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Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

reuters.com

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Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#181

Post by kassner »

fragmede wrote: post #160
paxys wrote: post #159

Earlier quoted context omitted.

None of these are problems if you put data centers far away from population. No one does that right now because it's a lot more expensive to set up and maintain, because you have to set up all the infrastructure from scratch. You know what's 10000x more expensive than that? Setting up the infrastructure in space.

Facebook put a data center up in Luleå, Sweden, which is in the north, far from cities, so it's not unheard of.

Their datacenter at Datavägen 15 is about 100 meters/yards away from residential buildings, not a great example.

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#182

Post by krcz »

vlovich123 wrote: post #173
nkrisc wrote: post #92

Earlier quoted context omitted.

It’s not an unsolved physics problem. Every satellite in space has to deal with it and even the ISS deals with it by having massive radiator arrays that face perpendicular to the sun. The problem with data centers in space is one of materials science and engineering: how to make radiators large enough and effective enough to cool it while also being economically feasible, both in terms of construction and getting the…

The maximum heat rejection capacity of the ISS is 126Kw. Musk’s proposal is to put 1 rack per satellite drawing 150kw using 110 m^2 of radiators (1/4th that of the ISS). The only way to do that is by running the satellite at 71-100C which is a problem for the chips to actually run. So the open questions are: * can they actually dump the heat and can they have the racks running so hot for so long * is it economical to…

Wouldn't it be possible to use heat pumps, making radiators 100C or hotter while running GPUs much below that?

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#183

Post by Eddy_Viscosity2 »

krcz wrote: post #182
vlovich123 wrote: post #173

Earlier quoted context omitted.

The maximum heat rejection capacity of the ISS is 126Kw. Musk’s proposal is to put 1 rack per satellite drawing 150kw using 110 m^2 of radiators (1/4th that of the ISS). The only way to do that is by running the satellite at 71-100C which is a problem for the chips to actually run. So the open questions are: * can they actually dump the heat and can they have the racks running so hot for so long * is it economical to…

Wouldn't it be possible to use heat pumps, making radiators 100C or hotter while running GPUs much below that?

That's how space heat radiators already work. Which, by the way, add significant costs to both energy and weight for space-based data center. The problem is once you 'pump' the heat out is what happens next. With out conductive or convective heat transfer, all that is left is radiation of that heat. Which is the slow.

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#184

Post by Eddy_Viscosity2 »

nkrisc wrote: post #92
vlovich123 wrote: post #83

Earlier quoted context omitted.

The Microsoft design of filling an airtight submersible structure with argon and dropping it to the bottom of the ocean floor is the alternative design - you’re not looking to do repairs but amortize the low cost of failures across the value you extract. The biggest issue with space is not repairability but heat - when you’re in a vacuum the only way to disperse heat is through black body radiation and that’s horribl…

It’s not an unsolved physics problem. Every satellite in space has to deal with it and even the ISS deals with it by having massive radiator arrays that face perpendicular to the sun. The problem with data centers in space is one of materials science and engineering: how to make radiators large enough and effective enough to cool it while also being economically feasible, both in terms of construction and getting the…

> It’s not an unsolved physics problem. Every satellite in space has to deal with it and even the ISS deals with it by having massive radiator arrays that face perpendicular to the sun.

The problem is not solved for something of this scale, I think its solvable, but no has done anything at the size these would have to be. And if the physics and engineering can be made to work, they are unlikely to be solved AND ALSO be economical.

It's classic type problem where the choices are:

- economical

- in-space

- big

Now pick two.

There is also the unsolved problem that the radiators would be absolutely massive in area. Making damage from flying objects, meteorites, space jump, close to 100% likely over any reasonable life span. Repairs would be expensive AF. Again economics is the driver of why this is dumb.

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#185

Post by rtkwe »

markasoftware wrote: post #72
onli wrote: post #67

Earlier quoted context omitted.

No. It really is a scam. Everyone with understanding of the physics involved wrote so. Heat dissipation + radiation + launch cost make it a no-go.

Heat dissipation isn't as big a concern as it seems: the weight of the solar panels is significantly larger than that of the heatsinks you'd need per typical modern gpu

It's not just the weight some outside groups have done the calculations and to dissipate the heat at the operating temperatures in the white paper without a heat pump to increase the radiator temp and thus efficiency requires a massive pump that would have to move nearly 69,000 kg of coolant per second continuously without fail.

