Tim at the movies: "Haha! I love how Deadpool breaks the fourth wall! Not that there is a solid fourth wall... kind of like the missing side of a linear aero spike engine."
No one on the Internet, let alone anywhere else on TH-cam, explains rocket engines as well as you do. We are very lucky to have you explaining things to us, incredible video and incredible work!
Hi, Tim. I try to watch all the SpaceX-focused channels. I think yours is the best written. You have less speculation and grandstanding than some others. Your vids are packed with information that is timely and focused. Thanks for sharing! Stay healthy!
Agreed, the focus on what's actually happening and not speculating on grandiose future potentials is one of the best reasons to follow this channel over others covering the same subject. It's very grounded reporting, if you'll excuse the pun.
@@JCStaling I quite enjoy the broad spectrum of content creators for the topic. We have bubbly, cranky, geeky, lofty, really a full 7dwarves suite of traits analysing in their own ways and sharing it with us.
what I love about Tim is he isn't just giving us the latest news about Space X, he also let us understand the technology itself and why it is important. as a nerd this is very important for me :D
I suspect that Raptor 2 is much more mature than Merlin after a similar time spent refining the design. After all, this isn't their first Rodeo! So I'm thinking they may get another 20 to 30% improvement, but not double from their current design.
@@jackinthebox301 It depends how you define AI of course, it’s such a widely used and often abused term, but if you take it as a computer algorithm designing parts as opposed to a human then in the aerospace industry an early example would be the Airbus A380 wing struts way back in the early 2000s that were “designed” (more like grown) using a software package called OptiStruct from Altair Engineering rather than a human engineer drafting them. Essentially the software is told the overall outer shape, the areas within that overall shape where material cannot go in order to allow wiring/hydraulics/etc to pass through, the properties of the material being used to construct the struts, and the force vectors that a particular strut will be required to carry (a vector having both magnitude and direction of course). The software then essentially “grows” the optimal structure that uses the minimum amount of material to meet all those constraints hence minimising overall weight. Altair Engineering uses the A380 as one of its main reference cases for OptiStruct but it has also been used widely for (arguably) less glamorous items such as radiator brackets in cars etc, essentially anything where minimising weight is an important consideration.
It isn't their first rodeo building an engine, but Merlin and Raptor are 2 very different kinds of engines. After the first flights are complete, they will know how much they can push the engines. I don't think they will double it, but I will not be surprissed if they do either.
Tim, you and youtubers like you, are the future of journalism. I have no doubt you could be a rocket engineer (or lead a team of them) yet you have the ability to explain it to the masses. True journalism that is needed now more than ever. Thanks for your hard work!
Tim, when you mentioned a 1:1 thrust to weight ratio, I was reminded of Astra's Rocket 3.3 LV0006 which had an engine failure moments after launch. The four remaining engines had enough thrust to keep the rocket flying, clearing the tower horizontally, but were unable to increase altitude until after some of the propellants had been consumed. I fully expect for the Raptor 2 of today to not be the final version of the Raptor, but there not be as large an increase in thrust as there has been between the first Merlin 1A and today's Merlin 1D. I can see a chance of the 33 Raptor 2s on the bottom of a Booster to function as a single extremely large aerospike engine.
That aerospike idea sounds a lot like the one on the General Dynamics NEXUS booster. Not sure if Starship has enough room on the bottom for that, though. NEXUS had to be super wide and short to accommodate that design.
@@J7Handle everything is a bad idea until someone proves it works, after that is a race from everyone else to catch up to the leader lets remember that 10 years ago everyone used to believe that reusable rockets where also a bad idea, imposible, a pipe dream or just smoke and hype from some rich guy without an enginering degree, and now lets look at the present hell there are still some people today who believe that reusable rockets arent any better than disposable ones
@@carso1500 Oh please, don't pull that whataboutism with me. Aerospikes aren't even remotely similar to reusable rocketry. Aerospikes, even just theoretically, have poorer performance than bell nozzles even when you solve all the other flaws. They are altitude compensating nozzles, meaning they can only outperform bell nozzles when they are used half of the time in thick atmosphere and half of the time in vacuum. That means they're pointless for Starship, as Starship spends all of its burn time in space and Booster spends almost all of its burn time in atmosphere. The aerospikes are only theoretically good for SSTOs, but as Falcon 9 and Starship have shown, those are also extremely crap. SSTOs spend more fuel to get several times dead weight to orbit and need several times more heatshielding (also extra dead weight) to get back down from orbit. Meanwhile, their only advantages over two-stage rockets are full-reusabilty (oops, Starship can do that anyway and do it better) and simplicity (oops, the massively complicated hybrid engines, heat shielding, and necessary weight savings make it far more complicated, actually). So aerospikes are useless precisely because they benefit only an already stupid idea. I could imagine aerospikes being useful for trying to get a rocket back from the surface of Venus, but then again, I can't imagine us bringing back _anything_ from the surface of Venus, and certainly not a rocket.
Could really use an updated video comparing all the specs, costs, improvements etc for all Raptor generations. This is epic engineering that needs to be well documented
This might be Tim's most under rated TH-cam submission. He gets props on a lot of what he's done, but I would suggest that his insights in this video are above average
Great explanation of Gravity Drag and why Thrust to Weight Ratio is so important Tim! I was waiting for you to bust out an "area under the force time curve" but you actually explained it super well without going even that far 😃
I think the best example of the TWR issue was the Astra (?) launch that traveled sideways after losing an engine until it burned enough propellent to get better than 1:1 at which point it started to gain altitude.
