Actually Elon has mentioned that 304 had better ductility. He didn’t use that word but based on all his tweets and interviews he explained that it bends before bursting or breaking and that’s more desirable. He mentioned this during the SN7 burst test. There is going to be another test with better welding techniques as well.
As a knife maker who works with stainless steel, including heat treating and cryogenic treatments, this was a superb video! Everything presented was in alignment with my limited understanding. Looking forward to more content if it as good as this.👍
Thank you, as material engineering student(EEIGM, Saarbrücken, Germany) i thank you. You helped me make connection between my major and the starship development :)
You say it's your first video, well you nailed it. I am a mechanical engineer from the Netherlands which works a lot for the semicondutor industry. These topics are daily topics for us (looking at materials etc). Your methodic analyses, your excellent image contents and your clear explanation is really great! So please go on with this. By the way, a also worked for aviation and space industry, one of the this which is strictly forbidden in the high tech fabrication industry is to use wire edm and sink edm, this due to the so called "white zone". If you ever out of topics, maybe this is one for you. All the best with you channel and please go on!
Thank you!!! I know that what I explain here is pretty much mechanical engineering 101, but I'm still really surprised that I didn't mess anything up :)
Pretty good for a first go. Please do more, Vojtech. I am not an engineer, I don't even play one on television. But I am a critical thinker. You did an excellent job of explaining the concepts with a nice amount of humor, the comment about the stainless steel kitchen, added in.
Thank you Fred! I am an engineer, but in a very non-spaceflight related field, so I am having fun learning. My videos will only get better over the time, I hope :)
I hovered over this video for a moment thinking is it even worth it after watching the Everyday Astronaut video. It absolutely was! Great job! I hope you keep the intro for the next videos
Thank you so much. Yeah, Tim is nailing it. His channel was definitely a partial inspiration for me, but I just want to do deep dives in stuff that I want to learn. I'll just be making videos that I would like to watch 🙂
The world needs more engineering explanations like this! The level of detail was good for a start. I would love to see you make more videos, and my only recommendation is the old joke: "how do I get to Carnegie Hall? Practice, practice, practice!" For a first video you did great! Keep going! Cheers!
Great job from a civil engineer! I have to say that this video explains (accurately!) stress-strain curves, strength, ductility, elongation and toughness better than most civil engineering lectures out there.
Amazing quality video, hard to believe this is your first, well done. Looking forward to seeing what other topics you will cover. Might i suggest a clapper to sync audio and video. Lip movement is slightly out of sync with sound
Thank you for the advice! I did not notice that. I guess I didn't even considered it since I recorded audio and video at the same time into the same file
Great video with an interesting subject! I’m a mechanical engineer with a good amount of experience in metallurgy, and your explanations were very clear and flawless. I’m not entirely sure if it would be clear for someone without a scientific background (but realistically, if you clicked on this video, you’re pretty much interested in the subject and eager to learn about it). Now some feedback on the form of the video. Visually, great camera, great light, great background. The rythm is good, no dips and lows, and I could see that you tried to make the narration interesting. Your diction is good, and your accent is not a issue to understand. I can see that’s your first video, so the following issues shouldn’t be too hard to fix. I’m not sure how to explain it, but your voice sounds a bit robotic, maybe regarding to reading the script or trying to hard to articulate. I can see as well a lack of confidence in front of the camera, so try to be more spontaneous and yourself! I hope I’m not too harsh, but I subscribed, and I want to see more!
Thank you so much for the comment! I'm not a mechanical engineer, I just dip into it here and there, so I never know what I don't know. I absolutely agree with the robotic voice. I think it is caused by the things - focusing too much on memorizing the lines, and having the microphone too far away forcing me to be louder and more articulate. I hope I'll fix that in the next video, which will be on Whipple Shield and MMOD risk management :)
blacksmith/metalworker here... Great explanation! Liked the clear, useful, well explained graphs, too. Obscure graphs are too often used without sufficient explanation in videos - you took the time to make sense of them, and their axes. Looking forward to more videos.
Wow, very nice video. I have a computer engineering degree so mechanical engineering is an area I never got to really investigate but have always been fascinated by. Thanks for the detailed analysis!
Terrific video! In a decade of UA-cam I've subscribed to less than a dozen channels. Here you've got me subscribed on your first video. I subscribed because your level of explaining the technical details is excellent. You introduce a term, define it, and apply it. That's the best way to teach, and I hope to see many more technical subjects related to spaceflight explained like this. Thank you!
I spend about 8-10 hours per day playing science YT videos (while I work from home and walk the dog). I think you should be very proud of this video. Many UA-camrs cringe watching their first videos after years of being in the biz. The audio quality of your video is good, with minimal echo. The graphs and material science was well explained. Easy to understand without prior, university level knowledge. The pacing is good. Not so fast I had to rewind to catch points, not so slow that I would get bored. A patron perk should be access to blooper moments that get cut out. 😋
Thank you Michael for the kind words! I do cringe even now watching myself :-) The audio definitely needs some improvement, but not more than my video presentation skills. Well, hopefully, those come with practice!
@@spaceflightexplained360 that cringe feeling is just imposter syndrome. Some eggshell foam on the walls and a better mic, and your audio will be perfect. But as is, it's good enough to not be distracting.
Good sound. Good lighting. Good editing. I’d say you’re most of the way there. The hardest part will be gathering compelling content over the long haul.
Thank you! There are definitely improvements to be made. I do have many topics I want to talk about and my videos will be coming out very slowly, so I'll cross that bridge when I come to it :)
Good dive into interesting subject - informative. Suggest Starship welds will be annealed during the test flight reentry, in which surface temperatures should exceed 1000°C then slowly cool after landing. Great work VH, love the set btw.
Looks like @Daniel Risacher and I both agree with you on this. Coupled with all starships up to SN 50+ will likely be cargo variants they will have this datasaet nailed to understand heating(annealing) results in various atmospheric reentry conditions. I have also been thinking a lot about basically oven proof robotic welders. Obviously super-expensive process both in terms of energy and financial capital; Oven heats Metal to be welded to annealing temps, welding medium is inside also same temp., Maybe even solid state infrared inside vacuum chamber (lol), there would be no insulation needed, and highly efficient as all energy goes into the piece being heated. Weld that piece under those conditions. Removes the need for flux mostly as well. I wonder what benefits would arise from a process like this if any.
