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This borders on science fiction. 88,000-and 1-million satellite clusters (as claimed in your link) are hard to take seriously, especially with the possibility of Kessler Syndrome. Also:

1. How do you cool your chips? Vacuum is a thermal insulator, so radiators are required to remove heat. nVidia (or even ASICs) require much and specialised cooling.

2. How does one radiation harden a H100?

3. I'm also seeing where TCO for these are 78x their terrestrial equivalents [0]. Is that financial sustainable?

And there still remain issues with power supply, regulations, and bandwidth. This feels more like a thought experiment rather than an actual serious engineering or business case.

[0] https://www.abiresearch.com/blog/data-centers-in-space

Mein Gott, you're not just making this up ( https://www.datacenterdynamics.com/en/news/neevcloud-and-agn... ).

But.. why?

Musk bandwagon-hopping? Investor bamboozlery? (Same diff?)

Is my borderline childish understanding of basic physics THAT off because I cannot see the value or utility (beyond a small smear of niche edge cases) of space-based compute?

- ed, disclosure: You seem to have edited your response whilst I was typing mine, adding in valuable links. Thanks!

Kerbal Space Program

It’s interesting that this is less funding/valuation than hundreds of other random B2B Series C/D companies that may not even exist in 5 years.

No point, just perspective.

They are charging around $14-15k per kg (~$5M per launch with a max payload of 350kg) but are also offering an additional 30% discount to make them cost competitive against ISRO.

Somewhat, but rocket engineering has some upward cost pressures that offset the savings from being in India: expertise is expensive even adjusting for the cost of labor (many staff are likely competing on salary with the rest of the world--rocket engineers/scientists are in high demand with lots of likely sponsors for immigration); aerospace materials/fabrication have a pretty global supply and patent chain even given how big and diverse India's industrial base is; safety and engineering tolerances are incentivized to meet global standards (many prospective launch/payload customers and investors are international), and so on.

I'm no expert, but I suspect that even if you apply a generous discount for being in India, Skyroot's economics are still quite impressive.

Edits: clarity

True, but:

Consider how many rocket development efforts squandered 10X to 100X the money, and >8 years, without making it to orbit.

Using solid fuel for their first 3 stages also makes it far easier. I'd take that as evidence of their management wisely picking a good shape for the org's learning curve. Vs. chasing the long-odds bragging rights & likely heartbreaks of a liquid-fuels-only version 1.0.

I can't tell if this is sarcasm, trolling, or delusion, so congrats, I guess.

SpaceX might fail for any number of reasons in the next ten years, but I would bet a lot of money that it won't be because they got outcompeted by Skyroot.

Probably meant the third country with a private sector capability to launch rockets, US and China being the other two.

So has SpaceX. It's becoming standard practice these days.

Liquid fueled launch vehicles aren't storable/able to be made ready at a moment's notice, unlike solids. Liquid fueled historical artifact:

https://en.wikipedia.org/wiki/SM-65_Atlas

There's a reason all modern silo based (and submarine) ICBMs are solids.

Right, but see the details for estimated range and the map. Not that India has any foreseeable need to nuke Argentina but it's not in range. It's entirely possible the public data is wrong and the Agni VI has a global range.

But by definition if you can put something into a 350x350 km low earth orbit (something like 7800m/s total delta V) you could also deliver a re-entering payload from your launch site to any other spot on earth, within the limitations of the inclination you're launching to.

> India's bureaucracy and MEA is beset with gandhian mindset who try to avoid confrontations and minimise belligerence, opposite of PRC wolf warriors I guess.

It isn't because of some purported Gandhian mindset. It's becuase India is in a pacing conflict with China and Pakistan, whereas China is in one with the US and historically the USSR. Assuming the Chagos Archipelago dispute gets resolved in the next decade (India and France backs it's return to Mauritius because Mauritius' police and military leadership are under direct Indian control [0] but the US prefers Chagos remaining under British control because we are closer aligned), India has no need to explicitly publicize ICBM capabilities that extend beyond China or Turkiye.

Additionally, publicly stating India has ICBM capabilities makes it harder to land transnational mining deals [1] because then discussions with Australia, Brazil, Canada, etc adopt a nuclear proliferation dimension as well as placing a target on India's private sector because of SpaceTech and DefenseTech's dual use implications.

[0] - https://thesecretariat.in/article/inside-raisina-hill-nsa-to...

[1] - https://www.ft.com/content/c5868e2f-8d19-4393-93be-2ad726a63...

Solid motors are simpler, but I wouldn't say they're more reliable. It was the solid booster failure that caused the Challenger disaster, and solid booster failures that have caused ULA's Vulcan Centaur rocket to be grounded. As you say, solids can't be throttled or turned off easily. They also can't be test fired. Yes, you can static fire a solid rocket and reuse the housing/nozzle/etc, but solids often fail due to imperfections in the propellant. Pockets of air or fractures in the propellant can cause a sudden increase in propellant surface area, which then generates more pressure, potentially blowing up the booster. With a liquid rocket, the engine can shut down if there's an anomaly. But with a solid, there's no option but to let the reaction continue.

There's also the issue that a solid booster must be "fueled" before it reaches the pad, meaning you have ground crew working around a large quantity of explosive material. A Brazilian solid rocket exploded on the launch pad, killing 21 people.[1] Liquid rockets can be made inert until everyone is far away, then loaded with propellant.

A big advantage of solid rockets is that they can be stored for long periods and quickly launched. This is handy for use cases like ICBMs, but not particularly important for commercial launches.

1. https://en.wikipedia.org/wiki/VLS-1_V03

Don't you need at least a little thrust ~40 mins later to circularize the orbit?

Obviously solid rockets can't be relit.

Could that be the use of the 4th stage?

Except you pay the weight for the nozzles on each stage.

That makes there be a mathematically optimal number.

Very good reminder!