I'm specifically interested in whether SpaceX is already implementing new techniques for improving landing accuracy on the Falcon 9 first stages in preparation for the massive accuracy required for the Starship booster and Starship to be caught by the catching arms on Mechazilla?
@@PhillMagGamerDad This will be interesting to see. The Mechazilla catch is in a lot of ways easier than the drone ship landings. The latter is moving in 3 dimensions, especially vertically, and F9 has to make that precise hoverslam touchdown. Starship is dealing with a stationary target. Elon explained in another recent Tim interview that it will take several seconds to pass down thru the arms, so it has time to make adjustments. But it does have to place that huge ship with its inertial mass within tens of centimeters before the arms can close in.
@@insertnamehere786, they don't. But if they're flying and landing Falcon almost on a weekly basis, doesn't it make sense to practise and fine tune your existing rocket to be as precise as will be necessary for Starship, and learn in the process without having to go through the fly-crash-improve-perfect model that SpaceX has been following?
@@PhillMagGamerDad fly, crash and repeat has proven to be an excellent way of doing it, rapid iteration and changes as they go have never fails spaceX as opposed to decades of behind close doors research and development wasting billions om God knows what. The proof Is in the pudding 🙃 ... if they unshackled spaceX then nasa would be left pissing into the wind
Been watching all your long form videos over the years. Brilliant effort, exceptional content, always. Thanks to all the contextual knowledge I've gained from all those videos over time, this engine comparison summary was perfectly short and sweet. But having said that, I think you did a brilliant job on making this video quite self contained, so it should appeal to both new and old audiences alike. Keep it up!
12:50 i think there is no better visualization for gravity drag than the sideways launch from astra They literally had 1-1 thrust until fuel started to be consumed Basically all the energy was consumed to oppose gravity
They're reportedly cooled using a heat exchanger and liquid nitrogen. By pulling a vacuum on the liquid nitrogen, it boils and cools. You can see videos of this on youtube (and see solid nitrogen). The propellants are pumped into the rocket cold, and the bulk keeps it cold for a time. If the propellants sit too long, they warm up to their boiling points, and must be drained. As for the pros and cons, the pros are that colder propellants are denser, so more mass can be stored in the tanks. The cons are that the tanks aren't that well insulated, and the propellants warm up with time, so there's a limited wait-for-launch time once the rocket is fueled. Also, cold propellants are typically more viscous (thicker) and may put additional demands on pumps (both in the rocket and in the ground support equipment). Tank ullage/pressure control may be more difficult as well, as the propellants condense air/nitrogen/... ullage gasses in the tanks. There is also the requirement for heat exchangers and/or equipment in the GSE to cool the propellants well below their boiling points prior to rocket loading.
I liked this production very well made and you use the word minus instead of negative which is how we say it in the UK. Also, you are not speaking too fast which means your information, is more digestible.
Thrust is only important to escape Earth's gravity, having in mind the the Mars venture It's possible that in the future we'll see: -Less powerful Earth-Mars and orbit-Mars raptors but with a higher ISP and build rate, mainly for the second stage -Very powerfull ground-orbit raptors for the orbit fuel station starship.
From Earth orbit to Mars will be second stages only, no first stages and no first stage engines. Launch from Mars will use mostly the 3 atmospheric center engines of the second stage, just like last year's test flights, but benefitting from lower Mars gravity to actually reach Mars orbit.
@@johndododoe1411 Yeah sorry I was wrong, I meant the second stage. Anyway if you want to launch 1000 starships that don't need to escape from the earth's gravity, I think it makes sense to design raptors that are faster and cheaper to build than focus mainly on thrust. Also the difference between the raprot sea-level and vacuum is only the Nozzle ratio
I'm actually surpised that SpaceX isn't exploring ion engines. They're the largest manufacturer of ion engines the world has ever seen, so they know a bit about it. I really expected an ion driven Earth-Mars Cycler in their plans.
@@gasdive they might have them planned, but "first things first". No need for a cycler when it has nothing to cycle between ;) But then it might just be that for the given weight it would take too much propellant, energy or engines, making it more complicated, expensive, etc. So I wouldn't expect them used on anything manned or time constrained.
Thank you, sir. Everything I know about rocket engines I learned from your excellent videos and, while I'm still quite ignorant compared to experts like you, it greatly enhances my pleasure because I know what people are talking about!
Love to see it's dimensions side by side with BE-4, it's nearly the same thrust now, but from the pics of I've seen it looks less than half the size. Pretty amazing. Can't wait to see Raptor 2 fly.
Awesome Tim! The one thing this video didn't touch on though, that was in the interview with Elon (amazing BTW), was how they "inline" the oxygen pre-burner... which I thought was really interesting. What i mean is it's directly in line with the center of the engine bell... and how that impacted the transfer of force to the vehicle. Super cool, thanks for all you do!
Force transfer is always a direct line up the engine. What they did is to build the oxygen pump inside that force transfer rod, using it as the walls of that part.
@@johndododoe1411 Right! Exactly. I was interested in hearing a little more about that. Obviously, using the walls of the oxygen pre-burner as part of that is brilliant - has it ever been done before? Other advantages besides weight? Very cool nonetheless.
@@cornbreadreturns296 Another advantage is that no torque is exerted by the liquid oxygen flow when the oxygen plumbing is coaxial with the engine. Oxygen accounts for about 80% of the fuel weight (approx 3.7:1 fuel ratio) so that is most of the propellant going straight down to the engines.
