Comment by sanj
3 hours ago
Does anyone understand the math behind this bit?
> In the right orbit, a solar panel can be up to 8 times more productive than on earth....
3 hours ago
Does anyone understand the math behind this bit?
> In the right orbit, a solar panel can be up to 8 times more productive than on earth....
Because the panel is positioned such that it's is always exposed to the sun.
1: There is no night or day.
2: There are no seasons.
3: There is no weather.
Basically, the primary motivating factor of putting AI in space is abundant solar energy. Otherwise, AI in space makes little to no economic sense.
To build on the economic/practical issues.
The useful life of cutting edge AI server hardware will require constant rotation of equipment to potentially remain competitive with more accessible solutions.
Heat management ( https://m.youtube.com/watch?v=-w6G7VEwNq0 )
Hardening of equipment for the environment. ECC isn't going to be enough. I would have to defer to experts about the best way to manage it, but it either means custom hardware, weight, or both.
Repairs are impossible. Hopefully a sat can degrade gracefully, but routine repairs on earth become significant outages/decreases in economic value of a sat over time.
Rocket launches have gotten much better, but are not perfect. Insurance is a thing. However, cost of equipment in a failed launch may be eye watering, rivaling a governmental military launch.
To give a datacenter in space constant exposure to sunlight, the orbit must be either very var away, or occasionally be on the other side of the earth from you. Either way, the latency is terrible. You can put them in a ring and only choose the one closest to you, but are you really going to keep moving your data from satellite to satellite? So, bad for interactive use, maybe OK for non-interactive use, if you can afford the 30 foot by 30 foot solar panel and a similar size radiator for an 8x B300. That will be about $15M for your $500K GPU set. Plus $7M for the launch at SpaceX public rates.
Hard to know, but there are some areas they are probably using:
* 24 hours of light vs. ~9 hours of light (e.g. winter)
* Panels perfectly perpendicular to sun 100% of the time vs. variable for fixed panels on earth
* No atmosphere
* No clouds
Presumably they get exactly the same amount of sunlight 100% of the time instead of a few hours peak on earth? I'd say 8x is in the right order of magnitude.
My layman expectation would have been much higher. It's got no atmosphere refracting anything and it's closer to the source of energy.
The distance from earth to the sun is 150 million kilometers and your orbit is probably only a few hundred kilometers up (and realistically it’s sun-synchronous and perpendicular to the earth-sun axis), so the distance change doesn’t really matter.
LEO isn't much closer to the sun, and the atmosphere probably doesn't absorb a huge amount at the wavelengths they work.