[trhway]

>1. The capital costs are higher, you have to expend tons of energy to put it into orbit

putting 1KW of solar on land - $2K, putting it into orbit on Starship (current ground-based heavy solar panels, 40kg for 4m2 of 1KW in space) - anywhere between $400 and $4K. Add to that that the costs on Earth will only be growing, while costs in space will be falling.

Ultimately Starship's costs will come down to the bare cost of fuel + oxidizer, 20kg per 1kg in LEO, i.e. less than $10. And if they manage streamlined operations and high reuse. Yet even with $100/kg, it is still better in space than on the ground.

And for cooling that people so complain about without running it in calculator - https://news.ycombinator.com/item?id=46878961

>2. The maintenance costs are higher because the lifetime of satellites is pretty low

it will live those 3-5 years of the GPU lifecycle.

[javascriptfan69]

Current cost to LEO is $1500 per kg

That would make your solar panel (40kg) around $60K to put into space.

Even being generous and assuming you could get it to $100 per kg that's still $4000

There's a lot of land in the middle of nowhere that is going to be cheaper than sending shit to space.

[trhway]

>That would make your solar panel (40kg) around $60K to put into space.

with the GPU costing the same, it would only double the capex.

>Even being generous and assuming you could get it to $100 per kg that's still $4000

noise compare to the main cost - GPUs.

>There's a lot of land in the middle of nowhere that is going to be cheaper than sending shit to space.

Cheapness of location of your major investment - GPUs - may as well happen to be secondary to other considerations - power/cooling capacity stable availability, jurisdiction, etc.

[estomagordo]

> with the GPU costing the same, it would only double the capex.

Yes, only doubling the capex. With the benefits of, hmm, no maintenance access and awful networking?

[ndsipa_pomu]

Don't forget the major problem with cooling

[iso1631]

> jurisdiction

This is the big thing, but Elon's child porn generator in orbit will be subject to US jurisdiction, just as much as if they were in Alaska. I guess he can avoid state law.

If jurisdiction is key, you can float a DC in international waters on a barge flying the flag of Panama or similar flag of convenience which you can pretty much buy at this scale. Pick a tin-pot country, fling a few million to the dictator, and you're set - with far less jurisdiction problems than a US, Russia, France launched satellite.

[blackoil]

Any idea, what is the estimated cost of a Google TPU. It may not make sense for Nvidia retail price but at cost price of Google.

[trhway]

Can only speculate out of thin air - B200 and Ryzen 9950x made on the same process and have 11x difference in die size. 11 Ryzens would cost $6K, and with 200Gb RAM - $8K. Googling brings that the B200 cost or production is $6400. That matches the numbers from the Ryzen based estimate above (Ryzen numbers is retail, yet it has higher yield, so balance). So, i'd guess that given Google scale a TPU similar to B200 should be $6K-$10K.

[ericd]

I think the disconnect is that with starship they’re targeting >200 tons/200,000 kg and $2m-$10m/launch, so the very optimistic case is more like $10/kg. Also, the production of a panel in sun sync orbit is many times one on the ground, doesn’t suffer seasonality/weather, and doesn’t require battery storage for smoothing/time shifting, so you’d need to deploy many times the number of panels on earth. Our home array in North America over the course of the year generates something like 1/7th of its theoretical capacity, overproduces in the summer, and underproduces in the winter.

[pclmulqdq]

> putting 1KW of solar on land - $2K, putting it into orbit on Starship (current ground-based heavy solar panels, 40kg for 4m2 of 1KW in space) - anywhere between $400 and $4K.

What starship? The fantasy rocket Musk has been promising for 10 years or the real one that has thus far delivered only one banana worth of payload into orbit?

[trhway]

it is obviously predicated on Starship. All these discussions have no sense otherwise.

> or the real one that has thus far delivered only one banana worth of payload into orbit?

once it starts delivering real payloads, the time for discussions will be no more, it will be time to rush to book your payload slot.

[gspr]

You are presented with a factual, verifiable, statement that starship has been promised for years and that all that's been delivered is something capable of sending a banana to LEO. Wayyyy overdue too.

You meet this with "well, once it works, it'll be amazing and you'll be queuing up"? How very very musky!

What a cult.

[ben_w]

I have no idea if SpaceX will ever make the upper stage fully reusable. The space shuttle having existed isn't an existence proof, given the cost of repairs needed between missions.

However, with Starship SpaceX has both done more and less than putting a banana in orbit. Less, because it's never once been a true orbit; more, because these are learn-by-doing tests, all the reporting seems to be in agreement that it could already deliver useful mass to orbit if they wanted it to.

But without actually solving full reusability for the upper stage, this doesn't really have legs. Starship is cheap enough to build they can waste loads of them for this kind of testing, but not cheap enough for plans such as these to make sense if they're disposable.

[ENGNR]

They also launched dummy satellites from the "pez dispenser", directly simulating the actual mission payload, about 4 months ago.