Thanks Tim for your detailed, awesome engineering analysis, AND your interview with Elon. All of this is well appreciated. Can't wait till your next analysis of improvements in Raptor 2.
15:08 It does make sense because indefinite reusability is probably impossible with rocket launch systems due to metal fatigue given the weight constraints. In the end they'll try to find the economic sweet spot between production cost savings and fuel savings. Maybe one day we'll see cheap expendable balloon drop tanks on a reusable engine section with a set of small more durable tanks for the suicide burn.
Thanks Tim! Another excellent analysis. I didn't realize there was already a Raptor 1.5 version in there. So, we're basically on the 3rd iteration then, with other prototypes having been tested with chamber pressure up to 330 BAR. I think they'll reach a production version of Raptor that hits that, when those other improvements get made that are required to support it. You're really making this stuff accessible to the masses, and challenging the next generation to get on board with this stuff, and ride along with some of these new ideas.
Great content, love how you break down complicated concepts into easy to understand, bite sized pieces. I couldn't wrap my head around why they would go for a lower ISP on R2, but your explanation helped a lot!
@@schonkat1982 Imho, it's just a update with thrust increase and some improving in details. Raptor 1A or Raptor 1.1 would be more accurate. But it's improving probably obtained at a high price.
Tim, could you please do a cross section walk through of the Raptor v2 detailing what each part does (to the best of your knowledge of course). From tank to exhaust. I've seen one done before using a 3D cross section rendering of Raptor 1 but having your video with updated information and design would be pretty cool. Thanks and Iowa Rocks!
I dont think he can really do that yet because he actually doesnt know yet how Raptor 2 is ignited. We will probably learn a lot more about these engines after they are launched.
In the last Musk vid. with them talking about raptor engines. Elon said in pretty plain terms, he can't speak much about the inside of the engine, as not to disclose what make their "sauce" special
@DinoCR , if you've seen a cross-section of the Raptor 1, you've seen all actual about the Raptor v2 (except its ignition method). The difference is only in secondary details.
The Space Engineer on twitter has some really cool cutaway diagrams you can learn a lot about Raptor from, if anyone is still interested. Currently the conversations on Spitter (space twitter) are almost entirely focused on Raptor 3. Find the right folks to follow and there is a huge wealth of knowledge to be found in that community.
Thanks for all you do to make rocket science digestible for the masses. I watched this video when you released it but I couldn't help myself from watching it again. You are an amazing guy thanks
Its got nothing to do with using imperial or metric units. This is physics & engineering so its all in ISO units. Just that the ones you recognise happen to be the same in metric.
The research, understanding and detailed explanations of such complex matters from someone who essentially learned on his own is admirable. I'm in awe. Bravo.
2 ปีที่แล้ว +4
Can't wait to see the orbital launch! Also, regarding Raptor 2, I'm cautiously optimistic and I think in a few years SpaceX will create a "Raptor 2.5" or something, with nearly no "fiddly bits".
Congratulations on this (and many) podcast. 3:19 I’m proud of my neighbor from the Falls portion of the Cedar river from the Rapids section. In Rochester MN now. What a honor for you.
Great video, thank you very much for your work, Tim. I study rocket engineering technology im BMSTU (best engineering uni in Russia). So it's always a big pleasure for me to watch great and simple videos on rocketry from a man who truly loves this topic.
That would only be the case for the outer ring of RBoost engines -- but the SH inner engines, and *all* *the* *Ship* *engines* need the ability to re-light, and they don't have main chamber igniters either.
I am biased, but I would personally love you to go more into detail about additive manufacturing/3D printing and how this engine/the entire modern space industry likely would not exist without it.
Thank you for what you do Tim. It's nice to see new videos coming out. We will all be right there with you (via TH-cam) for the upcoming booster tests. Cannot wait to see it pop off at 1.5:1 ratio!
Thanks Tim, I felt I had understood everything in your interview with Elon. However your additional coverage with reference to some of your earlier videos throws even more light on what was covered and the benefits they are delivering. Excellent 👍
I loved Musk's reaction to aerospike engines and the concept of boiling down more important variables into ISP. You can see he's working on a much grander scale than people who think those are important. It was great to see Musk try really hard to be interested and at the same time not hurt your feelings 🤣
Eliminating parts is great, but eliminating the main chamber igniters adds to making the start-up sequencing very complex. Was that a factor in the big propellant dump and big kaboom during testing this week? So, another great conversation with Elon. It's almost like we're all in a conversation with him, what you do is different than watching a conventional interview of him. How many days before your feet touched the ground after learning he watched your rocket engine video, and paid enough attention to note an error? :) (I understand your chagrin at the error; laborious research tripped up by a bad source that looked good at the time.)
My thought too. I love your calling it the "Kaboom". This reminds me of the Atari 2600 game called " Kaboom!" It was one of my favourites. (Yes, I'm old... and Canadian if you haven't figured that out yet :P
Presumably it's related to start up. Unsync'd startup of the two preburners means one of them gets a stoichiometric mix and burns far too hot, a shutdown to avoid that melting the engine could dump more unburned fuel than oxidiser. But the problems would all happen before the main chamber, removing igniters won't make any difference to the root cause. It may slightly mitigate this failure case slightly by igniting more of the fuel earlier but it's still not going to have enough O2 to burn inside the bell. You still get a fireball.
@@EagerSpace Understood. I was curious as to whether the amount of propellant flowed thru the engine during the spin-up was greater because of the start sequence. These things aren't always intuitive.
