A former NASA engineer with a PhD in space electronics who later worked at Google for 10 years wrote an article about why datacenters in space are very technically challenging:
I don't have any specialized knowledge of the physics but I saw an article suggesting the real reason for the push to build them in space is to hedge against political pushback preventing construction on Earth.
I can't find the original article but here is one about datacenter pushback:
But even if political pushback on Earth is the real reason, it still seems datacenters in space are extremely technically challenging/impossible to build.
We don’t even have a habitable structure in space when the ISS falls, there is no world in which space datacenters are a thing in the next 10, I’d argue even 30 years. People really need to ground themselves in reality.
Edit: okay Tiangong - but that is not a data center.
> We don’t even have a habitable structure in space
Silicon is way more forgiving than biology. This isn’t an argument for this proposal. But there is no technical connection between humans in space and data centers other than launch-cost synergies.
Okay, but a human being represents what, 200 W of power? The ISS has a crew of 3, so that's less than a beefy single user AI workstation at full tilt. If the question is whether it's practical to put 1-2 kW worth of computing power in orbit, the answer is obviously yes, but somehow I don't think that's what's meant by "datacenter in space".
I don't know, 10 years seems reasonable for development. There's not that much new technology that needs to be developed. Cooling and communications would just require minor changes to existing designs. Other systems may be able to be lifted wholesale with minimal integration. I think if there were obstacles to building data centers on the ground then we might see them in orbit within the next ten years.
The same things you are saying about data centers in space was said by similar people 10-15 years ago when Elon musk said SpaceX would have a man on Mars in 10-15 years.
We have had the tech to do it since the 90's, we just needed to invest into it.
Same thing with Elon Musks hyperloop, aka the atmospheric train (or vactrain) which has been an idea since 1799! And how far has Elon Musks boring company come to building even a test loop?
Yeah, in theory you could build a data center in space. But unless you have a background in the limitations of space engineering/design brings, you don't truly understand what you are saying. A single AI data center server rack takes up the same energy load of 0.3 to 1 international space station. So by saying Elon musk can reasonable achieve this, is wild to anyone who has done any engineering work with space based tech. Every solar panel generates heat, the racks generate heat, the data communication system generates, heat... Every kW of power generated and every kW of power consumes needs a radiator. And it's not like water cooling, you are trying to radiate heat off into a vacuum. That is a technical challenge and size, the amount of tons to orbit needed to do this... Let alone outside of low earth... Its a moonshot project for sure. And like I said above, Elon musk hasnt really followed through with any of his moonshots.
His time estimates are notoriously, um, aggressive. But I think that's part of how his companies are able to accomplish so much. And they do, even if you're upset they haven't put a human on Mars fast enough or built one of his side quests.
"We specialize in making the impossible merely late"
> A single AI data center server rack takes up the same energy load of 0.3 to 1 international space station.
The ISS is powered by eight Solar Array Wings. Each wing weighs about 1,050kg. The station also has two radiator wings with three radiator orbital replacement units weighing about 1,100kg each. That's about 15,000 kg total so if the ISS can power three racks, that's 5,000kg of payload per rack not including the rack or any other support structure, shielding, heat distribution like heat pipes, and so on.
Assuming a Falcon Heavy with 60,000 kg payload, that's 12 racks launched for about $100 million. That's basically tripling or quadrupling (at least) the cost of each rack, assuming that's the only extra cost and there's zero maintenance.
People always make this claim about world hunger elimination with no sources. Keep in mind we make more than enough calories to feed everyone on the planet many times over, it's a problem of distribution, of getting the food to the right areas and continuing cultivation for self sufficiency.
Even the most magnanimous allocators cannot defeat the realities of boots on the ground in terms of distribution. It is a very difficult problem that cannot be solved top down, the only solution we've seen is growth of economic activity via capitalistic means, lifting millions, billions out of poverty as Asia has done in the last century for example.
