbin time in a day ;)

[@ReneAltena]

Are you an engineer? I am. And the video did not give me an answer to the question in the title of the video.

[@michaeldeierhoi4096]

@@ReneAltena Then you need to watch the video again or even several times and google the definition of uncertain terms such as thrust vector control.

[@donaldstanfield8862]

Wow, and thanks for simple explanation of this rocket science!

[@hl9252]

Very Informative well done graphics keep up the great work

[@milowagon]

After landing on the drone platform, how do they secure the first stage for transportation ? The sea can be very quick to change. I watched Mercury as a child, this program has reignited my interest. Truly awe inspiring.

[@familykeepersca]

They refilled the fuel and fly back to the land base. Maybe

[@CPlater1]

They have an "Octograbber" robot on board the drone ships that comes out once it is safe, and it clamps the base of the booster.

[@familykeepersca]

@@CPlater1 Thanks. I didn't know about it. It would be dangerous under strong wind attack. Of course, they will choose a right time to do it.

[@stargazer7644]

A robot, officially named the Falcon 9 Securing Robot, but universally known as Octagrabber lives on the droneship and is deployed shortly after a booster landing. The robot is remotely driven from it's blast-proof shelter and positioned underneath the Falcon 9. Four arms then raise up and latch onto the Falcon 9 Octaweb, securing the booster.

[@xmugiwara528]

Here's how they do it according to this video: they're really good and put in the work.

[@awesomethings3489]

He briefed few basic principles which are really essential for understanding. As an engineer I get to know it. But he did well to make understand someone who doesn't know abcd of it.

[@mrdzin1209]

What do you expect? "LEARN THIS ONE SIMPLE TRICK THAT MAKE SPACEX LANDING POSSIBLE !? NASA HATE THEM!" ?

[@stargazer7644]

This works because GPS exists.

[@peterobbins5801]

This is amazing engineering technology. Like something from a science fiction film.

[@alrightydave]

Nice video, learned a lot. Not the most informative like David Ogawa's comment below which you should definitely read for more info, but definitely covered a lot in basic detail. Thanks for making this.

[@EinChris75]

5:50 - there is no boost back burn when landing on the drone ship. only needed for landing on land.

[@anatollegros3454]

Sometimes there is one, it alows the ship to be closer to the shore

[@diazchg]

Awesome video... Practical and understandable for EVERYBODY!

[@JPJamster]

thank you for the explanation!!!

[@smallstudiodesign]

Love your KZbin channel! 💖 - ✨🏆✨ - brilliantly presented, narrated & edited. Very informative.

[@Patchuchan]

Much of the success of both Spacex and Blue origin at landing rockets goes back to work done on the DC-X program.

[@vallhund2901]

The successful SpaceX landings that I've witnessed have been closer to 1 meter in accuracy rather than 10.

[@Reactordrone]

That can be a little visually deceptive given the size of the rocket. 10m is only 1/7th the height of the first stage.

[@alexanderchilvers1243]

@@Reactordrone Closer to 1/4, since the booster is 43m tall.

[@Angry.General1461]

How do they not burn up in the atmosphere during re-entry?

[@stargazer7644]

@@Angry.General1461 That's the purpose of the re-entry burn - to reduce heating on the rocket. Did you watch the video?

[@subbuilder3563]

Very well explained. Thanks.

[@Capthrax1]

the one where they have a hydraulics failure is pretty great to watch, the grid fins get frozen yet the booster compensates out of a spin that looked fatal and crashed into the water at such slow speed

[@technotoaster]

I thought i’d give credit where i think credit is due. You did a really good video and i certainly learned stuff. Thanks for taking the time to make the video. Remember, haters are a minority.

[@drahunter213]

4:19 This is how we get things done and do things right We don’t quit when something fails or goes wrong this is why technology in the past 50 years should’ve been worked on instead of giving up because of a failure...failure is a tool to make better versions of itself and everyone even the folks who fund/invest in these things have to learn that failure is part of the creation of great things...sadly these things cost money and investors turn tail at the first sign of failure which halts progress and that’s the reason we don’t see technology that can change our way of life

[@MrBazukaz]

True, imagine if they quit thinking that this won't work,i think the important part is to learn from those mistakes unless you correct those mistakes you can't achieve success

[@rtchow3000]

we would still burn whale fat if Edison quit on the 2000 tungsten bulbs or bee wax for candle. failure is a virtue that makes this world turn.

[@MrBurninCross]

The 'we' you're referring to is a very limited size club and are not in a cross section of the masses here or anywhere

[@fromagefrizzbizz9377]

@cass nortom Antarctica? You look up a travel agency that books such trips and book one. It's just that easy. 12,000 people do it per year. By ship, by plane, by dogsled and by ski. It's just that simple. What does MH370 have to do with anything?

