/sci/ - Science & Math

>>10325407
I want to have some of the scrap metal from it when its done.

>>10325407
Also, I think it looks like a space ship should, shiny and cool and somehow planet express. To me it looks like it is small, though I'm sure that's objectively false, it's my only annoyance.

>>10325427
skylab was 6.6m diameter. Starship is 9.

>>10325427

Guys, will SpaceX succeed? I'm fed up of this planet.

>>10325453
start saving money then, get in shape, and learn useful skills.
I'd start by getting off of 4chan

>>10325430
>>10325433
Yeah, objectivey, but it looks small. Either way it's the coolest bottom part of a space ship I've seen.

>>10325407
>Be me
>Launch day of the Starship Hopper
>3
>2
>1
>Liftoff!
>As it leaves the shadows of the launch tower the angle of incidence of the sun to the rocket coincides with the angle of incidence of my eye-rays to the mirror-polished surface equal each other
>My corneas when

>>10325407
NOOO What the fuck happened

>>10325478
>eye-rays
Are you Cyclops?

>>10326098
Mexicans didn't strap it down properly and the top half blew over, fortunately the bit with all the tanks and stuff is OK, just the tinfoil hat is fucked.

>>10326098
Elon forgot how to tie a clove hitch and the ropes came loose.

>>10326125
Well fuck
>>10326141
Guess they dont have Boy Scouts in South Africa

>>10326098
Something delightfully counterintuitive and completely to plan if Musk is to be believed.

>>10326197
He knows how to use a rifle and how to set up an ambush though.

>>10325407
Looks pretty fuckin counterintuitive to me.

>>10325317
www.dtic.mil/dtic/tr/fulltext/u2/a951011.pdf
https://apps.dtic.mil/dtic/tr/fulltext/u2/a951011.pdf
same doc PAGE 10
or just google "300 series stainless steel tensile strength low temperature"
pic related

>>10326378
>Testing temp (deg F)
Into the trash

It looks like a prop.

>>10326378
Reminder actively cooled metal structures for reentry were considered at least as early as the 60's.
Probably only considered because they are worthless for warheads. Passive ablatives work better there.

>>10325407
Elon is such a fucking retard for going stainless steel. His "improved heat tolerance" doesn't help much when the ship falls apart as soon as it hits the atmosphere. The idea is so dumb it hurts.

>>10325430
>>10325433
>*abandons it because its a nazi station*
heh, nothing personnel, goyim

>>10325407

This is because they are rushing things.
This is NOT a production model just a prototype so they are doing everything fast and loose.
Just bad luck.

>>10326098
an insurance scam. musk needs more money to feed more pipe dreams to make more money.

>heatshield test
https://twitter.com/elonmusk/status/1088680182540464128

>>10325478
you realise it's a convex cylinder so the sun's reflection off it to you will be vastly less powerful than the light that goes from the sun directly to you.

>>10326378
Tensile strength goes up for everything metal as things cool (because I know you're going to be an idiot about this, yes things can get lower results as they change phase, but after those points you see the same kind of progression), but certain grades of stainless don't hit a point where they suddenly become brittle/lose ductility. In fact, a lot of those tests are not valid because the metal remains so ductile at those temps compared to the ""strength"" gain (certain assumptions about the failure mode of the bar no longer hold), so the numbers you happen to be pointing to are not true ultimate tensile strengths, although the materials do behave well at cryogenic temperatures.

If you go back to my earlier comment, this is part of why I put "weaker" inverted commas and all, which isn't some sort of strictly defined inverse of "strength" but pointing you, a lay person presumably, to the idea that it's more likely to fail. They still do progessively worse at things like the Charpy notch test (which would be the kind of data you'd like), and just in general things tend to fail at extremes of temperature for all sorts of reasons.That this will involve welding large amounts of stainless, lots of holes for rivets, vacuum etc etc are all potential points of failure due to precipitation of different phases and stress concentrations (which are in a number of ways amounting to the same thing). The nose cone thing has really caused a loss of faith in me because it shows a very basic failure in designing something with any sense. Imo they shouldn't have bothered.

>>10326502
Not sure what the failed "nose cone" has to do with the properties of cryoformed steel vs aluminum or even carbon fiber for the intended application.
That last line makes it sound as if you are assuming the orbital vehicles will share the construction methods of the hopper which implies some level of retardation.

Here's your upvote, fellow redditor. Well deserved, well earned.

>>10326467
Stainless steel is stronger than either composites or aluminum you retard. This thing will not fall apart during reentry or anytime else, period. It may burn through if their cooling fails tough.

>>10326568
Total cooling failure implies insufficient landing fuel. Partial failure can be survived at the cost of scrapping the starship.

>>10326467
>raging anon on the basket weaving forum versus rocket scientists

You are delusional, sweetie.

>>10326622
Elon isn't a rocket scientist and all the actual rocket scientists at SpaceX were against is as per Elon himself.

>>10326568
It literally collapsed after being hit by a breeze of wind, shillboy.

>>10325453
They won't take you with them

>>10326672
>They won't take you with them

Space will be like the original Star Trek, all white with a few token smart minorities .

>>10326685
so it won't include you el goblino

>>10326484
webm

>>10326781
This is just a bunch of fuel-oxy torches with rosebud tips on
What did elon say the temperature test was at?

>>10326857
They probably don't know.
This is neither serious enigeenirg nor a scientific test, just PR to keep the hype going.

>>10326781
>>10326864
>>10326857
It seems they need to re-discover how stainless steel behaves at high temps.

>>10326864
Elon said 2000 F which means that's probably not acetylene
it could be any sort of natural gas, with a little bit of oxygen mixed in the torch to make it easier to ignite
the fire is so feathery and that temperature is so low that there's no way there's much oxygen in that flame

>>10325453
The whole purpose of "will Space X succeed" is to continue to justify the total ban for private citizens to research and engage in space exploration. I hope it does succeed, but I'm pessimistic because of the above. Space X makes it seem like space is open, but really Space X is just NASA (government funded) with a different name.
Now NASA's role got switched to shilling for global warming and Elon is doing NASA's old role, only difference.

>tfw got arrested, fined, and put on a watchlist for launching 1kg sugar rocket

>>10326873
>WTC narrative
Steel is extremely resilient when heated to a high temperature, unlike what the NIST report told you. Look up the Cardington Fire Experiments. The whole misnomer of "it loses 90% of its strength" is that even at 10% of its strength, steel is still strong.

>>10326891
For real? I don't doubt you though, the idea that space travel is free and open is a myth perpetuated by "private man" Elon doing it. In reality that's just a way to keep banning everyone else.

>>10326896
Sadly yes. Apparently you need license for dealing with explosives and bunch of other shit which my underage ass then didn't know. Things might have changed the last 10 years but I somehow doubt it, if anything it probably got worse.

On the topic of government bans I just remembered that german attempt at creating cheap rockets from 70's or so that was CIA'd. >https://en.wikipedia.org/wiki/OTRAG

>>10326484
>>10326781
>>10326857
>>10326864
>>10326873
>>10326881
Those ain't just Boring Company blow torches, their industrial torches used to cast engine bells.

>>10326948
bro, it's a bog-standard rosebud torch on a (probably victor) fuel oxy torch
there's nothing special about it, I'm going to buy one I saw at the pawnshop tomorrow

>>10326956
>>10326948
they've got something like this on it

>>10326666
Elon doesn't have anything to do with the science aspect you moron. LOL

>>10326864
Did you stretch before you did this much reaching?

more progress

>>10326968
>huntsville
>aka oldpspace central
No wonder BO still isn't orbital.

>>10325407
>>10326466
>>10326467
>>10326568
Is the actual Starship going to be made of stainless steel? I thought it was just for the hopper test.