If you're hellbent on arguing with a cult, it will be much cheaper to go down to your local Church of Scientology and try to convince them that their e-meter doesn't work.
As if company performance actually affected stock price when it comes to anything Elon Musk touches.
For fuck's sake, TSLA has a P/E of a whopping *392*. There is zero justification for how overvalued that stock is. In a sane world, I should be able to short it and 10x my money, but people are buying into Musk's hype on FSD, Robotaxi, and whatever the hell robot they're making. Even if you expected them to be successes, they'd need to 20x the company's entire revenue to justify the current market cap.
It's much easier to find a country or jurisdiction that doesn't care about a bunch of data centers vs launching them into space.
I don't get why we aren't building mixed use buildings, maybe the first floor can be retail and restaurants, the next two floors can be data centers, and then above that apartments.
Data centers don't do anything other than sit there and turn electricity into heat. They only emit nothing but heat (which could be useful to others in the building).
Mixed-use buildings with restaurants on the lower floors and residential on the upper floors are very common. Not sure what prisons have to do with anything.
> A former NASA engineer with a PhD in space electronics who later worked at Google for 10 years wrote an article about why datacenters in space are very technically challenging
It's curious that we live in a world in which I think the majority of people somehow think this ISN'T complicated.
Like, have we long since reached the point where technology is suitably advanced to average people that it seems like magic, where people can almost literally propose companies that just "conjure magic" and the average person thinks that's reasonable?
I can put things in a box that uses spooky electromagnetic waves to tickle water molecules to the point that they get hot and maybe boil off, given the chance? Sounds like magic to me
No, rockets landing themselves is just controlling the mechanism you use to have them take off, and builds on trust vectoring technology from 1970s jet fighters based on sound physics.
Figuring out how to radiate a lot of waste heat into a vacuum is fighting physics. Ordinarily we use a void on earth as a very effective _insulator_ to keep our hot drinks hot.
This is a classic case of listing all the problems but none of the benefits. If you had horses and someone told you they had a Tesla, you'd be complaining that a Tesla requires you to dig minerals where a horse can just be born!
It's a matter of deploying it for cheaper or with fewer downsides than what can be done on earth. Launching things to space is expensive even with reusable rockets, and a single server blade would need a lot of accompanying tech to power it, cool it, and connect to other satellites and earth.
Right now only upsides an expensive satellite acting as a server node would be physical security and avoiding various local environmental laws and effects
Lower latency is a major one. And not having to buy land and water to power/cool it. Both are fairly limited as far as resources go, and gets exponentially expensive with competition.
The major downside is, of course, cost. In my opinion, this has never really stopped humans from building and scaling up things until the economies of scale work out.
> connect to other satellites and earth
If only there was a large number of satellites in low earth orbit and a company with expertise building these ;)
You need to understand more of basic physics and thermodynamics. Fighting thermodynamics is a losing race by every measure of what we understand of the physical world.
No, people made fun of Elon for years because he kept attempting it unsafely, skirting regulations and rules, and failing repeatedly in very public ways.
The idea itself was proven by NASA with the DC-X but the project was canceled due to funding. Now instead of having NASA run it we SpaceX pay more than we'd ever have paid NASA for the same thing.
He also said he could save the us a trillion dollars per year with DOGE, and basically just caused a lot data exfiltration and killed hundreds of thousands of people, without saving any money at all
> It(Solar) works, but it isn't somehow magically better than installing solar panels on the ground
Umm, if this is the point, I don't know whether to take rest of author's arguments seriously. Solar only works certain time of the day and certain period of year on land.
Also there is so limited calculations for the numbers in the article, while the article throws of numbers left and right.
This is my second attempt learning Rust and I have found that LLMs are a game-changer. They are really good at proposing ways to deal with borrow-checker problems that are very difficult to diagnose as a Rust beginner.
