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Elon Musk Explains Why He's Building 'Starship' Out of Stainless Steel (popularmechanics.com)
Long-time Slashdot reader darkwing_bmf writes: In an exclusive interview with Popular Mechanics, SpaceX founder Elon Musk explains why stainless steel is the best material to build rocket ships, beating carbon fiber in cost, durability and even weight.
"As far as we know, this marks the first time the material has been used in spacecraft construction since some early, ill-fated attempts during the Atlas program in the late 1950s," reports Popular Mechanics.
"It took me quite a bit of effort to convince the team to go in this direction..." Musk tells them. But among the other benefits "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... But steel, you can do 1500, 1600 degrees Fahrenheit."
"As far as we know, this marks the first time the material has been used in spacecraft construction since some early, ill-fated attempts during the Atlas program in the late 1950s," reports Popular Mechanics.
"It took me quite a bit of effort to convince the team to go in this direction..." Musk tells them. But among the other benefits "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... But steel, you can do 1500, 1600 degrees Fahrenheit."
funding secured, my man. Now pass the Doritos
Musk not using SI units?
Maybe the shorts were right.
I should use this sig to advertise my book ISBN-13 : 978-1501515132.
I was frequently Debbie Downer about using CF for BFR. It's not a resilient material, and organics don't play well with LOX, nor does CF like operating at cryogenic temperatures; you're fighting against its innate material properties. I love the use of stainless. It's so much more forgiving, and people who know how to work with it are a dime a dozen. Just everything about this design will be so much easier. And cheaper. And faster. And safer.
I wouldn't be surprised if they outright build Starship and Super Heavy outside, shipyard-style. It wouldn't exactly be the first time giant pressuretight steel vessels designed for dealing with harsh conditions were built outside in salt-air conditions (e.g., almost every refinery on Earth). Corrosion rates in marine environments are on the order of decades to centuries per millimeter, depending on the stainless alloy (unlike alumium which is sensitive to salt) - and galvanic corrosion due to junctions with dissimilar metals (such as alumium) tend to corrode the other metal, not the steel (again, unlike alumium). There should be no issues with an under-construction rocket shell sitting outside for months until they can get it enclosed for more sensitive work on the interior. The LOX tank would need to be well cleaned, mind you, since LOX doesn't play well with contaminants (CH4 isn't particularly sensitive), and as always, welds need to be properly inspected.
It's an unconventional choice, but one which I've been really glad to see.
"Are you hungry? I haven't eaten since later this afternoon." -- Primer
Going by Mr. Musk's other fancy projects like the Hyperloop and his tunnels or even the flame thrower, the outlook for a stainless steel rocket is very dim.
Most of the time, Mr. Musk's cunning plans overlook some aspect and in the end they either fall very short on the original expectation or don't work at all. And if they work, liek the tunnels, they end up being about the same as those made by others.
In engineering there are very few overlooked secrets to revolutionise things like Mr. Musk always twitters. Fortunately most engineers aren't the fumbling dolts he thinks they are.
Probably this is just another case of dangerous half-knowledge - as usual.
Tell someone "That material can withstand 815 to 871 C!".
I'm in full support of metric units elsewhere, but that doesn't look, nor sound, nearly so exciting... C is just a terrible unit of measurement for expressing temperature. Even more true of weather ranges.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
It's actually going to be a time machine, not a spaceship. Musk: "If my calculations are correct, when this baby hits .88 C... you're gonna see some serious shit."
Going by Mr. Musk's other fancy projects like the Hyperloop and his tunnels or even the flame thrower, the outlook for a stainless steel rocket is... ...fantastic.
The hyper loop already has a demo tunnel built when many said NOTHING would ever be built. It completely validates the concept, to the point you can be sure to see commercial implementation.
The flame thrower turned out really well, to the point I was very sad I didn't get to order one before they were gone.
And of course, Tesla is practically the definition of success (so funny how you left that example out). Not to mention the many fantastic success SpaceX itself has had - in fact the most directly pertinent example, vs. the flame thrower.
It seems you lack the vision to understand when early phases of something portend future success.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
oops... elon isn't telling you one other detail. you aren't coming back. ok, two, he's a cheap c#nt ... titanium was just tooo much money for this poor billionaire and your lives aren't worth it. ;)
troll time
titanium or tungsten are anywhere from twice to four times better in regards durability, thermal expansion, and strength
...Rearden Metal instead? Dagny Taggart thought it was superior.