>>10327008
the whole thing. https://www.popularmechanics.com/space/rockets/a25953663/elon-musk-spacex-bfr-stainless-steel/

>>10326968
>Internet meme @torybruno

>>10327005
it's the world's largest R2D2

>>10327014
Oh damn

>>10327008
Full stainless steel and first of its kind active cooling system put in use. They were going to make it out of carbon fiber but that turned out too hard and expensive. Elon mentioned CF costed about 180$ per kilogram, while steel about 3$, and that is without considering the drastic simplification in manufacturing and its effects on cost and schedule. Expect different looking thing than the scrapyard diy tier hopper though.

>>10327181
>Liquid cooling systems literally not tested yet and way more complicated than any ablation material so far
>somehow it's going to be cheaper and less complicated
lmao

>>10327196
Anything is cheaper than ablation, it literally involves the expensive heat shield burning away. Active cooling is more complicated for sure but SpaceX has prior experience with it, the F9's heat shield is actively cooled.

>>10325430
I like this one better.

https://www.youtube.com/watch?v=qiMq-fdRhLo

>>10326125
https://www.youtube.com/watch?v=3m5qxZm_JqM

>>10327196
You do know what ablation means right? The stuff dumps heat by burning off, eventually meaning that an entirely new heat shield has to be manufactured, which isn't cheap. Active cooling is more complicated, but the only thing that needs regular replacing is the liquid coolant.

>>10326893

>>10326893
Obviously not strong enough to hold up the top of a burning building with the ass of a 747 lodged in it.

>>10326666
>It literally collapsed after being hit by a breeze of wind, shillboy.

Same thing would happen if it was made out of composites or aluminum, too. In fact it would be even more damaged as those are weaker materials, no matter the temperature. There are potential issues with stainless steel construction (mass, reentry heating), strength is not one of them.

new hole

>>10327754
Why drill fucking holes in the fuel tank?

regenerative cooling is currently employed in rocket nozzles
modern engines run fuel through pipes/channels in the bell to keep them cool, while the F1 engines used a similar technique to the proposed Starship design where they had a film of cooler gas running along the surface

>>10327754
>>10327782
You can see the metal lattice that reinforces the foil, this suggests the hole is only skin deep and for ventilation.

>>10327754
how delightfully counterintuitive

>>10326873
It's worth doing to make sure that all that insulation you see is actually performing as expected. There's also oxidation and fatigue that must be dealt with. The heatshield must function over the entire vehicle's life without being replaced. Second it's worth doing to make sure that your suppliers aren't fucking you over. Third the function of the heat shield is just so incredibly important that EVERYTHING is fucked if it doesn't work, so you better be damn well that it works before throwing down big wads of cash or putting lives on the line.

>>10326666
>Elon isn't a rocket scientist and all the actual rocket scientists at SpaceX were against is as per Elon himself.

my money is on elon and the engineers made a compromise that elon can test it out on a very restricted budget and because of this we are seeing this backyard assembly of a rocket. once he fails they will go back to cf,

>>10328092
>replying to yourself because nobody took your bait
that's all speculative nonsense

>>10328095
what?

>>10328116
you don't know anything about the internal design process that lead to stainless steel
all we know is that Elon claims it was his idea and his engineers were skeptical in the beginning but he brought them around

>>10328124
hence the "my money is on", you absolute retard.

>>10328092
You can't just switch out tooling like that, if SpaceX have gone for steel, their committed to it. Also, Elon controls the money flow as well so it's pretty much impossible to restrict his budget. This backyard rocket will not be sufficient to prove whether or not stainless steel is the right choice or not e.g. It won't be able to test the heat shield. The orbital prototype will, so SpaceX will have to pour significant money and resources into building it before they can decide whether steel is the way to go or not. Personally I think steel will stay, but I'm not sure about the active cooling, especially for high energy returns.

>>10328127
their "commitment" as of know consists of half a dozen welders and a crane.

>>10328134
And they also fired all their carbon fibre guys

>>10327782

they do this when they decommission any aircraft. guessing thats what they did.

Why the fuck does it look so stereotypical.
like something straight out of looney tunes.

Why does elon have to be such a fucking retard.

^
You've posted this very same post in every single thread so far

>>10328302
Just turns out to be the way to go, a hilarious coincidence

Iron spaceships holy lel

>>10328412
you know what the best part is
both the moon and mars are nearly nothing but iron oxide and silicon oxide on the surface, and you can liberate the iron pretty easily
the moon also has a very high concentration of titanium, which is fairly common on earth but is very spread out so hard to mine for
moon mining is going to be crazy if we ever get space industry up and running

>>10328134
>>10328188
And supposedly hired a bunch of metallurgists. Time is also money, they've committed a lot of people to work on this that could have been doing something else. The kind of tooling that's been mentioned (by Musk on Twitter) is also not something that allows a lot of change.

>>10328594

>>10328609
When did they start repairing the nose cone? Looks good as new.

>>10328609
You forgot to foil your fins, and trim that top toothpick

>>10327348

See, told you they were ventilation holes

>>10328188
>>10328564
This is such bullshit and you know it. They have spend billions on a factory and machinery for CF while the stainless steel is a backyard project basically.

>>10329302
>>billions on a factory
annon that factory is next to the USSR on things that exist right now...
The CF machinery can be sold at a loss and not for billions like you pull out of your ass....

>>10329302
It's a good thing actually.

Elon is retarded and in his rush he made the mistake that will bury him aka half assing it.

Assuming the whole concept works and spacex solves the hard things everyone else will be able to whip out something similar and make it 100x better and faster using available knowledge on what works and what not and essentially endless government funding.

Using advanced carbon fiber super lightweight materials instead of dead weight rusty steel (lol) or inefficient methane fuel are one of the prime targets for optimization.

If he gets his bfr working expect in 2-5 years Europe, Russia, and China to have their respective answers all vastly superior, probably even before he manages to sort all the kinks his rushjob design has.

Here in the EU there are talks already about Ariane 6 replacement so I think things will turn out exactly like that.

US always bets on some wunderwaffe like the shuttle and it never delivers and this time it will be no different.

>>10329315
You dont seem to understand. If you commit to something you actually spend money on it, not like this shit >>10329239
>lol guys we need ventilation just cut a hole in the shell and get a ventilator from home depot real quick

>>10329318
>inefficient methane fuel
This is bait

>>10329318
Neither Russia nor China will be able to make an engine as good as the raptor
Even if they get the design the metallurgy is beyond them

>>10329318
>Europe, Russia, and China to have their respective answers all vastly superior

Lol, your really overestimating Europe's speed of innovation and development e.g. over 8 years to develop Ariane 6, despite it having the same engine as Ariane 5. Russia has a dying space program and shouldn't even be considered as competition. China are a more reliable bet, but they seem to be focused on building SLS clones and their reusable LM-8 concept seems to have engine throttling issues.

>Here in the EU there are talks already about Ariane 6 replacement so I think things will turn out exactly like that.

The Ariane 7 is going to be a Falcon 9 replicate, powered by Prometheus Meth/Lox gas generator engines. Arianespace will struggle to field a reusable Falcon 9 equivalent by the mid 2020s; actually they've admitted they don't even want to, because it would force them to shrink their workforce and stop being a glorified jobs program.

>>10329332
shillboys actually believe this

>>10329334
>glorified jobs program.

With out these "glorfied jobs programmes" SpaceX wouldn't have any rocket engineers they can hire (alongside with the fact that without NASA they wouldn't have any money to pay them with).

I mean, I don't dislike Elon, he's better than most billionaires, but it is freaking obvious he's a government bebe. Nothing bad with that, but stop denying it.

