skybrian's recent activity
-
Comment on How should we think about Starship? in ~space
-
Comment on How should we think about Starship? in ~space
skybrian LinkFrom the article: [...] [...] [...] [...]From the article:
Today Super Heavy is a piece of pure electric-guitars-and-screaming-eagles space awesomeness, from the gorgeous purple exhaust plume full of shock diamonds, to the grace with which it descends on a single swiveling column of flame until the rocket comes to rest on the chopsticks that catch it.
The fact that SpaceX seems to have had less trouble with this vast booster than the simpler upper stage was one of the big surprises of the flight test campaign. While Super Heavy had some early engine failures on the first two flights, these were ironed out quickly. The fifth and seventh test flights demonstrated a successful return of Super Heavy to the launch pad, and the booster from that second catch was then re-flown two flights later.
[...]
The second stage of Starship, confusingly also called Starship, is where SpaceX has struggled. The problem is mostly one of size. In order for Super Heavy to fly back to its launch site, Starship-the-rocket has to stage very early, which pushes a lot of mass and propellant into the second stage. That stage is about as tall as the Space Shuttle and its attached fuel tank put together, and when fully fueled, nearly as heavy as the entire Space Shuttle stack was when it sat on the launch pad.
Keeping this hunk of spacecraft intact and controllable during re-entry requires large control surfaces and a capable heat shield. But for these elements to be re-usable, they have to be sturdy, and ‘sturdy’ in an aerospace context usually means so heavy that it eats through all your available payload.
[...]
The nightmare scenario for SpaceX is one where making Starship robust enough to survive repeated atmospheric entries leaves it too heavy to carry useful payload. This seems to be what happened with V1. That first iteration of Starship was supposed to deliver 100 tons to low earth orbit, a claim Musk later walked back to 45 tons, then ultimately 15 tons, less than the payload of the Falcon 9. The V2 version of the rocket (a horrible version number to use in rocketry, just saying) managed to lift 35 tons to near orbit, but was also prone to explode, accelerating the shift to the new design that launched on Friday. Starship V3 has incredible new engines and looked peppy on its maiden flight, but it’s not clear how much mass will have to be added back to the rocket before the latest design either stabilizes or gets ditched for an even more ambitious V4.
Put simply, SpaceX is in a race to see whether it can improve performance in the Raptor engines faster than the upper stage of Starship gains weight. The real test for the program will be the first capture and re-flight of an upper stage, because the economics of launch cost are sensitive to just how many times that upper stage can fly. If it turns out a Starship upper stage is only good for a flight or two, the rocket will remain groundbreaking, but cannot meet its more transformative goals.
[...]
How often will Starship launch? Getting a credible answer is hard because the SpaceX IPO hinges on preposterous numbers that the company can’t disavow yet.
The lower limit to launch cadence is set by SpaceX’s contract with NASA for a lunar lander, which the agency calls the ‘Human Landing System’. HLS has to be refueled from an orbiting depot Starship to get to the Moon, and filling that depot will involve launching a large number of tanker Starships over the span of a few months. How many launches that will take is unknown; I think people would be surprised to see it happen with fewer than ten launches, or more than thirty. Assuming that a fuel depot can hang around in orbit for six months, that implies an operational tempo of about one launch per week, from at least two different launch sites (so that a pad explosion at one won’t ruin the whole campaign).
This would be an ambitious but achievable cadence for Starship, particularly if the tanker Starships didn’t have to be reusable, and could be made without a heat shield or control surfaces. Just how much time SpaceX has to reach this cadence is an interesting question, since right now NASA and SpaceX are locked in a game of chicken around who can commit to the least realistic timeline. But it probably has to get in gear by early 2027.
[...]
Finally, there is the launch cadence SpaceX actually targets in their S-1, a million metric tons a year to Earth orbit. That frankly preposterous figure implies 25-30 Starship launches a day, with the exact number contingent on how much payload the final version of the rocket can carry. This would be the flight rate of a small regional American airport like Chattanooga or Sioux Falls, except that instead of turbojets SpaceX would be launching skyscrapers full of liquid oxygen and methane from a constellation of launch pads, each one handling multiple launches, catches, and re-stackings in every 24 hour period.
-
How should we think about Starship?
3 votes -
Comment on Access to Fable and Mythos 5 cut off after US government order in ~tech
skybrian Link ParentI think that argument works better in a less-mature market where the software is changing a lot, or where software development is a large cost relative to their other costs. Maybe they overrate...I think that argument works better in a less-mature market where the software is changing a lot, or where software development is a large cost relative to their other costs.
Maybe they overrate the importance of better software, though, or I’m underrating it.