[@fromagefrizzbizz9377]

@cass nortom Of course you can't cross it from north to south. You can only cross it north to north. Think about it dimwit. What makes you think you can't go there? The treaty doesn't say you can't, no matter what those frauds and charletans are telling you. 12,000 people per year can't be wrong. Messner and Fuchs walked it in 1989. In 1990 International Trans-Antarctica Expedition did it. Fiennes and Stroud in 1992. Ousland 1996. Arnesson and Bancroft 2001. felicity Aston all by herself in 2012. There are many more. Prove those are all fake. Come on, try. No you are not that rich. You're too stupid to have earned it, and too gullible to keep it. I've already proven you wrong, so you should give your imaginary money to me. Prove that MH370 didn't "crush". Come on, prove it. There's not a shred of evidence for that. And -plenty of evidence for saying it did *crash* moron.

[@slifer9990]

I know I cannot comprehend the sheer marvel that is the falcon 9! This is straight out of a sci fi novel

[@paulcarter2907]

WHAT EVER THE REASON, IT WORKS..CLEVER STUFF, BRAVO

[@sorenkair]

1:07 my good sir, learn about the wonders of easy ease!

[@TechforToastmasters]

An average Joe like me learned something. Thanks.

[@whitneyeaton5585]

Pretty much- JUST WOW! WELL DONE, KEEP IT UP

[@enrichingexchanges]

Beautifully explained!

[@Garryck-1]

Well.. that was disappointing.. was hoping to learn something I *didn't* already know. And you lost my upvote for this *very* inaccurately phrased question "How do they land 70m tall rockets weighing in excess of 500,000kg?" The simple answer is, *they don't* . The first stage, the only part that lands back on Earth, is around 40.5m tall, *NOT* 70m. The calculations I've found suggest that for a RTLS (Return To Launch Site) landing, around 64,000kg of fuel and oxidiser is needed. Barge landings require considerably less, because RTLS boostback consumes roughly 2/3 of that. So let's assume that (including an overly generous safety margin), around 100,000kg is reserved for landing. Factor in the dry mass of the first stage (25,600kg) and you have a returning mass of 125,600kg, which at touchdown will be about 50% of that. That's a hell of a lot less than 500,000kg! I'd have thought that somebody with an engineering channel would try to be a bit more precise with their figures. Especially considering the above numbers only took me around 5 minutes of online research to pull together. Colour me unimpressed.

[@ArtofEngineering]

I have already acknowledged this oversight in the pinned comment. I am aware that I should have provided the measurements of the entire Falcon 9 rocket as well as the measurements of the first stage by itself.

[@Garryck-1]

@@ArtofEngineering - Well.. it's not too late.. you can always edit and re-upload.. or put some corrections in an overlay, at least. Plenty of other youtubers do so, and over far less egregious errors than this.

[@Garryck-1]

@@ArtofEngineering - Oh.. and I don't see *any* pinned comment..you might want to look into that.

[@737smartin]

@Art of Engineering I appreciate that you acknowledged the errors and I agree that it’s a shame KZbin doesn’t support corrections when content goes astray. The sad result is a lot of well-intended misinformation just stays out there to be is seen and seen again. I still appreciated the video.

[@CorneBreed]

i also stopped the video there and came to the comments section

[@creativecreepyturtle1562]

NASA: **makes massive rocket** wait the costs didn’t come down SpaceX: imma strap 3 falcon 9s together to send a small car into space and make more money

[@ebony5766]

Absolutely incredible.

[@thomaspinto1111]

Wonderful engineering a great job!

[@freediverhd]

Lets face it - You don't have anymore insight into the accuracy than any other space x fan.

[@muzafarahmed9101]

do you think he was going to give away space x proprietary technology secrets?

[@Knightfire66]

why? he told everything... gps, internal sensors, fins, several thrusters, reignitable engine, main thruster vector control... for me the only breathtaking systems are the engine itself and the thrusters... all other stuff are also in millions of rc toys... but those engines are a revolution... how cn the thruster keep up with so much power?`how do they reignite the main engine in space?

[@operatorjewski9450]

Tell me then "spacex fans who are so intelligent" i want to know how they land it accurately.

[@anzelmasmatutis2500]

Take any of 1-6 listed item and READ in more detail about it.

[@michaeldeierhoi4096]

Let's face YOU just didn't understand the video. Don't feel bad because some other commenters were also confused.

[@RaisingSaintsAcademy]

I don’t think the general public truly understand this achievement! I mean, this is history making, which will concretely secure Elon Musk & Space X in future historical records for space travel!! 🤓

[@jamesahern9864]

5_30-31_2020 Hell yeah!

[@1_2_die2]

Fantastic explanation of a great achievement. Maybe you can make a follow-up video to this in January 2020, as we had hopefully experienced the successful attempts of Starship.

[@larryslemp9698]

Fascinating!! Wonderful production!!