>>10329338
>muh SpaceX is reliant on NASA funds

Sure it helps greatly with financing R&D, but SpaceX gets enough private contracts that the government money isn't needed for it to stay a float. Also, contracts don't equal subsidies contrary to what Arianespace seemingly believe.

>>10329330
fuck annon you beat me to it
that line gets me every time :D

>>10329349
It's almost like people think that cow farts aren't the future

>>10329341
>contracts are not subsidies

Yes they are.

Otherwise the US government could have contracted cheaper Russian launchers instead.

Why did they pick to contract an american company then?

Subsidizing their own.

>>10329330
LH is superior and methane requires the same technologyas LH to handle/store/pump the fuel in and outside of the launch vehicle.
There is absolutely 0 reason to go for methane over LH.

>>10329371
>Otherwise the US government could have contracted cheaper Russian launchers instead.

That's a strange thing to say, since the Falcon 9 is cheaper than Soyuz and even Proton, and that's before insurance comes into account.

https://www.youtube.com/watch?v=vqW0LEcTAYg

>>10329371
>cheaper russian launchers
shiggy
>>10329373
methane is a significantly larger molecule than hydrogen, and as such is much easier to contain
also it doesn't fuck up literally everything it touches with hydrogen impregnation

>>10329379
>and as such
And as such has a far lower isp

>>10329384
>And as such has a far lower isp

But a much better mass ratio from the higher fuel density, and less in the way of finicky valves that tend to misbehave at such low temperature.

>>10329384
The lower isp is largely compensated for by the reduced tankage dry mass and reduced gravity losses from higher thrust. To say nothing of cost and effects on reusability...
Situation is highly similar to how miracle propulsion like VASIMR get 4000 or so isp but before taking into account weight of power generation, radiators, and super magnets.

>>10328124
>all we know is that Elon claims it was his idea and his engineers were skeptical in the beginning but he brought them around

He did this before, it is why Merlin engine is using face shutoff. Turned out to be a correct decision in hindsight.

https://zlsadesign.com/post/tom-mueller-interview-2017-05-02-transcription/

>>10329384
combustion products are water, same as kerosene but with less big hydrocarbons in it from running it fuel rich
>>10329396
Tom Mueller gives some really good presentations

>>10328609
behold, the raw intellectual power of /sci/!

>>10329320
>Oldspace absolutely SEETHING

>>10329384
>muh isp

Specific impulse is a meme. Thrust, density, ease of handling (hydrogen is a bitch) are much more important.

>>10329413
ISP is very important for certain applications because rocket equation is a bitch, but the most important factor, ease of handling, and it's affect on part durability is the most important
can't have cheap space if you need to throw your engines, tanks and plumbing out every time you use your rocket

>>10329373
>methane requires the same technologyas LH to handle/store/pump the fuel in and outside of the launch vehicle.

No, methane requires only rather straightforward technologies similar to liquid handling oxygen, and you need that anyway. Heck, there is an entire industry centered on LNG. Hydrogen on the other hand is considerably colder and seeps into everything,
that is where real problems begin. Doubly so for a reusable vehicle.

>>10329413
>Specific impulse is a meme. Thrust, density, ease of handling (hydrogen is a bitch) are much more important.

For reusable vehicles to LEO, this is particularly true. However, for all that power, the specific impulse and dry mass of Starship give it limited to no capacity to directly send payloads beyond Low Earth Orbit. For some customers, this is going to remain a problem until orbital refueling is a proven and dependable technology. Large amounts of risk have lead to a very conservative industry.

>>10329442
>However, for all that power, the specific impulse and dry mass of Starship give it limited to no capacity to directly send payloads beyond Low Earth Orbit.

There's a big discussion about whether the Starship can send a payload to GTO or not, due to this. This would obviously be a problem for the commercial side of things, so I've suggested that SpaceX develop a small kick stage for GTO/GEO missions; it goes against the full reusability principle but gives Starship a lot of extra flexibility,

>>10329341
It is a known fact that SpaceX is not making profits on its privat launches.

Also, it is not just launch contracts. SpaceX exists because NASA decided it wants to concentrate on research programmes and outsource launching to privat companies. They literally went to SpaceX when it was small and insignificant and build it up from the ground.

>>10329442
Starship is literally dysfunctional without orbital refueling so its existence is tied to it. You bet the SLS crew will use the "in a single launch configuration..." argument in their defense. Payload to solar escape trajectory is often quoted as spectacular advantage advantage of the senate system already.
If orbital refueling fails for reasons not yet known to physics, re-purposing the SH to lift an entire F9 could be an option to satisfy everyone besides the payload fairing volume crowd.

>>10328476
>>10328412
>bfr has been blown out by silly 80kmh winds instead of supposedly flying in a few weeks because of company retardation
>retards are already claiming it's the answer to everything in all matters space exploration
imagine being this delusional

>>10329466
>It is a known fact that SpaceX is not making profits on its privat launches.
>t. Has no sources because none of this information is available

>>10329470
>the iq level of musk fanboys

F9 weighs 500tons its a whole rocket not tiny upper stage even the paper bfr booster can't lift that much.

>>10329470
>>10329475
You mean an entire Falcon 9 S2 right? This is similar to my kickstage idea, maybe a Raptor derived 3rd stage or one using a modified Super-Draco would be better, the Raptor design providing more ISP and the Draco design being much more cost-effective due to simplicity and 3D printing.

>>10329470
There is no point in doing interplanetary travel like SpaceX proposes anyways. The BFR will be configured to land on earth, and with that configuration it won't be able to land on Mars. The fins that are supposed to have air authority will do so on earth, but they do nothing in the much thinner mars atmosphere. The ship will be impossible to control there. Generally, it is also quite pointless to have such a gigantic ship as the landing vehicle, as the ascent will also be very difficult and costly in fuel. It makes much, much more sense to assemble an orbit-orbit taxi in space than what SpaceX wants to do.

>>10329509
Of all the proposed architectures for interplanetary travel, with an eye towards Elon's colonization purposes, SpaceX's method is the only way to go. Starship's hybrid of brakerons and 25 ton RCS thrusters will work fine.

>>10329475
Starship is already 1250+ tons fully fueled.
>>10329492
No, I was just pointing out a silly alternative use of the super heavy's lift capacity. Wasting it for a single small expendable upper stage seemed ridiculous.
There is no reason why refueling won't work. If something magical prohibits it from working for the Starship then the same will apply to space stations, depots, meme neil cylinders and everything else proposed. That would imply some universal law exists which essentially means "nofun allowed in space". Really, the idea that refueling doesn't work is just lazy.

>>10329509
orbit-orbit taxi is a fundamentally stupid idea when both your origin and destination have an atmosphere useful for aerobraking

>>10329515
if refueling won't work for Starship then it won't work for the ISS
wait, it already has, for fifteen years

>>10329509
>The BFR will be configured to land on earth, and with that configuration it won't be able to land on Mars. The fins that are supposed to have air authority will do so on earth, but they do nothing in the much thinner mars atmosphere.

What is RCS?

>>10329509
>The fins that are supposed to have air authority will do so on earth, but they do nothing in the much thinner mars atmosphere.

Pulled that one out of your ass. SpaceX showed a simulation of BFS landing on Mars, so it is obviously designed to do just that.

Video from yesterday

https://www.youtube.com/watch?v=i3-L01yOQy8

>>10329509
>>The fins that are supposed to have air authority will do so on earth, but they do nothing in the much thinner mars atmosphere.
wait Mars is like the Moon with ~0 atmo drag ??? Someone call NASA and tell them to not use heatshields on the 2020 rover.....
>>The ship will be impossible to control there
Send SpaceX a copy of KSP with realism mods so they can test Mars landing..... I guess a physics simulator is too expensive...
>>the ascent will also be very difficult and costly in fuel
The ship is a SSTO on Mars with a full tank

>>10329509
Completely wrong. The aero surfaces have nothing to do with the ability to land and their main use even on Earth will be in the thin upper parts of the atmosphere. If "aero control" is insufficient RCS exists and coincidentally has to be used generously on Earth too. It might seem wasteful to have a gigantic ship as landing vehicle, but if it is cheaper, easier, and actually works unlike using some unrealistic "optimal design" tincan then it is the way to go.