As Elon said, the startup is a dance. Precise valve timing coordination, flow ramp up rates and pressure spikes while crossfeeding the preburners with exact timing, fighting the flow restrictions and pressure drops associated with the autogenous pressurization system, operational restrictions required to avoid cavitation. They all mean the startup can't be faked with test procedures. The only way forward is to run their best model through actual operational conditions and that means putting methane and oxygen out the bottom. Booms happen. They wish it had been a windier day, no boom. Next time they will schedule for a higher wind. Maybe test in subsets, center thirteen, odd outer ring, even outer ring?
Great script thank you (plus a cool shirt). Good to see all your earlier hard work paying off as it all comes together. I *cannot believe* it's been three years already since your King of Engines video. And holy crap I just checked your subscriber count.
Hey mate!👆Thanks for watching. Tell expert Andrei jikh that you were referred by me for the right strategy on this profitable investment project to participate on it.Msg direct 👆✍️ . .
Hi this is abvery interesting video. I didnt know anything about this before. I like that part saying you said: "The best part is No part", that talks about making things simple
Again, Kerbal Space Programme has taught me a thing or two to understand this video. For example the losses to gravity, since i've been testing all kinds of first stages in KSP, i've come to the conclusion by myself that a loss in efficiency is often worth a higher thrust to mass ratio and the ensuing increased acceleration. Always amazed by the ammounts of knowledge i gained just by having fun with this game! Especially the way orbits work and how to change them.
Well, it turns out that this will be the last thing I watch on my way into rehab. I'll see y'all in about 35 days. Thanks for cheering me up right before I have to go take this step. I expect to see a bunch of trolling going on in my absence however so let it rip, folks! Oh, and some kind words might be kinda cool too, I guess. Thanks again Tim, you're a real inspiration :)
Tim, you explained Raptor 2 engine beautifully and elegantly. So educational and satisfying to watch. Thank you for the great work. Love all your viedos. And, cheers and Godspeed for the space X engineers and Elon.
There are very few TH-cam creators, journalists, entertainers who get LIKE even before video loads in. You, my friend, is one of them. Thank you for your work and enthusiasm!
Your ability to bring aero-spike engines into every conversation is astounding😂
Just like the mechanic who fixes my Cadillac! (Mad Magazine reference)
Tim at the movies: "Haha! I love how Deadpool breaks the fourth wall! Not that there is a solid fourth wall... kind of like the missing side of a linear aero spike engine."
Even with Elon Musk 😂
Aero Spike fanboy is what he is. What a sick puppy.
Getting rather sad now tbh
2 everyday astronaut videos in 1 week? What a treat!
Keep it up Tim!
Time for a Raptor 3 video
Agreed!
Yes please
Please!!
Didn't we learn anything from Jurassic Park?! Breeding Raptors is dangerous!
Raptor 1 was just a distraction for Raptor 2 to come out of the bushes and attack!!
Clever Girl...
All the Raptors are female
@@Crusader1984 life finds away… life finds a way.
@@Crusader1984 we just added a bit of frog...
Clever girls
No one on the Internet, let alone anywhere else on TH-cam, explains rocket engines as well as you do. We are very lucky to have you explaining things to us, incredible video and incredible work!
Hi, Tim. I try to watch all the SpaceX-focused channels. I think yours is the best written. You have less speculation and grandstanding than some others. Your vids are packed with information that is timely and focused. Thanks for sharing! Stay healthy!
Agree, agree, agree. Everyday Astronaut is an awesome channel
Agreed, the focus on what's actually happening and not speculating on grandiose future potentials is one of the best reasons to follow this channel over others covering the same subject. It's very grounded reporting, if you'll excuse the pun.
@@Vespuchian hmm, you wouldn't be refering to that "other astronaut" would you, the guy who's always "angry"? Lol
@@JCStaling I quite enjoy the broad spectrum of content creators for the topic. We have bubbly, cranky, geeky, lofty, really a full 7dwarves suite of traits analysing in their own ways and sharing it with us.
what I love about Tim is he isn't just giving us the latest news about Space X, he also let us understand the technology itself and why it is important. as a nerd this is very important for me :D
I suspect that Raptor 2 is much more mature than Merlin after a similar time spent refining the design. After all, this isn't their first Rodeo! So I'm thinking they may get another 20 to 30% improvement, but not double from their current design.
I'm inclined to agree. On the other hand, who knows what materials breakthrough could be on the horizon.
I work in the large fanjet development field. 5% improvement is nothing to sneeze at, 10% is gold!
@@UncleKennysPlace I'm curious if AI optimizations have made it into your line of work?
@@jackinthebox301 It depends how you define AI of course, it’s such a widely used and often abused term, but if you take it as a computer algorithm designing parts as opposed to a human then in the aerospace industry an early example would be the Airbus A380 wing struts way back in the early 2000s that were “designed” (more like grown) using a software package called OptiStruct from Altair Engineering rather than a human engineer drafting them. Essentially the software is told the overall outer shape, the areas within that overall shape where material cannot go in order to allow wiring/hydraulics/etc to pass through, the properties of the material being used to construct the struts, and the force vectors that a particular strut will be required to carry (a vector having both magnitude and direction of course). The software then essentially “grows” the optimal structure that uses the minimum amount of material to meet all those constraints hence minimising overall weight. Altair Engineering uses the A380 as one of its main reference cases for OptiStruct but it has also been used widely for (arguably) less glamorous items such as radiator brackets in cars etc, essentially anything where minimising weight is an important consideration.
