Sorry - I misunderstood you - I thought "simple piston" was Australian for Musk i.e. a pisshead!
Cont: Musk, SpaceX and future of Tesla II
- Thread starter a_unique_person
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arthwollipot
Observer of Phenomena, Pronouns: he/him
Understandable.
a_unique_person
Director of Hatcheries and Conditioning
If it was simple they would have done it already.
jeremyp
Philosopher
What do you mean extra plumbing? We haven't seen the fuel tanker version yet.
Anyway, it seems that the fuel system has two sets of tanks: the main tanks and the header tanks. The main tanks are used for going up and the header tanks are used for coming down. There are several reasons for this:
- it makes weight distribution better for descent
- you can't relight the engines in orbit from a tank that is 90% empty. All the liquid fuel will be in big bubbles floating around in gaseous fuel. The engines need liquid fuel, not gaseous fuel.
- once descending, the rocket spends part of its time on its side, that makes the fuel feed problematic. It's easier to solve this with smaller tanks that are more nearly full.
- boil off in orbit is a real problem. It's easier to insulate a tank against boil off if it is small.
So I'm not sure how they plan to design the refuelling rocket and I'm not sure how easy it would be to transfer unused cargo fuel to somewhere where it can be useful.
jeremyp
Philosopher
A simple piston that's as big as the diameter of the cargo tank? How do you seal the gap bwetween the piston and the sides? How do you push the piston in?
Jack by the hedge
Safely Ignored
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And there would have been an Apollo 18 if the money had kept coming. But it did not. It was possibly the most extraordinary feat humans have accomplished but when they had done it, the program ran out of justification for doing it again and again.
The Great Zaganza
Maledictorian
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to fuel spaceships in Orbit, we just need a really loooong hose.
Wudang
BOFH
Why not just get the fuel to the station with Amazon Subscribe and Save? After all, is it not written that where there is demand the Market (Praise to its Name) will find a solution?
Safe-Keeper
My avatar is not a Drumpf hat
Long hose? Hey, I know someone who act like they own a really long house. Lemme ask Gonk.
You know it's bad when not even his robot sycophant believes in him.
btw, no one tell him, he'd probably run to reprogram it.
acbytesla
Penultimate Amazing
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The value of us ever going to the moon is debatable. Although the program itself created many ancillary benefits. That said, it was very expensive. About 5% of the US budget for more than a decade. That's one hell of lot of bridges, tunnels, roads and schools that could have been built.
Now the good thing is that going today is likely to cost much less. Still, just going because we can, is a really dumb reason.
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arthwollipot
Observer of Phenomena, Pronouns: he/him
Sure, why not?
My point is that solving the pressure problem is not difficult. How about this one: the target tank is evacuated. Dock a high pressure fuel tank with one that contains a vacuum and the fuel will flow from one to the other.
And the reason we haven't seen it done yet is that in order to do it, Starship actually has to be able to get to orbit.
a_unique_person
Director of Hatcheries and Conditioning
Where does that piston exist? The tank is a high pressure container with very strict requirements for structural integrity. What drives it? How much does it weigh?
If it was that simple people would have done it already. This concept has been proposed and speculated on for decades.
arthwollipot
Observer of Phenomena, Pronouns: he/him
I'm not a ◊◊◊◊◊◊◊ engineer, mate. It's not my job to do the maths. It just doesn't seem to me like a simple pump is out of the question.
People have been pumping liquids against various gradients from time immemorial. Yes. People have done it already. The only thing that makes it less than simple is doing it in a vacuum, and vacuum-sealed rendezvous...es... in space have been a thing since 1971.
SpaceX needs to get Starship reliably to orbit and back first for it to happen. The pump is not the immediate problem.
a_unique_person
Director of Hatcheries and Conditioning
They can't be designing equipment and solving problems sequentially.
Sounds as if you have gone to the Musk University for Engineering……. ;p
Trebuchet
Penultimate Amazing
Dragon may be getting extra work. The Russians have borked their launch site for Soyuz!
novaphile
Quester of Doglets
Seriously, Arthwollipot is right on this.
