Why SpaceX Cares so Much About THRUST

[@SFS-V]

In thrust we trust

[@shuaebfromiraq4505]

In trust we thrust

[@SFS-V]

@@shuaebfromiraq4505 got it wrong sry, fixed it

[@shuaebfromiraq4505]

Was that gaslighting?

[@stick4077]

bro got gaslighted

[@furriesinouterspaceUnited]

In thrust we trust*

[@m_sedziwoj]

6:40 When comparing two graphs, it is better to both be in same scale.

[@rschroev]

Or maybe even better two line in the same graph.

[@SamSayaz]

​@@rschroev yeah an overlap would've been a lot clearer comparison

[@noahking5531]

I'll double down on this. When comparing two graphs, if they're not the same scale, they're useless.

[@cumiebaka]

yeah... it was very confusing to look at.

[@aday22_rl]

@@noahking5531 useless is a stretch

[@man-from-2058]

Also having a higher TWR means that you can stretch the fuel tanks to have more fuel while still having a reasonable TWR, which can already be seen in starship 2 & 3 consepts.

[@Piolet1549]

Yep I agree, higher TWR seems to always just make life easier

[@gasdive]

Looking at the video of IFT5 it looks like TWR sits between 1.45 and 1.5. That's with Block2 engines. There's definitely room to stretch SS, even before we consider Block3 engines.

[@JamesConnolly1994]

“Stay away from this guy” 😂😂😂😂 Brilliant

[@olafmesschendorp147]

Brilliant and true

[@asandax6]

That guy has both TDS and MDS

[@routybouty]

@@asandax6 None of his videos age well lol. I'm surprised of the amount of views though.

[@nuttyDesignAndFab]

man I grew up watching him, it's a shame he lost it

[@vmcprojects]

I subscribed as soon as he said that. This is my first time on this channel, but him saying that told me enough about this channel that he deserved a sub from me.

[@jackinthebox301]

Instant like for dunking on Thunderfoot.

[@RobotProctor]

Context? Why do we hate that guy?

[@harshsharma03]

​@@RobotProctor he's english

[@jackinthebox301]

@@RobotProctor He has a hate boner for Elon and has lost all subjectivity. He used to be a fairly rational bloke who critiqued obviously stupid scam ideas. He has no expertise in space, cars, neurology or tunneling yet feels like he is the ultimate truth when it comes to Musk’s ventures. His most die hard fans have similarly succumbed to the anti-Elon hate train. It’s exhausting.

[@tessellator1000]

Would love to see this guy do some TF / CSS debunk videos

[@Nutzername36]

@@RobotProctor Because he is right ;)

[@MarcStollmeyer]

So instead of needing 12 refueling launches per Starship, they will now need just 10.

[@just_archan]

You would rarerely need feel to the brim. Over 6km/s DeltaV on ship. You need less than 5 for moon and back

[@keepm4n]

@@just_archan landing included, staying in lunar orbit and returning, or just a flyby?

[@just_archan]

@@keepm4n included. Google DeltaV map. Then add TLO lunar orbit, landing, and back to lunar orbit.

[@TheEvilmooseofdoom]

How can anyone know how many launches it will take without knowing the capacity of any tanker and what the boil off losses would be over time, launch cadence etc? Absent a LOT of data these projections are just guesses. 4 or 40.. it's far to early to say.

[@MarcStollmeyer]

@@TheEvilmooseofdoom you ask some great questions. In Elon’s 2017 presentation he implied that a single refueling mission would be necessary. A year later 2. By 2020 is was clear that 3 wouldn’t be enough. Starship won Artemis implying 4 to 5. And yet Starship 2 specs clearly show a 12 to 1 ratio of payload vs fuel capacity… and Starship 2 has yet to demonstrate any payload to orbit capability. Now Starship 3 is significantly growing in size. That means more fuel required for a round trip but hopefully this time it can actually deliver significant payload to LEO. That all means that less than a year from Artemis’s first scheduled launch NASA had no idea how many refueling launches are needed just for Artemis’s landing stage. Let alone proof that in-orbit fuel transfer is viable. Starship is Artemis’s biggest risk by far and clearly many years away from being ready for prime time. That would be fine if Elon just wanted to develop starship on his own but now real scheduled missions and Billion’s of taxpayer dollars are invested in Starship to return us to the Moon. If it fails the US may not have another real moon program for decades.

[@visyxl]

space x should make a starship heavy, litterally falcon heavy but starship, more engines = moar boosters, moar boosters = kerbal engineering, kerbal engineering = veri good.

[@Vibechaser527]

no

[@furriesinouterspaceUnited]

Yes

[@theantsaretakingover]

I don’t think any form of water deluge or flame trench would ever be able to withstand nearly 70 million pounds of thrust lmfao

[@bob12688]

@@theantsaretakingoverwasint the iss launch almost a billion pounds in weight?

