I really think investors have sponged up the economics idea that growth can simply go on forever and don’t even consider the idea that there might be physical limits. I remember the Techno-Optimist Manifesto talking about raising everyone’s energy consumption by 1000 times…that means releasing more heat than we get from the sun, but I guess he figured the laws of thermodynamics were just one more puzzle for the engineers to work around. So many of these people live in a fantasy world where they assume rules can all be broken because they’ve never worried about them.
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Naive (raw quantitative) growth never goes on forever. Economic growth is something else entirely, and maybe needs different terminology to stop confusing people. Degrowth doesn’t even mean anything for the same reason. In my opinion.
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I wonder if we’d ever be able to engineer a material that could grow out at the inner surface (at a cooler temperature) as the outer surface degrades. Sort of like skin’s inner layers developing as the outer dead skin sloughs off.
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If such a material was possible, its use would have to consider the subject component’s mechanical design tolerances needed to achieve not just performance requirements, but also successfully sealing off (if required) from adjacent zones’ own conditions, i.e., temperature; pressure; and media. That would be a tough “ask”, but material sciences are – as seemingly always – way ahead of known/inevitable applications; see below for something along those lines:
‘Stunning’ discovery: Metals can heal themselves | ScienceDaily
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One possible way would be components forming the lowest layers combining to form metal crystals with inclusions (like carbon in steel) to harden the metal, or changes in density to create compressive stresses like in tempered glass.
The article is interesting. I’d like to know more about the mechanical testing. I assume it’s oscillatory.
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It would look like xylem, a transport mechanism, end-on to the surface. You’d need some kind of Maxwell’s demon traveling inward, always, eating the structure from the outside and feeding it to the inside. Or carry feedstock in the form of fuel or reaction mass. So… magic. Whatever. It would be incredibly fragile, just like the hollowed out high temperature turbine blades of current jet engine cores. Only moar.
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I was imagining the outer layer swept away (an ablation layer), with stores of material feeding the inner layer so it continues to grow.
Somehow.
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ETA:
Which isn’t as weird as it may sound. NASA used balsa wood for the camera mounts in the Ranger probes and the early Chinese spy satellites used oak as ablative heat shields on their film return buckets.
ETA 2:
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“SpaceX Starship” & “orbit” are two ideas that don’t really go together, in my mind.
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Oh, the flights have been suborbital for now by design. They can reach the velocity to become orbital. But not even SpaceX would want an unstable prototype this big and this heavy whooshing around in orbit and maybe coming down at the wrong place at the wrong time.
The elephant in the room right now is that everything that is supposed to fly in less than two years - HLS, the tankers, the depot - is designed around a performance of ~100 t to LEO.
Right now, they can do 40 to 50 t.
Not to mention that HLS, the tankers and the depot haven’t been built and tested yet.
The tanker/depot docking system hasn’t been built and tested yet and is a different kind of docking system than everything used so far.
The fuel transfer as it is needed for HLS hasn’t been tried yet. Pumping ~10 t from one tank inside a spacecraft into another tank inside the same spacecraft is something else than ~100 t between two docked crafts. Ob top on that, nobody knows the actual boil off rates yet.
Progress transporters have been topping up space stations since the Saljuts, but that’s in the order of ~800 kg of storables, not cryogenics, basically using a big syringe.
Yes, all of this can work and probably will work eventually, just not within the next two years.
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What is up with that rendering?
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I’ll just screengrab one of the comments from the article:
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