[viraptor]

> will come down to the bare cost of fuel + oxidizer

And maintenance and replacing parts and managing flights and ... You're trying to yadda-yadda so much opex here!

[trhway]

It is SpaceX/Elon who bet billions on that yadda-yadda, not me. I wrote "If" for $10/kg. I'm sure though that they would easily yadda-yadda under sub-$100/kg - which is $15M per flight. And even with those $100/kg the datacenters in space still make sense as comparable to ground based and providing the demand for the huge Starship launch capacity.

A datacenter costs ~$1000/ft^2. How much equipment per square foot is there? say 100kg (1 ton per rack plus hallway). Which is $1000 to put into orbit on Starship at $100/kg. At sub-$50/kg, you can put into orbit all the equipment plus solar panels and it would still be cheaper than on the ground.

[sarchertech]

It looks like you’re comparing the cost of installing solar panels on the ground with the cost of just transporting them to orbit. You can’t just toss raw solar panels out of a cargo bay.

[trhway]

>You can’t just toss raw solar panels out of a cargo bay.

That is exactly what you do - just like with Starlink - toss out the panels with attached GPUs, laser transmitter and small ion drive.

[sarchertech]

Best estimates based on the publicly available data I can find are that solar panels make up 5-10% of the manufacturing cost of a starlink satellite.

There’s so much overhead you’re hand waving away to make your numbers work.

[gf000]

> it is SpaceX/Elon

The known scammer guy? Like these ideas wouldn't pass the questions at the end of a primary school presentation.

[javascriptfan69]

100 x 100 is 10,000.

[bildung]

1 KW of solar panels is 150€ retail right now. You are probably at 80€ or less if you buy a few MW.

(I'm ignoring installation costs etc. because actually creating the satellites is ignored here, too)

[tpm]

installation of large solar plants is largely automated already

[iso1631]

My car costs far more per mile than the bare cost of the fuel. Why would starship not have similar costs?

[reverius42]

The bean counters at NVidia recently upped the expected lifecycle from 5 years to 6. On paper, you are expected now to get 6 years out of a GPU for datacenter use, not 3-5.

[blackoil]

To add space solar cell will weigh only 4-12kg as protection requirements are different.

[estomagordo]

source?

[blackoil]

:| Did rough calculations with help of ChatGPT. In space it need not be hardened for rain, hail, wind and dust but for radiation and micro meteors.

[shagie]

Compare the cost of a RAD750 (the processor on the JWST) to its non rad hardened variant. Additionally, consider the processing power of that system to modern AI demands.

[blackoil]

I just calculated the potential weight of solar cells in space. Can't say about cost. Idea is mot of the weight of panel is because of glass/plastic protection on top and frame, these are there to protect from rain, hail, wind and dust. In space the elements it will need protection from will be different. I could be completely off but have no claims on cost and feasibility of this.

[shagie]

A solar panel deployed to space isn't deployed in its open / unframed configuration. Rather, it's sent in a way that is folded up into a compact volume and then unfolds into the full size.

https://youtu.be/wkume9d4Ogw

You'll note that there is still a frame that it gets unfolded with and that you've got the additional mechanical apparatus to do the unfurling (and the human there to fix it if there are problems.

https://youtu.be/UX4cCKKFVrs

Again, you'll note that there is frame material there.

You don't have a sheet of glass on it, but space doesn't give you the mass savings you think it does.

https://youtu.be/6vjK9vGEw5Q

Those are cutting edge tech (designed to work at Jupiter's distance) and that's about 40 m^2 of space (ten times more than you're describing) and they mass 176 kg ( https://doi.org/10.1007/s11214-025-01190-6 ). If we assume that scales down linearly, the cutting edge technology for solar panels is 20kg for 4m^2 which is more than your estimates. ... And they have problems and can fail to deploy. https://spacenews.com/cygnus-solar-array-fails-to-deploy/ https://spaceflightnow.com/news/n1105/25telstar14r/index.htm... https://www.nasa.gov/history/50-years-ago-skylab-2-astronaut... https://ntrs.nasa.gov/api/citations/20210020397/downloads/Al...

You'll note that the Cygnus used the same design as Lucy, though smaller.

https://en.wikipedia.org/wiki/Cygnus_(spacecraft)

> Starting with the Enhanced variant, the solar panels were also upgraded to the UltraFlex, an accordion fanfold array, and the fuel load was increased to 1,218 kilograms (2,685 lb).

Digging more into Ultra Flex, https://www.eng.auburn.edu/~dbeale/ESMDCourse/Site%20Documen...

> Specific performance with 27% TJ cells: >150 W/kg BOL & > 40 kW/m3 BOL

So there's your number. 150 W/kg of solar panel array. 1 kW is about 7 kg.

They're not cheap.

https://spacenews.com/36576ousted-from-first-orion-flight-ci...

> In 2011, Orbital replaced Dutch Space on the project and gave ATK’s space components division, which was already supplying the substrates for Dutch Space’s Orion solar panels, a $20 million deal to provide UltraFlex arrays for later Cygnus flights.