[@sakshamShukla_]

@@bob12688 No. Starship already has twice the thrust of Saturn V.

[@mrmariusi]

Regarding the boost back, not only is the distance needed to cover shorter with Raptor 3, but the vertical speed and separation altitude are higher, so you have more time to cover the distance, so again, you need less horizontal delta V to cover the distance. On the downside, with Raptor 3, the horizontal speed in the "wrong" direction you need to cancel is higher. I did some back-of-a-napkin calculations. The upsides seem greater than the downside, so, indeed, more powerful engines lead to less fuel needed for backburn.

[@DalHrusk]

Long story short: Maximizing thrust is crucial in the vertical part of the flight. After the rocket turns horizontal, the specific impuls is crucial.

[@KiRiTO72987]

Loved the casual jab at thunderf00t and his constant misinformation and pessimism

[@Blob_2_Ship]

Massive respect for dunking on blunderF00t

[@orangeparrots5898]

this mispelling made this 10 times better

[@stainlesssteelfox1]

The trade-off in ISP makes sense for a re-usable rocket. When you're only using a vehicle once, you need to squeeze every possible bit of efficiency out of the propellant you have. With a re-usable rocket, you can simply refuel, as long as you have enough delta-v to reach a propellant source.

[@Piolet1549]

Another factor is that since spacex wants to recover the booster at the launch site, they want the booster to be going as slow as possible during separation in order to reduce boost back delta v. This naturally causes the size of the booster to shrink relative to the upper stage (booster does ~25% of the work with starship and falcon, whereas like an Atlas V booster does ~45-65% of the work depending on SRB config). The result of all this is that the ship is going slower and has less energy than a typical 2nd stage, meaning it has to eat more gravity losses than usual, meaning it needs more thrust. Traditional upper stages don't have this problem bc the high thrust boost stages burn for much longer. This is an interesting topic imo, should maybe make a vid about it

[@stainlesssteelfox1]

@@Piolet1549 Interesting. That makes a lot of sense.

[@mephisto8101]

Excellent video! I'd like to see more like it. Very well explained. One minor thing: If you format the diagrams the same for both vessels, the distinction becomes visually clearer. Right now, we have to look at the axis labeling to see the differences between very similarly looking curves. If you have the same scaling, one could see at a glance which of the curves reaches higher values. This makes it a bit easier to compare different vessels.

[@mofumofutenngoku]

I hate thunderfoot so much whenever he talks about rockets.

[@renchesandsords]

also, especially with a reusable rocket, a higher TWR means less fuel expended on the final landing burn as well

[@nikolatasev4948]

Great video! I find the difference between the payloads to be a lot more intuitive measurement than the differences in orbits at fuel depletion. Also, the Raptor 3 booster may be closer to the launch site at separation, but it is moving faster, reducing the benefit. On the other hand, due to its higher thrust, its landing burn (KSP players know it as the 'suicide burn') could be shorter and thus more efficient. On the other other hand, a shorter burn leaves a lot less margin for error, a millisecond delay due to a sticky valve would result in significantly more speed at landing... It's all tradeoffs in space.

[@nickl5658]

less margin for error means less flexibility landing in bad weather... which limits the time available to land. Which limits the launch cadence. And thus more fuel boil off while in space... as most launches will be refueling launches.

[@nikolatasev4948]

@@nickl5658 The weather is not much of a factor here. The wind may blow the rocket sideways, but near the ground where the landing burn happens, there are no up/down winds, so the they don't affect the landing burn. It may topple the rocket after landing, wind shear may put the structure under stress on the way down, but these things will be taken into account regardless of the engine thrust.

[@anatolyschmidt3665]

I think it would have been a good idea to also include air resistance, because higher TWR also usually means more air resistance

[@Piolet1549]

It prolly would have but I was trying to make this video in ~2 days so including the additional analysis would made things take longer so for simplicity sake drag losses were not included. Drag losses are also a modestly insignificant aspect to launches (typically

[@frjoethesecond]

I watched another video about this subject and here are some of the conclusions. 1: Atmospheric drag is a negligible consideration compared to gravity losses. By the time a rocket reaches supersonic speed, the air is already very thin. That being said.... 2: TWR must not get too high either. While rocket designers would love to boost the TWR as high as possible to minimise gravity losses, they have to keep it fairly low because... - If TWR is too high then there's too much pressure on the rocket's structure, especially at liftoff. - A high TWR also risks damaging payloads and injuring human occupants. If the TWR of your rocket is too high then you'll lose potential customers.

[@sr_aron]

@@frjoethesecondCorrect me if I’m wrong but should you aim for the highest twr possible, and then throttle it to what you need?