@@CalebFuel Ha! That is an interesting idea! Annealing by atmospheric reentry. There are two things that would worry me: 1) The annealing has to be controlled pretty well w.r.t temperature and time. If you heat it up too much or too little, you might make it worse. 2) Only the windward side will get a lot of heat, resulting in non-uniform process. Combined with 1), I it would be very hard to do well.
@@spaceflightexplained360 Very valid points. 1) I understand controlled heat treating and variations within the treating process can cause cracks and all kinds of bad things, however that is why I am hoping that through a 50+ starship prototype run, they may be able to nail this. One example is the ballistic coefficient of starship and the atmospheric conditions at various heights (extreme upper atmosphere) are well known quantities. Factor these into an orbit that keeps you at altitudes (think Heat Regimes) you want to be in for periods of time you need to be in. I understand this would be fuel dependent , likely having to reboost alot throughout the process, but hey we have to work on On-Orbit refueling too right? lol Where else is he gonna find an Annealing Oven big enough for Starship? 2) This is one I can not figure out. I am not sure of the effects of uneven annealing on any material much less 30X SS that Spacex is choosing to use. Also factoring that windward side will be covered in Tiles anyways .. I just dont know. Would be super cool if he figured out how to accurately heat treat all of SS and boost its performance characteristics immensely.
Actually reading through my last comment, my solution to 1) solves 2). Understand heat regimes, keep SS in altitudes that heat how needed , as needed , without ever going over thresholds thermally. With it unmanned , you can even roll the ship through the process to ensure even heating once you got the tiles hot enough on the bottom. Just have to dial in your values and thresholds for where you do and dont want to go.
This needs more explanation than just a simple sentence. Wouldn't annealing it, under any circumstances, require a temperature rise that would soften or weaken the metal? And in any event the heat of re-entry would likely be very uneven. Furthermore, he described heating it for a long period of time such as an hour in order to accomplish annealing. The idea of annealing on reentry needs a lot more explanation.
if you had any more video, I would check it out as I liked this one. I had been wondering about this very topic but didn't want to spend the time needed to inform myself, so this was great.
Thanks! Yeah, SpaceX is such a dynamic company that so many things and so publicly, that you can have several channels just doing the "news" on them. Don't get me wrong, I'm subscribed to few as well (and a subreddit), but I am interested more on "Why" and "How" than "What". Also, SpaceX will be only a part of what I want to cover, there will be lot of videos on universal concepts related to Spaceflight
Very well done.... I`m an inspector and engineer and you nailed it.... its all about the welds holding... thank you so much I look forward to more of your videos...
@@spaceflightexplained360 I inspect everything from rocket engines for Aerojet, airplanes, helicopeters, rockets,boats, all military hardware for Boeing, Computer wafer shaving machines and semi conductor molds for UMD (united mold and Die) , nuclear power plant welds, Medical tools and body attachments. I have inspected and rejected parts in 28 countries..... etc..... I`m retired but Space X has offered me a job and I`m considering it....... have a great day my friend
One additional thing that I hope the designers factored into consideration: The Charpy V-notch test is good for determining the toughness of a material, but in the case of Starship (not the early ones but full production models) the steel will be exposed to extensive radiation during it's weeks, or months, in space. Over time this will embrittle the steel, reducing it's toughness. The same thing is seen in steel used in Nuclear reactors. This additional embrittlement must be taken into account over the lifetime of the vessel or catastrophic failure (especially when heating up or cooling down the material) could result.
May be a double hull system or better still enter into a "Mothership" "Generation ship" specifically built for true space travel in the future. Each celestial object could have specialize crafts to suit take-offs & landings.
If you go to Outokumpu web you will see a lot of stainless steel information, grades, diff grades for multipel applications, grades for severe corrossion problems, grades for seawater app.. etc etc and also technical articles. Etc
Well presented and accurate. I worked in the US Space Program as a Mechanical Engineer. Surprised you did not mention "deformation hardening?" The physicals will increase even more on 304L tanks if they are pressurized past yield (about 10% into that segment of the curve.) Our product depended upon strength through staying pressurized. Also we had a gigantic (for the time the biggest ever,) robotic welder that had a reach of over 30 feet to weld inside the tanks nearing completion. Another consideration is "sugaring" during welding 3xx series. Purge gas can be used in a manner much more effectively with a robotic welder (on the inside of the tanks.) Great presentation, keep up the good work!
Than you George! I feel like work hardening is such complex and to me somewhat non-intuitive process that I did not want to go there. Especially when I have no idea what exact hardening they are using. Based on the public information, assuming 9 m diameter, 3 mm thick steel and 8.4 atm of pressure, the hoop stress is about 1260 MPa, which would suggest a highly hardened steel. But I just don't know...
@@spaceflightexplained360, they kept it really simple back then, K.I.S.S. Basically the vehicle (booster) was the fuel tank. There were minimal internal structures to support the load through the vehicle. Worse case were acoustic vibe loads (80g+) and when we hit the jet stream, (going 6,000 mph 150 mph "cross winds aloft.") To compound things Max Q/Max Buffet occurs before that, so the bird needed to be pointing just right at that point. (Visualize a empty soda can, and you can stand on it carefully, then have someone tap it and see what happens.) At each end of the tanks, we had supports like the engine thrust ring and the inter-stage adapter up top. If you just look at the cylindrical tank, WORK HARDENING was achieved by welding the tank up, and pressurizing the the tank into the yield range. You can visualize this as a "skin stretch past yield point," that IS the work hardening. You might imagine using a liquid and filling a tank to about 1,000-1,200 psi. like a "water hammer." This is about 3-5x worst case/SF=3.0 (although I worked on some components that had S.F. (Safety Factor) = 0.97! CRES 304L is an IDEAL material for this. Strength increases are 10-20% post proof. Therefore we could go thinner wall sheeting. So thin that I could push my hand and deflect the booster skin if the tank was not pressurized. In fact if the tank was NOT pressurized, it would collapse under its' own weight (actual thickness is classified, but it is thin.) This saved weight translated to about $50,000/pound of savings back then, prob 2x now. This was an added bonus! And it all came from earlier ultimate testing to destruction (fun stuff!) and analyzing the material properties. Sorry so wordy, love this stuff!
