/sci/ - Science & Math

>>10482057
How could we deflect something like this asteroid if it's so loosely held together?

>>10482064
I dont think we'd deflect something like this. This would be one of those things that would be better suited for a nuclear penetrator that shatters it before entry, and leave the atmosphere to disperse the energy difference.
Yeah its gonna fuck up quite a few satellites in orbit and dump a huge amount of energy into the atmosphere, but spreading that energy pulse over hundreds of thousands if not millions of cubic miles of atmosphere is much better than having it slam into the surface as one mostly intact chunk.

>>10482064
>>10482071
>they don't know about the gravity tractor

>>10482079
that the fuck is he doing in the pic?

>>10482085
vaping you luddite

>>10482092
the fuck?

>>10482096
vaping you luddite

>>10482079
>implying it works

>>10482110
>implying math works

>>10482124
>implying a spacecraft could have enough delta V with modern propulsion systems to have a non-negligible gravitational effect on an asteroid by hovering stationary nearby it for as long as it could before it ran out of propellant
ISHYGDDT

>>10482150

>enough delta V with modern propulsion

Don't forget this is a theoretical spacecraft, literally anything is possible in the future.

That's like arguing the James Webb telescope couldn't be built cause they needed to invent some things that didn't exist at the time. Instead, they invented the things they needed, and it was built.... mostly.

>>10482085
venting

>>10482064
There could be one large main solid body inside that's just covered with a layer of micrometeorites and smaller asteroids that have collected on the surface.

>>10482220
Seems unlikely, since the Brazil nut effect would result in the largest chunks of material rising to the top of the rubble pile with every impact. Bennu is most likely composed of sand grain sized particles with the biggest chunks of rock being only a few meters across and sitting on the surface.

>>10482215
I wonder what the internal tankage layout is like. Isnt it supposed to be common bulkhead?
Also, imagine the ice buildup on this thing once they fuel it fully for the first time.

>>10482215
>a fucking tea pot

>>10482161
>Don't forget this is a theoretical spacecraft, literally anything is possible in the future.
Get the fuck out of here isaac arthur this is a serious discussion

>>10482226
>common bulkhead?
yes, we watched them build the thing from the start an they only ever put in three domes (two caps and the common bulkhead)
>>10482161
If you want to go near future technological then the more effective option would probably be a combined gravity tractor plus solar concentration rocket. The spacecraft uses a solar sail as its means of keeping itself at a fixed distance from the asteroid, slowly altering its course via mutual gravity. At the same time the sail is concentrating the Sun's light onto a small spot on the surface of the asteroid, vaporizing it and producing hot gasses that expand away and generate thrust.
If you want to go bullshit theoretical then land a fission fragment rocket on the surface and thrust away at it to directly alter its course, at a low enough throttle setting as to not disrupt the structure of the object. This would work better for bigger objects since they have more gravity holding them together and would also be harder to move using the other methods described for the same reason, that being their much higher mass.

>>10482057
Damn you didn't post the debris plumes OP! Why the fuck does Bennu have debris plumes? What's causing them? Could Osiris-Rex get fugged by a floating rock or two? Is asteroid mining fugged for the near term because asteroid are more unstable than we thought?

Static hop tomorrow in case you missed it

>>10482238
It's because it has an escape velocity of none which means any tiny perturbation and those little pebbles go flying. A perturbation includes tidal forces stretching the asteroid and causing some rocks to settle and send out a minor shock wave towards the surface.

>>10482247
what's causing those tiny perturbations?
>> tidal forces stretching
from what. Prove that they are strong enough to eject debris like that.
>>a minor shock wave
a shock wave moves faster than the local speed of sound, how the fuck are tiny perturbations going to cause a shock wave?

>>10482057
Does this asteroid have carbon that can be used to make rocket fuel?

>>10482215
we get it, you vape

>>10482215
So they're going to put this thing on a reusable booster and accelerate it to hypersonic speeds to provide intercontinental passenger rocket service? I don't believe it.

>>10482356
ahem

>>10482356
you don't need to believe it for it to happen, friendo
though all things considered, a ETE rocket might actually be easier to work with than a plane
planes have to be very anal about weight and balancing, while a starship in passenger configuration will well below it's payload limit and not give a single fuck about cargo weight as a result

>>10482397
least intelligent comment of all time

>>10482356
Starship is probably capable of suborbital point to point flight without the booster

>>10482405
I wonder if Starship alone could go from New York to LA in like half an hour? Starship won't carry as many passengers as a 737 for example but it can make multiple round trips per day due to its much greater speed. If Starship tickets were competitive with jet travel prices it would make all current passenger jets obsolete.

>>10482425
the problem is noise and extra processing time.

Noise means that you have to have the launch sites far from populated areas. Processing time refers to the time it takes for you to begin the process of going on a particular method of transportation to the end. For instance, at an airport you get there like 2 hours early to get through security, check bags, board, push back, then there's time for land, disembark, leave terminal, get bags, etc. A "5 hour flight" is really ~8 hours altogether. if a starship flight is 30 minutes bit the total processing time (getting onboard, fueling, getting to the launch site, whatever) takes many hours then what's the point?

>>10482429
That processing time usually happens before the plane people will go on has even arrived to the airport, fueling and loading is surprisingly quick
The processing for a starship flight would happen before starship has even done it's previous flight

also, time saved is time saved, if a businessman can shave his transport time from 8 hours total down to 4, he'll be extremely pleased, and if he's going on a VIP starship that doesn't have as long a processing time, and that total goes down to 2-3 hours, even better

>>10482238
It's only one type of asteroid. Others are more solid. The further out you go the easier it gets as everything is more often held together with ice. There are still a lot of solid nuggets out there.

So when do we get one of these for Starship and/or Superheavy?

>>10482472
how do you know? And wouldn't you want an asteroid that's not entirely solid so that it could be processed more easily? Why bother doing complicated in vacuo drilling and cutting? In space cutting fluids aren't very economical. Carbonaceous asteroids, especially ones with metals are also the shit. You got all these nice volatiles. Carbon monoxide can be used to process metals via mond process, metals can be used to process hydrocarbons into plastics. You also have everything you need to reduce those chunky rocks to silicon and process it to very high purity by turning it into silane. From there one should be able to make solar cells and computer chips.

>>10482473
can't wait for the THICCness

>>10482486
The images I have seen of other asteroids. The data we have of asteroids which have collided with earth.

You raise some interesting points though. Early on, at small scale, it would be easier to just sift through the debris. Especially if the pieces are all of the same material.

However my interest in manufacturing is as simple as iron and charcoal for steel, clays for ceramic and hydrocarbons for tar. For a very long time this is all I would be interested in. The scale of industry I would require to fulfill my dreams is far beyond sifting through boulders on an asteroid. I kind of need mars and the belt industrialised.

I'd really like to pull co2 out of venus as well at some point and I have no idea where to get tne water but probably also the belt.

It's encouraging to know others are focusing on different details.

>>10482429
>Noise means that you have to have the launch sites far from populated areas.
The California launch/landing pad could be located in the central valley where population density is very low. Just put the Starship launch/landing pad near a high speed rail station. Then all the rich venture capitalists and tech executives could take a quick train ride to the Bakersfield Spaceport and fly to Tokyo or New York in less than half an hour. A side benefit is this provides a rationale for California high speed rail which is currently a train to nowhere.

>>10482215
After becoming the real-life monorail guy from Simpsons with the hyperloop thing Elon is working hard to become real life Mexican Space Agency from South Park.

>EUS officially cancelled
>SLS block 1b only aka "slightly better than FH but at 1/10th the price"

This is soft cancellation.

>>10482689
This is so retarded though. You don't spend 9 billion on the core stage and then save 1 billion on developing a new upper stage.

>>10482425
It can but it's not happening due to regulations and safety concerns and lobbyism for many years even if it starts doing intercontinental p2p.

On top of that the shorter the distance the less gain in speed versus conventional travel.

>>10482687
Mars? Si, fly

>>10482425
not obsolete, as a previous anon explained. But only remaining feasible for distances longer than car or fast rail but shorter than rockets. Probably about the 1-5ish hour flight range, or intracontinental in general if E2E needs to avoid land due to safety regulations or sonic booms

>>10482445
>also, time saved is time saved, if a businessman can shave his transport time from 8 hours total down to 4

Not if he has to pay 10 million dollars for a ticket.

