How SpaceX's New Raptor Vacuum Engine Is Different From Previous Raptors (and Other Stuff)
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- Опубліковано 30 вер 2020
- It's been a while since I talked about SpaceX's work on Starship, but in the last month I've been most excited by the reveal of the prototype for the Vacuum optimized version of the Raptor engine which is intended for the Starship upper stage.
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The flow separation on the shuttle clip was pretty neat, those are some scary forces.
These forces are some uber-powerful sonic waves, playing havoc on the surfaces...
I agree! I noticed that wobble on an rs25 engine video I watched just a couple weeks ago. Had no idea what was going on. Really spectacular breakdown, as always 🎖️
Which is why they didn't go for cutting their pipes out, rather brazing them.
Yes, the RS-25 had to perform not only off the pad, but almost all the way to orbital insertion. Compromises had to be made in nozzle design for its use as a sustainer engine. 0-17,500mph! The Rap-Vac operates only in vacuum thus can be more optimized for that single operating environment. Man does it start quick! Pressure start vs. RS-25 Head start The new RS-25 nozzles will feature a new channel wall nozzle to replace the 1080 stainless steel hand laid furnace brazed tubes in the current RS-25 inventory. I wonder if they will flex as much during start for SLS? Core Stage greenrun at Stennis coming soon! All 4 RS-25 engines have been powered up and gimballed using the new TVC systems.
It looked so cool
look at those shuttle engines warping, amazing
And to think the Borg went back in time to prevent us ever discovering how to do it!
...wait, never mind, wrong century.
Warp speed, engage !
I want to know what frequency they are vibrating at.
@@Lachlan.Wright the footage Scott used is available in full on youtube (I forget what exactly to search for sorry, but it's a glorious slowmo of the whole shuttle launch) and the red numbers at the side are frame times, so I don't think it would be too difficult to work out with a calculator and a key for how to read the times
That's incredible, I've seen that slo-mo before of the flow separation but never noticed the engines vibrating. Wow.
euuh! Vacuum test facilities .., I worked on the J6 test facility in Tennessee. The AF SRB vacuum test plant. I designed the test cell, the supersonic eductor, and the 20 toroidal vacuum steam jets. We ran a large boiler set for 3-4 day’s just to get enough hp steam for a 90 second run...those were the days!
I'd guess it's easier for SpaceX to just use the lower expansion ratio nozzle first and then test the larger nozze in space later.
If Starship ends up with 3 vacuum and 3 ground level engines anyway, testing these by flying into orbit with the ground level engines and testing the higher expansion vacuum engines should be easier for them.
And for launching cargo the performance of Starship would be overkill anyway, so the slight loss in performance wouldn't be that big of a deal.
So I guess there is a good chance these nozzles will first be used after deploying some sort of payload.
@@diesistkeinname795 probably cheaper to fly a test article on an F9 to LEO to test it :D
@@MrSapps
Well, I'm not sure if a vacuum raptor with an even larger nozzle than the tested one would fit into the fairings.
Allthough a raptor powered upper stage for Falcon Heavy would probably increase payload capacity significantly, especialy in high energy trajectories as the regular upper stage is significantly undersized for FH.
That could even be sufficient for an Apollo-style lander mission if they add active propellant cooling.
@@diesistkeinname795 It s unlikely we will ever see this. Their Falcon 9 and FH launch facilities aren't equipped to fuel a methane liquid methane upper stage. As well it would sort of defeat a huge part of what makes the Falcon 9 (and by extension the FH) such an effective launch vehicle. Rather than design totally custom systems for each stage they just took the same first stage hardware, modified it a bit, and created an upper stage as well as side boosters for the FH. This way they can reuse a lot of tooling and they can capitalize on an economy of scale with the common components. The two main priniciples behind the Falcon 9 (and the FH) are simplicity and modularity (at least thats what they appear to be based on their decisions up to this point).
Tullahoma - a plumber's wildest dream !
"Building prototypes faster than blow them up"
Woo, that sounds very promising!
that's your prototype destruction ratio, or pdr (not to be confused with a preliminary design review)
@@alexandresen247 I mean, it's just throwing money to accelerate development to breakneck speeds
@@prateekkarn9277 a small price to pay for salvation
@@merxellus1456_ *yes*_
@@RobertLutece909 I am sure SpaceX know what they are doing. They have been doing it since 2002, all under the strict guidelines from NASA...
have a great day
I like the little 3D man with his hands on his head in that disaster sim.
