Neutron First Thoughts - Design Analysis

Rocket Lab has revealed their larger next generation rocket, a rocket for 2050. In this video I analyze the design decisions for Neutron.
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Chapters:
0:00 Intro
0:31 Vehicle Overview
1:06 Positive Design Elements
5:31 Composite Booster
11:08 Future Upgrades
13:04 Final Thoughts

[@jamesrwinters]

From interviews after the intitial announcement it sounded like their plan was to use carbon fiber to get enough performance that they could make the other tradeoffs for reuse and still hit a decent performance with enhanced reuse.

[@bobabonanza9488]

Carbon fiber keeps the rocket mass down which means the rocket engines can run with better margins. I believe that is the idea behind the choice.

[@aDifferentJT]

Beck said in an interview that you have to choose your pain in an orbital rocket. The only reason that the engines and fairings and the like are able to be designed as they are is because of the lightness of the carbon fibre structure.

[@Apogeespace]

Definitely. And Neutron's flight profile makes the first stage do a lot of work, so biting the bullet and making it lighter is a massive help, and allows them to relax constraints everywhere else!

[@B0tch0]

Would metal fatigue be an issue? I could also see how practicality could a factor in using carbon fiber, they don't have the same infrastructures other launch providers have. If you make a dent in a metal structure it's pretty much ruined, carbon fiber seems to be more resilient.

[@espenha]

@@B0tch0 Carbon fiber is actually less resilient, if it is of equal strength. You get cracks, ply separation, etc. And the damage can be mostly internal to the material, and thus invisible to the naked eye, requiring an x-ray or ultrasound inspection to be detected. Which means that if someone, say, accidentally nicks the rocket with a fork lift, it's possible no one notices, before it fails catastrophically during pressurization or during max-Q. Metal on the other hand bends more than it breaks. On the fourth Falcon 1, there was actually an accident with the first stage, where it partially collapsed due to low pressure inside the tanks. The aluminium skin was dented, and some internal baffles were destroyed, but the stage was repaired, and it ended up performing flawlessly. The dents mostly just popped back out during pressurization. It was the first successful flight of SpaceX. (Forget about doing that with carbon fiber! The stage would be a total loss.)

[@espenha]

@@Apogeespace The first stage isn't doing much work at all, in terms of imparting horizontal velocity to the payload. Returning to the launch site precludes that. All the horizontal velocity imparted to the second stage means having to use more propellant to return the first stage to the launch site. This is the same for Falcon 9 and Starship, btw, when returning to the launch site. The second stages have to do most of the work. I'm sure this is a huge factor in trying to make the second stage as light as humanly possible.

[@B0tch0]

@@espenha I agree but I'm thinking about the carbon fiber's ability to "bounce back" to it's original state vs permanent deformation.

[@partyboi69er]

rocket lab are masters when it come to carbon composite. they have tested thermal loads on electron with success. we once thought a orbital class rockets with VTOL was impossible until it wasnt

[@aidancotter8599]

I think the material choice makes perfect sense, they've already done the hard work to get carbon fibre working on electron so they can afford to push it here

[@davidb3559]

We need more GOODNESS from Apogee.

[@edbm1432]

First off, loving the intro, and amazing work as usual. Its insane how well produced ALL of your videos have been, you 100% deserve more than 18k subs and if you keep it up 100k will come faster than you know!

[@mstem8987]

He's back! WOOHOO

[@Hafgren]

If they can develop a carbon composite that can withstand re-entry, I say more power to them, you can't improve on technologies if you never try to push the limits.

[@robertoaguiar6230]

Or they will use heat tiles, like spaceX.

[@jtengelbrecht4613]

@@robertoaguiar6230 They are only trying to return the first stage that has little to no horizontal velocity so the Neutron will only experience a fraction of the heat a Starship will when entering from orbit(or even worst from the moon or even mars). No heat tiles should be necessary, especially with their bell shape and blunt end that should push the shock wave further away from the vehicle.

[@thehaprust6312]

Already exists: en.wikipedia.org/wiki/Reinforced_carbon%E2%80%93carbon

[@WasatchWind]

Great video as always. I hope that we see some kind of crewed spaceflight on Neutron. Peter Beck has said that they are watching to see if a market for it arises - and I think one will.

[@Apogeespace]

I hope so too!

[@mm650]

Carbon Fibre's expense is irrelevant. Reusability means the expense can be amortized over many many flights. Also there's no reason that the graphite coating trick from Electron can't be used for the most thermally stressed parts of neutron. As to the pressure change issue, as long as the repeated stresses are within tolerances this should be fine... I'm pretty sure carbon fibre does not suffer from anything like metal fatigue. It would be interesting to compare and contrast a Neutron first stage made of Titanium and one made of carbon fibre. Titanium is of course also very expensive and hard to work with, but again that doesn't matter if you amortize over enough launches.

[@apollo8030]

Beck said in a Nasa Spaceflight interview that if the graphite coating works on electron it would also be used on neutron

[@andrewwhelan9664]

Neutron Starliner is so wonderfully cursed.