>>10482746
good thing that tickets wont cost anywhere near that amount

>>10482767
Yes they will. Also the transit time will be much longer than two hours for most people. There's nowhere you can put a launch pad in a 500 miles radius around New York or L.A.

>>10482767
>BlOcK 5 WiLL bE ReUsED MaNY TimEs WiThOuT RefuRbISHmenT

>>10482807
It literally is, you can see from the reused boosters that they have done pretty much fuck all to them

Just fuck off already.

>>10482887
>NeXt YeaR WE WiLL AcHiEVe 24H TurNARouNd

>>10482689
Wasn't the EUS actually done earlier, but then development restarted because the core was taking so long to get done that newer better technology for the EUS became available so NASA wanted to incorporate that?

>>10482768
There's no reason the Starship launch pad has to be 500 miles from LA or NYC. During Apollo, Saturn V rockets were launched from KSC less than 50 miles from Orlando which is a heavily populated area. High speed rail links from major cities would be more than sufficient to quickly transport passengers to the launching site.

hop has been postponed

>>10483148
>scrubbed due to weather
The wind must be really bad if it poses a danger to a 1 meter hop.

>>10483156
Remember when the engineering team had to be evacuated from the launch site last week due to lightning?

>>10483156
Well, if it's too windy you don't even do rocket stand tests.

Some anons here mentioned that Boca Chica is in the hurricane region so I really wonder how they want do deal with that when hurrican season starts.

>>10483029
No, EUS has not seen any development money yet. They did spend 500 million to slightly modify a DCSS though.

>https://www.teslarati.com/spacex-all-in-steel-starship-super-heavy/
Intredasting...

>>10483244
They will have to deal with it the same way NASA deals with it

>>10483056
It's the shill, ignore it

>>10483177
>lightning
>when on a giant block of conductive steel
Oh god oh fuck

>>10483328
Get some congressman to throw billions at it for little to no effect?

>>10482518
>>images of other asteroid
there aren't many close ups
>>collided with earth
only the big chunks survive reentry, so it's biased a bit.
>>charcoal
there ain't no trees in space. The ideal steel making processes for space are sadoway process and hydrogen reduction, then one sprinkles in that precious carbon.
>>scale of industry
bruh if you want big industry in space you gotta be able to make everything in space. That includes even the little things like microchips. I want a solar empire and it seems the fastest way to do that is to get a bunch of industry into space FAST with self replicating machines. Since it is difficult to build practical control systems without electricity one needs computer chips or really just a buncha big fat transistors(for rad resistance). It's going to take a while though, we need to do a lot more asteroid missions so we can understand asteroid missions. Near term the big worrisome thing about the debris plume is that this may actually be a problem:
https://www.theverge.com/2013/7/5/4496320/landing-on-asteroids-could-cause-a-zero-gravity-avalanche

>>10483328
They won't be able to build a rocket factory until hurricane season.

>>10482224
Brazil nut only applies to things resting on the surface of an external body under it's external gravity field, the only gravity field here is Bennu itself

>>10483414
the brazil nut effect seems to play a role on asteroids
http://planetary-mechanics.com/2018/01/28/the-brazil-nut-effect-on-asteroids/

>>10483390
This is the south, they might try prayer first

>>10483401
>there aren't many close ups
Every single object we've seen up close is a rubble pile

>>10483414
The outer layers of the asteroid rest on top of the inner layers, gravity pulls everything towards the center but the smaller particles fit under the bigger ones and so over time the big particles migrate outward towards the surface. The material of Bennu is obviously affected by Bennu's gravity otherwise Bennu wouldn't exist because its material would have simply drifted apart.

>>10483319
This is something non-brainlets have known for months, there's no reason to use carbon fiber structures for anything on BFR if they've found that steel offers better performance under the operating conditions of the vehicle. People who kept insisting that things like the engine enclosure on the first stage and the interstage faring would be CF because "It's lighter" are dummies.

>>10483482
>if they've found that steel offers better performance under the operating conditions

Which they don't know at all. They didn't even do the hops yet. Going all-in like that seems a bit immature.

>>10483472
I bet if you took a bunch apart you'd have a 50/50 shot of one big chunk in the middle that accreted the rest, a layer of sand, then boulder field on the surface

>>10483498
what they have found is that it's hundreds of dollars per kilogram of CF, with a high scrap rate and no way to just melt that shit down and try again

>>10483507
I doubt it.

>>10483510
It's not hundreds of dollars, CFC is more in the range of 60-80$/kg and the scrap rate isn't that high, either. But even if it was, the difference in building cost is below 10 million $.

>>10483498
>Which they don't know at all.
It's easy to test that shit on the small scale. While sometimes scaling it up to full size introduces new problems, it never ever fixes problems that show up on the small scale. If steel beats CF in the lab then you're sure as shit it beats it as part of BFR as well.

>>10483539
Include time and the more expensive hardware needed in your guesstimation. Also include the fact that you need way heavier TPS using CFC

>>10483539
I would imagine the scrap rate is higher for extremely large objects like rocket bodies with low margins

>>10483545
There is actually absoluetely 0 reason why you would pick stainless steel over titanium alloys.Titanium alloys are better in every category, and if you want it to be reflective you can polish it, too.

>>10483546
>Also include the fact that you need way heavier TPS using CFC

You can use heat tiles and transpiration cooling on CFC, too.

>>10483557
I dunno anon have you ever seen what LOx does to titanium?

>>10483566
>what are coatings

>>10483581
unreliable?

>>10483582
No.

>>10483586
Yes. Oh no, my oxygen tank got a tiny scratch during routine maintenance, and we're only now discovering it as we become a huge fireball.
Wow.

>>10483596
An aluminium coating is 100% reliable, stop spewing bs.

>>10483557
Titanium is a fucking headache to weld my dude, you have to shield the entire part with inert gas not just the spot you're welding, plus it's actually possible to start a titanium-oxygen fast fire if you use bare titanium to store LOx. The reason they're using stainless steel instead of titanium is because stainless steel will work anyway and give them >100 tons to LEO performance without costing a gorillion dollars in materials or construction costs.

supreme champion

>>10483561
You need much thicker tiles and a faster coolant flow rate to shield the CFC structure, adds weight.

>>10483610
in a world where millwrights exist, nothing is 100% reliable.

>>10483616
So are they going for a rocket that is optimized for reusability or are they going for a cheap throwaway rocket? If you use CFC, you save a lot of weight which you can now invest in propellant you burn before entering the atmosphere, taking out a lot of extra velocity and making reentry much more gentle. If you use titanium you have weight savings while also having a material that can handle high temperatures like no other known material can.

Stainless steel means low manufacturing cost, but also less reusability.

>>10483620
No, you don't need that at all. The heat tiles of the Orbiters weighed 500kg.

>>10483625
CFC is pure fuck to deal with, and can't handle extremes very well
He explained how titanium is similarly fuck
Stainless is the best one because of it's ruggedness and being the easiest to work with
if a CFC/titanium starship performs slightly better, but costs the same as 5 stainless, the stainless wins

>>10483557
You absolutely do not want titanium anywhere near LOx. While aluminum and steel can be made LOx friendly if you keep the elements smooth and keep the pressures reasonable, titanium is very reactive to LOx even with precautions. This issue gets multiplied when you need to have a reusable and reliable rocket. Also titanium is more expensive than steel IIRC.

>>10483639
So what if Titanium is fucky? You want to build a rocket that can be reused hundreds of times. So you are going with steel because it shaves a few millions off manufacturing cost? Yeah sounds like a good plan.

If they used Merlin engines it would kind of make sense, those are cheap engines so you would have an all-around cheap rocket in case the reusability doesn't quite work out. But they are using Raptors, one of the most complicated and sophisticated engines in the world. So that will mean having a cheap throwaway rocket to fall back on is not going to happen.

>>10483610
anon, there exists nothing on earth that I cannot break
give me a lifetime and I could break a mountain

>>10483616
how does Titanium do in vacuum welding?
it may become hyperviable on the moon

>>10483654
>If they used Merlin engines it would kind of make sense
Not really. A Merlin doesn't have the thrust and Isp to make it useful for BFR. Plus, the Merlin uses ignition fluid to start, which would mean that each space mission would be limited by how many times the engines could be relit.