In particular, an error on one line may force you to change a large part of your code. As a beginner this can be intimidating ("do I really need to change everything that uses this struct to use a borrow instead of ownership? will that cause errors elsewhere?") and I found that induced analysis paralysis in me. Talking to an LLM about my options gave me the confidence to do a big change.
n_u's point about LLMs as mentors for Rust's borrow checker matches my experience. The error messages are famously helpful, but sometimes you need someone to explain the why.
I've noticed the same pattern learning other things. Having an on-demand tutor that can see your exact code changes the learning curve. You still have to do the work, but you get unstuck faster.
Storngly agreed. Or ask it to explain the implications of using different ownership models. I love to ask it for options, to what if scenarios out. It's been incredibly helpful for learning rust.
>In particular, an error on one line may force you to change a large part of your code.
There's a simple trick to avoid that, use `.clone()` more and use fewer references.
In C++ you would be probably copying around even more data unnecessarily before optimization. In Rust everything is move by default. A few clones here and there can obviate the need to think about lifetimes everywhere and put you roughly on par with normal C++.
You can still optimize later when you solved the problem.
I am old but C is similarly improved by LLM. Build system, boilerplate, syscalls, potential memory leaks. It will be OK when the Linux graybeards die because new people can come up to speed much more quickly
The thing is LLM-assisted C is still memory unsafe and almost certainly has undefined behaviour; the LLM might catch some low hanging fruit memory problems but you can never be confident that it's caught them all. So it doesn't really leave you any better off in the ways that matter.
I don't see why it shouldn't be even more automated than that, with LLM ideas tested automatically by differential testing of components against the previous implementation.
Defining tests that test for the right things requires an understanding of the problem space, just as writing the code yourself in the first place does. It's a catch-22. Using LLMs in that context would be pointless (unless you're writing short-lived one-off garbage on purpose).
I.e. the parent is speaking in the context of learning, not in the context of producing something that appears to work.
I'm not sure that's true. Bombarding code with huge numbers of randomly generated tests can be highly effective, especially if the tests are curated by examining coverage (and perhaps mutation kills) in the original code.
Right, that method is pretty good at finding unintentional behavior changes in a refactor. It is not very well suited for showing that the program is correct which is probably what your parent meant.
That doesn't seem like the same problem at all. The problem here was reimplementing the program in another language, not doing that while at the same time identifying bugs in it.
Conversion of one program to another while preserving behavior is a problem much dumber programs (like compilers) solve all the time.
> I don't see why it *shouldn't be even more automated
In my particular case, I'm learning so having an LLM write the whole thing for me defeats the point. The LLM is a very patient (and sometimes unreliable) mentor.
I think the author is significantly underestimating the technical difficulty of achieving full self-driving cars that are at least as safe and reliable as Waymo. The author claims there will be "26 of the basically identical [self-driving car] companies".
If you recall, there was an explosion of self-driving car efforts from startups and incumbents alike 7ish years ago. Many of them failed to deliver or were shut down. [1][2][3]
Article about the difficulty of self-driving from the perspective of a failed startup[3].
Waymo came out of the Google-self driving car project which came from Sebastian Thrun's entry in 2005 Darpa challenge, so they've been working on this for more than 20 years. [4][5]
But that is the author's point. I don't see many of the same alternatives years later.
They have either shut down, got acquired or were sold off and then shutdown. Even Uber and Lyft had their own self-driving programs and both of them shut theirs down. Cruise was recently taken off the streets and not much has been done with them.
The only ones that have been around from more than 7 years are Comma.ai (which the author geohot still owns), Waymo and Tesla and Zoox, but they ran out of money and is now owned by Amazon.
As I understand, Comma.ai is focused on driver-assistance and not fully autonomous self-driving.
The features listed on the wikipedia are lane-centering, cruise-control, driver monitoring, and assisted lane change.[1]
The article I linked to from Starsky addresses how the first 90% is much easier than the last 10% and even cites "The S-Curve here is why Comma.ai, with 5–15 engineers, sees performance not wholly different than Tesla’s 100+ person autonomy team."