>>10329535
>The ship is a SSTO on Mars with a full tank

Not just a SSTO, it is a SS to Earth.

>>10329517
>inb4 it was never used for cryogenic fuel
Yes, I've been told that.

>>10329537
Not to mention that you need to have a "gigantic ship" anyway if you intend to establish a Mars colony instead of a mere flag and footprints mission. Cannot do that with small tin cans.

>>10329520
The U2 spyplane flew regularly in thinner air than Mars atmosphere, for hours. It will work.

>>10329538
Terribly inefficient. So many lost opportunities for various contractors to build the needed separate vehicles for each step. How can anyone support such wasteful idea?

>>10329538
my bad you are 100% correct

>>10329540
Yes. A lot of people often miss how the Starship is essentially a very large surface base once landed that would otherwise take years to build out of tincans.

>>10329546
This makes me think whether SpaceX will choose to expend a number of Starships to help kickstart the colony, by leaving them on Mars permanently and converting their tanks to pressurized habitats. 5000+ cubic meters of habitable volume.

>>10329520
>>10329535
Wow, they ran a simulation!

Maybe they should ask the russians how hard it is to land something on Mars

>>10329518
RCS won't help you much if you missed the landing field by a couple of hundred metres.

>>10329540
No, if Mars is suitable to be self-sufficient, it should be able to grow from a relatively small base, for which you don't need gigantic payloads. If it can't do that, colonization is pointless, anyways.

>>10329464
>so I've suggested
You are?

>>10329561
Maybe you should substantiate your bullshit if you want to be taken seriously, retard. Right now we know that Starship is being designed to land on both Earth and Mars and that is a fact.

>>10329330
There are better fuels, I don't know what the LH anon is going on about. You'd need a number of newer techs for that to work properly.

>>10329561
>if Mars is suitable to be self-sufficient, it should be able to grow from a relatively small base

Nope, it takes a large industrial base for Mars to become self-sufficient. Cannot do that with tin cans only.

>>10329567
It can be "designed to" fly to the center of the Milky Way, doesn't mean it will capable to do that. With the fins that are optimized for earth atmosphere it won't be able to land on Mars, period.

>>10329569
That's not how it works. If you need a large industrial base to mine ressources, you won't be able to mine enough ressources to keep the industrial base alive. If it can't do it small scale, it won't be doing it large scale at all.

>>10329568
I wonder if higher hydrocarbons such as ethane or propane would be a better choice than methane? Higher density may trump lower isp.

>>10329574
This notion that it cannot be done is is just pure speculation on your part. I think it is safe to say that any Mars colony must be rather large to be self-sustaining and actually capable of growing on its own. Again, it is not possible with a handful of small tin cans. Hence why Elon is all about landing lots of large and heavy payloads on Mars, not optimizing away every kilogram.

>>10329578
You might as well just go with kerosene at this point, methane isn't much different than RP-1, anyways.

>>10329559
Probably. It is highly doubtful that the first cargo versions landed on Mars will ever return so they are prime candidates for repurposing. Now even easier when they are made out of steel.

>>10329589
That's basic economics. If you need 10 tons of iron to mine 9 tons, you aren't going to be self-sufficient. This is what you are asking for, and it won't work.

>>10329590
No kerosene on Mars or anywhere else in space, so that is a non-starter. On the other hand, one can imagine that propane can be synthetised from Martian-made methane..

>>10329593
No, it is speculation on your part. Economies of scale enter into consideration, too, especially in a hostile environment of Mars. Maybe you need 10 tons of stuff to mine 9 tons of iron, but only 100 tons of equipment to mine a thousand tons of iron.

>>10329578
Methane is the simplest to make after Hydrogen. Not a factor if you are building a LEO ferry, but if it's expected to go further out and take part in more daring missions that make use of local resources...
CO is easy too but that could be deadly under certain conditions.

>>10329599
Ressource mining has nothing to do with economies of scale. Either there are easily mineable ressource deposits on Mars, or there aren't. It won't help you much setting up a giant industrial base if the ressources you are mining aren't covering the cost. If that was different, every country in the world would mass-export ressources.

>>10329578
Btw density is not that much of an issue once your volume grows sufficiently ie your rocket gets big enough, even reentry gets easier the fluffier you are. I'd prefer hydrogen over the methane if it didn't have issues other than density. Super dense fuels make the vehicle small and heavy so upper atmosphere can't slow it down before dipping into the lower parts where heating is much higher. STS integrated with the ET would have been an interesting animal to see.

>>10329595
Kerosene is a mixture of hydrocarbons and you can synthesize every hydrocarbon on Mars.

>>10329603
>If that was different, every country in the world would mass-export ressources.

Cost of extracting a resource is a very relative thing. There are indeed huge amounts of resource deposits on Earth that are not tapped simply because you have easier to extract ores elsewhere.

>Either there are easily mineable ressource deposits on Mars, or there aren't.

No, whether they can be extracted may very much depend on what kind of an industrial base you have.

>>10329609
Kerosene is used only because it comes from oil. We may use higher hydrocarbons as fuel on Mars, but it will not be kerosene.

>>10329613
You just don't seem to understand. If you can't find enough ressources to keep five habitats and a greenhouse alive, you sure as fuck won't find enough ressources to keep a whole city alive.

You can also maybe understand it that way: The average american consumes much, much more energy and ressources than the average african tribesman.

>>10329561
>>Maybe they should ask the russians how hard it is to land something on Mars
Maybe they should ask NASA how hard it is to land something on Mars

>>10329622
No, you dont seem to understand. Surviving on Mars is an inherently high-tech, energy and resources intensive task. Low tech survival (in essence, your african tribesman) is not an option. It will be an American lifestyle (metaphorically speaking, meaning energy, tech and resource intensive) or bust.

Now answer this: which society is more likely to sustainably support an "American lifestyle"? A society comprised of a handful of tin cans? Or an entire industrialized city on Mars?

The answer is obviously the second one. First one is a non-starter, both on Earth and on Mars.

Economies of scale will be crucial to establishing a self-sustaining base on Mars.

>>10329578
I was thinking about researching denser nitrogen based fuels. You can use them to enrich other fuels like methane too.

McGregor, Texas is about to receive a special delivery...

>>10329622
>The average american consumes much, much more energy and ressources than the average african tribesman.

And it is a result of having entire modern industrial civilization behind him. Same thing must be replicated on Mars for it to truly become self-sustaining.

>>10329640
Cool. Raptor was due to be test fired in February, it is about time.

https://twitter.com/elonmusk/status/1081572521105707009

To the muskfags
name literally one (1) reason why we should go to mars aside from "to make muh sci-fi fantasy real"

>>10329644
One is apparently being transported on a truck, accompanied by an M1D.

>>10329641
The average US citizen consumes twice as much energy as the average EU citizen.

>>10329640
>>10329644
Finally. Certain BO fellow will have to eat his words.

>>10329668
>tfw only 70% face

https://twitter.com/jeff_foust/status/1088088915771342848

>>10329635
It's not about the living standard or high tech. Obviously, you can take small high-tech facilities for in sitru production with you. But if there aren't enough ressources there for 5 people, there aren't enough for 500.000. Really not a hard concept to grasp.

>>10329650
As a practice before Earth becomes inhospitable to life due to runaway global warming.