>>10483654
>a few million
more like double, if not triple the cost and make it miserable to build

>>10483665
You can cluster almost 60 Merlin engines on a 9m diameter rocket. That would put the thrust only a bit below 31 Raptors. They can use other engines on the upper stage if re-ignition is an issue.

>>10483676
>You can cluster almost 60 Merlin engines on a 9m diameter rocket.
30 engines is already a mess to deal with. 60 would be a nightmare to do the plumbing for.

>>10483676
>60 (SIXTY) engines
WE WANT THE MEN TO WORK, NOT TO COMMIT SUICIDE

>>10483684
It's pretty much double what they put on the Falcon Heavy.

Makes me think, why develop a BFR at all, why not just cluster two more boosters on and call it the Falcon Super Heavy?

>>10483685
>30 (THIRTY) engines is what the Falcon Heavy already uses

>>10483686
because more burny bits does not equal more payload
there's a limit to how much the falcon core can carry, as well as being limited in diameter
to do bigger shit, they have to go larger across the board

>>10483686
>It's pretty much double what they put on the Falcon Heavy.
No? A Falcon Heavy has 27 active engines at launch, that's still less than what BFR has.

>Makes me think, why develop a BFR at all, why not just cluster two more boosters on and call it the Falcon Super Heavy?
SpaceX wants to be able to put 100+t to LEO. Falcon is a great rocket, but it has a hard performance ceiling due to its design. Extra boosters wont help. On top of that, Falcon is a very thin rocket so there are structural and aerodynamic limits on how big of a payload can be put on it.

>>10483633
The TPS on Shuttle weighed over 2 tonnes. Regardless in the Shuttle's case the issue was the extreme fragility of the tiles, not their mass.

Starship won't be using low density silica foam tiles because they're too fragile. It will be using something else which will certainly be heavier but more robust mechanically.

>>10483625
>If you use CFC, you save a lot of weight
Elon said specifically that they are gaining performance by switching to stainless steel over CFC.
>you save a lot of weight which you can now invest in propellant you burn before entering the atmosphere
nevermind I didn't realize you are retarded
>If you use titanium you have weight savings while also having a material that can handle high temperatures like no other known material can.
Titanium is good for up to 540 C. Higher than that and creep starts to occur and oxidation of the metal itself begins. Titanium isn't extremely heat resistant, that's a myth. Titanium overall pretty has all the mechanical attributes of mild steel, except it's much lighter by comparison and it doesn't machine easily.

>>10483642
high grade titanium ore will essentially be a waste product of lunar resource extraction
we'll need to learn how to make LOx tanks safe with structural titanium. How does the thermal expansion vary between titanium and stainless?

>>10483642
>Also titanium is more expensive than steel IIRC.
It's 20x more expensive than copper, if they tried to make a titanium BFR they'd have every tweaker on the eastern seaboard jumping their fences in the middle of the night trying to steal "scrap" metal

>>10483723
>Elon said specifically that they are gaining performance by switching to stainless steel over CFC.

Elon doesn't change physics. You could save dozens of tons of structural weight if used CFC instead of steel.

>Titanium is good for up to 540 C.

What a bunch of literal horse shit lol. They use titanium grid fins in block 5 why exactly you idiotic fuck?

>>10483728
we're aware that weight could be saved with CFC
weight is not the only thing that matters here
in fact, rockets have the funny bit where weight matters less and less the bigger you go

>>10483728
but you'd lose dozens of tons of structural weight to thermal protection

>>10483662
It works, but you can't use it to store LOx safely unfortunately. Storing LOx inside titanium is like storing fluorine inside aluminum; there's a passive layer in the way that stops the reaction going any further, but if you get one chip in that layer you can instantly start an unwanted combustion reaction. Titanium immersed in LOx is known to catch fire when struck with a hammer, for example.

However, titanium structures on the Moon wouldn't be a problem. Titanium is passively safe in gaseous oxygen +buffer gas, just like aluminum (conversely in pure oxygen gas even at reduced pressures both aluminum and oxygen and even steel can all catch fire). Any outdoor structures would be fine to build from titanium as well, obviously.

>>10483737
Titanium is going to be THE material for the lunar shipyards to build nuclear rockets for the belters

>>10483729
>we're aware that weight could be saved with CFC
>weight is not the only thing that matters here
>in fact, rockets have the funny bit where weight matters less and less the bigger you go

Weight matters a lot for reusably rockets. You want to bring them down again, and that will happen with almost empty tanks. So while the few dozen tons don't matter much on the launch pad, they matter a lot when the booster reenters the atmosphere. Either because reentry will generally be much softer because the ship is significantly lighter, or because you take more propellant and can make your reentry burn much longer (which will also make reentry much more gentle).

>>10483730
>but you'd lose dozens of tons of structural weight to thermal protection

No, you absoluetely don't. If you think steel is so good as a heat shield, than use that as your heat shield. There is no reason to build the whole rocket out of your heat shield material.

>>10483737
stainless, in my experience, is highly resistant to catching fire in pure oxygen environments even at high temperatures
the passivization layer of aluminum does a good job resisting it as well
something to do with rust expanding?
>>10483749
does steel have a higher structural max heating or not, anon? What's the highest temperature that each of these substances can reach before becoming unviable during reentry stress?

>>10483654
>So what if aluminum is fucky? You want to build a ship that can be reused thousands of times. So you are going with steel because it shaves a few millions off manufacturing cost? Yeah sounds like a good plan.

Steel is ubiquitous in all kinds of engineering because despite not being the strongest for its weight or the most corrosion resistant or the hardest, it is the cheapest and easiest to work with material to pick from and most of all it is GOOD ENOUGH. You don't need to absolutely push the limits of engineering to squeeze every drop of performance from every single use of a highly reusable vehicle. That's a mindset that ONLY exists in the field of rocketry and it only exists there because of the prevalence of expendable single-use rockets.

Show me ONE container ship made from aluminum. Aluminum has a higher strength to weight than the typically used mild steel, stands up better to salt water corrosion, results in a lighter ship that has less draft and therefore less friction even when fully loaded, etc etc, and aluminum only costs ~$1 more per kg. Despite this, ALL ships are made of steel because it's easier to weld and work with, and the tiny performance hit doesn't matter at all.

>>10483686
thrust != dV
thrust != payload

>>10483704
I think he meant a 60 Merlin engine BFR would have pretty much double the engines compared to FH.

>>10483728
>Elon doesn't change physics.
This is engineering. Can't weld CFC parts together, have to join them and the joints are much thicker and heavier by comparison. CFC Starship weighs more than Steel Starship because both materials have similar strength to weight ratio to begin with and the number of joins required for the stringers and baffles inside the tanks adds a severe penalty to CFC. Also using stainless eliminates a lot of TPS thickness and on the back of the Starship as well as the entire Booster no TPS coatings are required, the metal just needs to be shiny.
>They use titanium grid fins in block 5 why exactly
Not structural.

>>10483729
>we're aware that weight could be saved with CFC
Only for an expendable rocket and even then only if it used balloon tanks. Balloon CFC tank can't be beat because it has all the advantages of CFC strength to weight ratio with none of the disadvantages (the joints required for a baffle and stringer design that can support its own weight with no internal pressure, the TPS coatings etc required to make it reusable, and so on). However if your tanks are more complicated than a set of bottles with smooth interiors and naked or painted skins, then very quickly other materials catch up and surpass the performance of CFC in terms of reduced weight and increased strength.

>>10483774
does titanium or stainless have a higher non-structural heat maximum? titanium TPS may be a future upgrade path for Starship
they'll need a good (non-Russian) source of it tho

https://www.popularmechanics.com/space/rockets/a25953663/elon-musk-spacex-bfr-stainless-steel/

>The thing that’s counterintuitive about the stainless steel is, it’s obviously cheap, it’s obviously fast—but it’s not obviously the lightest. But it is actually the lightest. If you look at the properties of a high-quality stainless steel, the thing that isn’t obvious is that at cryogenic temperatures, the strength is boosted by 50 percent.

