zlacker

> radiating towards deep space

Literally ctrl-f heat in the pdf.

>>Feepin+(OP)
> radiators block out the sun. Nothing to do where they radiate but about the fact you need an absurd amount of them.

>>Feepin+(OP)
Yeah another poster did the back of the napkin math to find the area these radiators would have to have: twice the size of the pentagon. Launch cost: 30 billions.

This kind of pdf is what you get when your genius startup doesn't have a single engineer with half a brain and everybody does enough coke to believe you can beat physics with sheer enthusiasm.

That, or it is calculated fraud.

>>atoav+r2
Note: In my napkin math I forgot they could maybe use both the front and the back of the panel so it would be “merely” the area of one pentagon. I’ve edited that.

But the launch cost would remain the same as my original estimate because it was based on weight per “effective radiator area” of current best-practice space materials.

>>reaper+F3
Yeah there are clearly gains to be made by clever use of geometries etc, but the gist of your math is still sound.

Thesw kind of calculations are ballpark stuff. Even if they are a magnitude better these are still uneconomical numbers.

>>atoav+r2
Price depends on mass, and mass per area depends on conductivity, no? Maybe they have something cool going on with the material.

I should really get an AI to remake Guesstimate as a self-hostable site...

>>sunbum+O1
Oh I thought you meant outshine the sun from radiation. :)

Um, isn't that a secondary benefit? They'd also act as solar shades.

>>atoav+r2
Weird to call it fraud for not having mentioned or calculated what's literally the first most visible thing you see on their front page.

https://www.lumenorbit.com/

>>Feepin+77
You really think that? They have a material that has magical properties, is cheap enough, can produced by the ton and hide it just to make a space data center?

I am btw. not even sure if thermal conductivity is the limiting factor here, they still need to radiate that out and that is a function of surface area if I remember correctly.

Edit: Higher thermal conductivity helps with the thermal dissipation within the radiator, it does not affect the area of the radiator needed. Although it could affect weight if you roll it out thin enough. Still, this is quickly becoming the opposite of "simply putting a data center into space" and more like "decades of research on other topics". And AI is the vehicle to sell that.

>>Feepin+e7
Yeah, solar shades that are meant to cool the spacecraft, which is essentially a oven in need cooling already.

>>Veedra+N7
Not sure what you're on about, I have read their whitepaper in which they talk about building a large radiator assembly and mention the low temperature of space -- a fact that is absolutely irrelevant since the thermal capacity of a vacuum is nearly zero. In their table on page 1 they imply the cost of cooling is completely free in space, which I doubt, especially given the fact that the compute hardware you shoot up there is likely outdated within years and so you can hardly call a complex radiator of gigantic proportions that you had to shoot into space "free" unless you engage in very creative book keeping.

The low temperature of space is mentioned to trick non-critical people into thinking "wow smart, basically free cooling", when it is anything but. I am all for the idea of putting money into researching the topics needed to get those things going, but misleading investors like that is plainly wrong.

>>atoav+9b
From the paper,

> As conduction and convection to the environment are not available in space, this means the data center will require radiators capable of radiatively dissipating gigawatts of thermal load. [...] This component represents the most significant technical challenge required to realize hyperscale space data centers.

and

> A 5 GW data center would require a solar array with dimensions of approximately 4 km by 4 km

> [...]

> A 1m x 1m black plate kept at 20°C can radiate about 850 watts to deep space, which is roughly three times the electricity generated per square meter by solar panels. As a result, these radiators need to be about one-third the size of the solar arrays, depending on the radiator configuration.

Seriously, what more of an acknowledgement do you want? The paper covers everything you are complaining about in pretty plain and frank language.

>>Veedra+Hc
To be honest I am not sure how I overlooked that. Sorry.