[@isaacjohnson3503]

Just subscribed. I will watch all your videos as long as you make em. Good job!

[@Apogeespace]

Welcome aboard!

[@JustAnotherDayOnYoutube]

Great video, well thought out with many good points, the info graphics are very helpful as well.

[@hojoj.1974]

Excellent presentation. Thank you.

[@spencermanyet5336]

Yay new vid! I started rewatching the old one's lol

[@staticgrass]

Good overview, well done.

[@sinnerseekingsalvation779]

You have the absolute best intro (music and visuals) of any KZbin channel that I follow. Please never change it. Also, I certainly agree with the thought that a vehicle’s having a unique look is a thing worthy of applause. One of the things that most excites me about the various orbit-capable vehicles presently in development, is the diversity of their aesthetics (Neutron and Starship being the most obvious contributors thereto).

[@CausticLemons7]

Well said! I appreciate the way you laid out all your concerns and what they mean. Easy to understand and fun to watch!

[@Renagade5150]

Hey man always love your videos! Your breakdowns are top notch my friend. I did notice you put New Glenn in the line-up at the end though. That's very charitable, like putting Starliner in their as well LMAO

[@craigperry5662]

Kiwis have been making fiber reinforced plastics for decades. If you ask a Kiwi to build an intricate part of high strength and low weight you'll get a composite solution every time, and is easier to make than a metal part. To be honest I think the notion that carbon fiber is hard to manufacture into parts and structures is wrong....it just requires that you think about a new process and Kiwis have been thinking that way since the 50's. Craig

[@SteveEhrmann]

Excellent presentation! For the most part you explained your reasoning which made your conclusions more compelling. Once or twice you didn't explain, however (e.g., asserting that Neutron would be as or less expensive than a Falcon 9. This would have been easier to take on faith if somewhere you explained your experience or expertise. Don't be quite so anonymous and/or do script checks to discover early on where you might be making unsupported arguments. These are quibbles, obviously. Your material is generally first class, including 95% + of this video. Thanks for your service!

[@robertoaguiar6230]

I assume the neutron will be less costly to operate than Falcon 9 and heavy due to labor hours. They will reuse the hardware that would take more time to rebuild than to reuse, and discard the rest. They are using the same fuel as SpaceX raptor, but with a simpler engine. Landing legs, but fixed, etc. They are using carbon fiber simply because they have a robot printer that makes it, for everything else it seems the goal is to reduce maintenance personal. Beck even said retrieving the electron rocket with a parachute and a helicopter costs less than crewing a barge for one or two days.

[@topsecret1837]

7:02 this is a bit misleading. Rocket lab have already recovered 2 electron first stages nearly perfectly intact from the waters off of New Zealand. They found a way to get it to reenter without shredding itself; they just added the graphite aerogel just to ensure it can fly again, with not much concern for catastrophic failure that would prevent it totally from being refurbished.

[@osirisapex7483]

Great video as always! Succinct and well-presented analysis of Neutron as we currently know it

[@mj6463]

How come KZbin stoped recommending your vids? I’m subbed and haven’t seen either of your latest uploads. Love the stuff man, I think the channel will be crazy big one day.

[@Apogeespace]

I wish I knew

[@waynzignordics]

On the materials decision: Rocket Lab isn't just a rocket company, it's a carbon fiber pioneer. Nobody can do what RL does with carbon fiber. There's only so much they can do to innovate on the reusable rocket front, but carbon fiber is unlimited. It's akin to what Tesla (the auto manufacturer) is to software and AI.

[@2nd3rd1st]

Is comparing this rocket favourably to Starship even fair? Starship is ultimately meant to go to Mars and back, it has to satisfy completely different demands on design and functionality than Neutron.

[@mcarpenter2917]

Seems much more useful to compare it to the Falcon 9.

[@DataSmithy]

Since carbon fiber reduces the body weight by 3/4 compared to aluminum, the heat generated on re-entry should be much lower compared to a metal rocket of the same size. However, I agree that getting the carbon fiber skin to survive re-entry, and remain structurally sound over many flights will be their main challenge.

[@Cactus521]

I learned to fly at Falcon Field in Mesa, AZ, in an Allegro 2000 Light Sport aircraft in 2006. It had metal wings and a carbon fiber body. It was parked in the hot desert sun without degradation to its body. Carbon Fiber commercial aircraft have been sound given the temp extremes they go thru, from hot days to -40 F in the flight levels. The space shuttle thermal tiles I also believe were carbon fiber, certainly not metal. They only failed once, because the Columbia lost tiles in critical places, because of the ice that fell from the fuel tank. The Challenger disaster (which sadly happened on my parents' wedding anniversary) was different. Odd, off subject, the Haiti quake happened on my wedding anniversary and I lost my brother on his birthday in '09 quite unexpectedly, just months before my Mom passed from cancer, which we did expect and my Mom was OK with that. All of us in our family were space buffs--I was glued to the TV in 69 during the moon landing and also in 68 during the Xmas lunar orbit. However you'd never catch me in a rocket, I don't fear the flight, but weightlessness for an extended duration does not appeal to me--better for folks much younger, lol.

