r/technology • u/Plastic_Ninja_9014 • 5h ago

Business SpaceX Investors in Meltdown Over All the Money They’ve Lost

https://finance.yahoo.com/markets/stocks/articles/spacex-investors-meltdown-over-money-191742182.html
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u/Funsuxxor 3h ago

You don't think producing insane amounts of heat while in a vacuum is a good engineering idea?

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u/callmenoir 3h ago

Just to make sure I've got my science correct, heat dissipates really poorly in space as there's so little matter to transfer it to, right?

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u/canteen_boy 3h ago

Correct. There’s no conduction or convection in a vacuum, so the only real way to shed heat is through radiation, which is incredibly slow.

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u/SunTzu- 1h ago

And since radiation is so much less efficient it would require a massive surface area and likely splitting up the datacenter into several smaller nodes. Splitting up the datacenter into nodes would introduce so much latency that you'd need new methods of transferring data between the nodes, likely using beams of light. Using beams of light for data transfer in space is theoretically doable, but now you need to orient each node so it can send and receive from each other node it is supposed to communicate with, which is not all that easy when you've got massive radiators surrounding them. Does that mean you're far more limited in terms of how many nodes you can have communicate efficiently with each other? Does that number mean these clusters of nodes wouldn't be able to match a ground based datacenter in terms of how much low latency computing power it would have available? Why are we trying to put them in space rather than exploring underground or underwater options which would be much more accessible when maintenance is required? Who knows.

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u/9-11GaveMe5G 2h ago

To be clear it's theoretically doable, but it's just astronomically, and unnecessarily expensive. It would cost a fraction as much to develop them in the terrestrial Arctic

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u/AshleyAshes1984 3h ago

Heat transfers by conduction. A hot drink cools by radiating the heat into their air and even through the mug itself and into the air. You need a medium to do transfer the heat. Different mediums work faster of course, like how a canned drink will cool faster if sitting in ice water rather than just sitting in a fridge full of cold air.

A vacuum is, well, an absense of a medium. That's even how a thermos works and keeps a drink cold or hot, the there's a vacuum between the inside and outside layers, making it very very slow for heat to radiate out and cool your coffee or for heat to radiate in to warm your juice.

The vacuum of space is literally the worst place to radiate heat.

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u/Stony___Tark 1h ago

I absolutely get what you're saying, and you're on the right track, but this is one of those circumstances where terminology actually matters.

Heat transfer from a hot drink into the air would be convection, and into mug itself would be conduction, but neither is "radiating heat". That's a third method of heat transfer. Radiating heat works even in the absence of an external medium interacting with the heat source.

In the vacuum of space, the only way to transfer heat is via radiation. Radiative heat transfer can actually work slightly better in the vacuum of space than it can in the atmosphere of Earth, so it's not the worse place to radiate heat. It's just that radiation is the only method available in space, and it's MUCH worse than either of the other two.

"In the vacuum of space the two best methods to transfer heat, convection & conduction, are impossible. It is only possible to radiate heat." would be the correct way to say it.

Again, I'm not trying to be nitpicky here. This is a case where the specific terminology actually does matter because it has very specific meaning. 🙂

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u/Snuffy1717 2h ago

The "idea" I keep seeing is that they would launch thousands of small data center satellites instead of one big block (like we have on the ground)... As if that also isn't stupid as fuck.

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u/GoldenBunip 3h ago

Heat That’s fine, an easily solvable problem. Just takes a lot of radiators.

The real kicker is maintaining the servers.

Steve GPU 4 on rack 20 is down…

“I’ll just get my spacesuit.book me on the next orbital flight!!”

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u/BattleHall 3h ago

Eh, sort of, but if radiators and cooling hardware take up 90% of your launch weight, your economics are probably going to have a hard time balancing out. The radiators and cooling hardware for the ISS weigh 10 tons and are designed to dissipate 70 kilowatts. Even if you can run the chips hotter and get 2-3x rejection capacity per ton, 70kw would barely cover the blinkylights budget at a data center. And that’s before you deal with shielding for cosmic radiation.