STOP DOING ROCKETS AHHHHHHHHHHHHHHH

>>10329655
Average Mars citizen will consume even more.

>>10329681
what resources?

>>10329681
Mars has more than enough resources. The question is: can we extract them? Well, we certainly cannot with a bucket and a shovel. You need a whole mining industry for it.

>>10329695
You literally can extract ressources with a bucket and a shovel you absolute mong. That's the whole point. If you are going to need much beyond that, it will not be economical to do it anyways.

>>10329702
>You literally can extract ressources with a bucket and a shovel you absolute mong.

Not on a scale required for a Mars base.

sure is bait in here

>>10329693
Are you implying that Americans consume so many resources because the US is a Mars tier shithole?

>>10329702
the absolute delusion lmao
"bruh, just mine iron with your pickaxe and build stuff from it, it's just like Minecraft"
>>10329715
>>10329692
the redditor with the same fucking image appears

>>10329713
Because of the lower gravity, we can use much bigger buckets. And because of the thin atmosphere too, we can wield much wider shovels.

Economies of scale.

>>10329745
you can mine anything on any scale

>>10329750

>>10329745
This is literally how the whole humanity did it up until 200 years ago.

>>10329320
>If you commit to something you actually spend money on it
Maybe you do

>>10329905
SpaceX definitely does. This isn't a marginal project.

>>10329918
>marginal project.
That's exactly what it is. There is no machinery and no factory bought for it because they are not really going for stainless steel (yet). At the end of the day, I can understand it. This costs only a few million probably and worst case scenario is they go back to their old plans, best case they revolutionize space industry.

>>10327005
We turn of the century shipbuilding now

>>10329899
But you cannot live on Mars like it is 200 years ago.

>>10329936
You might be right, but they'll have already put a sizeable part of their logistics towards this project. A marginal project is usually without too many hard deadlines and using materials and equipment that's mostly already to hand or in place, otherwise it starts costing significant overheads on its own.

>>10329713
>>10329695
Yes, to begin with. Although it'd make a lot more sense to use a 1 ton skidsteer to speed things up. A single one of those can easily move a thousand tons of material in just a few hours, more than enough to keep up with any industrial process we'd realistically be setting up on Mars. That includes water extraction from crushed permafrost dirt, sulfur extraction from minerals to use later as a concrete-analog binder, iron ore smelting, processing of basaltic rock into rock wool insulation, etc.

Guys with shovels would be driving around in long distance rovers to prospect for useful mineral deposits and grabbing samples. Small machinery would be used for actual digging and transport.

>>10330070
Glad someone gets the explore-exploit tradeoff among other things.

>>10326948
That's spin-forming, not casting

>>10327785
F1 also ran fuel through cooling channels, the exhaust from the gas generator was dumped into the engine as a means of reducing the length of nozzle that they had to use cooling channels on. Merlin 1D Vac also uses this same method of dumping the turbopump exhaust into the nozzle.

>>10329425
Liquid methane is much easier to handle than LOx, far less explosively flammable

>>10329373
Liquid Hydrogen
>is 70kg per cubic meter
>boils at -252.9 C
>embrittles most metals
These attributes combined makes it very hard to produce a high power hydrolox engine. Due to its low density, a huge volume of hydrogen must be pumped per second to achieve the same mass flow rate as an engine that uses denser fuel, directly impacting thrust and thrust to weight ratio. Due to its low boiling point, hydrogen cavitates very easily and requires extra head pressure as well as much larger impellers with a lower pitch in order to pump it at the required mass flow rate, beyond the size increase necessitated by its low density. Since hydrogen embrittles most metals the alloys chosen for the engine hardware are usually not the best compared to other alloys that can be used in a non-hydrogen fueled rocket, leading to a further decrease in thrust to weight ratio. Hydrogen-oxygen does offer the best specific impulse of any practical propellant combination but it is better suited for upper stages where Isp is more important than thrust to weight ratio.

Liquid methane
>is 424 kg per cubic meter
>boils at -161.5 C
>neither embrittles alloys nor cokes up the engine
Liquid methane is very close in temperature to liquid oxygen. Unlike kerosene (RP-1) It does not gel up when it is chilled close to its freezing point, and at that temperature it is nearly as dense as kerosene. Since methane does not produce carbon deposits when it is partially burned it can be used in all three types of staged combustion engine, including most notably full flow staged combustion, the best performing engine cycle. Because of methane's higher density compared to hydrogen it requires a smaller pump to achieve the same mass flow rate, and because of its higher boiling point (bonus if sub-cooled methane is being used) much less head pressure is required to feed the pump without cavitation. Methane does also offer significantly higher Isp than RP-1, in fact it is the second most efficient fuel.

>>10329399
>combustion products are water
Water and CO2. Methane contains more energy than kerosene per kg because it doesn't have any carbon-carbon bonds, only carbon-hydrogen, and furthermore when densified by being chilled close to its frezing point methane contains more energy per liter than kerosene as well.

>>10329442
>However, for all that power, the specific impulse and dry mass of Starship give it limited to no capacity to directly send payloads beyond Low Earth Orbit.
This is actually because Starship needs to be able to come back, and thus needs to keep a lot of delta V in reserve, not because it doesn't have the delta V to send things on a one way trip. If NASA were willing to pay the extra $200 million to outright buy a Cargo Starship they'd be able to do as much as SLS one-way to Jupiter, which would still be a bargain price.

>>10329578
Rather than go for a heavier molecule it makes more sense to densify your light fuels with sub-cooling. SpaceX is doing this with their oxygen and kerosene on Falcon rockets already, and they're going to do it on BFR too. Kerosene isn't that good for densifying because it starts to gel up long before it freezes, methane however doesn't do that at all and remains totally liquid until it reaches its freezing point, and just before that point its energy density per liter is actually very close to kerosene's, yet the efficiency increase of ~20 Isp remains. It's the best of both worlds.

>>10329593
>If you need 10 tons of iron to mine 9 tons, you aren't going to be self-sufficient.
Duh retard, you don't use up 10 tons of iron to mine nine tons, you use ten tons of equipment to mine 9 tons of iron per hour continuously. A one ton digger could supply a small foundry with enough iron ore to pump out hundreds of tons of steel a week if the energy supply was there.

>>10330158
well what about ethane or propane? wouldnt that be like methane but even more energy dense?

>>10329609
Requires extra steps and extra input energy for no actual benefit, since it reduces Isp and only increases density by a few percent, something that can be gained by simply sub-cooling your methane instead.

>>10329641
>Same thing must be replicated on Mars for it to truly become self-sustaining.
Yes but until then they'll still have the entire industrial base of Earth to rely on. Mars colony citizens could live the exact same lifestyle as Americans with far less resource draw simply by not producing and using disposable products. A shitload of energy and materials used by people on Earth are things that were made to be thrown away.

>>10330171
If densified, only more energy dense per liter. Specific energy (energy per kilogram) of methane is the highest for any hydrocarbon. Again, if you're getting almost the same density as kerosene, for better specific energy and higher specific impulse, you're getting the best performance anyway. Also methane requires the least input energy to produce from CO2 and water, everything else requires extra steps in order to join the carbons together into longer chains.

>>10326666
The idea of paying scientists isn't that they direct what's done, it's that you're paying them to get done what you want. That's why they are supposed to be so useful. All you need is good refence material otherwise, a scientist who's only skill was that he memorized shit shouldn't even be allowed to call himself one.
In the apollo 13 movie, if the events of the film are true, those situations (and what Elon is trying to do) are what they are good for.

>>10326685
White people will research, design, and make effective, space travel.
Then white people will get banned from space as space oppressors, and there will be affirmative action making it much more difficult for a white person (also asian) to actually 'go into' space, so that black people can be called the pioneers of space.
Prove me wrong.