[@nolsp7240]

From all I've watched from other rocket enthusiasts' videos, it is my understanding that the heat generated by reentry is more a function of reentry speed and shape of the vehicle rather than mass/density.

[@DataSmithy]

@@nolsp7240 yes I have read that the heat increases by the cube of the speed of re-entry. However, my understanding is that with a lower mass vehicle (of the same size and shape), the actual speed will decrease faster, due to its inherent lower inertia, resulting in an overall lower heat load on re-entry. This is why SpaceX fairings and Rocket lab electron don't need a heat shield.

[@nolsp7240]

@@DataSmithy The falcon 9 fairings don't reenter with orbital speeds though. Neither does most first stage boosters.

[@hamjudo]

@@nolsp7240 If a first stage re-enters at orbital velocity, that means it reached orbital velocity, which means someone has achieved single stage to orbit. Single stage to orbit was done on the moon, but it has never been done on Earth.

[@tylersilcott7910]

Great video, like always, you gotta put out more content! At least once a month please!

[@Tomasz30899]

Very nice video! With limited information released by Rocket Lab you made a nice analysis.

[@ojomaze7777]

very interesting video

[@dannychen525]

Liked & subscribed. Like your minimalist graphics & video layout. I am a big fan of Neutron’s design approach that’s unlike any other rockets out there.

[@jaydaniels1790]

Thank you

[@ccib00]

Great vid as usual. I want to note that did you notice that most of the compromises on the non-structure parts are weight? The whole darn thing may be too heavy with stainless steel or aluminum. Maybe that is the reason for carbon fiber. Beck's interview sums up pretty well.

[@Apogeespace]

Yes exactly, the other compromises are probably not possible without a very light structure, I think Carbon Fiber is the right choice for Neutron.

[@richardmalcolm1457]

@@Apogeespace It's the right choice if it really can survive the thermal environment in rapid reuse launches. Obviously, if it can't, the entire architecture has to be reconsidered.

[@RogerM88]

The Neutron design approach makes total sense for current market to LEO, that's is moving towards more compact satellites. Also the launching infrastructure and Staff are a big part of the launching costs, not only the rocket.

[@leerman22]

They gotta name one of those boosters Jimmy!

[@erideimos1207]

Great!

[@GertieYTube]

With Boing dropping the commercial human space flight ball - I think their aim to go crewed is a good one

[@steveaustin2686]

That is a good point with all the commerical station designs planned. Sierra Nevada has a headstart with their Dream Chaser spacecraft though. It is scheduled to fly a CRS Demo mission this year for their 6 mission CRS contract to the ISS. Unfortunately, they look to be waiting on the BE-4 engines from Blue Origin to be delivered to ULA for Vulcan Centaur. SNC says that the Dream Chaser is launcher agnostic, so it's supposed to be able to fly on Falcon 9's. Since the Atlas-Vs are all already assigned out, if Vulcan Centaur is delayed too much, I wonder if they will switch to SpaceX.

[@jamieanderson6786]

This rocket is total bunk and will be redesigned as a metal rocket by same time next year once they work out the CF structures cant cope with both cryogenic stresses and the heat stresses of reentry. The structure will be full of inter-lamina stress fractures and also the resins will have deteriorated from pyrolysis and out-gassing during reentry, with likely only way to prevent this a complete coating of fixed heat shielding (adding weight) or ablative compounds that will need to be replaced before each launch. Lets see RL relaunch one of their Electrons they are getting back on parachutes first.

[@robertobruselas3952]

This is a wise and interesting point of view. Great analysis. European SpaceX fan.

[@danj8404]

On the fairing staying attached approach, then the top of the first stage below the fairing becomes part of the payload enclosure. The images of satellites being put in the fairing always shows it happening in a building and likely a clean room. Is Rocketlab going to clean the top of the first stage below the fairing and the inside of the fairing pieces before the next launch to that level?

[@saumyacow4435]

If you watch Beck's most recent interviews, it becomes clear that they understand carbon fibre well and have a material that will withstand the pressure cycles and temperature extremes. Also, Beck does say that that the use of carbon fibre on the first stage (not just the second) reduces mass to the extent that they don't need to get that performance back in more complex, more highly stressed engines. Also on the issue of cost. For a start this isn't a problem when you've reused the rocket many times. Also, Beck is quite correct in saying that manufacturing has advanced and automated tape layout does make it a lot cheaper. And that's important for the disposable second stage btw. Another thing is that all the talk about rocket structures and engines ignores that most of the costs of flying rockets isn't the rocket itself and this is where I think Beck has really nailed it. Even to the point of integrating the risers for the second stage into the first stage. This of course adds more mass to the first stage, but then again if you're using carbon fibre this then you've got the margin to do this.

[@Mysterious.Entity]

Great! A new competitor in the medium lift market.

[@CHMichael]

I like it - especially that you don't have to snag it out of the air when landing.