@@george1gall I would love to hear more of your stories! I assumed that you worked for Lockheed on Atlas III? One of the thing Elon was very specific about that they don't want a balloon tank. They want it to hold its own weight when not pressurized. So they have bunch of welded struts inside so I wonder, if the work hardening by controlled " inflation" would still be an option. It is super interesting to think about though, because it can be such a controlled process. What surprised me in what you said is that the tank was designed to survive over 3x the intended loads? That is a crazy safety factor for rockets, I thought it is like 1.1 to 1.4...
@@spaceflightexplained360 I worked for Space Systems, a division of General Dynamics. The vehicle was the Centaur which was stacked on the Atlas and Titan boosters. I did structural analysis and design work on the Titan IVB/Centaur. So I worked closely with Lockheed-Martin, USAF, Marietta, UT, Morton, Rockwell and a few others depending upon payload. The group next to ours was Atlas/Centaur, they were in the midst of conceptualizing the Atlas 5 when I was there. I saw many Atlas II and III's at the giant Class 1000 clean room at the shop. Balloon tanks are the most efficient, weight wise. I believe the Centaur program had a 95% success rate, which IMO sucked. Out of almost 250 launches that was 13 LOM's and three partials. But this is what we get when we go down a path so far that emerging technologies which were studied, tested and proven could not be implemented. 1950's tech. Politics played a big part, failures were like a battle loss during the Cold War. And, the vehicles were intentionally "expendable" and NOT man-rated. I love what I am seeing with SpaceX, Blue Origin and ULA. When I saw the success of Falcon 9's first stage return, I was like "YES!!!" as we had that and many other ideas on "vellum" lol. NASA actually built a proof of concept called DC-X but I don't think the technology (mostly guidance syst.) was there yet. Of course the re-usable concept was in full effect with the Space Shuttle which was cryo mains and solid SRM's, and strutted throughout. That said, I think Elon Musk overall is aiming more toward carrying people which will require steadfast reliability and egress. Added parameters. He uses a bold engineering approach, where concepts are quick to prototype and back-peddling is okay to do, and THAT is key to advancement. I am willing to bet he started with composites then went down the list. We actually used composites on later versions, but it was a headache, things like voids in the resin matrix out in space, thermal contractions rates at interfaces. And scale factors in general, (ie. make a giant composite tank, but using the same tiny fibers. No go.) Implementation of struts, longerons, trusses throughout the lower stages for sure seemed logic I bet. The issue becomes thermal contraction from the hypergolics, though not nearly as drastic as cryogenic fuels, will present stress concentrations at skin/struct interfaces. This implies the need to weld the shit out of it, which in turn means more weight. Thank goodness rocket engines are so much better now, so perhaps just add another motor and brute force it out. The hardening process for 304L I described required fixturing, containment, and safety structures. That was the higher safety factor req back then (5.0 is like for a bridge, LoL.) If it were possible, just pressurizing their 304L tank then adding structures would add about 10-20% more strength. It was all pioneering work which required proof testing, and it wasn't known if the catastrophic failure would play out as per predictions. For flight equipment, I often was using a SF in the 1.2 or 1.3 range but as mentioned, when I had one set of components come across my desk with SF=0.97, it got my attention. Analytical technology was not where it is now, and the existing materials were definitely being pushed to the max, beyond... That structure was for Shuttle C, a wingless shuttle proposed after the LOM of STS-51 L. It was for a filament wound kevlar spherical tank. The mounting struts actually. Never flew so it went under the rug. Hey, I didn't mean to hijack your channel. I'm sure there are tons of books about those pioneers, and the race to space. It's just really cool to see something like what you are doing on UA-cam. I know it takes a lot of time and effort. Thanks for doing that!
You took me back to my University Mechanical Engineering materials science class of 30 years ago. Great content and stellar job at the reasoning & explanation. Keep up the good work.
Great video Vojtech. Please keep them coming. You are nervous in this first video but you have a great screen presence and you have edited like a pro. I will subscribe straight away and can't wait for you to get really comfortable with doing these videos. I studied as a mechanical engineer and you covered all the aspects I wanted to be discussed. Really looking forward to more Vojtech. Thank you...
Excellent explanations, amazing for a first video. Loved the depth that you went to in all that you said. Keep going as the world needs many many more videos like these and remember in 10 years it will be something that you and the world will need and be very proud of.
I agree the welds appear to be the weak link. Video of the starship explosion showed rectangler pieces flying out of the fireball. That tells me that welds failed long before the parent material.
Man it was a long time since I saw a steel strain graph. Brings back memories from Uni. Keep up the good work, I think you're right on point with your analysis!
Nice honest opening; no jazz, no attention getting tricks. I like that you asked for an up or down score, after, the video. I hate those pushy types who insist on an up vote at the start. They get an instantaneous down vote, which I may or may not remember to change, after. I only give premature up votes to my regular heros; so I don't forget to give them credit. Well done.
Subbed! Great for first vid. Please add more lightings, no shadows, zoom out a little, better if we see both of your hands as you talk. So much potential!
10/10 and my feedback is: please show graphics and labels to distinguish between the two types of steel. Which you did... but I mean is, like add something to make it easier to study, like add a spring to the graph about 301
Your explication were great. Your understanding of engineering is evident, and really shows in how you are able to make explication that all of us can understand. It would be fun to take engineering classes from you. Keep making more videos!
I loved your way of explaining things. It was very informative but never went on so long that it got boring. So keep it up im subbing to see what you come up with next you really have a potential
Great stuff -? (I missed your name). A fairly concentrated effort was required by me that’s ok. It’s good to try to understand new topics and you explained things very well. I also like the quirkiness of the video and the hand drawn stuff. Thanks! 🚀
That was amazing! Good job with the video, it was very well explained. Do you think SpaceX will use 301 or completely different alloys in areas that are not directly in contact with the cryogenic fuel, like the nose cone and the bottom area around the engines?