11:32
Should have had a Kerbel standing next to him acting all "nothing out of the ordinary here".
@@JohnDlugosz Aka. That kerbal posing like "i'm the best" in front of a nuclear explosion
That is just Tim Dodd!!
And that's exactly what happened on Feb 2021 with sn9!!
I just adore these short little explainers that Scott does. I wondered about the relationship of the bell nozzle and atmosphere/no atmosphere, first time I've heard it explained clearly and simply. I also learned about the reasons for the exhaust shape in the test footage. This is what people initially hoped the internet would enable. Instead we got FB. goddammit
We can thank our fairer half.
@@sonnyburnett8725 what?
Amogh K. Umesh , The reason for FB and it’s success!.......
Go watch the final codec conversation of metal gear solid 2. It keeps getting more relevant each year.
great comment!
Man it's crazy that the simulation at 11:35 almost perfectly mirrored SN9's landing
The Vacuum start up sounded like one of those ceiling mounted heaters with the big fan on them 😂 A hell of a lot warmer I’m sure 🤣
Funny how sounds overlap.
Saw someone build and test a 1000 oscillator analogue synth.
And since the tuning of each oscillator varies with frequency and they're all slightly different, when tuned to be in sync for a specific frequency, they're out of sync for others.
So... He turns it on and slowly ramps up the frequency, and I swear the entire first 15 seconds or so is just this wall of noise that sounds like a jet engine spooling up.
Then out of nowhere in the space of 1-2 seconds it all goes into tune and starts to make an actual note. XD
I guess what that suggests is a jet engine sound is basically pink noise, but still. XD
@@KuraIthys Look Mum No Computer
Cost a touch more to run though XD
KuraIthys 🤣🤣 Crazy world lots of sounds 😂 it is crazy how similar things do sound. I mean those electric lawn mowers sound like drones somewhat then there’s the Tesla’s which can be like parrots 😂
Quiet Wanderer I mean we could brew the world a cup of Joe in the morning 🤣😂
Re: radiative cooling. You mentioned being inside a skirt, but another issue is there will, I believe, be three of them near each other and they can't radiatively cool towards each other.
Released just in time to sit down for dinner with this! This is the earliest I've ever been to a Scott Manley video, let alone one about SpaceX! :D
Same lol.
Same, I had a launch break at work :D
8:07 "The raptor is a more complicated engine". As if the RS-25 itself wasn't complicated enough.
Yeah, advanced might be a better word to use. :P
@@TechyBen Both are accurate. The RS-25 is a closed cycle hydrolox, the raptor is a full flow staged combustion cycle methalox, the only one of it's kind that has ever achieved full functionality.
But it is way more reusable & allot more powerful. Shuttle wasnt reusable as they would have hoped it ended up being referbishable which caused the cost to go way up from what they wanted.
@@theatom7264 the problem with shuttle wasn't the engines, the engines were the most reusable part. it was the falling heat shield, the freezing o-rings, the fragile aluminum structure, the extra weight from all the random crap congress wanted, the extra long wings, the duplicate 8-bit computers, the life-support systems, the requirement to have 7 crew at all times, the giant hydrolox tank, the fact that it was built and tested all across america, the toxic hypergolic fuels, the inability to properly improve the design, and the fact that they didn't even get enough funding to build spare parts.
the flying brick was a disaster.
@@jesusmora9379 Awesome synthesis, for a generation, having the shuttle on the cover of the school science and technology book meant "this is the top thing of the world", how things change when information is properly analyzed.
Thank you for making these videos with thorough, compiled information rather than jumping at every chance to make daily videos about what piece of sheet metal got trucked where at boca chica. You make some of the best videos on space news out there.
I just love the fact that their animations of bellyflop, over flip and success are exactly how the launches went later on
Damn I LOVE 'rocket science'...I only understand a small percentage of it, but I still LOVE it!!!!!
Same!!