It isn't their first rodeo building an engine, but Merlin and Raptor are 2 very different kinds of engines. After the first flights are complete, they will know how much they can push the engines. I don't think they will double it, but I will not be surprissed if they do either.
Raptor 2 is so CLEAN! Izan Ramos' models are incredible.
Tim, you and youtubers like you, are the future of journalism. I have no doubt you could be a rocket engineer (or lead a team of them) yet you have the ability to explain it to the masses. True journalism that is needed now more than ever. Thanks for your hard work!
Tim, when you mentioned a 1:1 thrust to weight ratio, I was reminded of Astra's Rocket 3.3 LV0006 which had an engine failure moments after launch. The four remaining engines had enough thrust to keep the rocket flying, clearing the tower horizontally, but were unable to increase altitude until after some of the propellants had been consumed.
I fully expect for the Raptor 2 of today to not be the final version of the Raptor, but there not be as large an increase in thrust as there has been between the first Merlin 1A and today's Merlin 1D.
I can see a chance of the 33 Raptor 2s on the bottom of a Booster to function as a single extremely large aerospike engine.
I love your aerospike idea. Having a large ring with many smaller engines should allow for this!
Enough with the aerospikes. They're a bad idea through and through.
That aerospike idea sounds a lot like the one on the General Dynamics NEXUS booster. Not sure if Starship has enough room on the bottom for that, though. NEXUS had to be super wide and short to accommodate that design.
@@J7Handle everything is a bad idea until someone proves it works, after that is a race from everyone else to catch up to the leader
lets remember that 10 years ago everyone used to believe that reusable rockets where also a bad idea, imposible, a pipe dream or just smoke and hype from some rich guy without an enginering degree, and now lets look at the present
hell there are still some people today who believe that reusable rockets arent any better than disposable ones
@@carso1500 Oh please, don't pull that whataboutism with me. Aerospikes aren't even remotely similar to reusable rocketry.
Aerospikes, even just theoretically, have poorer performance than bell nozzles even when you solve all the other flaws. They are altitude compensating nozzles, meaning they can only outperform bell nozzles when they are used half of the time in thick atmosphere and half of the time in vacuum.
That means they're pointless for Starship, as Starship spends all of its burn time in space and Booster spends almost all of its burn time in atmosphere.
The aerospikes are only theoretically good for SSTOs, but as Falcon 9 and Starship have shown, those are also extremely crap.
SSTOs spend more fuel to get several times dead weight to orbit and need several times more heatshielding (also extra dead weight) to get back down from orbit.
Meanwhile, their only advantages over two-stage rockets are full-reusabilty (oops, Starship can do that anyway and do it better) and simplicity (oops, the massively complicated hybrid engines, heat shielding, and necessary weight savings make it far more complicated, actually).
So aerospikes are useless precisely because they benefit only an already stupid idea.
I could imagine aerospikes being useful for trying to get a rocket back from the surface of Venus, but then again, I can't imagine us bringing back _anything_ from the surface of Venus, and certainly not a rocket.
Could really use an updated video comparing all the specs, costs, improvements etc for all Raptor generations. This is epic engineering that needs to be well documented
Thanks! Great work man. Love your videos.
Amazing work, Tim! Thanks so much for your time, effort, and attention to detail. And those renders are gorgeous! (Izan and Casper!)
Great as always, thanks!
Man Spacex is leagues ahead of anyone.
This might be Tim's most under rated TH-cam submission. He gets props on a lot of what he's done, but I would suggest that his insights in this video are above average
Great explanation of Gravity Drag and why Thrust to Weight Ratio is so important Tim! I was waiting for you to bust out an "area under the force time curve" but you actually explained it super well without going even that far 😃
Agreed. The tyranny of the rocket equation in one slide.
I got that reference
It's so refreshing to find someone who uses proper terms like "center of mass" instead of "center of gravity" and "meters" instead of "elbows"
I think the best example of the TWR issue was the Astra (?) launch that traveled sideways after losing an engine until it burned enough propellent to get better than 1:1 at which point it started to gain altitude.
Space Y
saw it rise because the gate was left open
P O W E R S L I D E
😂
Did everyone watch Wild Space yet? It's about the competition between Astra and Rocket Lab.
Hi Tim, great video as always!
Can you do a video explaining the navigation techniques and technologies for the landing of both stages
I'm specifically interested in whether SpaceX is already implementing new techniques for improving landing accuracy on the Falcon 9 first stages in preparation for the massive accuracy required for the Starship booster and Starship to be caught by the catching arms on Mechazilla?
@@PhillMagGamerDad do they need to improve falcon 9 landing tbh?
@@PhillMagGamerDad This will be interesting to see. The Mechazilla catch is in a lot of ways easier than the drone ship landings. The latter is moving in 3 dimensions, especially vertically, and F9 has to make that precise hoverslam touchdown. Starship is dealing with a stationary target. Elon explained in another recent Tim interview that it will take several seconds to pass down thru the arms, so it has time to make adjustments. But it does have to place that huge ship with its inertial mass within tens of centimeters before the arms can close in.
@@insertnamehere786, they don't. But if they're flying and landing Falcon almost on a weekly basis, doesn't it make sense to practise and fine tune your existing rocket to be as precise as will be necessary for Starship, and learn in the process without having to go through the fly-crash-improve-perfect model that SpaceX has been following?