After all, Elon Musk's opinion is way more significant than decades of scientific research.
: "If my calculations are correct, when this baby hits .88 C.
Someone above was asking why Musk didn't use C instead of F to refer to the temperature the hull can take...
You just demonstrated why - when talking about spaceships you only want to use F for temperatures so you don't confuse it with the use of C for speed. :-)
"There is more worth loving than we have strength to love." - Brian Jay Stanley
They built something like 500 balloon-tank Atlas missiles at Atlas II and they were extremely successful, every single one of them was stainless steel. They launched the last one in the early 2000's , and the Atlas II has a perfect success record. Hardly "ill-fated attempts one the Atlas program in the late 50's".
Musk, of course, is not using the stainless in an ideal manner, mostly for show. That's because he is more PT Barnum than Werner Von Braun.
The problem with stainless is that it's a bit brittle subject to stress cracking.
This is why here on earth steel or aluminum rather than stainless is used on boats for any structural/loading components. It's why more mundane things like "spiders" in washing machines are made out of heavy gauge aluminum and not corrosion resistant stainless like the rest of the drum.
I am not a rocket scientist or a materials scientist and can only assume they've done their homework but it just seems dumb on its face.
Gee Mr Buttfuck, I didn't notice you were a famous engineer - or any engineer - had ever built anything or ever known what you were talking about generally when your punk ass blathers online... because, wait for it, YOU AREN'T, and never did.
Just kidding, though his spaceships (like the Skylark) made out of special steel were the first thing to come to mind on reading this. https://en.wikipedia.org/wiki/... A lot of today's Science Fiction writers stand on the shoulders of JMS, who created Babylon 5, just as he stood on the shoulders of Doc Smith. 25 years just went by since the first airing of B5's first episode by the way. https://en.wikipedia.org/wiki/...
See subject: I read the series when I was in 7th grade (or rather, as many as they had then) - good stuff Kimball Kinnison & crew!
* MUCH of it during "reading break" during, of all places, GYM Class 1st 20 minutes (rest @ home - couldn't put it down) in 7th grade.
APK
P.S.=> IIRC, I started w/ "The Gray Lensman" but it's been 3++ decades since so, I could be "off/wrong"... apk
I wonder if they'll make it to the planet Mongo in that thing?
There's a reason nobody asks Ken Doll for his worthless opine on anything.
And I think I started with that one as well. Only later did I read the prequel novels of the IPC, and Smith's other famous series with the characters of The Skylark of Space.
Someone should explain to Musk that, even if stainless steel has a very high melting temperature, usually at just 400 degree Celsius stainless steel lose about 80% of his mechanical strength. If I'm not mistaken temperatures on re-entry from orbit can easily exceed 1000 degree Celsius, not a nice temperature for something that must withstand a certain amount of mechanical stress...
From looking at his post history he is unemployed and thinks the UN is trying to make. World government lol. Truly a slash dot stereotype.
Stainless steel (304) is about 3 times more dense than 6061 aluminum. Yet it's only about 10% stronger in tensile strength, and about 2.8 times better in Young's modulus. Meaning that you need more mass for the equivalent strength of aluminum. So you have to have more fuel, and more fuel (and volume in the tanks - which means they are also heavier) to carry that additional fuel.
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
Mine wasn't NEW so as far as "in stock", didn't really apply - I got my copy from my Dad who got me into reading & we got our material from used bookstores (often minus covers but didn't matter to me, it was "what's inside, counts" (as it does w/ people MOST of the time (except women, lol - has to be appealing OUTSIDE too if you 'catch my drift')). I always VALUED those places right into the early 90's (when I began seriously 'drifting' towards computers more which later on in this post, makes sense on another 'point' of mine imo). I had 1 such spot near me (the "1/2 price bookstore" which closed 2nd year I was living near it, bummed me out bad) right before computers "re-hit" me (started on mainframes & midranges, didn't like charmode interfaces but GUI "got me" (art & science combined imo)).
* The ENEMY was the 'Boskone' right? (Testing my "memory banks" on that note).
Anyhow - pretty cool running into someone w/ common-ground here! QUESTION: How old are you? I'm 54 as of last Thursday - & you? Just curious. I don't see a LOT of readers in the past 2 decades++ or so & especially from the youth. Perhaps THEIR "books" are what WE are on, NOW (computers & the internet (most fantastic library I've ever seen, great learning tool)).