[@bastion9514]

I have a feeling they will stick with carbon composite material because A. they know and trust in the limitations of the product and B. they would likely consider mass production of product inhouse will exponentially decrease the unit cost of the product. Would be interested in your thoughts on RL's CC production. Personally in terms of risk assessment I'm not sold on the hungry hippo design but the principal of reusability for the entire stage 1 is epic in my books. Great video keep up the good work

[@TheBestOfSweden]

Top quality

[@kirkpuppy]

Another great video, thanks. The legs have to retract or have some kind of heat shielding. The plume from the engines will expand at high altitudes and cook carbon fiber legs. I'm skeptical about the carbon fiber 1st stage as well. It's not just the heating during reentry, but it's difficult to make carbon fiber contain liquid oxygen. Clearly they have overcome this problem with electron, but how will it hold up with reuse?

[@1981Frederick]

i think the close static leg rather then the wide falcon 9, make if harder to land as it will be less forgiving of tilt

[@lawrencejohnson3259]

Interesting

[@williamthirry9914]

What is that background sound from your mic, I think?

[@alfihalma4320]

One of the other major upgrade could be the engine. Yes, to get it operational and then running for a while, a simple and reliable engine is needed. But they need to learn a lot while doing this. So far, they only know electric pump low MCC pressure engines. Once done learning, the could switch to staged combustion and easily increase Isp by 5 - 10% and therefore huge performance gains.

[@saumyacow4435]

Or they could just simply scale the tankage to suit. According to Beck, there's spare space inside that wide body. Besides I think that their "over 320" Isp claim is a little conservative.

[@theOrionsarms]

On the Electron coating isn't made of grafite, but some kind of aerogel, and obviously Neutron would have something like that, but only on the parts that would be heated by re-entering, minimizing termal load means minimizing surface exposure to that load, by choosing a shape that don't allow air flow to touch all vehicle.

[@schrodingerscat1863]

A reusable second stage is a total nonstarter for this design. The first stage would be no where near powerful enough to carry all the extra weight necessary for a reusable second stage. One of the big design problems that SpaceX have to overcome is the weight of the second stage compared to it's mass to orbit. This is one of the reasons they had to build it so big because there are economies of scale in this respect. It is also why they needed to develop extremely complex but highly efficient and powerful engines. The reason they are using carbon fibre for the body of the vehicle is going to be weight. For a rocket of this size making it from metal would just be too heavy for their low powered engines to make it feasible.

[@Apogeespace]

I agree mostly, but it is clearly on the table given Rocket Lab's comments, so I wanted to take a quick look at what that could be like.

[@HypaWave1701]

Beck did say the engine's will be overpowered for it's weight. He was interviewed as say this is for reusability but I think their's more to this.

[@espenha]

A reusable second stage is possible, in my view. But it would require changing everything about the second stage. FIrst, to get the needed performance boost for the added mass, they would want a new vacuum optimized staged combustion engine. Second, reentry would be a huge issue. However, the design wouldn't have to be a mini-starship. I think they could actually come up with a new design that takes advantage of the fact that the second stage and payload could be enclosed in the fairing of Neutron. As an example, this allows for having a blunt front on the second stage with a heat shield, with the payload stacked on top. After payload deployment, the payload holding mechanisms could retract to behind the heat shield, and the stage could do a capsule-like reentry. Once the stage has gotten through reentry, the second stage of Neutron shouldn't be too big to do a helicopter recovery. Something they will get a lot of experience with on Electron.

[@schrodingerscat1863]

@@espenha In other words a completely different design. The problem with trying to build a small version of starship is you lose economies of scale and end up with little to no payload capacity. This is why starship has to be so big to get the percentage weight to orbit to a reasonable level.

[@espenha]

@@schrodingerscat1863 Not completely different. The design I outlined could use the exact same first stage. And the first stage is the biggest challenge.

[@dr_tails658]

To me Neutron is the best example showcasing innovation on existing/proven designs. As you brought up they saw the early issues SpaceX was having with retracting the legs after landing, so they are attempting to address it. They have seen SpaceX's issues with fairing recovery, so they addressed it. These and more show how technology moves forward not attempting to straight up copy but really thinking through existing issues to solve/mitigate them and I hope they succeed in the future!

[@cheeseninja1115]

this is why I like Rocket Lab being in the competition for space, they may be behind SpaceX with "firsts" but they are quick learners and are great at adapting to the needs of the launch. They can play second place while making a more efficient version of what SpaceX does by learning from their mistakes. Its really bringing out the idea of an actual commercial market and some competition within the space sector.

[@danygauthier605]

Most likely the second stage reusible version will use a inflatable heat shield and parachute with helicopter catchup... so electron helicopter parachute catchup is a good practice... and they can launch a photo with inflatable heatshield to test the tech...

[@HypaWave1701]

Really enjoyable video you got a new subscriber 🤙 I have an odd feeling about Neutrons engines. Peter Beck is being far to coy about it (tight lipped). Also regarding the engine's name "Archimedes" when researching Archimedes engine/rocket something interesting keeps popping up. Steam powered.... Just a tin hat idea lol

[@antonpershin998]

Yes, Falcon 9 payloads are usually lightweight, but SpaceX uses RTLS rarely anyway. That's because LEO 28° launches are quite rare.