Thank you! I wanted to make that impression and I had inspiration from other high quality channels... I think I did well in the script and editing part, the main improvement left are my video presentation skills
This was really interesting and informative thank you! Seeing the graphs and a nice simple explanation of what they represented made it easy to grasp. I Look forward to your next video 🙂
This is awesome! Keep it up and more videos please! You nailed the backdrop. My SpaceX videos have always been changing background haha. Can see this channel getting HUGE. Thanks.
@@spaceflightexplained360 it's just so accurate! Hex tiles is quite the Easter egg. And I can't get my eyes off hottie Gwenn Shotwell 🔥🔥 Can't wait to see more and would be more than able to help you in any way.
Great video, good format! Even got me to LOL :D. Since you're asking for feedback: I found it slightly unnatural to see double light specks in each of your pupils (I guess due to the lighting setup). I would personally also prefer getting all important/unfamiliar words spelled out (for example at 3:26, "plastic/elastic deformation"), even if you erase them soon after for decluttering. Reading in addition to hearing helps parse & remember them better.
Thank you for taking the time to make a clear and concise explanation of what is a somewhat confusing subject for us (untutored) SpaceX fans. I hope to see many more going forward, and good luck n your new endeavor.
Thank you! I'm one of you, I admire SpaceX and the passion the people have and the difference they are making. Also it is plain cool. But I also love engineering that went into ISS and other things :)
Spaceflight Explained You did good. For most people interested, it's pitched perfectly. If people are interested in the 'why' then you need to have some level of technical information. I don't think you covered anything I did not learn in Material Science in high school. If more people learnt the science and engineering behind decision making then more people would be interested in STEM.
Excellent video. You touched on everything I could think of. There is a small distinction between toughness (the energy a material can absorb before breaking) and fracture toughness (the ability of a material to arrest crack growth). Typically Charpy tests are used to ensure good fracture toughness. And fracture toughness is what SpaceX would care about since all those welds are not likely to be perfect and contain tiny flaws that you do not want to grow into large cracks.
Thank you for the insightful comment. I was wondering that myself, but it is impossible to find the data for regular toughness. The fracture inducing notch definitely changes things a bit, but this is the most relevant experiment with some data available that I could find.
You are the first person ever to say that I don't have an accent haha. It is actually super strong. I turned to the subscriber count so that the low number (first video...) Doesn't discourage people from subscribing. It is a little above 2500 now, which is astonishing and unexpected.
I think it is worth thinking about after treatment. It would need to be a huge oven or maybe with inductictive heating, but when you can reduce the overall weight of the starship by let us assume 25% that would open up a lot of new options. Much higher payload, less fuel needed etc. When considering that there may be build thousands of starships it would be worth the effort to built the technology to heat treat the readily welded starships.
Amazing first video ! Starships are reusable and when they re- enter the atmosphere the SS can reach 1500C. Therefore a reused starship is annealed. Does that mean a reused starship is stronger than a new one ?
You don't want your steel to get that hot - that is a melting temperature. You definitely want to keep it below 1000 C or less, otherwise your work hardened steel will get weaker because of the annealing. It might be good for welds, but bad for steel.
I'll just leave this here... Hello there!
ua-cam.com/video/rEq1Z0bjdwc/v-deo.html
You are a bold one!
General Kenobi
Outstanding!!! 🤣
Actually Elon has mentioned that 304 had better ductility. He didn’t use that word but based on all his tweets and interviews he explained that it bends before bursting or breaking and that’s more desirable. He mentioned this during the SN7 burst test. There is going to be another test with better welding techniques as well.
Finally a real engineer vs the monitor engineers commenting on other youtube channels. Subbed
Genghis Khan agreed!
As a knife maker who works with stainless steel, including heat treating and cryogenic treatments, this was a superb video! Everything presented was in alignment with my limited understanding. Looking forward to more content if it as good as this.👍
Thank you! I really appreciate comments from anyone who works in the field!
I am a sheet metal worker who has been following Starship building. I love hearing more about the steel and engineering. Thanks.
Care to share your professional opinion on Starship design and engineering?
Damn, this is your first video? Nice work.
Jake Biddlecome agree ... I immediately subbed
Thank you, as material engineering student(EEIGM, Saarbrücken, Germany) i thank you. You helped me make connection between my major and the starship development :)
Same here :-)
You say it's your first video, well you nailed it. I am a mechanical engineer from the Netherlands which works a lot for the semicondutor industry. These topics are daily topics for us (looking at materials etc). Your methodic analyses, your excellent image contents and your clear explanation is really great! So please go on with this.
By the way, a also worked for aviation and space industry, one of the this which is strictly forbidden in the high tech fabrication industry is to use wire edm and sink edm, this due to the so called "white zone". If you ever out of topics, maybe this is one for you.
All the best with you channel and please go on!
Thank you!!! I know that what I explain here is pretty much mechanical engineering 101, but I'm still really surprised that I didn't mess anything up :)
Pretty good for a first go. Please do more, Vojtech.
I am not an engineer, I don't even play one on television. But I am a critical thinker. You did an excellent job of explaining the concepts with a nice amount of humor, the comment about the stainless steel kitchen, added in.
Thank you Fred! I am an engineer, but in a very non-spaceflight related field, so I am having fun learning. My videos will only get better over the time, I hope :)
Loved it. Good amount of quality content and no fluff or filler, great stuff
I hovered over this video for a moment thinking is it even worth it after watching the
Everyday Astronaut video. It absolutely was! Great job! I hope you keep the intro for the next videos
Thank you so much. Yeah, Tim is nailing it. His channel was definitely a partial inspiration for me, but I just want to do deep dives in stuff that I want to learn. I'll just be making videos that I would like to watch 🙂
The world needs more engineering explanations like this! The level of detail was good for a start. I would love to see you make more videos, and my only recommendation is the old joke: "how do I get to Carnegie Hall? Practice, practice, practice!" For a first video you did great! Keep going! Cheers!
Great job from a civil engineer! I have to say that this video explains (accurately!) stress-strain curves, strength, ductility, elongation and toughness better than most civil engineering lectures out there.
very good video production. good theme/length, good explanation, good background, not that much theory for non-pro welders. Thumb up!
Thank you! I wish I knew more about welding, both practice and theory...
Amazing quality video, hard to believe this is your first, well done. Looking forward to seeing what other topics you will cover.