[@frjoethesecond]

@@sr_aron It depends, but the answer is usually no. There's a limit to how low you can throttle an engine before it flames out. Usually around 60% is as low as you can go for a high performance engine. If your TWR was too high then you would be causing the sort of acceleration damage I mentioned in the last comment even at low throttle once your fuel runs low. Aside from that. When you design a rocket, you design it based on the engine selection. First you select an engine, then you build the rocket around the performance characteristics. A designer will only leave a small amount of the available thrust on the table and only so they can still fly if an engine goes out. You build your rocket to take full advantage of the thrust available by carrying more payload and/or more propellant. In cases where you're using different engines for different stages, you have more flexibility. You can design your upper stage engine to have more throttle range and use that depending on the mission. This is the approach Blue Origin is taking with New Glenn where the upper stage engine can throttle down as low as 40%. This gives them a much greater degree of flexibility in terms of carrying lots of different payloads with different masses to different orbits, all in the same mission. Hope this answers your question.

[@andresmartinezramos7513]

There are efficiency losses that come with throttling ​@@sr_aron

[@regolith1350]

Starship is already comically overpowered for virtually any normal payload a customer wants to launch, so that's clearly not what they're trying to solve. The most important "payload" Starship will launch is the propellant for its orbital fuel depots. Starship needs orbital refueling in order to do anything at all beyond LEO, and even a modest increase in launch capability could mean the difference between needing 4 tankers or 16 tankers (or more) to refuel a single Starship. The fundamental problem of Mars colonization (and a lunar outpost) is logistics. It's how to do things at scale, not about specific breakthrough technologies for bespoke one-off missions.

[@mr4kids.866]

Scale manufacturing, currently going faster than paper work passing from one desk to the other. Beside the obvious joke, payload planners and designers are already being encouraged to think big in what they will be able to put into space. Its takes a while for them to get the proposals passed and funded and atm it’s not guaranteed starship will be the same payload in the final design. Although the future is looking like many other commercial launch suppliers will also go big.

[@mephisto8101]

You have it a bit backways. Current payload sizes are a result of the restrictions imposed by available rockets. If you have higher payloads available for a similar price, then payload demands will increase accordingly. You could use cheaper materials and don't need to do expensive minituarization as you do right now. If you're interested in an expample, I can recommend "Across the airless wilds" and the problems they faced with designing the Apollo Rover around very, very tight mass and volume restrictions. Very similar problems with designing around harsh mass restrictions are encountered by practically all spacecraft and rovers. These mass restrictions drive the prize of shooting stuff into space higher, along with the transportation costs itself. Interestingly, you gave an examples in your own comment: when possible payloads become larger and cheaper, different kind of stuff can be done. Suddenly, orbital refueling becomes financially viable. I'm looking forward to these developments. We only need one working example, and other rocket manufacturers are then pressured into following up.

[@mr4kids.866]

@@mephisto8101 Once starship reusability is refined when someone says 16 rockets to refuel to get one out of LEO, they still think that means building 16 rockets and throwing them away. The same way they think that the cost of building the payload will stay the same. As you mentioned the miniaturisation and mass constraints of such payloads will massively reduce cost of development and manufacturing. It’s a paradigm shift that is being overlooked. 16 rockets, or 4 doing 4 flights. Also they will just be tankers. The human rated ships can just stay in space and travel back and forth. With the lower cost tankers going to LEO and back so lower build costs.

[@petersmythe6462]

Mars colonization seems very questionable at this stage to me, whereas the quick turnaround to the moon makes it seem like an excellent target.

[@mr4kids.866]

@@petersmythe6462 Both, moon first, going to Mars from the moon is a lot easier (relatively) then from Earth. It will for part of the development and integration of what will be needed on Mars.

[@mephisto8101]

Oh, another thing: a very important part of the "hover-slam" or suicide burn is the available TWR. The higher the TWR, the closer to the ground you can start the burn, limiting the time the rocket has to fight against gravity and decreasing the dV requirements of the burn.

[@Blob_2_Ship]

Here's a simple answer More thrust = more propellant mass than you could carry. NEVER STOP THRUSTING! 🔥 For Starship Block 2 and 3 they will need the extra thrust to carry more propellant which allows them to put more payload into orbit

[@theOrionsarms]

That is bad rocket science! Actually how much payload you can deliver into orbit is determined by rocket equation,some more thrust is useful only for reducing gravity losses, but this is only a minor factor that it's irrelevant for this specific case (starship versions), actually what it matters more is the initial mass over final mass, those are unknown factors because Musk refused to get a straight answer of how much starship prototypes weights, and future ones would have .

[@kazedcat]

​@@theOrionsarmsNope rocket equation deals with fixed wet mass and fix dry mass. Having higher thrust actually improves the dry mass to wet mass ratio because wet mass increases faster than dry mass with increased fuel capacity. The rocket equation is still correct but you need to modify the dry mass to wet mass ratio as a function of rocket thrust to see the effect of higher thrust in the equation.