To give an example of the difficulty of the last 10%: I saw an engineer from Waymo give a talk about how they had a whole team dedicated to detecting emergency vehicle sirens and acting appropriately. Both false positives and false negatives could be catastrophic so they didn't have a lot of margin for error.
Speaking as a user of Openpilot / Comma device, it is exactly what the Wikipedia article described. In other words, it's a level 2 ADAS.
My point was, he had more than naive / "pedestrian level" (pun?) understanding of the problem domain as he worked on Comma.ai project for quite some time; even the device is only capable of solving maybe about 40% of the autonomous driving problem.
The last photo appears to show the view out the author's office in Fort Mason. Didn't know they had offices there, that's quite a nice view of the Bay.
Cool! I'd love to know a bit more about the replication setup. I'm guessing they are doing async replication.
> We added nearly 50 read replicas, while keeping replication lag near zero
I wonder what those replication lag numbers are exactly and how they deal with stragglers. It seems likely that at any given moment at least one of the 50 read replicas may be lagging cuz CPU/mem usage spike. Then presumably that would slow down the primary since it has to wait for the TCP acks before sending more of the WAL.
If you use streaming replication (ie. WAL shipping over the replication connection), a single replica getting really far behind can eventually cause the primary to block writes. Some time back I commented on the behaviour: https://news.ycombinator.com/item?id=45758543
You could use asynchronous WAL shipping, where the WAL files are uploaded to an object store (S3 / Azure Blob) and the streaming connections are only used to signal the position of WAL head to the replicas. The replicas will then fetch the WAL files from the object store and replay them independently. This is what wall-g does, for a real life example.
The tradeoffs when using that mechanism are pretty funky, though. For one, the strategy imposes a hard lower bound to replication delay because even the happy path is now "primary writes WAL file; primary updates WAL head position; primary uploads WAL file to object store; replica downloads WAL file from object store; replica replays WAL file". In case of unhappy write bursts the delay can go up significantly. You are also subject to any object store and/or API rate limits. The setup makes replication delays slightly more complex to monitor for, but for a competent engineering team that shouldn't be an issue.
But it is rather hilarious (in retrospect only) when an object store performance degdaration takes all your replicas effectively offline and the readers fail over to getting their up-to-date data from the single primary.
There is no backpressure from replication and streaming replication is asynchronous by default. Replicas can ask the primary to hold back garbage collection (off by default), which will eventually cause a slow down, but not blocking. Lagging replicas can also ask the primary to hold onto WAL needed to catch up (again, off by default), which will eventually cause disk to fill up, which I guess is blocking if you squint hard enough. Both will take considerable amount of time and are easily averted by monitoring and kicking out unhealthy replicas.
> If you use streaming replication (ie. WAL shipping over the replication connection), a single replica getting really far behind can eventually cause the primary to block writes. Some time back I commented on the behaviour: https://news.ycombinator.com/item?id=45758543
I'd like to know more, since I don't understand how this could happen. When you say "block", what do you mean exactly?
I have to run part of this by guesswork, because it's based on what I could observe at the time. Never had the courage to dive in to the actual postgres source code, but my educated guess is that it's a side effect of the MVCC model.
Combination of: streaming replication; long-running reads on a replica; lots[þ] of writes to the primary. While the read in the replica is going it will generate a temporary table under the hood (because the read "holds the table open by point in time"). Something in this scenario leaked the state from replica to primary, because after several hours the primary would error out, and the logs showed that it failed to write because the old table was held in place in the replica and the two tables had deviated too far apart in time / versions.
It has seared to my memory because the thing just did not make any sense, and even figuring out WHY the writes had stopped at the primary took quite a bit of digging. I do remember that when the read at the replica was forcefully terminated, the primary was eventually released.