7:10 Hi Scott. The bright bands seen inside the divergence section I believe is "ghosting" of the cooling jacket structure in the walls, not flow separation. Also, if you reduce the throat in order to get your expansion ratio but you keep Pc the same, then thrust will decrease proportionately to the reduction in cross-sectional area of the throat due to the required reduction in propellant mass flux which drives chamber pressure. The only way to reduce the throats area and keep thrust the same would be to increase chamber pressure. This will have an affect on the propellant mass flux as well as thrust coefficient driving it up.
Great video as always!!!
I believe he was referring to bright "beads" not "bands" which would make it the bright spots right at the edge of the nozzle which would be the flow separation.
Ooh, I hope Scott reads your comment and posts a detailed response.
Elon described it as flow separation: twitter.com/elonmusk/status/1309385646033842176?s=20
@@scottmanley Succinct. Nice.
@@scottmanley Yes, that is flow separation. I am talking about the bands up inside the divergent section.
In addition to the packed-in nature of the Rap-vacs making radiative cooling unworkable, is the regenerative cooling needed to make the engine reusable with no overhaul between most flights? The space Merlin is disposable, after all.
I'm sure this wasthought about in the design but remember this isnt a final design vac Raptor. They'll likely go through a handfull of changes between now & when it starts leaving the atmosphere.
Merlin isn't disposable. It has been used for multiple flights, although it needed refurbishment
OP is talking about the vacuum optimized version on the second stage which burns up in the atmosphere when it's done.
@@chris-hayes Oh, got it. Thanks
Maybe they plan to reuse it in low pressure environments like moon and mars.
so designing in that feature now, might be cheaper than making a disposable version and s special reusable one.
"If you're falling, you definitely want your engines to start up quickly"
Don't I know it! *laughs in KSP*
The animation is exactly what happened with SN8,SN9 and SN10. 11:32
Wait, so they're literally using crumple-zones as shocks?
Guess this makes takes Lithobraking even more accurate as a descriptor.
If it works, and you can still use the vast majority of the faring for future testing/use, then it's still a decent design. Even if it is a crude solution.
SpaceX doing development testing for Tesla.
Apollo used it on the Lunar Module. No reason not to use it.
@@RavemastaJ I prefer to call it brutal elegance instead of crude, because they're actually meant to telescope up in a wedging action, IMO. The crumpling happens because the one-engined tilted ship puts too much weight on the first couple of legs to make contact, and the ship's moving slightly sideways, not straight down. The leg telescopes to the limit, then crumples further.
rdfox76 that was a one time use vehicle though.
Love that turbo pump start up noise - sounds like a door on the death star closing - on steroids :)
"Getting ahead of themselves, building prototypes faster than they can blow them up." I LOLed
Bold moves - we have yet to see a Raptor reignite in flight, or even sequentially between fuelings. I think this is the most interest aspect of SN8's potential flight.
Very good, informative video. I appreciate how no prior knowledge of rocketry is taken for granted, which made it very accessible and provided some clear explanations of topics I've been wondering about for a while. Good stuff 👍
Jesus. 5 months later, and SO MUCH PROGRESS!!! 🔥🔥🔥
XLR-99, the X-15 engine, had a white coating too called Rockide to help insulated the walls which were regen cooled too by the ammonia fuel. That bright/hot spot is caused by the phenomena of gases becoming opaque above a certain temp. Thanks again Scott for another professionally delivered video - Ken
Excelent video, you pointed things that I haven't notice before, like the wobbling nozzle of the RS25, i don't know how SpaceX will make not to break the piping of the cooling system of the Raptor Vac nozzle.
Amazing engineering
Wow. I love that we're living in this time to see all of this. We're taking the next step into exploring the vastness of space. People living 300 years from now will be looking back in amazement 💙
Scott your videos are always very interesting and informative. Always look forward to a new one dropping. Keep up the outstanding work boss 👍🏻🏴
SpaceX's ability to leverage technologies from outside the normal aerospace field has always been impressive. The milled core sandwich panel design with a thermal coating (Yttria stabilized Zirconia or similar) has been used in the gas turbine industry for years to manufacture combustion section components. The current generation of large power generation turbines operate at turbine inlet temperatures approaching 1600c for months at a time.
A wealth of information as always.
Always learning cool new things here👍 keep up the great work!!