[@theOrionsarms]

@@kazedcat that is true, but probably the dry mass of starship is so big that the improvement are insignificant, like I said in the first place we don't know exactly the dry mass, but we know that doesn't deliver any payload yet, and Musk said that probably few tens of tons is maximum, so more thrust isn't the answer, less dry mass it is!

[@rudra.patel.001]

AMEN TO THAT

[@kazedcat]

@@theOrionsarms The bigger the dry mass fraction the more significant is the impact of increasing thrust that allows increase in fuel. So if the dry mass is large it is even more important to increase thrust.

[@richardzeitz54]

First time viewer here. This is a pretty smart piece. I enjoy how digestible the information is. What I'd REALLY like is to see this coupled with some more technical stuff, like the rocket equation, that sorta thing. Using KSP to illustrate works for me, btw. Another KZbinr shared that every six kilograms saved with the booster equals one more kilogram getting to orbit, but every kilogram shaved off of the top stage is, of course, a full kilogram more payload that makes it to orbit. It would be interesting to see how that relates, re. thrust. Like how much more thrust on the booster, vs how much more on Starship, how that relates to mass to orbit. Sorry I'm not being very clear, but I'm no rocket scientist. Anyhow I'mma subscribe and see what else you produced. Good job!

[@Piolet1549]

This video was intentionally pretty surface-level because I was just trying to explain a pretty fundamental concept in rocketry. The video I just released today is much more technical and includes some actual math and actually somewhat talks about a lot of the stuff you mentioned. My plan was always to start a little basic and get more technical later on. Thanks for the sub!

[@richardzeitz54]

@@Piolet1549 great! I'mma watch it a little later today. I look forward to it!

[@cuteButKindaDeadlyBreloom]

Great vid. I take it that the Main thrust of the argument is that more thrust > greater payload capacity as well as some propellant savings for boostback burns. And yes I just wanted to have an an excuse to say “main thrust of the argument”. Pun intended.

[@StevenS.-up2pp]

Great video, I never really understood gravity losses before, but this gets it closer to intuitive

[@zachb1706]

Damn this channel is underrated

[@Piolet1549]

thanks!

[@pc_screen5478]

Raptor 3 will also reportedly not need the shielding so that's like 10 extra tons available for payload from that

[@JimBoIndy]

For me Thrust is Very Important, But Equally Important is the Depth 😊

[@andrewparker318]

1:12 Lmfao

[@MrTurboTash]

more thrust also helps with the oberth effect as you can shorten the burn window towards the more efficient part of the orbit.

[@kerbal8216]

This video was really good. I hope we can see more like this!

[@Piolet1549]

Glad you liked it, more to come!

[@OhmicContact]

Before watching, my assumption is thrust per square foot of area below the rocket determine how wide you have to make the rocket. If you get super high thrust you can make it more narrow which is more aerodynamic

[@rdbchase]

One would have to be particularly oblivious of rocket science to need that question answered. SpaceX needs to do something to increase Starship's payload capacity from zero to something approaching the 100-150 tons to orbit claimed for it, but improvement in Raptor likely won't be enough.

[@matejlieskovsky9625]

Regarding the booster, a higher TWR can also make the landing burn slightly more efficient!

[@SimonAmazingClarke]

Very interesting. I know these are broad brush calculations but the speed through the lower atmosphere is important too. Too much speed and the drag goes up exponentially

[@PetesGuide]

1:12 *_BASED_* And will someone please tell my what that foot guy is trying to do?

[@routybouty]

No idea. His videos age really poorly. Must just be a basement dweller.

[@archierush868]

I think he’s just trying to degrade Elon’s character to make him feel more successful than him just by saying stuff like: “this has to fail because [Project completely unrelated to topic which Elon did once and abandoned] failed, and a failure is a failure and you can’t learn from failures” or whatever. Basically any opinion has to do with spaceflight which comes out of TF’s mouth is irrelevant to the facts like saying the F9 was more expensive than the Shuttle for cargo to the ISS and reusing it wasn’t viable. He even debated over someone a few years ago with the Shuttle and Dragon by saying that the Shuttle was better since it “could” stay on the ISS for as long as the dragon, but it was never designed for it, and for some reason believes that $55M per seat for 6 months for 4 people is worse than $69M for around 2 weeks for 7-8 people. Theres a funny video making fun of his “breakdown” of Starship flight 4’s stream by pointing out every detail that he got wrong, which is basically all of it, which he could have very easily gotten right had he unmuted the stream. I’m glad I have his channel now marked as “Do Not Recommend” as around half of his videos now are anti-musk

[@barongerhardt]

@@archierush868 He seems to suffer from Musk Derangement Syndrome. To be fair the visions Musk shares often boarder sci-fi and are on unreasonable time tables. Several, like hyperloop, are a S*show. The last TF video I saw dumping on starship was the tech is there or close but it would take so much effort that it was unreasonable, hence impossible. Like the Berlin Airlift.