>>10325407
I think it is just a fad that will soon blow over.

>>10330459
I hope somebody takes the wind out of your sales.

>>10329332
>Russia
>not being able to make good engines

After seeing Musk's ridiculous "Loop" presentation and seeing how retarded electric vehicle concept is, I can only assume this will be a massive dud. I am however much more excited about the New Glenn which might be useful for establishing a Venus colony (Mars colonies are retarded, although Mars is an interesting scientific destination, albeit one that can be easily explored with sterile robotics).

I also question the business model, sure they'll have Falcon 9s sending crews up to the ISS for another decade, and their usual other business, but is Elon expecting the size of payloads to increase (when they are generally getting smaller) or is he just going to go broke trying to get to Mars?

>>10330655
>Venus colony (Mars colonies are retarded
absolutely discarded

>>10330664
would you rather live in Cloud City or fucking Antarctica + radiation?

>>10329373
in-situ resource utilization

>>10328412

>>10330666
"Cloud City" offers no resources of value and has a gravity well too deep to leave without a big rocket.

>>10330655
Is this bait or are you actually this retarded?

>>10330666
yes guys let's go to BURNING CRUSHING ACID HELLSCAPE and mine some suffering or something

>>10330682
Mars doesn't have any valuable resources you can't get easier elsewhere. We aren't going to these other planets for resources, we are going for exploration and settlement. Venus has acceptable gravity, radiation protection and temperature in the upper atmosphere. Mars would be a terrible place to live.

>>10330691
looks like someone needs to read the case for mars

>>10330691
It's not about the value of economic return to Earth, its about being physically capable of self-support.

>>10330690
this

going to Venus would be scary. If your airship fails, you fall into a cloud of poisonous, super-hot gas. Not only is your outside atmosphere hostile, but you are supported by an airship which is going to require maintenance. At least you can rely on the ground on Mars.

>>10330691
>We aren't going to these other planets for resources, we are going for exploration and settlement
You need resources to explore and settle a place, dumbass

>>10330710
with Mars you don't even have a reliable source of power. It's twice the distance from the sun as Venus is, so solar is 4x shittier not accounting for Martian nights and months-long dust storms. Imagine being stuck in a metal bucket when it's 200 degrees below zero outside and there's a 4 month dust storm -- sound like fun? Nuclear is possible but has many issues and may require further development, while solar panels are easy and inherently safe. On Venus you can have solar power 100% of the time as your floating habitation moves at 5 mph to stay in the sun using a propeller. And if the floating habitation fails? Get in your ascent vehicle and shoot back into space to link up with the orbiting habitat. With modern materials something like that is unlikely to happen.

>>10330710
>>10330711
>>10330695
oh and enjoy your radiation and the fact you can't even carry a child to term in 1/3 gravity. Great place for a colony guys! Our future lies in a cold dusty wasteland that looks like a nuclear hellscape

both marsfags and venusfags are retarded. space exploration has no intrinsic economic value right now, and won't have for at least several hundreds of years

*CRINKLE*
*CRINKLE*

>>10330828
>On Venus you can have solar power 100% of the time as your floating habitation moves at 5 mph to stay in the sun using a propeller.
Venus' atmosphere super-rotates around the planet meaning your habitat actually needs to move at 100 meters per second to stay in sunlight constantly, otherwise you're going to get 48 hours of sunlight followed by 48 hours of darkness.
>And if the floating habitation fails? Get in your ascent vehicle and shoot back into space to link up with the orbiting habitat.
Yeah, just do that with your entire fucking colony population retard.

>>10330842
bait

>>10330828
Scott Manley calculated wind power on Mars would produce 40% as much electricity as a turbine in Houston. Not great, but better than you might think (it's because of atmospheric composition, despite the air being thinner). It is available particularly during dust storms and is comparable to the output of solar panels on Mars.

>>10330842
>you can't even carry a child to term in 1/3 gravity

citation needed

>>10330859
>Yeah, just do that with your entire fucking colony population retard.
by the time you have a proper colony you will have multiple pods so any catastrophic flaw with one will be fixed by disconnecting it after evacuating the people. This isn't complicated.

>>10330842
>you can't even carry a child to term in 1/3 gravity
Can't do it in Venus' 0.9 G either

>>10330896
>>10330842
I don't think gravity is going to matter that much for pregnancy, the foetus is buoyant in a fluid.

>>10330882
>This isn't complicated.
t.retard

>>10330900
>foetus

>>10330907
Having trouble with things not being spelled how they sound anon?

>>10329650
Earth has an average IQ of 86. Mars will have the average IQ of astronauts. For humanity to have any chance of a bright future, we will need a smarter planet.

>>10330994
just go to Antarctica then retard
how can people be so fucking delusional and think all problems get solved if they suddenly go live in a barren wasteland dependant on earth

>>10331001
>just go to Antarctica then retard
Antarctica is under the provision of treaties of the governments that exist over the whole of the Earth. True freedom from other men only exists in the great expanse of space.

>>10331013
Mars would literally be more dependent on earth than any place on earth you absolute mongoloid
one "missed" delivery and you're absolutely fucked lmao

>>10326891

You should have fought it. In the US at least amateur rocketry is a protected hobby and the ATF and DOT have been ordered to stuff it by the courts. Rocket propellants are officially and legally not a explosives, and you don't need hazmat shit to transport them on public roads within your state. If transporting across state lines you can park before the state boarder, walk them across and put them back in the car on the other side.

That said some municipalities can still get after you under the fire code (*NFPA). You can always join NAR, TRA or fly under supervision of someone with fireworks exhibition license if your area bans unlicensed launches under the fire codes.

Cops don't know this area of law and most people are too stupid to learn it or get competent legal counsel with expertise in the subject. NRA and TRA both come with access to lawyers and a million dollars of insurance.

*NFPA is a company that wrights expensive books, they come out with a new edition each year just like text book companies so they can force . They are not a government entity, some municipalities choose to adopt NFPA bullshit because they are a bunch of faggots who should be strung up on the day of the rope.*

>>10331020
>one
Only with the world's worst logistics and planning.

Obviously no colony in space is free without independence from Earth-based terrestrial resupply. On Venus, the timeline for achieving that independence is "forever." On Mars, its "eventually."

STOP BUILDING ROCKETS REEEEEEEEEEEEEEEEEEEEEEEEEEE

>>10331037
>if we make literally sci-fi reality then mars can be independent
lmao, you do understand that earth will still have power over mars in your little scenario since Mars is a fucking radioactive wasteland and earth is, well, earth?
it's like saying "one day the Australian bushmen will be truly independent from American oppression and will be able to fight off an American invasion"

>>10331052
wew lad. Mars is going to be built by the best and brightest, not IQ of 60 or less Abbos.

>>10331056
>Mars is going to be built by the best and brightest
Quick IQ test: do you want to go do something where you'll likely die, if you don't die you'll lose your liberty, and you won't get support from or to see your loved ones ever again?

>>10331056
>I don't understand what an analogy is

>>10327782
How else are you gonna pour the fuel in, dumbass?

>>10331083
Your premise remains fundamentally flawed. It's like you don't know what the first priorities of any Mars base must be.

>>10331092
enlighten me anon

>>10331099
>enlighten me anon
ISRU. It is completely unsustainable to require perpetual terrestrial resupply from the Earth.

>>10331112
isru (which doesn't even exist yet) isn't a magical device which creates civilisations out of nothing and absolves planets from earthly influence retard

>>10331112
>>10331127
or in other words, in terms of my analogy
"the bushmen learned how to farm and make fire, they are truly free from American oppression now!"