Been looking forever for info on the landing legs.. good stuff thanks.
Excellent presentation, thank you Mr. Manley. SpaceX has made everybody curious on developments of Space technologies, so your clear explanation is right and proper...
I went to check the description for the starship landing video and I'm happy to see it there :D
Scott Manley. The best. Love from India. Keep up the great work.
I just love seeing Raptors start, you can truly feel the power like smack you right in the face, they don’t mess around!
Testing a vacuum engine at sea level. Big brain move.
Arjun Amin they really are stupid to do that
Well, do they have another option? It’s expensive to test a vac engine in an artificial vacuum. And you can’t just haul it into orbit. It is kinda dumb, to be fair.
@@gamingbelowzero542what you want them to just throw it up there and see what happens?
@@gamingbelowzero542 you're ignorant
@@gamingbelowzero542 the guys that you called stupid also responsible for the reusable rockets how about that? And what have you accomplished for besides becoming a keyboard warrior?
"That would probably set them back." There's an understatement.
Thank you Scott not much about the Raptor and it’s iterations out there yet! Can’t wait to see the gases as they expand until orbit 🚀
Been waiting for this topic
For 4 Years you have been my Nasa. Love you Scott!! Thanks fore explaning /expanding - on all the "in between" parts!
They already have the stacking alignment stringers mounted around the top of SN8, so it's "nosecone-ready." Speculation is that they will do cryo and pressure testing first, then stack and weld on a nosecone while still on the launch pad before the 15 Km hop.
Ok Scott, a hypothetical. If you were teleported to an alien planet where there were all the resources, materials, & fuels, and mechanical equipment and tools you needed, could you design & build a rocket to get you back into space? I think yes! Thanks for being our "Know How Guy".
This is a video about Raptor, but I never get tired of seeing that slow-mo Shuttle engine startup, especially as the Mach Diamond teeters on the brink and then 'pops' into existence.
Thanks for explaining this so clearly - any chance of a video about these vacuum engine test facilities? I'd love to know how they work and I'm sure there are some big numbers involved!
Ive been waiting for someone to talk about the variance in these engines!
🙃🤙!
Not much, bigger nozzel, your welcome
Good explanation of the way vacuum raptor engine works, thanks
first, love the launchpad and tower for the Saturn V! been wanting to do that for mine. Second love the thoughts and insight into the rap-vac. it will be interesting to see once they do a full orbit insertion of starship.
Very interesting watching this video AFTER the SN8 12.5 km extravaganza. A few things Scott didn't get right provide a gauge of the speed and flexibility of the Starship program.
One thing. The flaps on SN8 are not wings since they don't provide any lift and are there to do exactly the opposite, to create as much drag as possible. Otherwise an excellent video and incredibly informative!
Do you not call those flappy things on penguins wings?
@@Vatsyayana87 An amusing thought. But... Well, evolution has turned tetrapod limbs/hands into feet, flippers, and three kinds of wings (pterosaur, bats, and birds). A penguin's wings and a seal's or porpoise's flippers were both feet at one time, if you go back far enough in their evolutionary line. What we're dealing with here is the vagaries of language and its many inconsistencies. These 3 animals' limbs serve the same function regardless of the name.
But man-created wings on aircraft have specific ways they interact with airflow, and it's very different from how Starship's control surfaces work. No existing term is accurate, and all are actually misleading, especially wing. Some wish the innovative terms brakerons or elerons had been adopted, but Elon has settled on "body flaps" for now.
OK, I went way overboard here...
That ignition sequence....chills everywhere when the flames appeared
Thanks for the comprehensive and interesting walkthrough of the issues surrounding flow separation. I wonder if the ceramic coating will ablate over time and if recoating is built into the maintenance schedule. I didn't appreciate the scale of the vacuum raptor and the pipework needed for wall cooling.
Thanks for the Data and Context Scotty
for sure Scott the next couple of months will be very exciting I as a Lab padre member will be watching every second of it i hope you will too all the best stay safe
11:40. Dude. That's the exact trajectory taken by SN9. Whoa.
Also, it showed the first three flips failing and the fourth one a success. Hoping that's true.