Might i suggest a clapper to sync audio and video. Lip movement is slightly out of sync with sound
Thank you for the advice! I did not notice that. I guess I didn't even considered it since I recorded audio and video at the same time into the same file
@@spaceflightexplained360 video is excellent. the audio does need some attention. On my surround sound your voice kept jumping between speakers.
Great video with an interesting subject! I’m a mechanical engineer with a good amount of experience in metallurgy, and your explanations were very clear and flawless. I’m not entirely sure if it would be clear for someone without a scientific background (but realistically, if you clicked on this video, you’re pretty much interested in the subject and eager to learn about it).
Now some feedback on the form of the video. Visually, great camera, great light, great background. The rythm is good, no dips and lows, and I could see that you tried to make the narration interesting. Your diction is good, and your accent is not a issue to understand. I can see that’s your first video, so the following issues shouldn’t be too hard to fix. I’m not sure how to explain it, but your voice sounds a bit robotic, maybe regarding to reading the script or trying to hard to articulate. I can see as well a lack of confidence in front of the camera, so try to be more spontaneous and yourself!
I hope I’m not too harsh, but I subscribed, and I want to see more!
Thank you so much for the comment! I'm not a mechanical engineer, I just dip into it here and there, so I never know what I don't know.
I absolutely agree with the robotic voice. I think it is caused by the things - focusing too much on memorizing the lines, and having the microphone too far away forcing me to be louder and more articulate.
I hope I'll fix that in the next video, which will be on Whipple Shield and MMOD risk management :)
@@spaceflightexplained360 Great! I can't wait then! :D
@@spaceflightexplained360 Oh man, looking forward to the next video already. High velocity impact mechanics are weird and fascinating.
A riveting story arch with well explained details, love this!
No rivets......just welds...... LOL
blacksmith/metalworker here... Great explanation! Liked the clear, useful, well explained graphs, too. Obscure graphs are too often used without sufficient explanation in videos - you took the time to make sense of them, and their axes. Looking forward to more videos.
Thank you! I had to recreate those graphs from multiple more obscure plots in my sources, so that helped to communicate the message better.
Wow, very nice video. I have a computer engineering degree so mechanical engineering is an area I never got to really investigate but have always been fascinated by. Thanks for the detailed analysis!
Great! I'm EE/Math and I'm relieved that this video was seen be few experts in the field and they gave it thumbs up.
Welcome to the space community and your content was amazing, my jaw dropped when you said this was Video#1.
Thank you!
Thanks for take time to put it together. Nice video. I think if you can produce some computer animated graphics could improve the videos.
Can't wait for your next videos!!
Very soon!
first video? Wouldn't have guessed. Nicely produced, dude. Keep going..
Great content and style Vojtech, keep it up please!
Terrific video! In a decade of UA-cam I've subscribed to less than a dozen channels. Here you've got me subscribed on your first video.
I subscribed because your level of explaining the technical details is excellent. You introduce a term, define it, and apply it. That's the best way to teach, and I hope to see many more technical subjects related to spaceflight explained like this. Thank you!
Thank you for the praise! I was lucky enough to have a lot of good teachers in my life, so it is sort of natural way to learn things for me.
Nice work on your first video, very informative. :)
I spend about 8-10 hours per day playing science YT videos (while I work from home and walk the dog). I think you should be very proud of this video. Many UA-camrs cringe watching their first videos after years of being in the biz.
The audio quality of your video is good, with minimal echo. The graphs and material science was well explained. Easy to understand without prior, university level knowledge.
The pacing is good. Not so fast I had to rewind to catch points, not so slow that I would get bored. A patron perk should be access to blooper moments that get cut out. 😋
Thank you Michael for the kind words! I do cringe even now watching myself :-)
The audio definitely needs some improvement, but not more than my video presentation skills. Well, hopefully, those come with practice!
@@spaceflightexplained360 that cringe feeling is just imposter syndrome. Some eggshell foam on the walls and a better mic, and your audio will be perfect. But as is, it's good enough to not be distracting.
Great presentation, great to see a love of learning taking hold. Looking forward to seeing where you can take this.
Looking forward to the next one.
This was so good! The animation and walk-through of the toughness pendulum is so accessible to anyone and yet information-dense. Thanks, keep it up!
Thank you so much! My goal is to make videos that I'd like to watch, and the way that makes me understand it 😁
Excellent information, finally a bit of engineering.
Really great info and great production for a first video!
Great stuff! Well presented and explained. And this is your FIRST video?!!
Great description ... outstanding job on your first video!
Good sound. Good lighting. Good editing. I’d say you’re most of the way there. The hardest part will be gathering compelling content over the long haul.
Thank you! There are definitely improvements to be made. I do have many topics I want to talk about and my videos will be coming out very slowly, so I'll cross that bridge when I come to it :)
Good dive into interesting subject - informative. Suggest Starship welds will be annealed during the test flight reentry, in which surface temperatures should exceed 1000°C then slowly cool after landing. Great work VH, love the set btw.
Looks like @Daniel Risacher and I both agree with you on this. Coupled with all starships up to SN 50+ will likely be cargo variants they will have this datasaet nailed to understand heating(annealing) results in various atmospheric reentry conditions.
I have also been thinking a lot about basically oven proof robotic welders. Obviously super-expensive process both in terms of energy and financial capital; Oven heats Metal to be welded to annealing temps, welding medium is inside also same temp., Maybe even solid state infrared inside vacuum chamber (lol), there would be no insulation needed, and highly efficient as all energy goes into the piece being heated. Weld that piece under those conditions. Removes the need for flux mostly as well.
I wonder what benefits would arise from a process like this if any.
@@CalebFuel Ha! That is an interesting idea! Annealing by atmospheric reentry. There are two things that would worry me:
1) The annealing has to be controlled pretty well w.r.t temperature and time. If you heat it up too much or too little, you might make it worse.
2) Only the windward side will get a lot of heat, resulting in non-uniform process. Combined with 1), I it would be very hard to do well.
@@spaceflightexplained360 Very valid points.
1) I understand controlled heat treating and variations within the treating process can cause cracks and all kinds of bad things, however that is why I am hoping that through a 50+ starship prototype run, they may be able to nail this. One example is the ballistic coefficient of starship and the atmospheric conditions at various heights (extreme upper atmosphere) are well known quantities. Factor these into an orbit that keeps you at altitudes (think Heat Regimes) you want to be in for periods of time you need to be in.