>>10331132
Yes, because we all know that as soon as its possible to run an open flame and grow crops that Mars colonists will declare independence. /s

>>10331127
>isru (which doesn't even exist yet) isn't a magical device which creates civilisations out of nothing
>he typed on his computer made from resources mined and refined and manufactured into products in situ

>>10331148
You've either argued against yourself or made an argument so crazy it doesn't make sense.

>>10331148
>I like to broaden definitions despite clearly understanding what is meant by isru in terms of space exploration to sound smart
>>10331142
>retard doesn't understand analogy for the third time
it's like playing catch-up as a snail with a human. earth in its worst state is always going to be more hospitable and a better place to live than mars, and this is under the assumption that martians will somehow delete human societal patterns and form a perfect society. earth will always be miles ahead in terms of resources and technology in contrast to mars. I'm sorry to tell you anon, but you watched too much the expanse

>>10331159
Literally never watched The Expanse. Realistically, resources are not everything. You should know by now that Political Will and Morale come first, and resources are second.

>>10331127
>isru (which doesn't even exist yet)
what

>>10331460
You think it exists?

>>10329371
Or.....the DoD uses SpaceX to launch their classified shit into orbit instead of Russian launchers because classified shit and all.

>>10331460
>what
In-Situ Resource Utilization.

>>10331469
of course it exists. what are you on about?

>>10330868
Literally nonsense mate, mars atmosphere is 2% of earths, you can’t produce power from that
Wind power on Venus on the other hand, has lots of potential

>>10327355
The rocket here isn't, but skyscraper steel certainly should be and the man who designed the WTC designed them with a commercial jet crashing into them in mind and wrote about how it would easily handle such an event.

>>10327754
Will final version be like this? I know this is the fake version of the rocket but don't forget to fix this in the real version please.

>>10331565
2% the density, 20x faster on average.

>>10331577
Final legs have a sort of steel collar/band welded on all the way around that hides that, it's on the other legs.

>>10326378
Elon Musk's God powers defy laws of physics.

>>10331565
>2% density
>300mph wind speed

>>10325407
>/sci/'s thoughts on Starship Hopper
It's an ugly piece of shit.

>>10330994
space for the spacenoids
Sieg Zeon

The BFS is supposed to do mainly beyond Earth missions. Elon talks about that steel can tolerate temperature up to 1500°C. However, the reentry heat from lunar, mars, asteroids, or other beyond earth transfers is >2900°C. Stainless steel will not survive this. So either the BFS is not going to fly beyond LEO, or it is not going to be reusable.

Generally speaking, it is extremely hard to imagine how an interplanetary/lunar spaceship is supposed to be reusable. The space shuttle thermal tiles are pretty much the closest thing we have to alien-magic-technology. There is a video on youtube where a cube of the tile material is put on an oven for several hours, and just seconds after being taken out you can pick the red glowing cube up on the corners without any problems. It just came out of an oven that is >1200°C hot and you can just pick it up. That's insane.

https://www.youtube.com/watch?v=Pp9Yax8UNoM

And the thing is, not even these super-tiles would be able to survive lunar or mars reentry. There is absoluetely nothing that can survive that. The only way to go is putting a thick ablative heat shield on it, which however is the opposite of reusable, and for a ship the size of the BFS would also considerably cut into payload capabilities (e.g. the heat shield will certainly weigh a lot)

>>10332049
>The BFS is supposed to do mainly beyond Earth missions. Elon talks about that steel can tolerate temperature up to 1500°C. However, the reentry heat from lunar, mars, asteroids, or other beyond earth transfers is >2900°C

Guess it's a good thing that the primary heatshield is an interstitial layer of fuel that flows out of the underside of the vehicle, creating a thermal barrier.

>>10331756
you and everybody else mate lol
>>10332049
active cooling on the shield, the high temp steel can reach just means they have more wiggle room in their cooling design, as compared to carbon composites which will delaminate or whatever at a couple hundred C and aluminum which turns into a puddle at 600 C

>>10332057
This is supposed to be open-cycle, e.g. the liquid gets sweaten out and is then lost. The amount of liquid you would need to keep the ship cool from 2900°C for the duration of the reentry would be way more than a BFS can carry.

If it was closed-cycle/regenerative (e.g. the same way you cool a nozzle), then there wouldn't be enough time for the liquid to cool down enough, so that is also not possible.

>>10332066

>>10330859
>as your floating habitation moves at 5 mph to stay in the sun using a propeller

it has to travel 5mph over the surface to maintain position relative to the terminator, but the winds at the habitable altitudes are 120+mph

>>10332066
>This is supposed to be open-cycle, e.g. the liquid gets sweaten out and is then lost. The amount of liquid you would need to keep the ship cool from 2900°C for the duration of the reentry would be way more than a BFS can carry.

The propellant they're dumping overboard to keep the vehicle cool is estimated to be about 10 metric tons of methane. With (very roughly) about 840 square meters of reentry surface area at the base of the Starship, compared to the ~517 square meters of surface protected by Reinforced Carbon Carbon and High-temperature reusable surface insulation tiles (and a total surface area of 1105 square meters), there's a lot of surface that needs to be protected. The Shuttle's thermal protection system, which involves about 40% less surface area than the Starship, ultimately massed 8,574 kilograms, while being limited to reentry from Low Earth Orbit. If SpaceX keeps the fuel purge for vehicle reentry cooling below 12 tons, they save mass over the Shuttle's thermal protection system.

>>10332074
Not him, but the burden of proof is on you that such a system can work.
It has never been done before there have been 0 prototypes or test for this magic system. At this point it's just another meme claim by Musk he has to demonstrate that it's possible.
Lmao oldspace heatshield lets just use this approach that nobody has ever tried I am sure this won't cost 500 million dollars to develop. lmao oldspace take that NASA 420 pedo lmao ai kek mars kek hyperloop kek

>>10331272
but a nice environment is
which mars doesn't have

>>10332079
no, the burden of proof is on SpaceX, and they won't tell me their numbers, so I'm going to grab a bag of popcorn and hope one of them blows up

>>10332079
>It has never been done before there have been 0 prototypes or test for this magic system.
lmao it's literally the technology that has been used to protect rocket engines, like the Rocketdyne F-1, from being destroyed by their own exhaust.

>>10332085
the injection method is different but the principle is the same on the F1

>>10332066
Based on what you said, Hopper isnt going to mars...the target is the moon. Unless there is some revolutionary metal that can do this by the time musk actually plans to go mars which can take the heat then its pointless.
Granted i think the whole idea of a rocket with 4 people stock inside a small cavity for 8 months without any additional modules accompanying them like cycler attached is down right retarded(like lets put a metal tube in winding caves to rescue those football boys retarded)
The second something breaks or there is an oxygen leak half way to mars , mars missions are dead in the water for years

>>10332078
12 tons to cool almost 1000m2 from 2900°C, sure thing buddy.

omg just report this dude

>>10332095
b-but muh engines are cooled like that too!

>>10332098
STOP CRITICISING MUSK HE IS SAVING HUMANITY

>>10325407
Does stainless steel become extraordinary when cooled to a really cold temperature?

>>10332095
>12 tons to cool almost 1000m2 from 2900°C, sure thing buddy.
>cool from
>implying it ever reaches 2900 degrees celsius to begin with

>>10332099
Where will you be when spacehopper fails spectacularly?

>>10332093
The reentry heat from mars and moon is approx the same, mars is a bit hotter but not by much. I actually think Elon doesn't plan to make it reusable. Elon always goes to where the government money is, so his real plan probably is to say "look, whatever you want to do with the SLS, I can do it for much less" and that's it. This would also fit why he wants to go for super-cheap stainless steel, he wants to make a super-cheap expandable rocket. It's also the same thing they did with the Falcon 9, really. They marketed it as a reusable rocket, but all design decisions went towards making the building cost as low as possible (e.g. produce a very cheap expendable rocket).

