[abalone]

> using wireless communication means even less bandwidth between nodes, more noise as the number of nodes grows, and significantly higher power use

Space changes this. Laser based optical links offer bandwidth of 100 - 1000 Gbps with much lower power consumption than radio based links. They are more feasible in orbit due to the lack of interference and fogging.

> Building data centres in the middle of the sahara desert is still much better in pretty much every metric

This is not true for the power generation aspect (which is the main motivation for orbital TPUs). Desert solar is a hard problem due to the need for a water supply to keep the panels clear of dust. Also the cooling problem is greatly exacerbated.

[Retric]

You don’t need to do anything to keep panels with a significant angle clear of dust in deserts. The Sahara is near the equator but you can stow panels at night and let the wind do its thing.

The lack of launch costs more than offset the need for extra panels and batteries.

[abalone]

What’s your source for that claim? Soiling is a massive problem for desert solar, causing as high as 50% efficiency loss in the Middle East.[1]

[1] https://www.nlr.gov/news/detail/features/2021/scientists-stu...

[Retric]

A relevant quote from that article.

“The reason I concentrate my research on these urban environments is because the composition of soiling is completely different,” said Toth, a Ph.D. candidate in environmental engineering at the University of Colorado who has worked at NREL since 2017. “We have more fine particles that are these stickier particles that could contribute to much different surface chemistry on the module and different soiling. In the desert, you don’t have as much of the surface chemistry come into play.”

[abalone]

You’re not summarizing the article fairly. She is saying the soiling mechanisms are environmentally dependent, not that there is no soiling in the desert. Again, it cites an efficiency hit of 50% in the ME. The article later notes that they’ve experimented with autonomous robots for daily panel cleaning, but it’s not a generally solved problem and it’s not true that “the wind takes care of it.”

And you still haven’t provided a source for your claim.

[Retric]

I’m saying the same thing she is, that soiling isn’t as severe in the desert not that it doesn’t exist.

The article itself said the maximum was 50% and it was significantly less of a problem in the desert. Even 50% still beats space by miles, that only increases per kWh cost by ~2c the need for batteries is still far more expensive.

So sure I could bring up other sources but I don’t want to get into a debate about the relative validity of sources etc because it just isn’t needed when the comparison point is solar on satellites.

[abalone]

You are again misquoting the article. She did not say soiling was "significantly less of a problem" in the desert. She in fact said it "requires you to clean them off every day or every other day or so" to prevent cement formation.

You claimed it was already a solved problem thanks to wind, which is false. You are unable to provide any source at all, not even a controversial one.

And that's just generation. Desert solar, energy storage and data center cooling at scale all remain massive engineering challenges that have not yet been generally solved. This is crucial to understand properly when comparing it to the engineering challenges of orbital computing.

[LargoLasskhyfv]

Shouldn't swarms of quadcopter drones zipping around the panels be able to handle that?

Wouldn't even need to be that 'autonomous', since the installation is fixed.

More like the things simulating fireworks with their LEDs in preprogrammed formation flight over a designated area.

[imtringued]

You don't need quadrocopters. Solar panels arranged in rows have rails that cleaning robots can drive on.

[funcDropShadow]

The same panel produces much more electricity in space than at the bottom of the atmosphere, because the atmosphere already reflects most of the light. Additionally, the panel needs less glass or no glass in space, which makes it lighter and cheaper.

Launch costs have shrunk significantly thanks to SpaceX, and they are projected to shrink further with the Super Heavy Booster and Starship.

[cmsj]

Space doesn't really change it though because the effective bandwidth between nodes is reduced by the overall size of the network and how much data they need to relay between each other.

[kimixa]

Yup. We don't use fibre optics on earth rather than lasers because of some specific limitation of the earth's surface being in orbit would avoid.

We use them because they're many orders of magnitude cheaper and simpler for anywhere near the same bandwidth for the distances required.

[abalone]

> We don't use fibre optics on earth rather than lasers because of some specific limitation of the earth's surface being in orbit would avoid.

That's incorrect. Lasers can suffer from atmospheric interference and fogging on earth.

Here is a post from NASA explaining why they like laser communications better than RF in space.[1]

[1] https://solc.gsfc.nasa.gov/modules/kidszone7/mainMenu_textOn...