Felix Schlang at What About It? provided another great update on SpaceX. He noted the new alloy 304L that will be used for some parts and progress on the heat shield. There was a reminder that Elon expected to go through about twenty Starship prototypes before reaching the first commercial-ready Starship.
Spacexvision.com had an animation of a fleet of 100 SpaceX Starships leaving the Earth.
Some parts will use 304L, as it has higher toughness at cryo temps. Will move to internally developed alloys probably end of year.
— Elon Musk (@elonmusk) March 14, 2020
We’re now building flight design of Starship SN1, but each SN will have at least minor improvements, at least through SN20 or so of Starship V1.0.
— Elon Musk (@elonmusk) December 28, 2019
SOURCES- Elon Musk, Felix Schlang – What About It?, SpaceXvision
Written By Brian Wang, Nextbigfuture.com
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
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If Musk has shown anything, he’s shown that repeatedly risking everything, can make some truly astounding things happen.
As for landing down range, I think the plan is to land it, partially refuel it, and fly it back under its own power.
The thing is, aluminum is both lighter AND weaker than steel. And is much more heat sensitive.
In aircraft, they typically use 7075, which is relatively strong for an aluminum alloy, (And machines nicely for aluminum, not at all gummy!) at about 60KPSI yield strength properly heat treated and worked. Great stuff!
But you can’t weld it, really, which is why they assemble aircraft using rivets and glue.
And, that’s at room temperature. Heat it up to a few hundred degrees F, not even C, and you might as well be building the rocket out of chewing gum. But, of course, passenger aircraft don’t get hot, do they? Except the Concorde, which conspicuously wasn’t made of aluminum… The Space Shuttle was made of aluminum, and they needed those fancy insulating tiles, and blew cold air through the airframe as soon as it landed, so it wouldn’t heat up as the delayed heat pulse reached the frame. The wings would literally have sagged if not for doing that.
Now, full hard 304L has a yield strength at room temperature of about 140KPSI, is still decently strong at elevated temperatures, and welds well. And, interestingly, while the yield strength of 7075 might go up to 90KPSI at cryogenic temperatures, 304L can go up to a couple hundred KPSI.
So, I guess the bottom line is, if you didn’t intend to do any welding, and were only concerned with room temperature properties, aluminum WOULD make sense. Not otherwise.
Perhaps – I was thinking that the lower weight per area with aluminum might be a deciding factor. (My guesstimate was 35% less weight per unit area based on relative density and the thickness of Starship steel and Falcon9 aluminum). Also the cost of metal might be lower, since sources I’ve found seem to indicate both metals cost around the same amount per ton.
But I have also read that Super Heavy may do without a re-entry burn, so would need to endure higher temps and wouldn’t need as much left-over fuel.
But dropping the re-entry burn would also mean it lands far down-range, which would pretty much kill the idea of landing where it took off, which I thought was one of the big goals for it?
I doubt the aluminum shell; After going through the learning curve to get the welding right, no reason to do it again, 304L is affordable enough, all they have to do to save money is not make the transition to that internally researched version they’re talking about.
And even doing that might not make sense; The Super Heavy and the Starship might have enough commonality that making sure they only have the better grade of stainless in their inventory system would be worth it as a safety measure.
Yep, that was what I was thinking – also that it’s in some sense a scaled up Falcon – SH may have an aluminum shell, to save weight. Landing legs may be different than Falcon or Starship. Will there need to be more grid fins or larger, to handle the larger size? Etc. So it’s not a slam-dunk.
” Starship hop and fly sub-orbital, safely land. Super Heavy build, test, hop, fly and land – should go faster than Starship development.”
Should go a LOT faster, considering that almost all the problems are going to be common. The Super Heavy issues will primarily relate to the large number of engines.
Sure, but once they’ve got the going up part working, paying customers will be paying for the subsequent iterations. Each trip up a paying customer, each trip down a test.
If you want to conquer space then you must be willing to pay the price in blood and treasury.
Only 20 iterations? Seems to be a bit optimistic. To me the easiest part is the take off. The glide and landing will be the most difficult. The Starship will have the flight capability of a wounded duck. And landing on those stubble legs, I just don’t know if that is going to work.