[@econojon]

I still want to know how they're planning on setting up a clean room for the satellite installation when the fairings are attached to the first stage.

[@aDifferentJT]

Beck said in an interview that the main structural design load is actually on the ground during construction, transport, and handling and so the beam swinging into the flat sheet isn’t miles away from that.

[@manngaiho1012]

I would actually object to the claim that carbon composites hold up better on the ground than metal. in the 90s a Delta II Blew up mid-air due to a GEM rocket motor (A SRB motor with a composite casing) rupturing from a crack originating from improper ground handling and storage. This *could* happen to steel structures too, but the ductility of steel makes detecting damage from improper handling more noticeable sometimes (depends on how ductile/brittle we are talking). And with SpaceX and Starship they have demonstrated that they can pop out the dents during transport simply by pressurizing the tanks afterwards and checking for damage.

[@slaphappyduplenty2436]

Y do kiwis insist on having ibeam newton cradles around their space ports, it makes no sense

[@barryscott6222]

Maybe RL has a silent partner designing (and building) a crewed second stage for Neutron.

[@pit5000]

Here’s my idea for the future of neutron: the whole first stage can be modified to be the second stage of a very large booster by just stacking it on top. Include a long/slow reentry burn and it should be a problem.

[@jonmaddi8230]

Apogee, didn’t mention anything about the weight of neutron. Rocket lab has Specially formulated carbon composite. makes the rocket extremely light-weight. This helps during reentry in amount of heat that will be generated.

[@per619]

The word is that RKLB has made unique great strides in carbon fiber. So maybe this material may be better for them than others.

[@mr.president6922]

is there any potential Spacex will switch the final production flaps & landing legs materiel to carbon fiber or titanium to decrease the mass ???

[@fredi9204]

Highly recommend Peter Beck's interview by NASASpaceflight. It covers all challenges and decisions behind the design. Beck put huge emphasis on operating costs as opposed to material and design costs. This is interesting contrast to Musk who rarely mentions labour costs or cost of running a fleet of ships/platforms. I think the difference is that SpaceX is projected to have huge economies of scale. The same number of equipment and people is needed to launch 1 and 100 times, or 1 and 100 tons at a time. The flipside is that theoretical min cost/kg to orbit can rarely be achieved due to difficulties coordinating full capacity utilization. If you build a $100M satellite, would you pay 2% ($2M) to get it on orbit when and where you want precisely, or 1% ($1M) hitching a ride with others on set date? There is a reason why taxis and buses coexist. I do not think that Rocketlab is a direct competitor to SpaceX, but rather they aim to serve different customers. Their respective approaches play to their strengths. Now, who wants to see Neutron with Raptor 2?

[@espenha]

There is definitely some overlap in the customer base. If SpaceX is actually successful in getting the cost of a Starship down to say $20 million/launch, it could be competing with Neutron at say $10-20 million/launch. A fully reusable bus could easily compete with a taxi where you have to replace ~15% of the taxi after every trip. Even if there is only one passenger. I also wouldn't underestimate the head start of SpaceX. Starship will almost certainly be flying this year, while Neutron will be flying in 2024-2026, probably. Basically, by the time Neutron is making it's first flight, Starship will (probably) have flown dozens of times. It will (probably) have a proven record of reliability, and it will (probably) be an easy sell to the satellite customers. Rocket Lab is definitely the company I hold most hope in, except for SpaceX, though. I don't at all believe SpaceX will get a monopoly on orbital launches. I am a Rocket Lab shareholder.

[@fredi9204]

@@espenha That is a fair argument. I'd say that Neutron's 2nd stage looks like they strapped the cargo to an off-the-shelf engine with bare minimum of anything to make it go in the right direction and orbit. It is probably very cheap. Ultimately Rocketlab will have to manage full reusability - just like everyone else.

[@trendfollowingtrades2784]

The concept of carbon fiber construction sounds great, but if you run the vertical stress calculations with maximum loaded propellant mass, I think that you’ll find it difficult to see any advantage in carbon fiber to get larger gross mass rockets to orbit 🚀

[@Nutzername36]

All hail to the Algorithm!

[@yulpiy]

finally

[@kenhelmers2603]

LOL I notice you left out SLS, tickled me. I like the Neutron

[@johnbuchman4854]

I didn't notice any discussion of the landing approach and landing burn. Is the first stage going to take advantage of its diameter to bleed off more speed in a StarShip bellyflop or is Neutron coming down like Falcon 9's first stage "tail first all the way"? If bellyflop, does Neutron have header tanks?

[@Apogeespace]

As far as we know Neutron comes back mostly straight down like Falcon 9. It does have wing strakes which help it glide and bleed off speed / temp slower.

[@AlcidesBan]

Of course they are solving at least 2 problems with Falcon 9: the legs and the fairings recovery. I don't know if the barge landing is a problem but it's a way to save money. I don't think to add crew capability is so easy. I like the design and the compromise for example I'd like SpaceX could implemented the Superheavy with fixed legs because we all like the Mechazilla but it's another complexitiy added before even try to flight.