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#186

Post by tekne »

WalterBright wrote: post #123
abfan1127 wrote: post #104

Earlier quoted context omitted.

I think corrosion is the big issue here. perhaps that is where the leak comes from.

Water under high pressure will find any weakness. (For example, the places where the wires go in and out.) Corrosion indeed is always a problem.

Not if the datacenter itself is operating at the same internal pressure as the water around it

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#187

Post by bakies »

munk-a wrote: post #94
bakies wrote: post #91

Earlier quoted context omitted.

It's so, so cheap to buy tap water and dump it on the heat exchange.

With well considered engineering it doesn't even need to be tap water. If you have a closed loop thermal conductor that interacts with the components themselves you can then use really trashy contaminated water that just needs to be clean enough not to actively erode the heat transfer mechanism. We have setups like this all the time that use condensed air via cooling towers or salt water immersed heat sinks to discha…

It's the same reason we use single use plastics. No matter the politics the business decision is going to use the cheapest option available. I'm confident that all the hyperscalers could create datacenters that don't affect the local community basically in anyway. There's been data centers hidden in plain sight for decades. The demand drives it to the lowest common denominator

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#188

Post by hcknwscommenter »

cucumber3732842 wrote: post #141
croes wrote: post #133

Earlier quoted context omitted.

Nobody said space data centers are impossible, it’s just wasteful and ineffective.

Right, but nobody's sure just how wasteful. And at these scales small factors make or break things. That's why it's hard to predict who's bullshitting. A fairly small unforeseen factor here and there adds up to wild financial success or failure over the course of an entire project.

I think that's an incorrect way of looking at it. A small unforeseen factor is almost always going to be a negative factor, not an unforeseen benefit. Space is a hostile and unforgiving environment without an easy way to bring things back, fix stuff, and/or re-deploy. A small mistake on the engineering, planning and/or implementation is likely to sink the whole thing worse than the napkin math suggests is almost certain failure anyway. Similarly, there are few ways to "get it right" and many ways to fail.

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#189

Post by WalterBright »

tekne wrote: post #186
WalterBright wrote: post #123

Earlier quoted context omitted.

Water under high pressure will find any weakness. (For example, the places where the wires go in and out.) Corrosion indeed is always a problem.

Not if the datacenter itself is operating at the same internal pressure as the water around it

Interesting point. But also consider:

1. pressure may compromise the electronics

2. water pressure increases very rapidly with depth. You'd have to pressurize the data center with a liquid with the same density

3. even a small differential will produce leaks

Re: Short sellers notch $8.7B profit as SpaceX shares dip to IPO price

#190

Post by zugi »

nijave wrote: post #108
zugi wrote: post #76

SpaceX has accomplished spectacular things in reusable launch vehicles and space-based networking. It will soon restore the heavy launch capability that the US lost when it retired the Saturn V in the 1970s, but in an affordable and sustainable manner. SpaceX is almost single-handedly keeping the US ahead in space. I'm bullish on SpaceX as a company in terms of technical accomplishment. Buying SPCX would make sense a…

>but in an affordable and sustainable manner Affordable is a bit questionable. It's heavily subsidized by Starlink and government. Not completely clear what happens to price if SpaceX doesn't keep launch demand propped up with their own business.

SpaceX bids on competitive government space launch contracts and wins most of them because they're more reliable and often half the price of the competitors, or less. Government is now essentially subsidizing SpaceX's space launch competitors, giving them more expensive contracts on which they often fail to deliver, only because the government doesn't want to be dependent on a single space launch contractor. So complaints government subsidies seem misdirected.

Many companies have tried to launch LEO space-based communications constellations, starting with Iridium 30 years ago. Starlink is first and only so far to succeed at scale and provide truly global internet access. Indeed having the space launch and communications business joint has helped both of them. Indeed that helped SpaceX drive down launch costs, given their reusability and economies of scale. Having two very successful business lines integrated and synergistic seems like a massive plus, so I guess don't see the concern about the Starlink part of the business "propping up" the space launch part of the business.

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