>Most steels, as you get to cryogenic temperatures, they become very brittle. You’ve seen the trick with liquid nitrogen on typical carbon steel: You spray liquid nitrogen, you can hit it with a hammer, it shatters like glass. That’s true of most steels, but not of stainless steel that has a high chrome-nickel content. That actually increases in strength, and ductility is still very high. So you have, like, 12 to 18 percent ductility at, say, minus 330 degrees Fahrenheit. Very ductile, very tough. No fracture issues.

>Fracture toughness is a property where if something has a small crack, does the material tend to arrest the crack, or does the crack propagate? So as you go through repeated vibrational multiple stress cycles, how much will a small imperfection in the material propagate?

>There’s a trick here, though, which I think is quite important, when you consider this as a reentry vehicle. See, here’s the other benefit of steel: It has a high melting point. Much higher than aluminum, and although carbon fiber doesn’t melt, the resin gets destroyed at a certain temperature. So typically aluminum or carbon fiber, for a steady-state operating temperature, you’re really limited to about 300 degrees Fahrenheit. It’s not that high. You can take little brief excursions above that, maybe 350. Four hundred, you’re really pushing it. It weakens. And there are some carbon fibers that can take 400 degrees Fahrenheit, but then you have strength knockdowns.

>>10483751
>stainless, in my experience, is highly resistant to catching fire in pure oxygen environments even at high temperatures
https://www.youtube.com/watch?v=JlSeHSDc-Do
This fucked with me when I first watched it, all the stainless needs is a hot spot (burning contaminants for example) and it can catch fire itself. I think the reason is because the stainless gets hot enough to actually melt, and then that droplet of molten steel can burn without forming any oxide layer and continue to heat up, and then melt more metal in a runaway combustion reaction.

>>10483791
With steel, now you’ve got something where you can comfortably be at a 1500 F interface temperature instead of, say, a 300 F, so you have five times the temperature capability at interface point. What that means is that for a steel structure, the leeward side of the back shell does not need any heat shielding.

On the windward side, what I want to do is have the first-ever regenerative heat shield. A double-walled stainless shell—like a stainless-steel sandwich, essentially, with two layers. You just need, essentially, two layers that are joined with stringers. You flow either fuel or water in between the sandwich layer, and then you have micro-perforations on the outside—very tiny perforations—and you essentially bleed water, or you could bleed fuel, through the micro-perforations on the outside. You wouldn’t see them unless you got up close. But you use transpiration cooling to cool the windward side of the rocket. So the whole thing will still look fully chrome, like this cocktail shaker in front of us. But one side will be double-walled and that serves a double purpose, which is to stiffen the structure of the vehicle so it does not suffer from the fate of the Atlas. You have a heat shield that serves double duty as structure.

Yeah.

To the best of my knowledge this has never been proposed before.

RD: This is a huge change.

EM: Yes.

RD: Where will the steel come from?

EM: It’s just 301 stainless. Let me put it this way: 304 stainless is what they make pots out of. There’s plenty of it.

RD: What will this do to your schedule?

EM: It will accelerate it.

RD: Because it’s easier to work with?

EM: Yes. Very easy to work with steel. Oh, and I forgot to mention: The carbon fiber is $135 a kilogram, 35 percent scrap, so you’re starting to approach almost $200 a kilogram. The steel is $3 a kilogram.

RD: This is a good idea.

EM: Yeah.

>>10483796
yes, but that doesn't happen to stainless
https://youtu.be/xZAAmgfjr-0
here's a good example of what I'm talking about with mild steel, and it straight up doesn't work on stainless
could not tell you why

>>10483749
>does steel have a higher structural max heating or not, anon? What's the highest temperature that each of these substances can reach before becoming unviable during reentry stress?

Re-read this sentence:

>If you think steel is so good as a heat shield, than use that as your heat shield. There is no reason to build the whole rocket out of your heat shield material.

>>10482110
Sounds like someone hasn't made their own EM Drive yet

>>10483799
>where you can comfortably be at a 1500 F interface temperature

Somebody should call Lockheed Martin, these idiots kept building their supersonic airplanes out of Titanium this whole time!

>>10483784
Titanium at 600 degrees starts to oxidize really quickly, it doesn't exactly burn but you wouldn't want to expose it to temperatures that high for more than a few seconds. Incidentally that's about the temperature the grid fins on Falcon reach during entry. I'm sure there are some fancier titanium alloys around that can handle continuous exposure to even higher temperatures in air, but another thing about titanium alloys is that welding them ruins them in the area aroudn the weld. It's just a nightmare to work with. Furthermore, if you actually got your titanium parts hot enough that they were glowing an obvious red, they'd start to soak up nitrogen from the air and embrittling themselves rapidly. For these reasons stainless steel is probably superior as a TPS material, it's just a lot more stable.

Anyone know what this poster is about? From the movie The Beyond

>>10483806
there are extremely good reasons to build the whole rocket out of it
have you ever heard of "hot structure"?

>>10483791
based

What do you hope will happen regarding space exploration/travel before 2030?

What do you think will happen regarding space exploration/travel before 2030?

>>10483815
I don't think we've ever had a spacecraft get assists from all four giant planets + Venus before, and I don't think they'll line up again for a few hundred years
could be useful to really fling something out there
>>10483823
shut the fuck up, questionnigger

>>10483825
I sure bet you feel stupid now.
Anyway, where can I find the poster at least?

>>10483823
>What do you hope will happen regarding space exploration/travel before 2030?
More amateur rocketry.

>>10483830
Any tips for a person looking to get into that?

>>10483828
you're still a nigger and I literally just google reverse image searched your image and it's an edited version of a popular chart of cosmic exploration, with a bunch of dumb meme shit added to it

>>10483801
I mean, the wire is burning in pure oxygen in the video I posted. It's a stainless steel wire, pretty heavy gauge too. I think cutting with oxyacetylene doesn't work because even when you make the torch oxygen rich, it isn't PURE oxygen, there's still at least a little bit of acetylene being burned and those combustion products form a buffer gas. Buffer gasses are extremely effective at retarding a combustion reaction, the nitrogen buffer gas in the air is why a wood log takes an hour or so to burn rather than seconds.

Anyway I think our original discussion was about how titanium is dangerous to use to store pure oxygen but aluminum and stainless are pretty much safe. I didn't want to appear like I'm challenging that. Titanium requires very little activation energy to start rapidly burning in pure oxygen and even less in liquid oxygen, whereas both aluminum and stainless require a lot of activation energy. You basically have to melt a bit of the metal part in contact with the pure oxygen to get a self sustaining reaction going, and even then It'd probably just burn a small hole in the wall then stop. titanium on the other hand once on fire in the presence of pure oxygen will continue to burn until there's not much left even if started from a single spark (or in the case of LOx, a cavitation bubble collapse).

>>10483808
I have one of those, it heats up hot pockets pretty good

>>10483837
pushing the cutting gas button will literally blow out your heating flame sometimes, oxygen greatly outnumbers your fuel gas

>>10483828
I have literally found it but I won't post the full version

>>10483843
>Insulting Tanz' memory by using his life's work for your fucking hot pocket

>>10483815
It's the (simplified) path of every space probe launched up to (arbitrary date probably like 2016 or whenever that graphic was made).

I searched 'paths of every space probe' and it's literally the first result, too big to post here though so here's a link
https://i.kinja-img.com/gawker-media/image/upload/t_original/l3vye3e2fuammmbkjqm2.png

>>10483833
For starters? Estes rockets. If you want something more advanced, then Tripoli Rocketry Association offers some services. For maximum simplicity so for solid propellants, I don't think liquid propellant engines for amateurs have really developed.

>>10483846
>>10483843
>>10483841
Retard

>>10483847
Thanks, It seems like it'd make a cool wallpaper/poster.

>>10483850
I'll look into it, ty

>>10483846
>imagine replying to the wrong post

>>10483846
>replying to the wrong man
>>10483847
>too big to post here

>>10483849
>Retards*

>>10483857
That poster is actually really interesting.

>>10483860
three of us, if you're not lying

>>10483857
>all image files are the same size
I'm too lazy to rescale something from 4 megs to 2 for an anon, anon

Hey guys, uh, when Rydburg matter?