[@archierush868]

@@barongerhardt well, not impossible, but not easy. I guess TF thinks that if something is difficult and he can’t think of a way of doing it, it’s impossible and you should never continue trying to work on it.

[@barongerhardt]

@@archierush868 Without going back to watch it, the main point was on needing something like 12-25 launches to use starship to refuel starship for longer missions.

[@shuaebfromiraq4505]

This is a very good interdiction to the spaceflight community for new comers

[@Piolet1549]

thanks, the goal of this video was to explain a more foundational topic in a detailed and understandable way

[@shuaebfromiraq4505]

@@Piolet1549 no problem ❤️❤️ Love your content btw

[@oneistar6661]

Thank you. Incredible explanation, visualization and calculations.

[@nikohamil538]

Its very simple to go from launch to orbit you need a tractor to go from orbit to Moon/Mars etc you need a sportscar Thats why F-1 had crazy thrust but low Isp but J-2 had 1/6th of thrust but crazy Isp

[@JuPiTeR_0211]

yeah nasa engineering

[@macnguyen9414]

Space x: we build rocket.Dont blow up, more thurst.We good to go😂

[@PhysicalEngineering]

bro this video lacks alot of quality but has alot of dedication the graphs and the microphone and everything are things you could improve

[@mpendulojwara]

was really hoping that F9 booster makes it 😢😂 this is a really informative video, liked the data charts and numbers.

[@Piolet1549]

Thanks!

[@abhijeettube1]

Really nice video. Thanks

[@azureforks.]

It's payload to orbit, in payload to orbit we trust.

[@jacobbaumgardner3406]

Man, I was boogieing to that music, literally.

[@EveryoneWhoUsesThisTV]

When you have no plans to use solid boosters, you need to make sure your bipropellant engines have the thrust to compensate..... :) The Merlin is the posterchild for TWR.

[@HansJakobshagen]

I'm wondering about the conversion between MJ/kg and km^2/s^2. Should that not be the same? How do you end up with slightly different numbers?

[@JustinTimeCuber]

8:16 why are the numbers different? km^2/s^2 and MJ/kg are equivalent units

[@terracub]

Oh my god did you see how startled those birds were. The FAA must look into this. Where are the environmentalists. There were birds that were startled my God people. Are we going to let this stand or are we going to send in the FAA and the environmental groups to do yet another review. This sounds like a perfect opportunity to waste millions of dollars. what are they waiting for!

[@Piolet1549]

who cares about mars the birds are getting scared... NOOOO!!!!!

[@Meyer-gp7nq]

Birds were meant to fly

[@lb2791]

Maybe don't build your launchpad where you will destroy and disrupt important natural habitats with every launch? Oh but I forgot, when Musk does something it's automatically correct. I get that mars is neat but we have the most extraordinary planet we know of right under our feet, there is no need to destroy it.

[@terracub]

@@lb2791 what are you talking about NASA has been launching from Cape Canaveral for over 50 years and many rocket accidents have happened and it's still the most beautiful place on the planet

[@jamesogden7756]

Soooo, you're telling me that some environmentalists will ship birds to Mars just to impede SpaceX? 😂😂😂 Aww, it was supposed to be funny. Watch the idiots actually try.

[@Michaelonyoutub]

It should be noted that while more TWR is great, it also means that everything will experience a lot more g's of acceleration and that can be an issue if not avoided. A TWR of 2 means 2g of acceleration, 2x Earth's gravity. Now 2x times Earth's gravity is not that bad, you get that on most roller coasters, but as the fuel in the fuel tanks gets used, the weight of the rocket decreases, causing the TWR to rise. The simulation shown here has the peak acceleration, just before the fuel tanks empty of 4-6g, which is nearing the brutal levels fighter pilots train for, and thus not necessarily that nice for normal untrained people. It is not just people either, many payloads and even the rocket's own electronics can be susceptible to breaking under too much acceleration. Too much acceleration can be mitigated by reducing thrust when fuel is low, but throttling a rocket engine is actually pretty hard, it has restrictions, and is generally pretty rare. While SpaceX has developed an engine that can throttle, it still can't throttle really low, it has a point of minimum thrust where you can't lower it any more or it will destabilize and potentially tear itself apart. So if your TWR got too high, you might not even be able to throttle down enough to avoid TWR problems. Luckily SpaceX actually have a solution to this too, and it is their use of multiple engines. If your TWR of all of your engines is too high, just turn some off and use fewer. SpaceX is already doing this with Falcon 9 with their booster boost back and landing burn using only a single engine in the middle of the 9 engines. They need 9 Merlin engines to take off, but an empty booster needs only 1 to land. That actually means that if they were to use all 9 with a near empty booster, it would have a TWR of at least 9.