It is trivial for a piston pump, to create a high pressure on one side, to move material from one vessel to another.
People have been doing that since the invention of steam engines.
(Pumping in water to be made into steam against the pressure of the pressure vessel).
I agree that sealing the interface between the two sides would be interesting, but again, that's a solved problem in the world.
Have you never used pneumatic/air tools?
Developing a mechanism to operate the release would be fun.
It is trivial for a piston pump, to create a high pressure on one side, to move material from one vessel to another.
People have been doing that since the invention of steam engines.
(Pumping in water to be made into steam against the pressure of the pressure vessel).
I agree that sealing the interface between the two sides would be interesting, but again, that's a solved problem in the world.
Have you never used pneumatic/air tools?
Developing a mechanism to operate the release would be fun.
Trebuchet
Penultimate Amazing
SpaceX is pumping cryogenic propellants around their sites all the time. But doing so on orbit will probably be slightly different. Or a lot different. I've no idea if they are planning to do so.
You can, of course, accelerate the transfer by pressurizing the supplying side, as with an inert gas. They do some of that anyhow during launches. It gets trickier in zero-G, so you may have to apply a slight acceleration to keep the stuff where you want it.
You can, of course, accelerate the transfer by pressurizing the supplying side, as with an inert gas. They do some of that anyhow during launches. It gets trickier in zero-G, so you may have to apply a slight acceleration to keep the stuff where you want it.
Roger Ramjets
Philosopher
And your point is? Sometimes (quite often actually) things don't go entirely according to plan. The Cybercab won't enter production until next year, and then will need months of testing before it goes 'live'. Meanwhile Tesla is just using production Model Y's - currently with safety passengers but this will soon change. For whatever reason they haven't managed to get 500 of them out so far. I don't know what the holdup is, but considering that they have only been trialing their robotaxi service for a few months I don't think it's a big deal. Tesla has typically been very cautious about introducing new products. The Cybertruck was trialed for 4 years, and the Semi for nearly 3 years now.We haven't talked about Tesla for a while. How are sales going
Oh.
Never mind. There is always autonomy to save the company. How's robotaxi going?
Musk cuts Tesla Robotaxi plans in Austin: instead of 500, there will be about 60 driverless cars
Elon Musk has sharply scaled back plans for a Tesla robotaxi pilot fleet in Austin. While last month he promised 500 cars by the end of the year, he is now talking only about "roughly doubling" the number of vehicles available.mezha.ua
Oh.
Tesla doesn't need 'saving'. Their push into robotaxis and robots is unneccessary at present, and is actually quite risky. But you don't get real innovation without risk. Many other companies are pouring billions into similar projects. Some, like Google, are continuously losing money without much progress. Others haven't produced anything at all. The company that first 'cracks' these technologies stands to win big. But 'winning' isn't Musk's goal - he's interested in what the technology will do for us, not the profit that could be made. That's why he's willing to take risks that others aren't. You can bet that Tesla will continue to put as much effort as they can into pushing the boundaries, which is a good thing.
But of course you don't care about that. It's all about cancelling Musk because he's a Bad PersonTM. Yeah he's not perfect, but neither were many of the great innovators of the past. If liberals hadn't taken an immediate dislike to him over irrelevant issues he might not have veered right like he did. But other automakers are sucking up to the Trump administration too, for obvious reasons. Perhaps if Democrats hadn't snubbed Tesla, who was actually helping them achieve their goals, Trump wouldn't be President now and Musk would be sucking up to Harris instead. Harris even admitted recently that giving Tesla the cold shoulder was a mistake.
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Roger Ramjets
Philosopher
I just watched a video about American trucks in Europe. Turns out the Cybertruck isn't the only one 'banned' there due to pedestrian safety concerns. But many are exploiting a loophole to get them onto European roads. If that isn't corrupt and immoral...