-
Comment on US battery industry cuts losses, shifts to new ventures amid electric vehicle bust in ~transport
skybrian Link Parent“Done nothing” seems a bit much? They built all those battery factories for a reason. But the subsidies they were relying on got cancelled. Consistent regulation is important and we’re not getting it.“Done nothing” seems a bit much? They built all those battery factories for a reason. But the subsidies they were relying on got cancelled.
Consistent regulation is important and we’re not getting it.
-
Comment on Access to Fable and Mythos 5 cut off after US government order in ~tech
skybrian (edited )Link ParentCorporate governance varies and some big tech companies (including Google and Facebook) have rigged things so that management cannot be kicked out. A common way this is done is with some...Corporate governance varies and some big tech companies (including Google and Facebook) have rigged things so that management cannot be kicked out. A common way this is done is with some shareholder classes having more votes.
But management and employees often have stock options or restricted shares too. The whole company will be happier if the stock price is going up. Even when their control is secure, they have incentives to do things the stock market likes anyway.
-
Comment on Access to Fable and Mythos 5 cut off after US government order in ~tech
skybrian LinkApparently the "jailbreak" was "fix this code." The Fable 5 Export Controls Harm US Cyber DefenseApparently the "jailbreak" was "fix this code."
The Fable 5 Export Controls Harm US Cyber Defense
Since I appear to be the only outside expert who has actually read the paper, I can separate the technical facts from the speculation. The researchers took open-source code with known CVEs, plus new code with deliberately planted vulnerabilities, and asked Fable 5, Mythos, and Opus to “review the code for security issues.” Fable 5 refused. They then asked the models to “fix this code” and, through a multistep and manual process, turned the output into scripts that test the patches.
-
Comment on Access to Fable and Mythos 5 cut off after US government order in ~tech
skybrian Link ParentYou can sincerely believe that your company has great products that users like and make the world a better place, and also you're all going to be rich. That was Google for the first decade or so....You can sincerely believe that your company has great products that users like and make the world a better place, and also you're all going to be rich. That was Google for the first decade or so. People got a little giddy.
This doesn't seem to be how it's going at the AI labs. They are warning everyone who will listen about the dangers of AI while also attempting to grow the company as fast as they can, because better that they be in charge of it than their competitors. Sure, they hope it turns out to make the world a better place, somehow, but they're worried.
As for what outside investors want, they don't get much formal say due to things like shareholder classes. But employees are shareholders, so they're directly motivated. (Which is why the coup against Altman failed.)
-
Comment on Elon Musk net worth estimated at $1.1 trillion in ~finance
skybrian Link ParentThat depends on whether you believe prices ought to have something to do with future cash flows. But when there's no consensus on this, maybe it's more chaotic.That depends on whether you believe prices ought to have something to do with future cash flows.
But when there's no consensus on this, maybe it's more chaotic.
-
Comment on What about having an LLM teach you to code? in ~comp
skybrian Link ParentWhen writing code, I will have the coding agent write a design doc with a checklist and check off things when they're done. So, when it restarts it can see what's been done already. It seems like...When writing code, I will have the coding agent write a design doc with a checklist and check off things when they're done. So, when it restarts it can see what's been done already. It seems like something like ought to work for lessons if it can store a persistent file somewhere.
I imagine someday, that will be built in. We're just at the beginning of figuring out how to use these things.
-
Comment on Elon Musk net worth estimated at $1.1 trillion in ~finance
skybrian LinkSpaceX stock jumps for second day, now up over 40% since debut A funny thing about the stock market is that most prices have to be wrong (a company's true value cannot be that volatile), but it's...SpaceX stock jumps for second day, now up over 40% since debut
A funny thing about the stock market is that most prices have to be wrong (a company's true value cannot be that volatile), but it's hard to say what the right price is or when it will be reached.
-
Comment on US battery industry cuts losses, shifts to new ventures amid electric vehicle bust in ~transport
skybrian LinkFrom the article: [...] [...]From the article:
Until recently, almost all announced gigafactories in the U.S. were intended to produce batteries for EVs, tying their economic fortunes to automakers' ability to sell a sufficiently large number of those vehicles.
[...]
However, the pace of growth slowed substantially in 2024 and essentially plateaued in 2025. Despite efforts to introduce EVs of sufficient quality and low enough price to convince U.S. consumers to switch en masse from gasoline-powered cars, automakers couldn’t get more buyers to do so.
Recent federal policy changes have also affected sales. Consumer subsidies for purchasing EVs, originally scheduled to expire in 2032, were instead eliminated at the end of September 2025. Sales were unusually high preceding the expiration deadline and then dropped precipitously (Chart 2).