APK
P.S.=> I'll always be grateful my Dad got me into reading around 5-6 yrs. of age - 1st w/ comic books (army & horror comics THEN 'superhero' ones w/ HULK) & then onto Sci-Fi "pulp" short stories (which I thought ROCKED) - I can't help but feel it helped me later get a NEAR PERFECT "SAT" verbal score & helped me become a national spelling bee contestant in 5th grade (reading a lot helps, no questions asked)... apk
Everyday Astronaut
Just imagine a beowulf cluster of slash dot stereotypes.....
elan musl isn't a famous engineer either. he's just famous and he has enough money to pretend he's an engineer without having his engineer employees call him out
A demo tunnel, that can't do jack else
I dare you to drive a mile in LA at rush hour in under 4 minutes.
Musk can.
And as the tunnel obviously works and was built as easily as he claimed, at the low cost he claimed, there will be many more to come.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Those chinese prisoners have the best organs Jerry, the best!
And if any engineering let themselves convinced by that, fire them. What is important is the tensile strength of steel versus temperature. e.g. in a fire steel beam get weakened at far lower temperature than melting point. At about 600-700 degree celsius your steel lost half its strength. You can see that at warehouse fire among others, steel beam get weakened and it crumples long before meeting melting point. Now the question is, what do carbon fiber at those temp, and is that important versus steel weakening. I can't answer that. I was just indicating melting temperature is not what you look at in most applications.
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
I was 100% in-doc with Musk, he could do no wrong. His ideals had me at go and was bought in. Over the past 2 years, I've started to see things that have made me double take. He really is starting to come, undone. I don't think it's the science or the idea/dream, it's something else and I can't figure it out. Maybe it's drugs or the high press has changed him, but his image is everything and his PR is suffering.
Telsa needs to revamp, the trucks and roadster are not going to make it.
SpaceX needs a better method of landing and recovering parts, small wins + more often = success over a big one, in one go.
Musk, I'm behind you, still, but you need to get this shyt together.
I'm a bit over 60 years old, fwiw. Yes, used book stores ftw. I scored a used first edition of Babel-17 at one. It's in good shape, and it brings back memories of the first time I read it. I still like physical copies of books, though I buy the e-books of authors I like to support. My local library has a thrift shelf where they offer their retired paperbacks, hardcovers, and even DVDs and Blu rays, for a quarter or less (a buck for the disks though), and they also have book sales in the basement once in a while. Btw, most of Galaxy Magazine has been scanned and uploaded to archive.org. Amazing stuff! Just look for the zoom feature on the page, otherwise the text is too small to rad, imo. Many classic SF novels have been scanned at archive.org as well, and can be checked out. All totally legally of course! https://archive.org/details/ga...
Contrary to what Musk says transpiration cooling was proposed may times, it was never implemented because it didn't have obvious advantages for non-reusable spacecraft and was though to be fragile. However, in reality it will probably be a lot less fragile than the Space Shuttle TPS.
Titanium has a *WAY* higher melting point than stainless steel, is less than 60% as dense, and more than twice as strong. It's only about one and a half times more expensive than stainless steel per unit volume, however, but because of its increased strength, I'd imagine you may also be able to use correspondingly less, and therefore get a more performant material for the same or lower cost.
File under 'M' for 'Manic ranting'
Tungsten has the highest melting point of any metal, and I believe the highest of any known element.
Why not use that? Does it have shit properties in regard to strength, etc?
See subject: So you ARE from around the same 'timeframe'/generation as myself (close enough) so it makes sense you too are a 'reader'. You noted Galaxy. I read TONS of tales from that one & OLDER material from the 20's/30's/40's/50's too (considering I read this in the 1970's that is) & it was GREAT! I loved it. Amazing Science Fiction (iirc, that was a serial title of that era I liked) etc.
I will take a book in my hand as I lay back in a comfortable spot & read ANYDAY over "modern media" (even film, though it's a close second) because unlike film, YOU are the director of the scenes painting them in your mind (better than a movie) & there is NOTHING LIKE not being able to put a good book down (or even falling asleep with one still open on your face, lol) - reading is that good!