I understand this would be fuel dependent , likely having to reboost alot throughout the process, but hey we have to work on On-Orbit refueling too right? lol
Where else is he gonna find an Annealing Oven big enough for Starship?
2) This is one I can not figure out. I am not sure of the effects of uneven annealing on any material much less 30X SS that Spacex is choosing to use.
Also factoring that windward side will be covered in Tiles anyways .. I just dont know.
Would be super cool if he figured out how to accurately heat treat all of SS and boost its performance characteristics immensely.
Actually reading through my last comment, my solution to 1) solves 2). Understand heat regimes, keep SS in altitudes that heat how needed , as needed , without ever going over thresholds thermally. With it unmanned , you can even roll the ship through the process to ensure even heating once you got the tiles hot enough on the bottom. Just have to dial in your values and thresholds for where you do and dont want to go.
This needs more explanation than just a simple sentence. Wouldn't annealing it, under any circumstances, require a temperature rise that would soften or weaken the metal? And in any event the heat of re-entry would likely be very uneven. Furthermore, he described heating it for a long period of time such as an hour in order to accomplish annealing. The idea of annealing on reentry needs a lot more explanation.
AMAZING VIDEO SIR - Your first video? AMAZING again - your explanations and the live "drawing" style fit so well. Really REALLY enjoyed this video
if you had any more video, I would check it out as I liked this one. I had been wondering about this very topic but didn't want to spend the time needed to inform myself, so this was great.
Nice video! Lot's of people doing superficial coverage of SpaceX, this is much more in-depth but very well explained, very interesting!
Thanks! Yeah, SpaceX is such a dynamic company that so many things and so publicly, that you can have several channels just doing the "news" on them. Don't get me wrong, I'm subscribed to few as well (and a subreddit), but I am interested more on "Why" and "How" than "What". Also, SpaceX will be only a part of what I want to cover, there will be lot of videos on universal concepts related to Spaceflight
Very well done.... I`m an inspector and engineer and you nailed it.... its all about the welds holding... thank you so much I look forward to more of your videos...
Thank you! What is your exact expertise of I may ask?
@@spaceflightexplained360 I inspect everything from rocket engines for Aerojet, airplanes, helicopeters, rockets,boats, all military hardware for Boeing, Computer wafer shaving machines and semi conductor molds for UMD (united mold and Die) , nuclear power plant welds, Medical tools and body attachments. I have inspected and rejected parts in 28 countries..... etc..... I`m retired but Space X has offered me a job and I`m considering it....... have a great day my friend
Excellent description. No useless talking for the sake of elongating the video. I liked it.
One additional thing that I hope the designers factored into consideration: The Charpy V-notch test is good for determining the toughness of a material, but in the case of Starship (not the early ones but full production models) the steel will be exposed to extensive radiation during it's weeks, or months, in space. Over time this will embrittle the steel, reducing it's toughness. The same thing is seen in steel used in Nuclear reactors. This additional embrittlement must be taken into account over the lifetime of the vessel or catastrophic failure (especially when heating up or cooling down the material) could result.
May be a double hull system or better still enter into a "Mothership" "Generation ship" specifically built for true space travel in the future.
Each celestial object could have specialize crafts to suit take-offs & landings.
Excellent explainer! I now know more about stainless steel than i ever thought I would.
If you go to Outokumpu web you will see a lot of stainless steel information, grades, diff grades for multipel applications, grades for severe corrossion problems, grades for seawater app.. etc etc and also technical articles. Etc
Anyone else notice the Elon-gation at 6:04? ;)
haha! i said the same thing ='D
:)
fargh nothing to wet your pants about, standard engineering term that's been used for probably a couple of hundred years
@@mache1966 Didn't know Elon Musk was THAT old?????
@@mache1966 Serious much?
Well presented and accurate. I worked in the US Space Program as a Mechanical Engineer. Surprised you did not mention "deformation hardening?" The physicals will increase even more on 304L tanks if they are pressurized past yield (about 10% into that segment of the curve.) Our product depended upon strength through staying pressurized. Also we had a gigantic (for the time the biggest ever,) robotic welder that had a reach of over 30 feet to weld inside the tanks nearing completion. Another consideration is "sugaring" during welding 3xx series. Purge gas can be used in a manner much more effectively with a robotic welder (on the inside of the tanks.) Great presentation, keep up the good work!
Than you George! I feel like work hardening is such complex and to me somewhat non-intuitive process that I did not want to go there. Especially when I have no idea what exact hardening they are using. Based on the public information, assuming 9 m diameter, 3 mm thick steel and 8.4 atm of pressure, the hoop stress is about 1260 MPa, which would suggest a highly hardened steel. But I just don't know...
@@spaceflightexplained360, they kept it really simple back then, K.I.S.S. Basically the vehicle (booster) was the fuel tank. There were minimal internal structures to support the load through the vehicle. Worse case were acoustic vibe loads (80g+) and when we hit the jet stream, (going 6,000 mph 150 mph "cross winds aloft.") To compound things Max Q/Max Buffet occurs before that, so the bird needed to be pointing just right at that point. (Visualize a empty soda can, and you can stand on it carefully, then have someone tap it and see what happens.) At each end of the tanks, we had supports like the engine thrust ring and the inter-stage adapter up top. If you just look at the cylindrical tank, WORK HARDENING was achieved by welding the tank up, and pressurizing the the tank into the yield range. You can visualize this as a "skin stretch past yield point," that IS the work hardening. You might imagine using a liquid and filling a tank to about 1,000-1,200 psi. like a "water hammer." This is about 3-5x worst case/SF=3.0 (although I worked on some components that had S.F. (Safety Factor) = 0.97! CRES 304L is an IDEAL material for this. Strength increases are 10-20% post proof. Therefore we could go thinner wall sheeting. So thin that I could push my hand and deflect the booster skin if the tank was not pressurized. In fact if the tank was NOT pressurized, it would collapse under its' own weight (actual thickness is classified, but it is thin.) This saved weight translated to about $50,000/pound of savings back then, prob 2x now. This was an added bonus! And it all came from earlier ultimate testing to destruction (fun stuff!) and analyzing the material properties. Sorry so wordy, love this stuff!