@@PhillMagGamerDad fly, crash and repeat has proven to be an excellent way of doing it, rapid iteration and changes as they go have never fails spaceX as opposed to decades of behind close doors research and development wasting billions om God knows what. The proof Is in the pudding 🙃 ... if they unshackled spaceX then nasa would be left pissing into the wind
Been watching all your long form videos over the years. Brilliant effort, exceptional content, always. Thanks to all the contextual knowledge I've gained from all those videos over time, this engine comparison summary was perfectly short and sweet. But having said that, I think you did a brilliant job on making this video quite self contained, so it should appeal to both new and old audiences alike. Keep it up!
Thanks!
I should also added that many parts were transferred to the vehicle, similar to jet engines, makes install & removal process easier
And I believe, for the booster, some (starter-)parts are even moved to the launch mount!
@@ErikBongers I believe for the outer ring- they only have to start up on launch; the inner ring of gymballing engines have to re-light for landing.
@@ErikBongers stage 0, as SpaceX calls it.
I've been following space obsessively since I was 5 (Apollo 7). I still learnt stuff in this one. So great. Thanks.
12:50 i think there is no better visualization for gravity drag than the sideways launch from astra
They literally had 1-1 thrust until fuel started to be consumed
Basically all the energy was consumed to oppose gravity
Bedankt
I would love a deep dive on sub cooling cryogenic propellants, pros, cons, how they keep them cold during fueling. Always been a mystery to me.
Interested to create own rocket?
They're reportedly cooled using a heat exchanger and liquid nitrogen. By pulling a vacuum on the liquid nitrogen, it boils and cools. You can see videos of this on youtube (and see solid nitrogen). The propellants are pumped into the rocket cold, and the bulk keeps it cold for a time. If the propellants sit too long, they warm up to their boiling points, and must be drained.
As for the pros and cons, the pros are that colder propellants are denser, so more mass can be stored in the tanks. The cons are that the tanks aren't that well insulated, and the propellants warm up with time, so there's a limited wait-for-launch time once the rocket is fueled. Also, cold propellants are typically more viscous (thicker) and may put additional demands on pumps (both in the rocket and in the ground support equipment). Tank ullage/pressure control may be more difficult as well, as the propellants condense air/nitrogen/... ullage gasses in the tanks. There is also the requirement for heat exchangers and/or equipment in the GSE to cool the propellants well below their boiling points prior to rocket loading.
I’m from Iowa too and I deeply appreciate and enjoy your content. You should do a deep dive into all the COPVs of a rocket. Thank so much Tim!
I liked this production very well made and you use the word minus instead of negative which is how we say it in the UK. Also, you are not speaking too fast which means your information, is more digestible.
Sensational video, and very easy to understand. A nice balance with the longer form as well. Well done!
Thrust is only important to escape Earth's gravity, having in mind the the Mars venture It's possible that in the future we'll see:
-Less powerful Earth-Mars and orbit-Mars raptors but with a higher ISP and build rate, mainly for the second stage
-Very powerfull ground-orbit raptors for the orbit fuel station starship.
From Earth orbit to Mars will be second stages only, no first stages and no first stage engines. Launch from Mars will use mostly the 3 atmospheric center engines of the second stage, just like last year's test flights, but benefitting from lower Mars gravity to actually reach Mars orbit.
@@johndododoe1411 Yeah sorry I was wrong, I meant the second stage. Anyway if you want to launch 1000 starships that don't need to escape from the earth's gravity, I think it makes sense to design raptors that are faster and cheaper to build than focus mainly on thrust. Also the difference between the raprot sea-level and vacuum is only the Nozzle ratio
I'm actually surpised that SpaceX isn't exploring ion engines. They're the largest manufacturer of ion engines the world has ever seen, so they know a bit about it. I really expected an ion driven Earth-Mars Cycler in their plans.
@@gasdive they might have them planned, but "first things first". No need for a cycler when it has nothing to cycle between ;)
But then it might just be that for the given weight it would take too much propellant, energy or engines, making it more complicated, expensive, etc.
So I wouldn't expect them used on anything manned or time constrained.
Nuclear is the the way for humans to get to mars. The Only practical way on a large scale- either direst thermal or electric.
Thank you, sir. Everything I know about rocket engines I learned from your excellent videos and, while I'm still quite ignorant compared to experts like you, it greatly enhances my pleasure because I know what people are talking about!
Love to see it's dimensions side by side with BE-4, it's nearly the same thrust now, but from the pics of I've seen it looks less than half the size. Pretty amazing. Can't wait to see Raptor 2 fly.
You're only getting better and better.. thanks for all your hard work..
Those models of the engines are incredible! Especially getting the rats nest of piping on the Raptor 1!
Thank you for mentioning our igniters at 7:12 :-)
Awesome Tim! The one thing this video didn't touch on though, that was in the interview with Elon (amazing BTW), was how they "inline" the oxygen pre-burner... which I thought was really interesting. What i mean is it's directly in line with the center of the engine bell... and how that impacted the transfer of force to the vehicle. Super cool, thanks for all you do!
Force transfer is always a direct line up the engine. What they did is to build the oxygen pump inside that force transfer rod, using it as the walls of that part.
@@johndododoe1411 Right! Exactly. I was interested in hearing a little more about that. Obviously, using the walls of the oxygen pre-burner as part of that is brilliant - has it ever been done before? Other advantages besides weight? Very cool nonetheless.