[@agreeable4334]

I made the mistake of looking at stormfeet after you told me not to i will not make that mistake again.

[@TheInterestingInformer]

Ksp and data analysis? Instant sub. How do you collect the data from the game? Mods?

[@LinKongDa]

The long and short of it. the faster you get out of the gravity well(earth) and atmosphere the more OVERAL efficient is your overall Rocket. Thus a bigger Thrust is better.

[@mathewferstl7042]

because starships performance is waaaay lower than (publicly) expected

[@Nutzername36]

thank you. Seeing all the soot in the flame of starship its obvious that they are burning -a lot- fuel rich. Either to not burn the engine or the pad or both.

[@TheEvilmooseofdoom]

Starship is still in development, why not wait until they have a finished version before deciding if they hit their design goals? Or is that too logical?

[@mathewferstl7042]

@TheEvilmooseofdoom yeah spacex must be a bunch geniuses that they've had to retroactively design two new starships because the original one that was always meant to be the only design was massively under performing.

[@florianschneider3982]

@@mathewferstl7042 Give me an example of something where the first design was successful.

[@mathewferstl7042]

@florianschneider3982 this isn't the first design? Starship has undergone multiple redesigns before settling on the current one. It has become the basis of HLS, the tankers and depot. It's only once they got flying they realised it's underperforming such a large margin new Versions of the vehicle and engine have to deigned. I don't know why you insist on coping and seething for Elon musk. Get a life

[@electric_boogaloo496]

TWR is well and good for commercial operations, but for NASA Artemis missions, SpaceX engines and vehicles just don't have the ISP and delta V.

[@airwaffle]

i did not know that thrust made such a big difference. also, is this your college paper in video form o smth? very detailed and very epik!!!

[@swatbdaim1888]

ill use this knowledge in my ksp rockets

[@DeathmetalChad]

3:43 SPACE FLIGHT SIMULATOR

[@HuginKvalsvik]

How did you get starship in ksp?

[@MohamedMoursy-vv6mh]

what are the mods that you used in the starship, superheavy and raptor 2 & 3?

[@ixion2001kx76]

How did you get flight telemetry out of KSP?

[@AbsoluteHuman]

9:31 The payload _difference_ will rise though? I mean, the whole payload will become smaller, but in the end it's the difference of being able to reach some high orbit at all...

[@AbsoluteHuman]

Payload difference percentage I mean

[@josephmoore4764]

Gravity loss can for sure be a drag, pun intended. But anything outside of the initial vertical is all about Isp. You can throw on a second engine and double fuel consumption, but that will burn through the fuel twice as quickly, which is why the rocket equation omits the thrust of rocket in its calculation. For this reason hydrogen upper stages have been the go-to choice, until this new starship came about, despite the low thrust and engineering difficulties. Even spacex's best claims of raptor isp is 380, which has yet to be verified, against ~465 seconds for decades old engine, which could potentially be improved upon. That by itself is about a 25% increase in delta-v. Hard to say what that means for payload, but it could be calculated for certain arrangements. The mass fraction change does go against hydrogen a little bit, but not so much to make a very large difference.

[@Nutzername36]

Its not that easy. YOU. NEED. GIANT. TANKS. FOR. HYDROGEN!

[@Gammaduster]

Well made video, you may want to reduce background audio vs your voice just a tad as an improvement

[@MKJ8888]

Amazing video! Subscribed! And also, from where have you such a beautiful KSP Starship model?

[@Piolet1549]

Starship Expansion project, here's link: forum.kerbalspaceprogram.com/topic/206555-1125-starship-expansion-project-sep-v220-june-23rd-2024/ would also recommend getting Starship launch expansion for the pad: forum.kerbalspaceprogram.com/topic/203952-1129-starship-launch-expansion-v05-beta-may-31/

[@dandel351]

I came here just to see Starship launch again ....I can't be bothered waiting until late Nov early Dec or even 2025..🚀⭐

[@ReidMerrill]

Thunderf00t is great

[@fredrikcarlen3212]

lol

[@TheEvilmooseofdoom]

@@fredrikcarlen3212 It's funny to hear people praise thunderfool. He does gull a lot of people though.

[@yOkay_]

Yes he is a true clown

[@drachefly]

The dude managed to make incorrect criticisms of creationism.

[@mofumofutenngoku]

A great fool.

[@inpatol3204]

Ok so less efficiency is more efficiency? Yeah that makes sense.

[@JakeB-Real]

SpaceX isn’t the only 1

[@ADobbin1]

More thrust from the same amount of fuel means you can lift more weight using the same amount of fuel making the cost per ton far less. Ideally you want a dollar per ton cost wise. If you can get less money per ton even better.