Not if they sell a service someone wants and use their profits for making this.
That’s rather called “free enterprise” and “using your earnings as you see fit”.
Pedant mode on/
The model A was a successor to the model T.
Pedant mode off/
The largest money burn in history
Note that I said “Early colonies”. However, the need for common effort for common survival will influence the longer term.
Colonists who experienced living on the edge of survival will likely decide to pair rights and responsibilities in a practical manner.
E.g. a citizen’s right to a survivable environment, along-side a universal duty to do a share of work to maintain that environment. And a duty to provide aid to anyone who needs help to survive, paired with a duty/debt to that person to pay for reasonable efforts in that regard.
SpaceX has a long way to go yet. Based on the development path so far, SpaceX will go through a series of failures and ships to achieve each of the following goals :
What % of human cultures have stayed communitarian and gone without money? What does that tell you about human beings?
The greatest part of lots of space colonies will be that lots of things will be tried. We will once again discover what works and what doesn’t.
Same way Ford got to the Model T, by going through Model A through S and iteratively improving until he got to something worth calling a stable Version 1.0 . Then they mass produced and kept iterating.
Early colonies will likely be ‘communitarian’ – no money being exchanged, everyone doing it for the big win of surviving until they can thrive.
OTOH, they might tend to be intolerant of what they might call “weakness” – e.g. someone who gets depressed to the point of being an emotional drag on the whole community.
The material costs of maintaining that individual would probably not be a major factor, so long as they aren’t using more than ‘their share’, because the person can’t be easily replaced anyhow.
That is largely why there is poor support for such expenditures among “the needy, the slackers and moochers” and more generally, the poorly educated class. It doesn’t improve the quality of their own lives to fund esoteric undertakings that will benefit others way down the line, if ever.
Since when is it frowned upon when politicians blindly follow the will of the great unwashed masses, that used to be the gold standard.
Make that about 21…
“He noted the new alloy 304L that will be used for some parts and progress on the heat shield.”
LOL! Could have saved so much development time if he’d just asked me what grade of stainless to use in the first place. Great stuff, 304L, there’s a reason we use so much of it in the automotive industry.
I’ll be interested to see what they come up with for a successor alloy, though. They got that full flow pump system working, and that required some serious metallurgical chops to pull off.
It’s an exciting age to be alive in, I’m just pissed off that the space age got put on hold for most of my life, and only took off again as I was approaching retirement.
After two generations the people who live in space and the people who live on Earth will view each other as savages.
Yep and on top of all that you have the ever present reality of decompression to keep a culture honest. If a generation slacks off then that generation is counting down the days until something critical fails. Societies are going to look down on loafers.
Elderly will help “earn their keep” and raise the grand kids. That’s how most cultures work for a great reason.
Not a lot of room nor regard for the needy, the slackers and moochers in a space habitat. People who politicians of all kinds in any Earthly democracy profess loudly to love (because if there’s something they can do, is vote).
On space you will have to carry your own weight in the community, and the only entitlements will be for those that made their part for the settlement, when they are old and frail.
And probably even then, the settlers will have a rather open minded attitude towards ending your own suffering painlessly and with dignity, and specially, not be a burden to others.
Yeah, scandalous, I know.
I strongly suspect that indigenous laws and culture would be very utilitarian and quite off-putting to the cultured class on Earth.
Why take on the debt burden and let people who think that you can tip over Guam make your laws?
Edit: Your average representative of either political party has NO skin in the game and probably doesn’t understand what a Martian colonist is dealing with.
All.. very.. familiar.
state number 51 and 52 on the moon and mars respectively?
It could be hard for some people to get used to the idea that USA and its allies will have many interplanetary spaceships relatively soon.
With suddenly a lot more cargo and stuff to be found in space, and people going in their merry ways to deep space and other planets, for their own non-national-priority and rather personal purposes.
It feels preposterous, something that we got used to be disappointed about the state of the world.
Not anymore people, it seems this time it’s for real.
Yeah, there will be disappointments, yes there will be accidents and some people will die. But that was (and is) true for airplanes too, and there they are.
The bloom of progress, when it is raised in newfound freedom, can’t be stopped.