>>10483867
you posted an old version of the poster, with a larger filesize, and a smaller resolution
I found this on the internet and didn't scale it at all

>>10483874
I'm sorry but this is an english speaking mongolian underwater basketweaving appreciation bulletin board

>>10483799
>You flow either fuel or water in between the sandwich layer, and then you have micro-perforations on the outside—very tiny perforations—and you essentially bleed water, or you could bleed fuel, through the micro-perforations on the outside.
What happens if the flow of coolant liquid gets interrupted? Does the Starship then burn up during reentry? It seems unprecedented and unsafe to have an active reentry cooling system like this. A passive system like the silica tiles on the space shuttle wouldn't have this problem.

>>10483927
you'd probably have a bit of melt on a panel and need to replace it
supposedly plan A right now is to run the orbital prototype without any cooling, see where the erosion is, and repair them out while adding some cooling there

>>10483927
>run out of coolant
>this means that you’ve run out of propellant
>die anyways
I don’t see the problem

>>10483932
it's also more resistant to bird strikes, falling ice, and glancing gunfire

>>10483936
How do you know that? Having liquid sweat out of tiny pores sounds extremely unreliable.

>>10483948
that's why there's a lot of pores dumbass

>>10483932
>I don’t see the problem
Power failure. Fuel pump failure. Clogs in the propellant feed lines. There's lots of ways for the flow of coolant to be interrupted other than running out of fuel. Relying on an active system for safety is like trying to keep a Tyrannosaurus Rex in its enclosure by using an electrified barrier. Everything is just fine and dandy until the power fails.

>>10483948
-no moving parts
-If one area gets clogged it’ll naturally unclog for a variety of reasons (thermal expansion, pressure buildup
-uses fuel, which you already have
-this means no wasted dry mass when landing on non atmospheric bodies
-already a proven concept (turbine blades, some NASA research, leading wing edges of high performance spy planes and stuff)

>>10483952
if the power fails you’re dead anyways lol

>>10483927
>What happens if the flow of coolant liquid gets interrupted?
The spot that gets hot either melts the blockage or melts the steel, making a new hole for coolant to flow out of and lowering the temperature again.
>Power failure. Fuel pump failure.
Pressure fed, as long as valves stay open the coolant keeps flowin
>clogs
of what? If it's anything like frozen methane or water ice it just melts as soon as the temperature in that spot increases since there's no cooling there. To prevent FOD clogs just put a big enough sieve around the sump that someone would have had to have left an entire load of laundry inside the tank for it to clog.

>>10483958
>-uses fuel, which you already have
Maybe Im a complete brainlet but if you use the fuel would it not, you know, ignite?

>>10483958
>-If one area gets clogged it’ll naturally unclog for a variety of reasons

lol no

>>10483971
Gaseous methane by itself? Nope, not that far outside of the combustion chamber

>>10483971
it takes time for shit to burn, anon
when you're moving at mach 25 the time it takes to heat up and then leave your sphere is longer than it takes to burn

>>10483961
>if the power fails you’re dead anyways lol
Its more than possible to lose power to an individual subsystem and not the entire vehicle. Circuit breakers can trip, wires can break, circuit boards can fail, etc. Its much safer to have a heatshield that just works passively like Dragon and Soyuz.

>>10483874
>superdense yet stable form of deuterium
>nuclei so close together a relatively low power laser can induce fusion conditions
>fusion reaction actually propagates through entire fuel particle before it can blow itself apart
>no tritium required, no billion degree stable plasma confinement, rydberg matter can be stable for billions of years
what's the catch, sounds like we could build a legit fusion torch drive using this stuff if it's real

>>10483974
The heat shield is for atmospheric reentry, so it would be in contact with oxygen.

>>10483976
Yeah, but the ship is also really big. Sounds a bit dangerous to cover it in methane.

>>10483971
Even if the methane catches fire the energy released will be negligible compared to the reentry plasma and to the cooling effect of the transpiration system. The nature of the coolant method means that a layer of relatively cool methane vapors is what's closest to the skin of the vehicle, insulating it directly, and as you move away the methane gets hotter and hotter as it is absorbing infrared light from the glowing plasma and acts as a buffer that stops conduction. For burning methane to have any effect it'd have to catch fire very close to the skin, but there's no oxygen there to burn with.

Also all of this would be taking place at very low ambient pressures where combustion is pretty much not possible anyway. There's a reason SCRAM jet engines are very difficult.

>>10483977
eh? transpiration is also passive, anon
there aren't even any pumps, just a valve that you check before you start reentry

>>10483994
it just makes your reentry fireball purple
shit'll be cash

>>10483982
The methane-atmosphere boundary would be at a distance from the skin of the vehicle itself, so no burning methane would be in contact with the vehicle. The whole point of the methane vapor cloud is to act as a buffer that absorbs infrared light and flows quickly tot he side and away form the vehicle, while the shiny skin reflects the rest of the visible light. The methane transpiration cooling system does cool the skin directly but more importantly it keeps the heat of reentry 'at arms length' as it were.

>>10483995
If one part catches the fire the whole heat shield will quickly be lit, and the methane that keeps pouring from the pores will keep it going. Eventually the steel could melt and the rocket would explode.

>>10484005
with what oxygen, anon?
there's no oxygen that high up in the atmosphere

https://elib.dlr.de/62969/1/VanForeest_AIAA-39070-373%5B1%5D.pdf
>Water cooling is demonstrated to be extremely effective. The models are cooled down from temperatures over 2000 K to tem- peratures lower than 300 K, using only little amounts of water. Compared to transpiration cooling using a gas (in this case nitrogen), a water mass flow of only 0:2 g=s cools the models down to much lower temperatures than is achieved for gas cooling. Even a gas coolant mass flow 5 times as high does not reduce the temperatures to the same level

Not methane but still interesting

>>10483982
At very low pressure, probably too low to support combustion. Remember a rocket engine can only burn in space because the chamber holds the gasses back and allows them to build up pressure, a diffuse cloud of methane in the upper atmosphere of Earth would almost certainly not combust.

>>10483994
Why. The vehicle will be surrounded by a 5000 C ball of entry plasma anyway, what's a thin layer of 1800 C buring methane gonna do? There's still a layer of pure methane that won't be burning right next to the skin that would absorb and deflect that heat anyway.

>>10484010
Yes there is. Oxygen hitting your ship with 27000kmh is the reason you need a heat shield.

Interesting, I always thought Soyuz have only this potato targeting camera we usually see during docking.
There is also on board camera on rocket but during the launch we see only CGI.
I wonder why Roscosmos don't show it live.

>>10484018
no you need protection from the nitrogen, oxygen is too heavy and sinks to lower in the atmosphere
that's why people need oxygen masks to climb mount everest

>>10484005
>oh no our ship is surrounded by a burning methane fireball! good thing it's designed to handle plasma literally 4x hotter than that.

>>10484018
Explain why heat shields are needed at Mars then, where there's no oxygen. Or at Jupiter. Venus. Titan. Etc.

>>10484028
>I'm sure glad this ship is surrounded by a burning methane fireball instead of that dreadful reentry plasma

>>10484016
A direct flame is different from plasma. It will melt the steel similarly to how the burners do in the video that Elon recently posted.

>>10484021
There is oxygen in all layers of the atmosphere.

hmm

>>10484031
I never said there is only oxygen.

>>10483998
>solenoid that activates the coolant valve fails
>astronaut has to perform an eva to manually open the valve
>since fuel is now flowing out of the heatshield, reentry must begin immediately
>there is no time to recover the astronaut who is now left stranded in a decaying low earth orbit
ground control to major tom?

>>10482071
You may be right, but it sounds a lot like getting shot with a shotgun instead of a rifle.

Either way, you're fucked.

>>10484033
Yes, unironically. It's 4000 C colder.

>>10482445
>if a businessman can shave his transport time from 8 hours total down to 4

If, yes.

But the processing time includes the time it takes you to get to and from where the vehicle takes off and lands. Even assuming the each allows for using existing airports for that (which I'd assume it would) there is still the question of whether something as loud as a huge-ass rocket is going to be allowed to take off close to population centers, for multiple flights a day.

>>10484038
>It will melt the steel similarly to how the burners do in the video that Elon recently posted
You mean it won't? like at all? Retard. Heat is heat, any material heated to 6000 C becomes a plasma and if you blow that plasma over something it will heat it up just like it were a hot gas (it will also directly attack the surface due to the radicals produced at the molecules of the air are dissociated by the extreme heat, making it significantly worse than a fireball).