[@jtjames79]

Because gravity. TWR > Delta V.

[@vikkycb7948]

I belyrhe answer is simple Other dont focus on Thrust as they use Solid rocket boosters to achieve thrust.

[@philbarker7477]

It’s been very obvious for quite a while that Spacex have a big weight problem.They have been adding stringers and other strengthening components for 3 years now.All made of - steel ( Iron).The craft was always heavy due to the initial materials decision but it’s gotten far worse over time.Hence the need for a massive increase in trust even if it compromises longevity - they have no choice.

[@denysvlasenko1865]

They can start building from titanium when reusability is ironed out so that they can expect at least 20 successful landings out of a stage.

[@TheEvilmooseofdoom]

@@denysvlasenko1865 I doubt they switch to titanium. Have you ever worked with it?

[@Vtoltini]

What mods do you have cuz my starship keeps flipping

[@Thermospon]

You just have the starship flight 1 data pack

[@jujuteuxOfficial]

have you taken in account the reduced thruster weigtht? (of about 1.9t per engine compared to raptor 1) also, there's a rocket payload calculator out there, after doing some checks, the result is quite different, the raptor 1 version can carry about 151 tons to orbit while raptor 3 results in a 226t to orbit

[@willernst8376]

I like how when thunderfoot dunks on spacex you should stay away from him, but when smarter every day does it, it is brave and needs to be said.

[@LoisoPondohva]

One of those things is not like the other

[@petersmythe6462]

Now do you see why Reliant > Swivel?

[@petersmythe6462]

And no, I don't mean as a launch stage engine. Reliant is just better than Swivel under virtually any conditions.

[@mtfe-1144]

Would you like to elaborate on why you dunked on Thunderf00t? Im not exactly in the loop.

[@LoisoPondohva]

He has lost all objectivity some time ago now when talking about anything to do with Elon. Don't know if it's personal, political, is better for the algorithm or whatever, but the fact is, a big proportion of his new content is about SpaceX and other Musk projects, and at least in case of SpaceX, he has long given up on acknowledging truth, science or anything else if it gets in the way of pure hate. Sad to see, really. And I'm not talking about hard criticism, that's welcome. As an example, the last orbital test he was simultaneously live streaming, predicting some catastrophe at each step, getting visibly irritated when nothing was happening. Then the control surface caught fire and he spent next 20 minutes maniacally laughing and saying I told you so. But then the ship managed to make a soft landing anyways, which drove him mad enough that he actually screamed for a couple of minutes, calling SpaceX engineers (that were cheering in the official stream) idiots and worse for thinking it was a success. Then he disconnected, only to return later with a 3h ramble of a podcast where he tried to come up with reasons that every step of the process, the company, the vehicle and more was ultimately absolutely a failure, going as far as implying multiple times that SpaceX faked parts of the launch stream with AI to cover up that it was actually a failure.

[@mofumofutenngoku]

He won't shut up about Elon Musk.

[@orangeparrots5898]

3:55 meters a second per second??? is it not just enough with meters per second??

[@hafizuddinmohdlowhim8426]

Because the storage time to store the propellant is limited. 😅

[@AbiemMiqyal-qf4xu]

Smaller lift more payload

[@cmbaz1140]

as a man i also care about thrust...

[@th232r6]

Wouldn’t the “wasted” delta v be the area under the curve NOT the final recorded Z value?

[@Piolet1549]

Idk if this makes sense but the curve I showed IS the area under the curve. This is because each second of losses is equal to (the losses in that second) + (the total losses of every second before that). If the graph was formatted differently you would take the integral, but because it includes the sum of the previous terms, you don't. If you did actually find the area under the curve you would get a giant number that is way higher than the total delta v of the vehicle

[@PhysicalEngineering]

bro what is this asmr microphone brooo

[@timothyblazer1749]

It's all about TWR, and TT. :-)

[@rokadamlje5365]

And yet, the acceleration at MECO was like 2.5G in past 3 flights...

[@Piolet1549]

I assume ur talking IRL. But yes I was aware of that when making the vid, several reasons for the difference. First, I fully depleted the super heavy, making it lighter at MECO than IRl (if I staged when they do irl, G's max G's would've been ~3.5). Second, SpaceX likely throttles super heavy down for MECO, very common practice to reduce loads, Falcon 9 does this. Third, I think the dry mass of the vehicles in this mod are a little low. Liftoff TWR seems normal but when its empty there's just too much power. I've had to throttle the 3 center booster engines down to like ~20% to get the thing to hover during landing-dosn't seem quite accurate. Hope that all made sense

[@Oscar-vs5yw]

I like the video idea, but bad data presentation on 6:50, graph comparisons should be performed with the same scale.