þ: The ballpark would have been tens of millions of rows.
What you are describing here does not match how postgres works. A read on the replica does not generate temporary tables, nor can anything on the replica create locks on the primary. The only two things a replica can do is hold back transcation log removal and vacuum cleanup horizon. I think you may have misdiagnosed your problem.
Theoretically yes, but the method that is currently implemented (Hartree Fock) is notoriously inaccurate for molecular interactions. For example it does not predict the Van Der Waals force between water molecules.
I’m planning to add support for an alternative method called density functional theory which gives better results for molecular interaction.
In quantum chemistry, you decide where the bonds should be drawn. Internally, it's all an electron density field. So yes, you can model chemical reactions, for example by constraining the distance between two atoms, and letting everything else reach an equilibrium.
> wrap a small number of third-party ChatGPT/Perplexity/Google AIO/etc scraping APIs
Can you explain a little bit how this works? I'm guessing the third-parties query ChatGPT etc. with queries related to your product and report how often your product appears? How do they produce a distribution of queries that is close to the distribution of real user queries?
How third parties query your product:
For ChatGPT specifically, they open a headless browser, ask a question, and capture the results like the response and any citations. From there, they extract entities from the response. During onboarding I’m asked who my competitors are and the response is going to be recongized via the entities there. For example, if the query is “what are the best running shoes” and the response is something like “Nike is good, Adidas is okay, and On is expensive,” and my company is On, using my list of compeitotrs entity recognition is used to see which ones appear in the response in which order.
If this weren’t automated, the process would look like this: someone manually reviews each response, pulls out the companies mentioned and their order, and then presents that information.
2) Distribution of queries
This is a bit of a dirty secret in the industry (intentional or not): usually what happens is you want to take snapshots and measure them overtime to get distribution. However a lot of tools will run a query once across different AI systems, take the results, and call it done.
Obviously, that isn’t very representative. If you search “best running shoes,” there are many possible answers, and different companies behave differently. What better tools do like Profound is run the same prompt multiple times. From my estimates, Profound runs up to 8 times. This gives a broader snapshot of what tends to show up everyday. You then aggregate those snapshots over time to approximate a distribution.
As a side note: you might argue that running a prompt 8 times isn’t statistically significant, and that’s partially true. However, LLMs tend to regress toward the mean and surface common answers over repeated runs and we found 8 times to be a good indicator- the level of completeness depends on the prompt(i.e. "what should i have for dinner" vs "what are good accounting software for startups", i can touch on that more if you want
As I understand, in normal SEO the number of unique queries that could be relevant to your product is quite large but you might focus on a small subset of them "running shoes" "best running shoes" "running shoes for 5k" etc. because you assume that those top queries capture a significant portion of the distribution. (e.g. perhaps those 3 queries captures >40% of all queries related to running shoe purchases).
Here the distribution is all queries relevant to your product made by someone who would be a potential customer. Short and directly relevant queries like "running shoes" will presumably appear more times than much longer queries. In short, you can't possibly hope to generate the entire distribution, so you sample a smaller portion of it.
But in LLM SEO it seems that assumption is not true. People will have much longer queries that they write out as full sentences: "I'm training for my first 5k, I have flat feet and tore my ACL four years ago. I mostly run on wet and snowy pavement, what shoe should I get?" which probably makes the number of queries you need to sample to get a large portion of the distribution (40% from above) much higher.
I would even guess it's the opposite and the number of short queries like "running shoes" fed into an LLM without any further back and forth is much lower than longer full sentence queries or even conversational ones. Additionally because the context of the entire conversation is fed into the LLM, the query you need to sample might end up being even longer
for example:
user: "I'm hoping to exercise more to gain more cardiovascular fitness and improve the strength of my joints, what activities could I do?"
LLM: "You're absolutely right that exercise would help improve fitness. Here are some options with pros and cons..."
user: "Let's go with running. What equipment do I need to start running?"