>>10484038
>there's no oxygen in all layers of the atmosphere
exosphere is mostly hydrogen and helium popping off like the fizz on a soda
does thermosphere have similar effects?

>a direct flame is different from plasma
good thing the methane coming out of the pores needs to mix with the hypersonic atmosphere first, and so is a distant plasma radiating heat instead of a plasma (flame) in contact
>>10484040
>my nuts didn't get pinched off by this harness, did they?
>nope, still there
>>10484057
solenoid failure should be survivable, the methane transpiration is needed for rapid reusability
that's how they're going to be designing/testing the orbital starship
>>10484070
I know, it's just a funny statement

>>10484070
>>10484033
It's not about the temperature, it's about the combustion you retards. Having methane explode on your heat shield is not something you want to have.
Though they are probably going to end up using water anyways so who cares.

>>10484043
Uh huh, and I didn't either. I said explain why we need heat shields at those places if hot oxygen is the only reason we need them on Earth
>Oxygen hitting your ship with 27000kmh is the reason you need a heat shield
Your direct quote.

>>10484081
"only" is from you, not from me.

>>10483056
>Saturn V rockets were launched from KSC less than 50 miles from Orlando

How many did they launch a day?

Comparing what will be tolerated a couple of times a year for a dicksizing contest to defeat International Communism (tm) and make the world safe for democracy and goodness with what will be tolerated multiple times every day so rich guys can shave 2 hours off a transcontinental trip may not be a meaningful exercise.

>>10484078
>Having methane explode on your heat shield is not something you want to have
I agree, so good thing there's literally no way that could possibly happen with this transpiration cooling setup because the ambient pressure is too low, the rate of methane-air mixing is orders of magnitude too slow to be relevant to the vehicle as it blows through the air at km/s, and by the nature of the coolant system the skin will only be in contact with pure methane anyway meaning any combustion reaction further out will act exactly like the radiative thermal effects of the reentry plasma regardless.

>>10484078
it wouldn't burn until it mixed with the LITERALLY hypersonic atmosphere you flaming dumbster fire, which wouldn't happen until it had already flowed well past your spaceship

>>10483465
Not sure you can do this with rubble piles...

>>10484083
lol
you said
>Oxygen hitting your ship with 27000kmh is the reason you need a heat shield
I said
>Explain why heat shields are needed at (places with atmospheres that do no contain oxygen)
-because oxygen content is entirely irrelevant to the requirement for a heat shield.

Unfortunately you have already been blown the fuck out.

>>10484109
wow savage lay it on him

>>10484091
>implying rich people won't just do what they want and the rest of us will just have to deal with the noise pollution
such is life
>>10484103
>not an asteroidal object
yeah comets are icy so they fuse together under their own weight, rocky objects on the other hand need to be way way bigger in order to have high enough internal pressure to start to make the minerals bond together and essentially metamorphose.

>>10483684
>30 engines is already a mess to deal with. 60 would be a nightmare to do the plumbing for.

For fun, here's a nice simulation of what happens when you use more engines than you engineering and tech can cope with.

https://www.youtube.com/watch?v=9VgQK9vrf_c

>>10484097
At which height does it experience peak heat? Challenger exploded only 14km above the ground. There is plenty of oxygen there to cause an explosion.

>>10484098
In the lower parts of the atmosphere the velocities are way lower and it would definetely not happen behind you.

>>10484109
You should look up at which altitude heat shields receive maximum stress and why.

>>10483723
>Elon said specifically that...

I do not mean any disrespect for Mr. Musk when I say that businessmen sometimes say things that are intended more to have a desired PR impact than they are to accurately describe how business decisions were made.

>>10484128
when the velocities are way lower you can just shut it off lol
don't need a heatshield then

Most Chad space agency?

>>10484133
That's not how it works you mong. Mach 10 at a thick atmosphere generates more heat than Mach 20 at thin atmosphere.

>>10484138
Mach 10 is still hypersonic
mixing won't happen fast enough

>>10483815
Here's a good one.

>>10483994
>Yeah, but the ship is also really big. Sounds a bit dangerous to cover it in methane.

Wrapping your vehicle in flammable shit is a proven concept, friendo.

>>10484128
>Challenger
Didn't fail due to reentry buddy, it failed because an SRB exploded. Columbia on the other hand burned up at an altitude of 64 km, where the atmospheric pressure is roughly 1000 times less than at the surface.

>>10484130
He went on to lay out the rationale behind exactly why they are going to get better performance with stainless and it made sense/seemed perfectly reasonable. He didn't just offhand say
>"Uh, yeah so uh, uh, the uh, change to stainless uh steel is because, the change is, it's, uh, see with CFC you get a lot of wasted material and it turns out that with steel you can get better performance. So the stainless steel version will have more payload, significantly more payload. Uh, yeah. So the stainless is better"

>>10484167
>low atmosphere
also hydrogen meme and venus airship meme

>>10483401
Slip up on the charcoal. Admittedly I have not looked into steel manufacturing in space. I fully expect to be able to get all the steel I need from Mars and I anticipate others will be responsible for that process.

I have serious doubts that asteroid mining will be done in the initial stages of space colonisation. The focus of industry will be on Mars for a very long time. It simplifies things. In this case your manufacturing industry would be much better off on Mars adapting to low-g instead of inventing a whole new series of processes for zero-g. Please consider this.

The moon I think will become a spaceport, quarantine facility and military outpost for global superpowers. Any industry there will be dealing with immense amounts of red tape. Whoever controls the moon will control earth by proxy, and so no individual government will be allowed control of the moon and no company will be trusted by all sides to not throw big rocks down at the earth.

I don't see the loose debre as much of a problem. Firstly you don't need to land your whole ship, just a smaller craft and early belters will probably be hunting for gold. Interestingly the processes you have described will probably have caused the gold to settle right at the center of the asteroid. Food for thought,, this is new to me.

Anyway secondly if you match velocity with the asteroid insted of orbiting it you will be travelling at the same speed as the debree and you just need to cover your rocket exhaust etc to prevent objects getting in there and causing issues.

As a final point I suspect asteroid mining will involve encasing the entire thing in a bag, can or balloon. It would be heated, spun, the different elements extruded and a solid lump of slag would be left in place. You are right about one thing. Asteroid mining is hard and I haven't come up with a fleshed out plan for actually mining them.

>>10484114
>>not an asteroidal object

Fuck, you are correct, I messed up.

On the other hand, I do see a lot of images of asteroidal objects with clearly defined craters. Not sure you can do THAT with a pile of loose rubble.

>>10484199
Sure you can, we simulate craters in the lab by firing little pellets at fine dust beds. As long as the impact isn't big enough to completely demolish the asteroid it'll leave a crater, not much of the ejecta will land though, especially on a smaller asteroid.

>>10483465
Admittedly most of my research has a strong focus on bodies with meaningful gravity. I do not like the complexity inherent to a zero-g working environment.

Human expansion will out of necessity follow a Mars->Supermassive Orbital Habitat route. That habitat is my interest. It's possible and it could be done within our natural lifespan.

>>10484198
>As a final point I suspect asteroid mining will involve encasing the entire thing in a bag, can or balloon. It would be heated, spun, the different elements extruded and a solid lump of slag would be left in place. You are right about one thing. Asteroid mining is hard and I haven't come up with a fleshed out plan for actually mining them.
That would require literal centuries in order to melt that entire mass and allow it to cool again, even for a relatively small asteroid of a few hundred meters across. Much more efficient to bag them as you suggest then just pick through the rubble for the chunks of rock that hold the resources you want, or if you're dead set on full recovery melt/crush/dissolve each rock individually and process the entire asteroid step by step.

>>10484214
You are right. How to sort the debre quickly and effectively in zero-g though. I spent probably the last decade trying to work this stuff out and everything is immensely complicated. You need a centrifuge. My plans for small scale manufacturing required that a band be installed around the asteroid and a can on a cable would spin around on it.

You can't mount that kind of a band on a ball of debre. I don't want to wait, so when people started to seriously consider living on Mars it was much simpler to drop the asteroid mining and focus on orbital construction techniques and a design for the structure.

People should, and I believe they will, go to live on Mars. However the lower gravity, poor atmosphere, contaminated environment, lack of vegetation etc concerns me.

I am pre-emptively preparing to accomodate the needs and concerns of the first colonists to leave Earth. I don't want space to be the third world.

