Comment on Datacenters in space are a terrible, horrible, no good idea.
NotMyOldRedditName@lemmy.world 8 hours agoWe already radiate heat away just fine in space, it’s just a matter of how much space do you need to use to do it and all the implications of what that would mean for any given satellite. I wouldn’t call it free, because you need the hardware to do it and the extra weight reduces the payload capacity of whatever you’re sending up, but we can do it.
Starlink also uses laser links to talk to each other which these satellites would also use. So you go up from land, bounce around with lasers in space until you’re close to your ground station, then come back to earth and route to your home.
Fiber is still the better option on land if you can get it there, but there are a lot of places it’s never going to get laid.
brucethemoose@lemmy.world 8 hours ago
Plugging it into this formula:
projectrho.com/public_html/rocket/heatrad.php
I get a circular radiator at least a kilometer wide, assuming the radiator is quite efficient, a rather modest datacenter, and very hot coolant (70C).
…Realistically, the coolant temperature would need to be much lower, and dissipate much more, so the area gets very large real quick.
I cannot emphasize how expensive a functional 2km+ radiator would be in space. It’s mind bogglingly expensive.
NotMyOldRedditName@lemmy.world 8 hours ago
For 100kW? I’m not going to try and figure things out from that massive site.
brucethemoose@lemmy.world 7 hours ago
100kW? Nvidia BGX 200 servers are 14kW each, not counting the interconnect, or anything else. According to nuggets I’ve read online, we’re talking 200 megawatts for an Earth-based AI datacenter these days, without something exotic like underclocked Cerebras WSEs
Plugging 200 megawatts into this:
www.calctool.org/…/stefan-boltzmann-law
I get about 0.46 square kilometers, depending on the coolant temperature and ultimate efficiency of the system.
I have no clue what the construction of such a monstrosity would look like, but if it was a simple 0.5 inch aluminum sheet, it would weigh like 15,000 metric tons.
NotMyOldRedditName@lemmy.world 7 hours ago
They aren’t making a datacenter like on earth. They’re putting up a ton of satellites that will each generate about 100kW.
Everyone keeps thinking they’re putting these massive things up there, they are not doing that.