Hello Scott, Thank you for all these explanations on rockets from the past and to Spacex currently. Just turned 69 in August and grew up fascinated by the early days of rocketry. I bought many solid engine hobby kits and and they really didn’t alway go straight up on lift off lol. I love the ones with a second engine that would pop out the Parachute.. ))))) good times late 50’s and through the 60’s you other intrests are fascinating as well Thank you Again , Ian
11:30 full scale test, to iron out bugs..very USSR
Except USSR tested maybe 1 engine out of every 50 they tried to fly. That alone makes it black and white.
That’s what NASA did with the Saturn V.
USSR didn't had the powerful software modeling tools that SpaceX (and all other Space companies) nowadays use. And I have a feeling that SpaceX have a sizeable edge on the quality of their software, compared to the other players in the field...
Love this channel. Great content
The nozzles are manufactured by machining grooves into the exterior of the nozzles. Than these grooves are filled in with a special wax. Then the nozzle is dipped several times into an electro plating tank of inconel 719 until a layer about 3/4 inch thick gets built up. Than the nozzle gets final machining and finally the special wax is melted out leaving behind the grooves. I saw this process on another video.
I'd bet that the flash of a flame is the methane with the cryo puff being the LOX before ignition. I'm no rocket surgeon, but that makes sense to me with the engine layout and the cooling method. You'd want to get the cooling started which would dump some of the fuel into the bell, the igniters would cause the fuel to combust, then the oxidizer would push that out rapidly as the oxidizer pump spooled up.
Was expecting an analysis of the Delta IV scrub but this is better :-)
Great stuff Scott! Cheers from AUS
Great video mate, I'm learning alot
Another great video Scott. Thanks.
interesting and informative post, cheers Scott.
Great vid Scott, question: Does flow separation during flight ever cause a pogo oscillation effect on the performance of the engine as well?
Watching this video in September 2021 it is amazing how much progress SpaceX has made in 11 months: SN8/9 launched and crashed, SN10 landed and exploded, SN11 crashed, SN15 landed successfully. Starship and the booster have been stacked, now we are awaiting the first orbital Launch. Falcon 9 fairings are now routinely recovered from the water, crew dragon is operational, the first private Crewed Mission is about to launch and about 20 additional starlink launches.
All this in 11 months... Mind-blowing! Awesome!
"and hopefully..." scott, we're all fans here... just admit we all want to see it belly flop hard, in high definition, 4k, 120fps, with 4k high speed replays. it would be glorious. landing would be nice, but what would be better is a massive explosion. in fact, the first 8k high speed footage we should have is slow motion of that thing greeting the earth a whale out of hitchhikers guide to the galaxy.
i'd rather not "so long and thanks for all the fish". we really need humans on other planets before the world ends (or we get dragged onto another dark age).
Either way, i really hope they build a landing pad FAR away from the main facility, currently the landing pad they used for the hops is a little bit too close to the fuel farm if it comes in fast and can't stop. Blowing that up would set them back quite a bit.
@@knealis76 Yeah, that would be way too Kerbal-ish...
I'd be fine with seeing a nice neat 'looks-easy' touchdown, on the order of the parallel landing of FH side boosters.
Totally out of context, but now that it's in my head, good luck getting it out. Listening at 5:05 and reading Scott's shirt simultaneously=uhh... 😁
Scott, could you please put more video clips with interesting audio in this?
It really helps convey the majesty of the experience.
Also, incidentally, I watch your channel but have no useful vision, so these audio clips give me a since of scale and timeline that words alone struggle to convey.
Or, alternatively, can you direct me/us to a reliable source of launch, test, and flight audio for these various wonders?
Thanks for your videos.
And, by the by, you have such clear explanations that I feel your information is actually fully conveyed, a rarity in a service that relies so predominantly upon those visuals to illustrate points people seem to think they can't by words alone.
You are an excellent presenter and have excellent content.
Fly safe.
Great topic choice, haven’t seen this discussed
Wow! Giant boat nets catching faring chutes and videos of Shuttle RS25 engines buckling to illustrate flow separation! Heaven help me I love mega nerdy stuff so much!