APK
P.S.=> That's cool you have that available - ever since I entered computing, it's been a rarity for me (on reading other than technical information) & the lateness of my reply is due to trolls I have to fend off who IMPERSONATE me (or STALK me by UNIDENTIFIABLE anonymous posts every day here) & here's two examples https://science.slashdot.org/c... & a reply to gweihir (who KNOWS they do it to me as they try "stir up others" against me) https://science.slashdot.org/c... - unbelievable some people have NOTHING BETTER TO DO than bug me, lol - oh well & NICE speaking to you about Sci-Fi reading! apk
See subject: APK Hosts File Engine 1.0++ 64-bit for MacOS h t t p : / / a p k . i t - m a t e . c o . u k / A P K H o s t s F i l e E n g i n e F o r M a c O S . z i p
Yields more security/speed/reliability/anonymity vs. any 1 solution (99% of threats use hostnames vs. IP address most firewalls use) more efficiently/FASTER + NATIVELY 4 less!
Vs. "Bolt on 'MoAr' illogic-logic" slowing you hosts speed u up 2 ways: Adblocks + Hardcode fav. sites u spend most time @ vs. competition loaded w/ security bugs (DNS/AntiVir) + overheads slowing u (messagepass 'souled-out' to advertisers easily detected & blocked addons + firewall filtering drivers) & their complexity leads to exploitation!
* ONLY 1 of its kind in GUI 4 MacOS!
(Better vs. Windows model in speed/efficiency)
APK
P.S.=> Protects against ALL known & unknown vulnerabilities. Now supports port filters in hosts. My work is world-class & China copied it because they can't do better. I am God's gift to Slashdot... apk
STOP IMPERSONATING me on /. & DO get on topic!
You can't help you're an immature little BUTTHURT no-mind, lol! I blew you away in TONS OF PLACES and easily dust your no-mind bullshit blatherings.
* IMITATING me as you do proves you WISH you were ME though!
APK
P.S.=> Hopefully, this 'sinks in' to your DULL BRAIN @ last, finally (for the 100th time now)... apk
Shall I tell you? It's the least I can do. Steel isn't strong boy, flesh is stronger!
I hate that about some stainless steel refrigerators and other appliances. Some stainless is ok. Others are fingerprint magnets. All those smudges and fingerprints make it look so unkempt. It's really embarrassing when company comes over. "Look where they put the BFR honey. They knew we were coming and couldn't even take the time to clean it up a little. Tsk Tsk".
The Russians have won. They have made the world a cesspool of distrust, greed, fear and hate.
Which part of a rocket structure, the tanks, hull, fairing etc. is expected to resist temperatures much above two or three hundred degrees Celsius? The engines, yes, but they run a lot hotter than the melting point of stainless steels and are actively cooled where necessary.
I can't think of a cost benefit for using stainless steel in an aerospace environment except if Musk plans to build something like the trans-Pacific Tokyo Express, a multi-Mach ballistic passenger transport which would have a hot re-entry as it re-enters thick air from the troposphere. Using a heat-resistant stainless steel would reduce or eliminate the need to replace ablative thermal coatings after every flight.
There's an experimental supersonic aircraft, a precursor to the SR-71, the BAC-188 (now in in the RAF museum at Cosford) which was made from stainless steel to investigate aircraft skin temperature effects at high speeds. It was never intended to be a production aircraft though.
You've even IMPERSONATED me here talking to others - butt out & mind your own business freak.
APK
P.S.=> Unbelievable - you REALLY ARE SICK IN THE HEAD stalking me you know - don't YOU have BETTER things to do? Apparently not (you're a LOSER, freak)... apk
See subject: That link won't work so you give away you're impersonating me moron...
* Like I said before - unbelievable!
APK
P.S.=> YOU are a TOTAL LOSER weirdo... apk
Yes, I bet it was Musk who "convinced the team" to go with stainless steel. Because amongst his various accomplishments in life, he's also smarter than scientists and engineers who have spent decades studying, designing, and building actual spacecraft.
I feel sorry for the poor suckers who decide to put their lives in his hands, but he has a way of inspiring people to lunatic belief in his nonsense.
Everyone knows water freezes at 32F, and they don't care what temperature water boils at as they can just see it's boiling (or steaming and don't enter a temperature to boil - they just turn on heat until it boils.
So the numerical alignment of 100 to boiling is totally worthless, while having weather forecast temperatures that do not need decimal points to be accurate is much nicer for comprehension. When you get between 70-80 degrees there starts to be a lot of variance in what temperature people adjust clothing, In C that is 21.1 to 26.6 which gives you half the whole numbers to express what it will be like outside.
"There is more worth loving than we have strength to love." - Brian Jay Stanley