@@george1gall I would love to hear more of your stories! I assumed that you worked for Lockheed on Atlas III?
One of the thing Elon was very specific about that they don't want a balloon tank. They want it to hold its own weight when not pressurized. So they have bunch of welded struts inside so I wonder, if the work hardening by controlled " inflation" would still be an option. It is super interesting to think about though, because it can be such a controlled process.
What surprised me in what you said is that the tank was designed to survive over 3x the intended loads? That is a crazy safety factor for rockets, I thought it is like 1.1 to 1.4...
@@spaceflightexplained360 I worked for Space Systems, a division of General Dynamics. The vehicle was the Centaur which was stacked on the Atlas and Titan boosters. I did structural analysis and design work on the Titan IVB/Centaur. So I worked closely with Lockheed-Martin, USAF, Marietta, UT, Morton, Rockwell and a few others depending upon payload. The group next to ours was Atlas/Centaur, they were in the midst of conceptualizing the Atlas 5 when I was there. I saw many Atlas II and III's at the giant Class 1000 clean room at the shop.
Balloon tanks are the most efficient, weight wise. I believe the Centaur program had a 95% success rate, which IMO sucked. Out of almost 250 launches that was 13 LOM's and three partials. But this is what we get when we go down a path so far that emerging technologies which were studied, tested and proven could not be implemented. 1950's tech. Politics played a big part, failures were like a battle loss during the Cold War. And, the vehicles were intentionally "expendable" and NOT man-rated. I love what I am seeing with SpaceX, Blue Origin and ULA. When I saw the success of Falcon 9's first stage return, I was like "YES!!!" as we had that and many other ideas on "vellum" lol. NASA actually built a proof of concept called DC-X but I don't think the technology (mostly guidance syst.) was there yet. Of course the re-usable concept was in full effect with the Space Shuttle which was cryo mains and solid SRM's, and strutted throughout.
That said, I think Elon Musk overall is aiming more toward carrying people which will require steadfast reliability and egress. Added parameters. He uses a bold engineering approach, where concepts are quick to prototype and back-peddling is okay to do, and THAT is key to advancement. I am willing to bet he started with composites then went down the list. We actually used composites on later versions, but it was a headache, things like voids in the resin matrix out in space, thermal contractions rates at interfaces. And scale factors in general, (ie. make a giant composite tank, but using the same tiny fibers. No go.) Implementation of struts, longerons, trusses throughout the lower stages for sure seemed logic I bet. The issue becomes thermal contraction from the hypergolics, though not nearly as drastic as cryogenic fuels, will present stress concentrations at skin/struct interfaces. This implies the need to weld the shit out of it, which in turn means more weight. Thank goodness rocket engines are so much better now, so perhaps just add another motor and brute force it out.
The hardening process for 304L I described required fixturing, containment, and safety structures. That was the higher safety factor req back then (5.0 is like for a bridge, LoL.) If it were possible, just pressurizing their 304L tank then adding structures would add about 10-20% more strength.
It was all pioneering work which required proof testing, and it wasn't known if the catastrophic failure would play out as per predictions. For flight equipment, I often was using a SF in the 1.2 or 1.3 range but as mentioned, when I had one set of components come across my desk with SF=0.97, it got my attention. Analytical technology was not where it is now, and the existing materials were definitely being pushed to the max, beyond... That structure was for Shuttle C, a wingless shuttle proposed after the LOM of STS-51 L. It was for a filament wound kevlar spherical tank. The mounting struts actually. Never flew so it went under the rug.
Hey, I didn't mean to hijack your channel. I'm sure there are tons of books about those pioneers, and the race to space. It's just really cool to see something like what you are doing on UA-cam. I know it takes a lot of time and effort. Thanks for doing that!
Well done. Thanks for the detailed explanation...was well presented, good script, and very plausible conclusions. Thanks again!
Very informative, clear, with all necessary background information.
Keep the good work, Vojtech!
Loved your detailed explanation. Keep going.
Great content and presentation! Looking forward to more deep dives into how SpaceX is challenging the accepted practices for building rockets
You took me back to my University Mechanical Engineering materials science class of 30 years ago. Great content and stellar job at the reasoning & explanation. Keep up the good work.
That is awesome to hear! Engineering induced nostalgia :) Thanks a lot!
Great video Vojtech. Please keep them coming. You are nervous in this first video but you have a great screen presence and you have edited like a pro. I will subscribe straight away and can't wait for you to get really comfortable with doing these videos. I studied as a mechanical engineer and you covered all the aspects I wanted to be discussed. Really looking forward to more Vojtech. Thank you...
Thank you so much! It is kind of 101 of mechanical engineering, but I'm still happy that I seemed to make no obvious mistakes
Excellent explanations, amazing for a first video. Loved the depth that you went to in all that you said. Keep going as the world needs many many more videos like these and remember in 10 years it will be something that you and the world will need and be very proud of.
I agree the welds appear to be the weak link. Video of the starship explosion showed rectangler pieces flying out of the fireball. That tells me that welds failed long before the parent material.
Great work man. Keep it coming.
Man it was a long time since I saw a steel strain graph. Brings back memories from Uni. Keep up the good work, I think you're right on point with your analysis!
Nice honest opening; no jazz, no attention getting tricks. I like that you asked for an up or down score, after, the video. I hate those pushy types who insist on an up vote at the start. They get an instantaneous down vote, which I may or may not remember to change, after. I only give premature up votes to my regular heros; so I don't forget to give them credit. Well done.
Looking forward to your next upload!
Subbed! Great for first vid.
Please add more lightings, no shadows, zoom out a little, better if we see both of your hands as you talk. So much potential!
10/10 and my feedback is: please show graphics and labels to distinguish between the two types of steel. Which you did... but I mean is, like add something to make it easier to study, like add a spring to the graph about 301
Your explication were great. Your understanding of engineering is evident, and really shows in how you are able to make explication that all of us can understand. It would be fun to take engineering classes from you. Keep making more videos!
Thank you so much! I think that the process of figuring these things on your own makes you understands and explain it better
This was a good video mate. Showing the temperature graphs was super interesting.
I have been looking for this info for ages. Thanks.
Superb and very clear. Thank you very much!