LLM: "You're absolutely right to wonder about the equipment required. You'll need shoes and ..."
user: "What shoes should I buy?"
All of that is to say, this seems to make AI SEO much more difficult than regular SEO. Do you have any approaches to tackle that problem? Off the top of my head I would try generating conversations and queries that could be relevant and estimating their relevance with some embedding model & heuristics about whether keywords or links to you/competitors are mentioned. It's difficult to know how large of a sample is required though without having access to all conversations which OpenAI etc. is unlikely to give you.
short answer it depends and idk. When I was doing some testing with prompts like "what should I have for dinner" adding variations, "hey ai, plz, etc" doesn't deviate intention much. As ai is really good at pulling intent. But obv if you say "i'm on keto what should i have for dinner" it's going to ignore things like "garlic, pesto, and pasta noodles". Although it pulls a similar response to "what's a good keto dinner". From there we really assume the user can know their customers what type of prompts led them to chatgpt. You might've noticed sites asking if you came from chatgpt, i would take that a step further and asked them to type the prompt they used.
But you do bring a good perspective because not all prompts are equal especially with personaliztion. So how do we solve that problem-I'm not sure. I have yet to see anything in the industry. The only thing that came close was when a security focused browser extension started selling data to aeo companies- that's how some companies get "prompt volume data".
I see what you are saying, perhaps no matter the conversation before as long as it doesn't filter out some products via personalized filters (e.g. dietary restrictions) it will always give the same answers. But I do feel the value prop of these AI chatbots is that they allow personalization. And then it's tough to know if 50% of the users who would previously have googled "best running shoes" instead now ask detailed questions about running shoes given their injury history etc and that changes what answers the chatbot gives.
I feel like without knowing the full distribution, it's really tough to know how many/what variations of the query/conversation you need to sample. This seems like something where OpenAI etc. could offer their own version of this to advertisers and have much better data because they know it all.
Interesting problem though! I always love probability in the real world. Best of luck, I played around with your product and it seems cool.
> Our agreement with TerraPower will provide funding that supports the development of two new Natrium® units capable of generating up to 690 MW of firm power with delivery as early as 2032.
> Our partnership with Oklo helps advance the development of entirely new nuclear energy in Pike County, Ohio. This advanced nuclear technology campus — which may come online as early as 2030 — is poised to add up to 1.2 GW of clean baseload power directly into the PJM market and support our operations in the region.
It seems like they are definitely building a new plant in Ohio. I'm not sure exactly what is happening with TerraPower but it seems like an expansion rather than "purchasing power from existing nuke plants".
If history repeats itself ... tax payers will be fitting the bill. Ohio has shown to be corrupt when it comes to their Nuclear infrastructure. [0] High confident that politicians are lining up behind the scenes to get their slice of the pie.
The weasel wording is strong here. That's like me saying that buying a hamburger will help advance the science of hamburger-making. I'm just trading money for hamburgers. They're trying to put a shiny coat of paint on the ugly fact that they're buying up MWh, reducing the supply of existing power for the rest of us, and burning it to desperately try to convince investors that AGI is right around the corner so that the circular funding musical chairs doesn't stop.
We got hosed when they stole our content to make chatbots. We get hosed when they build datacenters with massive tax handouts and use our cheap power to produce nothing, and we'll get hosed when the house of cards ultimately collapses and the government bails them out. The game is rigged. At least when you go to the casino everyone acknowledges that the house always wins.
https://taranis.ie/datacenters-in-space-are-a-terrible-horri...
I don't have any specialized knowledge of the physics but I saw an article suggesting the real reason for the push to build them in space is to hedge against political pushback preventing construction on Earth.
I can't find the original article but here is one about datacenter pushback:
https://www.bloomberg.com/opinion/articles/2025-08-20/ai-and...
But even if political pushback on Earth is the real reason, it still seems datacenters in space are extremely technically challenging/impossible to build.
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