I want it to be the future. I want it to be better than Earth.

Why do SpaceX fans have such a huge persecution complex?

>>10484262
>I can't provide well grounded criticisms so I'll just blame fanboyism lol

>>10484266
What?

>>10484262
They don't. You're just seeing a vocal minority who bitch alot.

>>10484248
i always assumed it'd just be done the same as on earth. Dump water on it, grind it into a slurry, solve it in acid or lye and seperate what you want via precipitation or floatation.

>>10484303
Yes but...
>precipitation
>floatation
Not in zero-g. You need a centrifuge.

>>10484307
A centrifuge to dump your slurry in seems like much less of a problem than the large amount of water, energy and ridiculous amount of chemical engineering equipment you're gonna need to regenerate all that acid/lye/depressants/floatants.

Recoverable Ariane rocket when?
https://www.youtube.com/watch?v=tV29pEvZvZw

>>10484310
Is this more or less retarded than SMART reuse?

>>10484341
Well, it's been officially cancelled and 'SMART' hasn't...yet

>>10484310
that seems like what the russians came up with for their energija rocket in the late 80s, just without recovering the tanks.

>>10484182
wow he really does talk like that, doesn't he

>>10484198
the moon is probably the best source for titanium in the whole solar system

>>10483847
I actually have that poster up on my wall.

INTERESTING POST I've found
apparently there's a subsonic region in between the bow shock and the spacecraft
due to the flow separation there it should be easy to fill that space with almost nothing but methane, so no burning can occur

>>10484399
Bro it literally says flow separation happens around the 90 degree mark lol, not at the front. Subsonic flow is 0-45 degs, flow sep at 90. 0 being the front.

>>10484205
>Sure you can, we simulate craters in the lab by firing little pellets at fine dust beds in 1 g.
Not at piles of assorted boulders in negligible gravity.

>>10484198
>Slip up on the charcoal. Admittedly I have not looked into steel manufacturing in space. I fully expect to be able to get all the steel I need from Mars and I anticipate others will be responsible for that process.
N
>I have serious doubts that asteroid mining will be done in the initial stages of space colonisation. The focus of industry will be on Mars for a very long time. It simplifies things. In this case your manufacturing industry would be much better off on Mars adapting to low-g instead of inventing a whole new series of processes for zero-g. Please consider this.
I
>The moon I think will become a spaceport, quarantine facility and military outpost for global superpowers. Any industry there will be dealing with immense amounts of red tape. Whoever controls the moon will control earth by proxy, and so no individual government will be allowed control of the moon and no company will be trusted by all sides to not throw big rocks down at the earth.
G
>I don't see the loose debre as much of a problem. Firstly you don't need to land your whole ship, just a smaller craft and early belters will probably be hunting for gold. Interestingly the processes you have described will probably have caused the gold to settle right at the center of the asteroid. Food for thought,, this is new to me.
G
>Anyway secondly if you match velocity with the asteroid insted of orbiting it you will be travelling at the same speed as the debree and you just need to cover your rocket exhaust etc to prevent objects getting in there and causing issues.
E
>As a final point I suspect asteroid mining will involve encasing the entire thing in a bag, can or balloon. It would be heated, spun, the different elements extruded and a solid lump of slag would be left in place. You are right about one thing. Asteroid mining is hard and I haven't come up with a fleshed out plan for actually mining them.
R

>>10484471
no, that's flow separation of the subsonic flow from the sphere, not between hypersonic and subsonic flow at the shock front
the hypersonic flow outside the shock front doesn't mix with the subsonic flow

>>10484477
he cute

>>10484494
Nobody or thing that uses that vile word is "cute". More like reprehensible and disgusting. A sign of an uneducated racist who is afraid of people because of an arbitrary trait.

>>10484309
My ideas began branching out because of the complexity and mass requirements. Not to mention the safety risks of operating a centrifuge around a crumbling asteroid.

I was so desperate for ideas I was looking into using enourmous arcs of electrical discharge to melt chunks of asteroid and using magnets to suck up the good stuff. Hah! Engineer that for me... Easier to just use orbital bodies with enough gravity.

>>10484352
Titanium is over-rated. I'm sure military will take an interest. As soon as there are people making money in space they will want their own ships to enforce taxation. Still convinced the moon will be goverment/military controlled. Additionally moon industry taxation is much more easily enforced. Not the place for me.

>>10484516
yeah, moon will be red tape central, but Mars will be free
space for the spacenoids, kesler syndrome when

The heavy booster has a fuck ton of engines, how exactly do you fit all that plumbing and nestle the engines correctly. It seems like an almost herculian task to handle. Falcon heavy is 3 rockets tied together under one system. Maybe the booster can continue flying even if one or two blow out?

>>10484546
I wish there was more discussion on the super heavy booster, it's the most important and complicated part of this whole system. Thirty-one raptors, over 3 million kg, 63 meters long. AND its going to land itself.

>>10484595
the hardest part of the whole operation is tying all those engines together, the landing itself part and the size are easy in comparison, and the landing itself is just down to your ability to throttle a few engines (it only needs a few)

>>10484501
First day on 4chan?

>>10484805
I don't get why people delight in posting dumb shit like that image, enjoy your vacation
just append nigger and a (you) at him the next time you make a post

>>10484816
>I don't get why people delight in posting dumb shit like that image
Shock value, they like negative attention. People like like that were most likely those kids you knew from middle school who would make dead baby jokes.

>>10484816
It's just /pol/s undercover agents making sure everyone knows they are watching.

>>10484816
The fact that it triggered you so much just proves that you're a reddit invader piece of trash.

>>10484816
Stop making work for the jannies and stop feeding the trolls.

Are you a newfag ffs. It was getting nice in here.

>>10484899
I spent half an hour with a man who was willfully and belligerently wrong earlier, which got everybody else mad and then I spent an hour arguing with them
I just wanted to post pictures of rockets and call them ugly trashcans

>>10484602
Hopefully SpaceX does make the same mistake the Soviets did by not doing tests of the assembled stage before launch.

Wherefore doest the travelling lamp beshrew us?

>>10484925
What a big fire. New images from the satellite heading to the sun?

>>10484925
What would happening to the sun of its gas suddenly stopped burning?

>>10484148
>Here's a good one.
Where's all the cool photos of Neptune and Jupiter?

>>10484198
Dont hold your breath, all that shit you lost wont happen until 2500

10484961
You didn't even try, so you don't get a (You)

based mods

>>10484955
it'd turn red, grow out to the size of the orbit of the earth, and start burning helium

>>10482473
cringe as fuck

>>10484987
helium doesn't burn

>>10484991
not with that attitude, it doesn't
>>10484946
I did a google reverse image search and it appears to be from some redditor's amateur astronomy

>>10484961
>Dont hold your breath, all that shit wont happen until 2040.

Fixt

Boeing delayed again wew
https://www.reuters.com/article/us-space-boeing/boeing-delays-by-months-test-flights-for-u-s-human-space-program-sources-idUSKCN1R12QR

space is getting dat flag

>>10485014
What's with the vitriol here against everyone that isn't SpaceX?

>>10485020
it's just funny because they've been delayed before
also what's wrong with rooting for SpaceX?

>>10485022
>it's just funny because they've been delayed before
What? How is that funny?
>what's wrong with rooting for SpaceX?
Who said that?

>>10485014
yeah holy shit, RIP Boeing
>>10485025
it's fucking hilarious
I laughed during AMOS-6 as well

>capitalist shills will defend wastefulness such as this

>>10484177
Columbia did not initially burn up because of heat shield failure, it was ripped apart by aerodynamic forces due to it losing its' aerodynamic profile.

>>10485022
Nothing
Beyond Elon fanboyism, spacex is actually getting shit done
Everyone else just postures

>>10485056
>SpaceX HQ after BFR fails

>>10485100
eh? no, that's SpaceX HQ right now, because they threw out all the tooling for big composite tanks
apparently they're shit?

>>10485096
don't forget about the consuming vast quantities of cash with minimal benefit

>>10485125
San Pedro is just a big empty yard (now), pretty far from Hawthorne

>>10485127
kek fucking SLS

>>10485127
>>10485137
That's really only true for the big four (Boeing, Lockheed, Northrop Grumman, Airbus.)