[@SteenLarsen]

SpaceX also wants to re-use the second stage. Elon stated this is extremely difficult and I think this is one reason why Starship needs very efficient engines and a complex stage 0 allowing for the complete elimination of the landing legs.

[@martinslaba7249]

"Vast majotiry of payload is below 8t. " That is true now, but doesnt starship change this? 100+t per launch mean you can stop aimning for as-light-as-possible satelites.

[@stevegroves4221]

What protects the carbon fibre legs at ignition? anyone know? Love the idea of swapping out the "hungry-hippos" for a re-usable come back stage.

[@yulpiy]

i'l take second

[@parkershaw8529]

The success of Neutron not only depends on RKLB does a good job, but also how weel Starship turns out.

[@mattjackson9859]

Falcon 9 is now considered "traditional" 🙂

[@saumyacow4435]

Thanks for bringing up the issue of a reusable second stage for Neutron. I'd actually like to see a serious discussion on how this could be done. What do you think? I think that you're going to need a ballute of some sort. Rely on the relatively low mass and surround the engine with a ballute. So you have a low ballistic coefficient. You'd also need a wide enough conical ballute to shadow the tank structure well.

[@thehaprust6312]

Recovery poses a problem, as the structure won't allow it to land. They would have to do a mid-air recovery like the are trying with Electron.

[@saumyacow4435]

@@thehaprust6312 Prob so.

[@MechEngDommo]

I actually think keeping a disposable and cheap 2nd stage is a really good plan. It uses the same style of engine as the first stage, so by having the disposable 2nd stages you can keep engine production going more easily (e.g. create demand). I think this vehicle will be fairly competitive against the falcon 9, but still will lose out to the starship for sheer economy. Overall though I think it will be successful because it will give an affordable B option to spacex and be more suitable for smaller cargos that might not want to ride share on a starship.

[@AdjustinThings]

What I'm more concerned about than any of the stuff you bring up is the ability for the fairings to actually remain closed, open, and reclose. In every animation so for, it has the fairing hinge point on a circle. Think about how such a hinge would work. What mechanism would pull it open? How will it close? I pointed this out in the cargo animations for Starship recently. They showed a cargo bay door opening in a similar way with the hinge of the cargo bay connecting to a radiused area of the ship. Recent video from Starbase has shown that they have abandoned this design in favor of a side hinge opening.

[@joshuaashton1929]

Have the hinges on the inside, and then have the middle of the hinges be able to expand and contract

[@AdjustinThings]

@@joshuaashton1929 Its not that easy. Theres the mounting plate for the second stage is there. Think about what a cars trunk hinge looks like. Its comparatively huge and takes up a lot of space. Thats what the hinge would need to look like to open from the inside. Is there only one hinge per fairing petal? Thats a weak point. If there are two then the hinges need to be massive to allow for the radius of the body. Go look at a tube for a little while and think about the actual mechanism before handwaving away the whole issue. Its more complicated than you think it is.

[@Apogeespace]

I don't think they have quite figured out the fairings yet, and if I had to guess they'll probably end up looking slightly different.

[@TheSkystrider]

Wow dude in a sea of click bait analysts you sure do an extremely good job of presenting data and your thoughts on it. Fantastic video. Props to being concise! Too many videos present long winded stuff but you say so much in a shorter timespan. 👍

[@---jc7pi]

One thing people miss about Falcon 9 legs is that they also serve as air-break. The terminal velocity is reduced by a huge amount when the legs drop. This allows the Falcon 9 to use less fuel on landing. This is something I never see mentioned in comparison. Now I assume Neutron will have better overall air-breaking as its so fat in the lower part.

[@espenha]

That's not accurate. The legs fold out right at the end of the landing burn, and by that time the air resistance is fairly negligible. You can see it in how the grid fins have stopped moving because they no longer have any control authority. kzbin.info/www/bejne/oonKfax5jtqMd5Y

[@jtengelbrecht4613]

I feel that Peter knew that there is plenty of Elon haters and gave them plenty of talking points about why Neutron is better. In his presentation/interviews he often used SpaceX as a bench mark and explained why their design is better while ignoring the obvious tradeoffs. He also sold CC as a wonder material of perks that just does everything better and is the obvious choice for any rocket. When watching him it sometimes feels like they made a list of everting SpaceX does I tried to figure out how they can do it different and sell it as the better way of doing things. I just hope that all their choices work out together. I like the Neutron design and also that they are taking rocket tech in a whole other direction compared to SpaceX. They came up with some solution I really didn't expect and I hope we can still see plenty of Neutron launches.

[@WilliamDye-willdye]

Have you tried contacting Mr. Beck for an interview? He's done quite a few of them lately.

[@_K3PLR]

Neutron could definitely launch cygnus

[@misterx168]

13:23 Wait, will Terran R still be a thing?

[@aldenconsolver3428]

I wish them well, the retractable legs are only little different than falcon 9 however as for potential problems. A failure of one of those legs to extend will still cause probably loss of vehicle, that said I would like to see SpaceX go to that design on the exploration Starships (with more area since the landing zone will not be prepared). Anyway, in the wonderfully expanding low cost to orbit market falcon 9 is an old vehicle and its not surprising that neutron can find a place in that market. In not many more years spaceX will need a new falcon 9 or surrender that segment of the market.