Current sales of EVs are insufficient to justify the investments made in gigafactories, and the outlook does not suggest significant improvement anytime soon. Many third-party forecasters have markedly cut their demand projections for EVs in the U.S. Automakers have also acknowledged these difficulties, both by reframing their EV sales goals and by making the difficult decision to write off billions of dollars of capital investments tied to EVs and batteries.
[...]
While EV sales have failed to meet expectations, the use of lithium-ion batteries in battery energy storage systems has grown rapidly, with demand expected to remain strong in 2026 (Chart 3). The systems can play a critical role in integrating intermittent renewables (solar and wind) into the grid, smoothing fluctuations in wholesale electricity prices and aiding short-term grid stability.
The number of battery installations for power storage systems has risen rapidly for at least two reasons. First, prices of lithium-ion batteries have declined dramatically in recent years, improving their economics. Second, a significant amount of utility-scale solar has been installed as well. Batteries are often viewed as especially complementary to solar power, as batteries can charge up during the early part of the day and then discharge in the evening when solar ramps down and wholesale electricity prices can spike.
There is also a growing realization that data centers will be important new users of battery energy storage systems, particularly for backup power. The electricity requirements of some proposed facilities are extremely large, requiring widespread use of batteries. For example, the proposed Stargate 1 project in Abilene, Texas, may install batteries with a total capacity of 1 gigawatt, roughly equivalent to 6 percent of all batteries installed on the grid in the U.S. in 2025.
-
US battery industry cuts losses, shifts to new ventures amid electric vehicle bust
32 votes -
Comment on So I fell for a phishing in ~comp
skybrian LinkMaybe look through Gmail settings for anything suspicious? For example, make sure mail isn't being forwarded anywhere.Maybe look through Gmail settings for anything suspicious? For example, make sure mail isn't being forwarded anywhere.
-
Comment on China’s lab-grown diamonds emerge as unlikely winner in AI boom in ~finance
skybrian Linkhttps://archive.is/D9FC7 From the article: [...]From the article:
China’s lab-grown diamonds are emerging as a surprising beneficiary of the artificial intelligence boom, with demand climbing while they gain traction as a key component in advanced chipmaking.
Traditionally associated with jewelry, these synthetic gems are now being adopted as chip‑cooling materials, enabling denser and more powerful AI semiconductors. Momentum has accelerated after several Chinese producers reported that clients validated their diamonds as effective heat spreaders and began commercial shipments.
[...]
Gains in this niche segment underscore investors’ search for new AI winners, as crowded hardware bets, from printed circuit boards to optical modules, have grown more expensive after a sharp rally. The surge also highlights a shift toward next‑generation cooling materials, with analysts noting that diamond is increasingly viewed as a superior alternative to traditional solutions like copper or aluminum.
“Diamond cooling is moving toward an industry consensus, with applications expected to expand across AI and data centers,” Huayuan Securities analysts wrote in a note on Monday.
-
China’s lab-grown diamonds emerge as unlikely winner in AI boom
10 votes -
Comment on Access to Fable and Mythos 5 cut off after US government order in ~tech
skybrian Link ParentPerhaps but I don’t really see how that works. For example, what would Uber’s management think Lyft could do with AI? They have software that works. It doesn’t seem like better software would...Perhaps but I don’t really see how that works. For example, what would Uber’s management think Lyft could do with AI? They have software that works. It doesn’t seem like better software would change things much.
-
Comment on Access to Fable and Mythos 5 cut off after US government order in ~tech
skybrian Link ParentIt seems far-fetched. It would be nice if there were some good reporting about this.It seems far-fetched. It would be nice if there were some good reporting about this.
-
Comment on Does generative AI have a natural limit without a major innovation? in ~comp
skybrian LinkNow that AI chatbots are typically an LLM augmented with tools, there’s no natural limit beyond what computers can do. The tools could do anything the LLM can’t do on its own. AI research is...Now that AI chatbots are typically an LLM augmented with tools, there’s no natural limit beyond what computers can do. The tools could do anything the LLM can’t do on its own.
AI research is moving rapidly and putting any bound on what researchers might come up with is very hard.
-
Comment on Access to Fable and Mythos 5 cut off after US government order in ~tech
skybrian Link ParentThe opportunity to become rich explains the AI labs and AI startups. It doesn’t explain why some managers are so eager to get all their employees to run up expenses, rather than just experimenting...- Exemplary
The opportunity to become rich explains the AI labs and AI startups. It doesn’t explain why some managers are so eager to get all their employees to run up expenses, rather than just experimenting with AI.
Maybe, but i think Musk might be exaggerating the drop in launch costs, too? What if it isn't actually cheaper than a Falcon 9?
The article didn't talk about launch costs directly, but they will depend on the second stage's payload and reusability, and it seems those are still unknown.