@@cornbreadreturns296 Another advantage is that no torque is exerted by the liquid oxygen flow when the oxygen plumbing is coaxial with the engine. Oxygen accounts for about 80% of the fuel weight (approx 3.7:1 fuel ratio) so that is most of the propellant going straight down to the engines.
Smashed it again Tim. Thank you so much for you and your team's work.
Thanks Tim for your detailed, awesome engineering analysis, AND your interview with Elon.
All of this is well appreciated. Can't wait till your next analysis of improvements in Raptor 2.
so informative and concise. great job Tim.
Still hard to believe this is actually happening 😁
Tim, nice job explaining a very complicated machine and making clear the differences. Thank you.
15:08 It does make sense because indefinite reusability is probably impossible with rocket launch systems due to metal fatigue given the weight constraints. In the end they'll try to find the economic sweet spot between production cost savings and fuel savings. Maybe one day we'll see cheap expendable balloon drop tanks on a reusable engine section with a set of small more durable tanks for the suicide burn.
airplanes can get over this "weight fatigue" no problem
Thanks Tim! Another excellent analysis. I didn't realize there was already a Raptor 1.5 version in there. So, we're basically on the 3rd iteration then, with other prototypes having been tested with chamber pressure up to 330 BAR. I think they'll reach a production version of Raptor that hits that, when those other improvements get made that are required to support it. You're really making this stuff accessible to the masses, and challenging the next generation to get on board with this stuff, and ride along with some of these new ideas.
Great content, love how you break down complicated concepts into easy to understand, bite sized pieces. I couldn't wrap my head around why they would go for a lower ISP on R2, but your explanation helped a lot!
These videos are part of the reason I now work at the Cape for ULA.
Curious to know how much of the Raptor 2 simplification was due to removing the R&D sensors from Raptor 1
Yeah, the raptor 2 looks like raptor one. In fact, it looks like an unfinished raptor one.
So, is it's different engine at all?
@@schonkat1982 Imho, it's just a update with thrust increase and some improving in details. Raptor 1A or Raptor 1.1 would be more accurate. But it's improving probably obtained at a high price.
@@aerospacer994 that sounds more plausible, thank you
Hvala!
Tim, could you please do a cross section walk through of the Raptor v2 detailing what each part does (to the best of your knowledge of course). From tank to exhaust. I've seen one done before using a 3D cross section rendering of Raptor 1 but having your video with updated information and design would be pretty cool. Thanks and Iowa Rocks!
I dont think he can really do that yet because he actually doesnt know yet how Raptor 2 is ignited. We will probably learn a lot more about these engines after they are launched.
Do you have a link to the video you are talking about?
In the last Musk vid. with them talking about raptor engines. Elon said in pretty plain terms, he can't speak much about the inside of the engine, as not to disclose what make their "sauce" special
@DinoCR , if you've seen a cross-section of the Raptor 1, you've seen all actual about the Raptor v2 (except its ignition method). The difference is only in secondary details.
The Space Engineer on twitter has some really cool cutaway diagrams you can learn a lot about Raptor from, if anyone is still interested. Currently the conversations on Spitter (space twitter) are almost entirely focused on Raptor 3. Find the right folks to follow and there is a huge wealth of knowledge to be found in that community.
Thanks for all you do to make rocket science digestible for the masses. I watched this video when you released it but I couldn't help myself from watching it again. You are an amazing guy thanks
As it turns out, Raptor 2 produces more beautiful fireballs, too!
you can say what you want about musk but spacx and the science behind it is so amazing!
I am so glad you do the video in metric and not the other unit of measure that we shall not mention, thank you.
Its got nothing to do with using imperial or metric units.
This is physics & engineering so its all in ISO units.
Just that the ones you recognise happen to be the same in metric.
The research, understanding and detailed explanations of such complex matters from someone who essentially learned on his own is admirable. I'm in awe. Bravo.
Can't wait to see the orbital launch!
Also, regarding Raptor 2, I'm cautiously optimistic and I think in a few years SpaceX will create a "Raptor 2.5" or something, with nearly no "fiddly bits".
Congratulations on this (and many) podcast. 3:19 I’m proud of my neighbor from the Falls portion of the Cedar river from the Rapids section. In Rochester MN now. What a honor for you.
i like how tim lists the pre reqs at the beginning of the video...wait is this a class? will there be a test?!?
Incredible work as always Tim!
Can you do a video on Raptor 1/Raptor 2 vs. Raptor 3?
Great video, thank you very much for your work, Tim. I study rocket engineering technology im BMSTU (best engineering uni in Russia). So it's always a big pleasure for me to watch great and simple videos on rocketry from a man who truly loves this topic.
They realized that if they remove torch ignitors from the main combustion chamber, they can just use the ground support equipment instead!
no, how do you think they restart them in flight?
That would only be the case for the outer ring of RBoost engines -- but the SH inner engines, and *all* *the* *Ship* *engines* need the ability to re-light, and they don't have main chamber igniters either.
I was talking about the ground equipment that ignited B7 the other day lol, but thanks for the mansplaining
Bravo!! 👏👏 This is your best video yet Tim. Way to go!
I am biased, but I would personally love you to go more into detail about additive manufacturing/3D printing and how this engine/the entire modern space industry likely would not exist without it.
Thank you so much for the work you put into these videos , the interviews and the research you put in is astonishing.
What rocket engine is best for cleaning?
A vacuum optimized one.
Aw man that's cheesey
Thank you for what you do Tim. It's nice to see new videos coming out. We will all be right there with you (via TH-cam) for the upcoming booster tests. Cannot wait to see it pop off at 1.5:1 ratio!