[@nickcollins1528]

You are adding weight to the rocket in fuel if you're doing a return to launch site

[@saumyacow4435]

You could of course have a reusable second stage and keep the same basic design - which is to keep the second stage protected by the fairing and hung from the payload separation plane.

[@jtengelbrecht4613]

The heating the second stage will experience will be much x10 worse than the heating of the first stage

[@saumyacow4435]

@@jtengelbrecht4613 Which is why the second stage would need a suitable thermal protection system. The one I'd like to see is a conical ballute that inflates around the engine, thus keeping the wake plasma away from the tank. Add a bit of active cooling to keep the engine itself (relatively) cool.

[@jtengelbrecht4613]

@@saumyacow4435 Might work in theory but still doesn't mean its going to be cost effective. At least a ballute should keep it from sinking/submerging and having to be completely refurbished . I not sure if they will be able to predict the semi orbital ballistic trajectory good enough to catch it like the electron first stage. The payload to LEO/gross rocket weight for a falcon 9 is 2.9% where the Neutron according to the stats RL have given they are aiming for 1.67%. Unless they make the vehicle more capable with higher eff engines I doubt that they can afford to add any weight. Personally I think it is a big mistake ignoring the efficiency of the engines. The margins of rockets are very low and saving fuel for them to return just cuts it even thinner. The falcon heavy weight less than 20% more but can carry 2 times the load. At the end of the day we can only wait and see who made the best guess.

[@saumyacow4435]

@@jtengelbrecht4613 Well its simply speculation on my part. We won't know until we see what the dry mass of RL's second stage actually is. Its possible that a ballute may not be workable on the existing Neutron design, but may work if the Neutron were scaled. Or it might be the case of using it on launches where you're not using Neutron's full payload capability so therefore you can squeeze in the ballute. I would also assume a parachute and helicopter recovery as they do for Electron. Or it might be the case that the second stage and engine are so cheap to produce that it never pays to reuse. Again, my thinking has more to do with what happens if you had a scaled (heavy) version of Neutron - where the second stage probably needs multiple engines. Do the economics change then? The price you're paying for lower efficiency engines is a larger first stage. Since you're reusing the first stage and the cost of fuel is all but irrelevant, that's a good design trade. A more efficient engine on the second stage is another issue. But, where are the payloads above 15 tonnes? (Neutron can carry up to 15 tonnes in expendable mode). Incidentally, Beck in an interview has hinted at a version of Neutron with larger first stage fuel tanks (the current design leaves spare room). Is there an engine upgrade in the works?

[@jtengelbrecht4613]

@@saumyacow4435 Before they can upgrade their engine they need to make their first rocket engine with a gas generator included. Increasing the size of the first stage won't amount to much if they can only land back on site. Every m/s the booster accelerates the 2nd stage it has to decelerate and more to get back to the launch pad. Peter Beck has dismissed the idea of a barge so far. I was comparing the falcons +/- 15,8ton payload capacity to the 8 ton target of RL for the Neutron to LEO. If they make a bigger Neutron with a more expensive 2nd stage than yes it will make it more sensible to try and save it but the larger it is the more difficult it will be to reenter intact. Another option is to just have the thrust puck detach with the engines and just recovering the most expensive part. I agree with your assessment that the cheaper engine makes up for using more fuel although this argument becomes weaker the more times your able to use that engine. Will be interesting to see what the cost to company far a launch is once it is done. Since they return the fairing and require less ground support(barges) it should be interesting to compare the $/kg of the vehicles. Ill be impressed is they can manage to do it for less than $40million/launch.

[@upthere5826]

3:33 Devils advocate. It depends on how many you vehicles you have. If you have one set of everything and it all needs to be put back together and it;s coming from all over the place then it's going to take you a long time. Especially if it's landing back on it's lunch site (those ground crew guys need something to do). But if you have multiple that can be pieced together it saves on launch sites. Rather than landing back where you lifted off from, you land back at base. Everything can be checked refitted and moved on. Rapid reuse of anything that goes through that much stress is a goal. And I wish all the best to them.

[@lewismassie]

Engineering is more than anything the art of compromise. Neutron seems to hit every one. When discussing the downsides of reusable systems usually the downside is quite obvious. For example, the Starship landing system is a hurdle, SMART hasn't got a heat shield yet, and Neutron''s composites need to hold up. The difference here is that RocketLab already have loads of experience with their system's downside, wheras none of the others do. I'm not sure you could come up with a better reusable rocket design with current (or near-current) technologies.

[@akira28shima32]

Unless RocketLabs invented a new carbon fiber or ways of layering it together that’s a lot better than current technology, I have no idea how Neutron can be reusable.

[@AdjustinThings]

@@akira28shima32 Neutron is coming back from around the same altitude as electron. Its not coming in from orbit. Electron is already reusable. Neutron will be doing a boost-back burn as well to slow it down so it will be returning even slower than Electron. Add in the fact that Rocket Lab is testing heat shielding laminates on electron already, Neutron should not encounter any thermal problems.