I forgot that this video was made before the 15km hops were done until after I started watching and something I noticed is some of the disaster sims look very similar to the way SN8 and 9 impacted the ground. Also Scott inadvertently predicted that it would take all of the engines firing to make it land properly. xD
Yes, some of the simulations looked like SN9. Fun to see what thought Scott had about the testing of SN8
Awesome, thanks Scott! Re: flight build..., surely they have to have a nosecone for aerodynamics and obviously the front flaps - smaller mass simulator though? Cheers... 🍻
The Right Stuff
... for my morning coffee. Good explanation of not so daily tech.
Remember that there have there been various sci-fi shows where you have something that clones itself and it turns out badly?
Yeah. Look at his shelves
Worse yet, they could be cubes
I think they're neat...
You're being rude man, not cool.
@@R3bel02 oh totally not my intention, just trying to be funny
Oh god, I just noticed that one is rotated 180° along it’s horizontal axis relative to the other
Good job scott
I suspect the chamber coating to be Zirconium Oxide. The color is correct from what I can see in the video. This coating has been used in AB assemblies for many years and provides good thermal protection in a similar type environment.
0:06 i like that design of saturn V behind you
Nice. I can't wait for SN-8!
What do you think the range safety system is like for SN 8? Could they get away with just an engine cutoff system if the IIP gets close to the limit, or would the FAA mandate a more active destruct capability?
11:32 Love the human figure in the lower-right in full "OH NO!" stance.
“Having large nozzles aren’t for everyone “-
-Scott Manley.
🤝
Ain't it the truth, pal, ain't it the truth.
Great news
Thanks again for sharing your great video
Really good info, tks!
Thanks Scott. You’re the man.
Scott, please explain the various colors in the exhaust.
methane flames + the metal the engines are made of + various starting chemicals like TEB that burn green
Doug Golde Scott has a whole video on rocket exhausts.
blue: full combustion
yellow, orange: incomplete combustion/fuel rich. This is the color of incandescent carbon.
green: TEB boron
There's no TEB in raptor.
Thomas Row correct. Big spark plugs
Hi Scott. Love your work.
Hi, have you seen how the nozzle of the Vulcain is produced? The nozzle is also produced from a copper core with channels milled into it. But then the channels are filled with wax and a nickel jacket is galvanized onto the core. Don't know if other engines use a similar technique, but it is certainly interesting.
So SpaceX uses lithobraking legs as well? Sweet. My KSP experience is useful once again! :P
Scott, great video as always. Can I ask a question, with all the science and tech going into these engines why is it not possible to change the shape of the nozzle when it arrives in space? Or some of the engine could be shut off on ascent and then transformed before turning back on. Might save fuel
Nice, thanks for the video
As a machinist machining channels in copper is the worst thing possible to do Such a gummy material I would love to see the finished part how to finish looks
Very cool stuff...i always assumed the space shuttle engines shook because of shear power involved making thier mounts oscillate.
The bellyflop maneuver will be incredible to see!
Solution to header tank pressurization is to use large cylinders filled with fuel, and a piston pushing down on it, to feed the engines. Four of these arranged linearly in a circle, will do a perfect job, regardless of starship orientation.
They’re going straight to 15km, and not doing a 150m before it
Didn't he just have the hundred fifty test in this video?
dosmastrify which is why I’m correcting him and saying that Elon is gonna make SN8 go straight for 15km
@@dosmastrify He means SN8, won't do a 150 m test like SN5 and 6 did.
@@user-lv7ph7hs7l ah, thank you
@@StarshipFairing you think...i think too but i gotta say Scott is more connected then myself and most likely yourself, so we will see. But my understanding is SN8 is only for a 15k and with nosecone.
shit, we are on SN17 at this moment, the progress is impressive
In addition to flow separation, over-expanded nozzles incur negative pressure thrust, which literally sucks the rocket backwards. It's exit pressure minus ambient pressure times area at exit equals pressure thrust. Also worth noting that almost all rocket engines are over-expanded at sea level. This is because they tend to fly up, to higher in the atmosphere where the pressure is comparatively low, so it makes sense to optimize them for a compromise between sea level and performance at altitude.
great content thank you!
I wonder if it's possible to have some kind of vanes (separators) or ridges/riffles inside the large expansion nozzle, to reduce flow separation instability, similar to how baffles are used on the F-1 injector plate to eliminate burn instability.