Thanks Tim, I felt I had understood everything in your interview with Elon. However your additional coverage with reference to some of your earlier videos throws even more light on what was covered and the benefits they are delivering. Excellent 👍
Fantastic and informative video! Thank you Will Wheaton!
I loved Musk's reaction to aerospike engines and the concept of boiling down more important variables into ISP. You can see he's working on a much grander scale than people who think those are important. It was great to see Musk try really hard to be interested and at the same time not hurt your feelings 🤣
Hands down the best space everything channel
Eliminating parts is great, but eliminating the main chamber igniters adds to making the start-up sequencing very complex. Was that a factor in the big propellant dump and big kaboom during testing this week? So, another great conversation with Elon. It's almost like we're all in a conversation with him, what you do is different than watching a conventional interview of him. How many days before your feet touched the ground after learning he watched your rocket engine video, and paid enough attention to note an error? :)
(I understand your chagrin at the error; laborious research tripped up by a bad source that looked good at the time.)
My thought too. I love your calling it the "Kaboom". This reminds me of the Atari 2600 game called " Kaboom!" It was one of my favourites. (Yes, I'm old... and Canadian if you haven't figured that out yet :P
Not a factor. The test this week was a spin-up test; it was not planned to lead to ignition.
Presumably it's related to start up. Unsync'd startup of the two preburners means one of them gets a stoichiometric mix and burns far too hot, a shutdown to avoid that melting the engine could dump more unburned fuel than oxidiser.
But the problems would all happen before the main chamber, removing igniters won't make any difference to the root cause. It may slightly mitigate this failure case slightly by igniting more of the fuel earlier but it's still not going to have enough O2 to burn inside the bell. You still get a fireball.
@@EagerSpace Understood. I was curious as to whether the amount of propellant flowed thru the engine during the spin-up was greater because of the start sequence. These things aren't always intuitive.
As Elon said, the startup is a dance. Precise valve timing coordination, flow ramp up rates and pressure spikes while crossfeeding the preburners with exact timing, fighting the flow restrictions and pressure drops associated with the autogenous pressurization system, operational restrictions required to avoid cavitation. They all mean the startup can't be faked with test procedures. The only way forward is to run their best model through actual operational conditions and that means putting methane and oxygen out the bottom. Booms happen.
They wish it had been a windier day, no boom. Next time they will schedule for a higher wind. Maybe test in subsets, center thirteen, odd outer ring, even outer ring?
Great script thank you (plus a cool shirt). Good to see all your earlier hard work paying off as it all comes together. I *cannot believe* it's been three years already since your King of Engines video.
And holy crap I just checked your subscriber count.
"It looks like it is incomplete" 😁 .... Elon Musk
Thanks for following these topics and breaking it down.
Elon is not on your Patreon list..
Great chat Tim thanks.
Every one is a gem.
I wish Scott Manley was invited to be with Elon.
Tim's waving hand never ceases to catch me off guard when I start his videos
Bravo Tim... Keep doing what you're doing !!!
watching all ur vids is like a full uni course I love it, thank you!!!!!
Exceptional clarity. That is an art form.
Amazing content as always.....thanks Tim! 🤟
I have really missed those videos! Super cool that you have startet making them again :D
Thanks for good stuff.
There will always be improvements.
great explanation, straight to the point and no bla bla
Best day ever. I'm in cc for a launch and got a new everyday astronaut video
This Video was great!!!!! It is not a flop!!!
Hey mate!👆Thanks for watching. Tell expert Andrei jikh that you were referred by me for the right strategy on this profitable investment project to participate on it.Msg direct 👆✍️
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Hi this is abvery interesting video. I didnt know anything about this before. I like that part saying you said: "The best part is No part", that talks about making things simple
Solid straightforward and packed full of wonderful nerdy detail. Love it TIm.
Thanks Tim... Great info... You are responsible for all my rocket science knowledge to this day
Another Excelent job Tim!
Wow, great quality content and easy to understand
Again, Kerbal Space Programme has taught me a thing or two to understand this video. For example the losses to gravity, since i've been testing all kinds of first stages in KSP, i've come to the conclusion by myself that a loss in efficiency is often worth a higher thrust to mass ratio and the ensuing increased acceleration. Always amazed by the ammounts of knowledge i gained just by having fun with this game! Especially the way orbits work and how to change them.
Well, it turns out that this will be the last thing I watch on my way into rehab. I'll see y'all in about 35 days. Thanks for cheering me up right before I have to go take this step. I expect to see a bunch of trolling going on in my absence however so let it rip, folks! Oh, and some kind words might be kinda cool too, I guess. Thanks again Tim, you're a real inspiration :)
GO GET EM!!! Proud of you for taking the time and effort to work on yourself! Stay strong, focused, determined and disciplined!!! You got this 💪
Tim, you explained Raptor 2 engine beautifully and elegantly. So educational and satisfying to watch. Thank you for the great work. Love all your viedos.
And, cheers and Godspeed for the space X engineers and Elon.
Tim - Great video, as usual :) Thanks!!
Tim, bravo for the concise & informative rocket science explanation. It is appreciated.
Great Stuff mate!!
Wow, look at that aggressive environment when they start up, one engine, mind blowing. Thanks, Tim
There are very few TH-cam creators, journalists, entertainers who get LIKE even before video loads in. You, my friend, is one of them. Thank you for your work and enthusiasm!