[@robertoaguiar6230]

Both Rocket Lab and SpaceX made a profitable business launching payloads with Electron and Falcon 9. Then they created newer engines to improove costs but instead of retrofiting it to the rocket they already have in operation they made a much larger one... I wonder if these rockets with lower launch costs will see enough demand, otherwise they will lose space for companies like RAF, Virgin and Astra.

[@jtengelbrecht4613]

I think Rocket lab is miles ahead of Virgin and Astra since they have past the stage of getting a solid rocket and are already focusing on reuse. I feel sorry for most of the start-up since SpaceX has moved the goal post significantly over the last 6 years. Btw rocket lab is not profitable and will probably only ever become profitable is Neutron succeeds, in fact I believe that's why they had to make Neutron.

[@YaMumsSpecialFriend]

RL are already adept at utilising carbon fibre, so I’m pretty sure they’re leveraging their current knowledge and skill sets for upscaling.

[@jtengelbrecht4613]

I somehow doubt that they even really considered using anything else.

[@GameArchiver]

Even if Neutron is a success, Starship will still be the preferred choice for inter-planetary missions.

[@towel9646]

It seems all these rocket companies want their own falcon 9

[@rainer9825]

Good video - not quite as good as your previous ones. The buisness case is going to be tough. Its not 2014 any more. SpaceX has cornered the launch market and they needed to become their own customer with starlink to make it work. RKTLB needs a big anchor customer. Second area of concern is the engine. I like the approach, but developing a rocket engine is hard and takes years. I think they will make it, but it could take way longer than intended. I hope RKTLB will succeed with Neutron, but i don't like the odds.

[@MattSimmonsSysAdmin]

I'm not certain that RTLS causes Neutron to have fewer re-entry forces than Neutron. I believe that Neutron's mass and profile cause it to experience a relatively small amount of stress, but I do not know for sure.

[@phillipdelatour7729]

It absolutely does. Simple physics. Boostback burn reduces horizontal velocity, it will add a bit in the opposite direction but if you think about a SpaceX ship landing the alternative is to keep burning downrange. Edit: Apologies, i reread your comment and it compares Neutron to Neutron so i don't actually know what you were comparing but will leave my comment up anyway.

[@MattSimmonsSysAdmin]

@@phillipdelatour7729 Sorry, I meant to say that I believe Electron's current re-entry forces are somewhat lesser than Neutron on RTLS due to the relatively small mass of Electron, but again, I haven't done the math, only a gut feeling. Obviously both are coming in hot, but Electron doesn't (seem to?) have any method of slowing itself before it achieves terminal velocity in the thicker parts of the atmosphere, and parachutes definitely work. Compare that to the early F9 parachute recovery attempts, which failed tremendously, and the mass of Neutron S1 seems closer to F9 1.0 S1. Again, no math has been done on my part for this.

[@jayrod9979]

They will need to be able to.have a sea recovery to maximize performance so they can recover down range on heavier payloads. This is why SpaceX has the droneship recovery for most launches. Only the lightest launches have enough margin for a Return to launch site(RTLS) booster recovery.

[@Apogeespace]

Right now Rocket Lab plans for all reusable launches of Neutron to be RTLS. Marine assets are super expensive to operate and they want simple reuse. So the 8t to LEO is with RTLS.

[@petersvancarek]

Carbon fiber laminate is more resistant to higher temperatures than aluminium alloys! Common laminates can make it to resistance against temperature of 260°C! Compare it to aluminium alloys ability to withstand 200-250C! Whats more, there are carbon laminate formulations which allows preparation of carbon laminate survive 800°C indefinitely! You can start to compare this to steel with heat resistance. Of course for reentry some other things may be needed depending on flight profile. For example light weight heat shielding tiles if the vehicle accelerates to much higher speeds than falcon 9. In my opinion, the carbon fiber laminate is better material for starship as well. Much more expensive, yes, but also much more rewarding if the reusability of the scale projected for starship will be realized. Starship may have much higher payload capacity with carbon fiber hull. Look, originally the stainless steel was looked as on as on miracle material- starship wasn't even planed to use heat shield! (from what I remember) But it ended with heat shield which deleted the main advantage of this heavy material.

[@jndivetrips3765]

SpaceX NEEDS bleeding edge Raptor 2s to make Starship work because their design choice for metal makes the stack heavier and because they are also pursuing full reuse. It was a tradeoff.

[@cameronh3260]

Also Starship was never even fully optimized for weight, they just welded shit together in a field and were like "thats good enough"

[@soup-nazi6824]

If you make the first stage metal then you have to have engines that are busting their bolts to get to orbit-carbon fibre is the difference between every other rocket company & rocket lab & is their field of expertise....

[@lemonlime1508]

I like how you didn't compared this to Starship. I like it Cause i don't think it's a fair comparison. '100+ tons with full reusability VS. 8tons with 75% reusability.' that's just not fair. 😂🤣😅🤐