[@Asterra2]

4:32 Doesn't the Raptor 3 carry the potential for significantly lowering the overall weight of the vehicle?

[@Piolet1549]

Yeah reason I said that was bc it hasn't actually been fitted to any vehicles yet so I just wanted to play it safe in case it ends up weighing more than expected

[@SleepyGamerPR]

Bro got resurrected. Yay

[@kipkipper-lg9vl]

you can't have a max performance engine pushing material limits on a reusable system period, they will break constantly

[@Schinkeldink]

well yes but actually no. if you push the limits, you can just take a step back and e voilà you have an engine running reliably where once was the limit. sure there are exceptions but till now it seems to hold true

[@kipkipper-lg9vl]

@@Schinkeldink they are not doing that, they are up to raptor 3 and they have not backed off the performance at all so far a raptor has failed on every single flight which is a bad look for something that will supposedly be human rated

[@sakshamShukla_]

@@kipkipper-lg9vl When you have that many raptors in each flight it's the best time for it to fail. More engines=more accurate estimation of risk rate per raptor. If 1-3 raptors are for redundancy then they already have succeeded in reliability. Where you do need reliability is on the vacuum raptors and that is less dependent on thrust.

[@luigeribeiro]

@@sakshamShukla_ You didn't get the point, SpaceX has two requirements for Starship (among several others) a) high thrust b) fast turnarounds (days or even hours) , which are conflicting. The higher thrust implies not only in a high probability of failure during flight but also in more frequent long inspections and repairs between launches. This situation in turn implies more operational costs.

[@sakshamShukla_]

@@luigeribeiro Don't you think the stainless steel body can inherently take more thrust from the raptors?

[@svenb4475]

Why stay away from thunderf00t? he has valid criticism, maybe takes it a little personal sometimes but thats not just his fault.

[@rootpill]

He is the personification of the Dunning-Kruger effect. Watch his reaction to Flight 5 as he seethes and copes, hoping for anything to go wrong. A few years ago, he also claimed that Starlink would never succeed because the 'data' supposedly didn't support it.

[@mofumofutenngoku]

@@rootpill He has made so many "this will absolutely fail" claims that turned out to be absolutely wrong.

[@wetsock6334]

Why stay away from Thunderfoot?

[@mofumofutenngoku]

Have you seen his videos on Space X recently? He is a flat out liar.

[@frantisekjanecek1641]

Thank you. But you used terrible wrong notation - km/km is 1, not km^2.

[@baxtermullins1842]

Thrust is not the Gold! It is thrust to weight ration and now reusability!

[@Piolet1549]

Yeah ur right, but thrust is a more universal word. Vid prolly wouldn't do as well if I put TWR in the title

[@maxkojin]

gotta go fast

[@sairian]

I mean.. who doesn't?

[@help1ng316]

Wait... Why should i stay away from Thunderfoot? First time viewer.

[@qutibplay1152]

Самое важное, что автор не учитывает и не знает - импульс двигателей, что является чуть ли не основной характеристикой, на равне с тягой. Хорошо, раптор 3 будет более мощный. Но за счёт чего? За счёт импульса(экономия топлива) или этот эффект был достигнут благодаря увеличению КПД сгорания смеси?

[@TheLetmewatchthisvid]

Why the thunder foot hate... he's not wrong about space x

[@TheEvilmooseofdoom]

Thunderfool is wrong a lot.

[@mofumofutenngoku]

Thunderfoot is wrong about space x.

[@calvinwilliams3700]

Simple answer is delta V

[@LinKongDa]

I have Zero confidence in the landing catch mechanism. Even with a 95% success rate of a catch. the 5% failure will destroy the launching platform. the catch tower and the fuel farm. Setting the whole program back to square 1.

[@miguellopez3392]

That's why they are building another tower, and just like falcon 9 they will improve the landing accuracy to the point that a failures cost can be sponged by the savings of having the rocket on a catch tower.

[@kefpull6676]

1:13 why the jab at Thunderf00t???

[@fafnirbane]

I would guess because Thunderf00t has a tendency to never give due credit when SpaceX avhieves something new. Just look at the latest video about the mechazilla catch. It's just a tirade about how it's not really amazing because it's "a waste of taxpayer money" and how SpaceX originally promised way more for that money. ... All of which could very well be true and valid points. But the packaging is just very anti-anything-touched-by-elon-musk. The reality is a bit more nuanced. It feels like he outright denies the sentiment that space has become exciting again and SpaceX is achieving amazing milestones. I still think Thunderf00t is useful to watch though.

[@mofumofutenngoku]

Because t-foot is a flat out liar when it's anything to do with Space X.

[@aktab9]

​@@mofumofutenngoku Please give an example

[@aktab9]

Because he is a SpaceX musk cultist 😅. They don't realize the false promises of musk.