>>10332102
some types of stainless don't become very brittle when cooled, which is basically magic, yes
>>10332104
he's not here to have a conversation, he's just having a stroke, so report him

>>10332108
Boy, he sure is dumb for making all those revisions to his expendable rockets to make them be easier to reuse when his real goal is to milk those sweet government expendable vehicle launch contracts.

Any news on the engine testing?

>>10332082
Nice environment is literally detrimenal. It is why Africans cannot for a functional society while barely hospitable nordic countries thrive. Humans need adversity or they degenerate. And that is why in the long term, Mars colony society will be superior to anything on Earth.

>>10325407

Look, sorry if I am being a wet towel here, I hate to spoil the fun, but can anyone fill me in on where this meme has come from?

I keep seeing this playground toy "space hopper" being posted all the time. I know lots of people on /sci/ are trolls or a bit retarded, but honestly, all joking aside, no one with a brain thinks this is for real.

So hasn't the trolling of the idiots gone on long enough? I just dont see anything funny about this anymore.

>>10332131
>Implying Earth governments won't enforce diversity quotas and administrative oversight

>>10332109
>it doesn't get brittle
So then that means it is possible to take advantage of a density increase from cooling the steel just the right amount, similar to how if you heat steel just the right amount it will be stronger than if you cool it to a slightly lower or higher temperature (density anomaly).
I am wondering if similar anomalies exist as you cool toward absolute zero, where you get a 'spike' increase or decrease in density in comparison to the otherwise gradual change. It not being brittle means it is an even better idea.
I mean if you made steel into a bose einstein condensate state it'd probably be super duper strong as long as it wasn't brittle, as you say. But maybe if you spend less energy and just cool it a lot but not all the way to BEC, it will still be usefully stronger.

>>10332131
>anon tries to disprove anthropology and history of human societies in two sentences
Nordic countries were literally Africa-tier shitholes until 400-600 years ago.
Why am I even arguing with you, you're too retarded to understand why mars won't be in any way superior to earth because of simple extreme environmental factors. it's like researchers on Antarctica (but with an environment 400 times worse and several million kilometers away) trying to revolt against the rest of the earth

>>10332133
I like that you think it looks unreal, that's why I said I want some of the steel at the start of the thread. I could (probably have to get licenses because freedom) try and super cool it to a bose einstein condensate and test if its impenetrable.

>>10332141

*sigh*

>>10332049
Shuttle tiles were optimized for weight saving and this caused them to be incredibly
>expensive
>brittle
>hygroscopic - they could absorb water like a sponge and upon heating exploded like concrete under thermite
STS never leaving LEO meant all its elements' capabilities were designed with that in mind, including the heatshield. There are many options for reentry heat protection outside of ablative materials or "tiles". Active heatshield alone has so many variants they are essentially different things.

>>10332114
It's not like the scheme isn't working. SpaceX is incredibely highly valued for such a small company, because it's "le reusable rocket company", when in reality 95% of their launches are expendables just like everbody else's.

>>10332085
>It can cool an engine so it can cool a vehicle during reentry.
Literally kys you retarded brainlet, stop making leaps and use your brain.

>>10332216
>when in reality 95% of their launches are expendables just like everbody else's.

Wrong, 15 out of their 21 launches in 2018 were with landing.

>>10332236
Landing =/= reusing

>>10332242
11 out of 21 were reused (and a partial reuse for Heavy)

>>10332057
>creating a thermal barrier.
That is not a mechanism at play in this. There are only 3 ways that heat travels: conduction, convection, radiation. In a low pressure/vacuum environment the first two are practically non existent, the primary mode is radiation. Adding more fluid earlier on in reeentry will increase the other two modes.

>>10332298
The primary mechanism of reentry heating is atmospheric compression. The highest intensity zone of heating is localized a distance away from the entering body, with a slightly cooler zone in actual contact with the reentry vehicle. Filling that gap with onboard coolant will conduct some of that heat away from the spacecraft, reducing the thermal load on the structure. The high reflectivity of the stainless steel helps prevent radiation from having as much of an effect.

>>10331552
Who/what has used ISRU?

>>10332331
>The highest intensity zone of heating
You are using shitty terminology bud.

>will conduct some of that heat away from the spacecraft
That makes no sense. They're hoping to use a phase change to cool, but that aside heat would still conduct from where it's hotter to where it's colder.
>The high reflectivity of the stainless steel helps prevent radiation from having as much of an effect.
Stainless steel isn't that reflective, it may LOOK that way, but it absorbs a lot of radiation. You've also got to consider what having a layer of liquid methane will do, might be better or worse, I don't know. I doubt they do.

>>10332367
>I don't know. I doubt they do.

That's the problem, your assuming that some of the brightest aerospace engineers in the country don't know what they're doing just because you don't.

>>10332367
>You are using shitty terminology bud.
Its 4 in the damn morning and I've been up all night.

>That makes no sense. They're hoping to use a phase change to cool, but that aside heat would still conduct from where it's hotter to where it's colder.

It's not phase change cooling. They're sinking the heat into a high heat capacity fluid, the propellant, that is unceremoniously dumped out of the ship.

>Stainless steel isn't that reflective, it may LOOK that way, but it absorbs a lot of radiation.

It does both. High reflectivity surfaces have very poor emissitivity.

>You've also got to consider what having a layer of liquid methane will do, might be better or worse, I don't know. I doubt they do.

Far be it from me to second guess the actual engineers, Anon; neither should you.

>>10330640
They stopped making good ones decades ago.

>>10332408
There's a difference between develop and build; Russia still build good engines but haven't developed a good one since the 1980s, if you count the RD-180/191 not as different engines but just variations of the RD-170.

>>10332405
>High reflectivity surfaces have very poor emissitivity.
It's almost like they're the inverse of each other. Buddy, you don't know what you're talking about unfortunately, I'm just going to clear up a couple of bits tho. Musk wants the cryofluid to act literally like sweat, it evaporates at very low temperatures at normal pressure and will generally be at sub atmospheric pressures on the way down. It will definitely be evaporating in this scenario. However, this will increase heat transmission, much like how sticking your hand into the steam from boiling water will burn like fuck unlike sticking your hand above very hot but not boiling water. It may work well, or it may lead to something that works well, but the idea that the cryofluid will somehow push the heat away is nonsense.

>>10332394
>can't even tie down a nosecone or build it FUCKING INSIDE
yeah I'm sure they're very bright lmao
>inb4 this isn't the engineers fault
but it speaks very much of the state of the company

>>10332548
Your seem to be under the impression that the hopper was built solely by SpaceX, when in fact the majority of it's exterior has been built by Caldwell, a water tank company. It's currently unknown how involved the SpaceX staff are with the hopper's construction, are they just ordering the subcontractors around? Are they only working on the craft's internals? We can't play the blame game when we don't know who's doing what.

>>10332581
>each of this facts somehow makes the situation better and not 10x worse

STOP
DOING
ROCKETS

>>10332656
the biggest musk fans are literally neolib leftists you retard

also you posted this sentence three times already in this thread, stop spamming

>>10332665
no I'm a different guy, I post it as well. I just liked that picture.

>the biggest musk fans are literally neolib leftists

they're more leddit r/the_donald conservatives these days. There is a LOT of hate for him from the left after he mentioned who runs the media - go into any leftist hugbox which isn't dedicated to space and you'll see he's almost universally hated there

>>10332511
This is a montecarlo simulation of a 70 degree cone experiencing reentry. Take specific note of the zone of highest heating - and that the peak thermal flux is a distance away from the entering body.

I haven't forgotten how thermal dynamics works. It would be wise not to neglect the known behavior of the atmosphere.

they're doing things