>"A City on Mars" (2024)
https://nss.org/wp-content/uploads/NSS-JOURNAL-Critique-of-A...
I find it hard to believe that launching and operating data centers in space would turn out to be cheaper than solar, wind, and batteries down here on the ground.
From the rebuttal: "We are at the start of an upward curve of technology development that if allowed to continue for another 50 years, will make it as easy to reach space as to fly to Australia."
People were saying that fifty years ago. Didn't happen. Go rewatch "2001". And read NASA's "The Tyranny of the Rocket Equation". There's only so much you can do with chemical fuels.
>read NASA's "The Tyranny of the Rocket Equation"
He calls for "new paradigms of operating and new technology," which is what SpaceX delivers. On-orbit refilling gives the advantage of orbital assembly without the cost of separate spaceships. Instead of Petit's "building the pyramids" Shuttle example, SpaceX is cranking out water towers.
Certainly that's a new paradigm vs the old NASA way. Don't forget that NASA was forbidden from working on depots due to a certain senator's conflict of interest.
https://www.extremetech.com/extreme/296094-nasas-space-launc...
I guess these things aren’t literally exclusive, but it’s pretty amusing that elsewhere the rebuttal argues that we’re deep in a great stagnation which we need space exploration to pull us out of. (In the bit where he is arguing against the idea that we should wait a century and then maybe try to colonize space with greater technology)
> The slowdown in GDP growth is not mere paranoia, but an economic fact. Part of the problem with seeing clearly the stagnation all around us is that we need to compare ourselves to what might have been, not to the 1950s as the authors do.
This rebuttal is... poor, I guess? Not disingenuous or anything, but lots of wishful thinking and (for lack of a better term) "inside baseball"-objections.
Like sure H3 might be a byproduct of other mining on the Moon, but the hard part is the mining at all yes? It's wishful thinking to handwave away another hard problem and then say "this rebuts the other hard problem". Or "we'll get the metal for a Venus cloud city by moving asteroids into orbit" - yeah... if we can move and mine asteroids, building on Venus would be a lot easier but we can't do those things? Or an assumption of high enough immigration rates to offset genetic diversity concerns - space travel is hard, expensive, and all of this is at (or beyond) the limits of current engineering why assume a certain scale?
There's a fair amount of "only Musk and/or Bezos say X, but there are others in the community you say not-X" - which I'm sure is true but seems irrelevant? Like it or not, a handful of rich folks (and Hollywood and other popular media collectively) set the bounds of discussion here. Most telling in the rebuttal around Moon and Mars settlement, where the argument seems to be "A City on Mars is right, but we should also be talking about Venus and Titan (etc.)" - if I grab a random non-expert off the street, they're gonna list Mars, Moon, and maybe "space stations". Heck, didn't the current NASA admin announce plans for a nuclear reactor on the Moon? Presumably that's to power something (not that I expect it to ever be built) base-or-settlement-y?
A City on Mars is a pop-sci book so I'm sure there are plenty of issues, but (at least as a non-expert) the critiques I've seen (and this one in particular) are really poor.
"One modern idea that O’Neill did not consider is to move server farms in space, where power is cheap and you can dump heat into space with a black piece of metal."
Hmmm.
> "One modern idea that O’Neill did not consider is to move server farms in space, where power is cheap and you can dump heat into space with a black piece of metal."
Minor quibble - radiators are white in the visible spectrum.
https://space.stackexchange.com/questions/8851/why-arent-the...
> The radiators on the ISS are a high-emissivity white paint, meaning that they are dark in the infrared spectrum where the heat is emitted. They are white in the visible spectrum to reflect sunlight.
> The radiators on the shuttle are have a two-layer coating: a silver reflective layer covered by a thin Teflon film. The Teflon layer is opaque to infrared light, so the high emissivity of Teflon dominates. Visible light passes through the Teflon layer and is reflected by the silver layer, so the solar absorbance is low.
https://www.nasa.gov/wp-content/uploads/2021/02/473486main_i... - page 14 shows them extended and testing at Lockheed.
I was very interested to see in that rebuttal that they explicitly called out ‘datacenters in space’ as a means of ‘exporting’ solar power to the earth.
> As the Weinersmiths point out, the ease of generating solar electricity in space is foundational to space development. They focus on the challenges in beaming power back to the Earth, but the “power” could be returned to the Earth in other ways, such as by doing energy intensive manufacturing in space, with the result that we do not need the power on the Earth itself. One modern idea that O’Neill did not consider is to move server farms in space, where power is cheap and you can dump heat into space with a black piece of metal. If this was done on a large scale, the carbon impact of data services on the Earth would drop greatly even if power is not beamed back to the Earth. There are almost certainly other ways we can use power in space to do things in space that benefit people on the Earth.
So the original article seems to think that cooling is a significant challenge and that solar power in space is not ‘that much’ more effective than on the earth, and the other that cooling is trivial and that solar power is easily obtained. I’m inclined to go with ‘space is hard’ as that seems to comport with my other readings, but obviously the critique of ‘a city on mars’ is advocating for space exploration and is so motivated to minimize the difficulties.