Amazing in-depth video. Looking foward to more!
Great engineering principles and insights. Well presented.
Very good explanation, great video! please keep the videos coming!
Your first video? Wow! It’s great. Thank you for the clarity of your explanations. Looking forward to much more.
Thank you Simon for the kind words!
Great video! You explained a very difficult concept in an incredibly clear way. I'm excited to see your future videos.
Awesome first video, man! Informative, accurate and to the point.
I loved your way of explaining things. It was very informative but never went on so long that it got boring. So keep it up im subbing to see what you come up with next you really have a potential
Classy and clear. Subscribed. Thank you, Vojtech.
Great stuff -? (I missed your name). A fairly concentrated effort was required by me that’s ok. It’s good to try to understand new topics and you explained things very well. I also like the quirkiness of the video and the hand drawn stuff. Thanks! 🚀
Nice and short explanation. Keep it up!
Great video and especially for your first!
Great video - please feel free to do more of these on any other topic starship related !
That was amazing! Good job with the video, it was very well explained.
Do you think SpaceX will use 301 or completely different alloys in areas that are not directly in contact with the cryogenic fuel, like the nose cone and the bottom area around the engines?
Probably the best first video I've ever seen!
Great Job on your first informational video. Well done! looking forward to your next one.
This channel has some good potential. Keep it up!
I knew exactly what you were talking about and i'm still not sure how you explained it so concisely in just 11 minutes. Nice work, great video
That is awesome, thank you! I hope you will like the future videos too!
Subbed. Excellent research and good presentation!
If that's your first video then wow.
Well presented and enjoyable to watch and listen too.
Nice one bro. X😁😁👍👍
Wow, this was your first video? Until you said that at the end, I assumed you were a well-established creator of high-quality content. Great job!
Thank you! I wanted to make that impression and I had inspiration from other high quality channels... I think I did well in the script and editing part, the main improvement left are my video presentation skills
Best explanation of 304L yet. Thanx. :)
This was really interesting and informative thank you! Seeing the graphs and a nice simple explanation of what they represented made it easy to grasp. I Look forward to your next video 🙂
good vid man. I like it. Would like to see more in depth analyses on material choice as people just seem to forget that materials matter.
Very well explained, good research
This is awesome! Keep it up and more videos please! You nailed the backdrop. My SpaceX videos have always been changing background haha. Can see this channel getting HUGE. Thanks.
Thank you so much! I created only one more additional backdrop, so they might not be changing very often :)
@@spaceflightexplained360 it's just so accurate! Hex tiles is quite the Easter egg. And I can't get my eyes off hottie Gwenn Shotwell 🔥🔥 Can't wait to see more and would be more than able to help you in any way.
Great video, good format! Even got me to LOL :D. Since you're asking for feedback: I found it slightly unnatural to see double light specks in each of your pupils (I guess due to the lighting setup). I would personally also prefer getting all important/unfamiliar words spelled out (for example at 3:26, "plastic/elastic deformation"), even if you erase them soon after for decluttering. Reading in addition to hearing helps parse & remember them better.
Came here from Reddit. Great vid man, thank you! Keep it up!
Thanks for watching!
PLEASE make more content! I have absolutely loved every one of your Spaceflight Explained uploads. PLEASE!
Thank you for taking the time to make a clear and concise explanation of what is a somewhat confusing subject for us (untutored) SpaceX fans. I hope to see many more going forward, and good luck n your new endeavor.
Thank you! I'm one of you, I admire SpaceX and the passion the people have and the difference they are making. Also it is plain cool. But I also love engineering that went into ISS and other things :)
As a mechanical engineer with a Masters, you did an excellent job. Subscribed,
Thank you so much! I'm sure it like 101 lesson, but it's great to hear that I didn't mess it up!
Spaceflight Explained You did good. For most people interested, it's pitched perfectly. If people are interested in the 'why' then you need to have some level of technical information. I don't think you covered anything I did not learn in Material Science in high school. If more people learnt the science and engineering behind decision making then more people would be interested in STEM.
Great first video man!
I'm impressed it's your first video. UA-cam space star here you go! :)
Great job for your 100th let alone just your 1st.
I subscribed and I'm looking fwd to your next
Excellent video. You touched on everything I could think of. There is a small distinction between toughness (the energy a material can absorb before breaking) and fracture toughness (the ability of a material to arrest crack growth). Typically Charpy tests are used to ensure good fracture toughness. And fracture toughness is what SpaceX would care about since all those welds are not likely to be perfect and contain tiny flaws that you do not want to grow into large cracks.
Thank you for the insightful comment. I was wondering that myself, but it is impossible to find the data for regular toughness. The fracture inducing notch definitely changes things a bit, but this is the most relevant experiment with some data available that I could find.
First video... wow:)
Great to hear what an actual engineer thinks about this.
BTW, what country are you from?
Hi there and thanks! Originally from the Czech Republic, now living in the US
@@spaceflightexplained360 Ah, ok. That explains why your name sounds a bit Polish, while you have a pretty normal American accent:))
@@spaceflightexplained360 why do you have the number of subscribers switched off?🤔
You are the first person ever to say that I don't have an accent haha. It is actually super strong.
I turned to the subscriber count so that the low number (first video...) Doesn't discourage people from subscribing. It is a little above 2500 now, which is astonishing and unexpected.
@@spaceflightexplained360 ok, that makes sense. 2,5k in 2 weeks... keep it up!
I think it is worth thinking about after treatment. It would need to be a huge oven or maybe with inductictive heating, but when you can reduce the overall weight of the starship by let us assume 25% that would open up a lot of new options. Much higher payload, less fuel needed etc. When considering that there may be build thousands of starships it would be worth the effort to built the technology to heat treat the readily welded starships.
Great first video. Hope you do more deep dive one's like this.
Amazing first video ! Starships are reusable and when they re- enter the atmosphere the SS can reach 1500C. Therefore a reused starship is annealed. Does that mean a reused starship is stronger than a new one ?
You don't want your steel to get that hot - that is a melting temperature. You definitely want to keep it below 1000 C or less, otherwise your work hardened steel will get weaker because of the annealing. It might be good for welds, but bad for steel.
Spaceflight Explained thanks hopefully the heat tiles will keep it within reasonable temperatures !