Everyone else has to be lean or they die.

>>10485125
>apparently they're shit?
No, SpaceX just doesn't have the money to develop them properly along with their new rocket. Their first stage especially will take a big performance hit by using a different material, but they simply plan on making it larger and improving Raptor's performance to compensate.

>>10484177
>it failed because an SRB exploded

>>10485151
What?

>>10485151
you're right, it's more accurate to say that an SRB exploded due to gross negligence

>>10485154
a shuttle SRB has never "exploded"

>>10485158
every Shuttle SRB was a controlled explosion

>>10485158
"containment failed"

*mogs your shitty shuttle designs*

>>10485231
wow lewd
is Starship okay with us looking down her top like that???

>>10485231
>>10485234
>"orbital prototype"
>no internal structural support whatsoever
What did they mean by this?

>>10485241
put it in later it'll be fine

>>10485241
The big cylinder actually looks like it has some rims inside for reinforcement, they could be slosh baffles like Elon mentioned. Also as >>10485248 mentioned the fuel tank bulkheads will likely add most of the starship's structural rigidity and they haven't been put in yet.

>>10485241
Calling it orbital was just an obvious bullshit statement like the thing with the video where they heat the tiles using flame torches although that tells you nothing about reentry.

The cultists are eating it up though see here >>10485248 and here >>10485296 so Elon has achieved his goal.

>>10485301
derp derp derp

go back to the hole you crawled out of ULA shill. No one likes you and no one wants you.

>>10485305
>T R I G G E R E D

>>10485241
Suborbital?

>>10485324
the thing they're building is currently claimed to be the orbital prototype
my speculation is that it's going to be some sort of insane SSTO thing for testing heatshields and reentry controls

>>10483319
Remember back in the day when Muskrats would show this picture every time you told them BFR is a pipe dream?

>>10485326
So what happened to that precious part of tooling? Oh no, OMG Elon what are you doing?

>muskrats
it's the fuckboy again
report and hide, gentlemen

Why don't SpaceX test out this liquid cooled heatshield by using it on unmanned Dragon flights first? Get a smaller scale version working before using it on a large vehicle like Starship.

>>10485355
>Why don't SpaceX test out this liquid cooled heatshield by using it on unmanned Dragon flights first? Get a smaller scale version working before using it on a large vehicle like Starship.

Dragon's only customer is NASA, and they're picky about experiments made during their contracted missions - and that contract includes carrying material back to Earth aboard Dragon.

>>10485355
because:
A. Dragon's a cold structure, so a heatshield that would melt dragon might be perfect for Starship
B. NASA wants all Dragons in one piece with no fuckery, because they paid for those experiments to come back in one piece and aren't taking chances.

>>10485355
They once floated the idea to turn Falcon second stage into a starship mock-up.
Don‘t think that‘s still on the table though

>>10485383
something about too much design work to build a test article when they could just build a few full scale ones from the start

>>10485056
Capitalism won the space race, commie

>>10485355
Dragon is made out of different materials, different structure, and different everything. Just launching it will cost millions, modifications needed probably more. Small scale testing can prove more difficult and costly than going directly to full scale tests.

>>10485383
Thats so dumb

>>10485433

You can win space all you want we already won the Earth.

Good luck living on mars lol.

>>10485457

>>10485167
>liquid boosters
;_;

>>10484351
people don't think it be like this but it do.

>>10485056
I doubt they'll just toss all that out. It'll probably get melted down and reused for something.

>>10485056
>implying carbon fiber BFR wasn't a misdirection from the start
somewhere in china there is a team of reverse engineers that are being absolutely buttblasted right now

>>10485167
I still don't understand why they never made major changes to the shuttle after either of the disasters. Liquid boosters would've not only been safer, but likely cheaper to refurbish aswell. You'd think that 1.5bn per launch price tag would drive something like that, but I guess not.

>>10485145
>No, SpaceX just doesn't have the money to develop them properly along with their new rocket
no
>Their first stage especially will take a big performance hit by using a different material
no
>but they simply plan on making it larger and improving Raptor's performance to compensate
no, the design is the same height/weight and uses the same thrust engines as the last design to feature CFC structures yet Elon explained in several paragraphs worth of interview that they are getting significant performance gains just by switching to stainless.

>>10485151
>I don't understand shorthand

everyone already knows that the booster failed because the O-ring failed because the launch happened when it was too cold out the night before because NASA had 'go' fever. Everyone also already knows that the launch probably would have been fine if there weren't also very strong high altitude cross winds that hammered the temporary plug of burned rubber preventing a burn-through of the booster casing and caused it to blow out, allowing a jet of hot gasses to blow onto the external hydrogen tank until it ruptured and caused the vehicle breakup.

>>10485167
>Liquid boosters
aww hell yeah the controllability improvements alone woul-
>using LOx/LH2 engines
Into the trash it goes.

>>10485307
not really.

>>10485241
M O N O
C O C K
D E S I G N

>>10485531
Because of the SRB cartel. Thousands of jerbs in Alabama would have been lost! Got to keep those SRB engineers employed so we can keep our ICBMs working without officially spending money on scary nukes! That's why SLS is still being built with SRBs.

>>10485542
Ah shit you're right, I always forget about the governmental factor.

>10485326
>10485327
>zero replies
oof

>>10485525
Yeah at the recycle center, no way SpaceX is doing anything else with that pile of scrap other than selling off or just dumping it.

>>10485546
Not him but you are replying to him lol.

>>10485567

new spadre drone footage https://youtu.be/_HVx5YC41KM

>>10485642
this thing gonna fly today?

>>10485643
couple second short burn, don’t think it will lift off all at

>>10485237
black sections? Also it looks like it has a much more aggressive taper, unless those wedges in the back are for a bulkhead

>>10485521
Greetings fellow American patriot. I noticed you have some interest in liquid fueled rocket boosters.

I couldn't miss your keen eyes on rocketry, and I assure you, you need to look no further - the Boeing Company has just the thing you need!

Boeing just happens to have* an American Sized All-American Made in USA liquid powered rocket booster which is the most powerful American Made rocket booster ever made in the United States of America.

You heard that right: all American Made XXL sized liquid fueled rocket booster, American Flag included!

Maybe you are wondering where is the catch, well, there isn't one!

Boeing fully expects to have one of those rockets nearly fully assembled and available for sale, just waiting for its customer, in the coming months, and it could be YOU who could be the lucky owner of that amazing piece of American engineering!

How about it? Would you like to sign the deal right here and right now? Know! Chances like this happen once in a lifetime, I personally assure you, you won't get another chance like this, Boeing is providing you with an opportunity you can't afford to miss!

Should we create a new thread for the testing?

>>10485805
Fuck off, /sci/ is a slow board, this thread will probably last 24 hours more.

>>10485813
Not when the fireworks start....these threads go relatively quickly as well.

>>10485823
More posts on a bump limit thread do not make it die faster. Only more new threads will do that.

>>10484262
40 years of blatant incompetence and the worst corruption in spaceflight will make even the biggest optimist jaded. If do not have a persecution complex, you are doing it wrong.

livestream for those not already watching
https://www.youtube.com/watch?v=L7zia2HqOOc
testing any minute now. starhopper is venting gas as we speak

>>10485925
>any minute now

Yeah have fun watching that for 6 hours

>>10485952
honestly, I will

>>10482227
wait, is Elon trying to make russels teapot real?

>>10483724
Dunno about thermal expansion, but titanium has half the stiffness of steel.

>>10485925
venting

Can whoever makes the next thread start adding "/sg/ - " to the subject so it's easier to find in archives and thread watcher?

>>10486145
Done
NEW THREAD
>>10486162

>>10485823
we could reach a thousand posts and still have time left on the board because after bump limit it's dictated by the speed of the board, and /sci/ is fucking slow
>>10486163
you fucking retard

>>10486244
This thread is already dead KYS

>>10486308
we are literally on page seven
we will be here until after I have gone to bed tonight

>>10485921
>If do not have a persecution complex, you are doing it wrong.
Why is that so common on the internet? I'm not just talking about spaceflight, I mean in general.

we still here, nigga
we still here

We're on page ten and I'm...
Still alive

>>10487424
it's like, holy shit, you know?
why are newfags so gay

>>10486316
metaposting is even gayer than newfags who don't know how image boards work