Neal Stephenson Thinks Rockets are an Overhyped Technology (politico.com) 220
Every Friday Politico interviews someone about "The Future in Five Questions". This week they interviewed Neal Stephenson (who they describe as "the sci-fi author who coined the term 'metaverse' and now a Web3 entrepreneur in his own right.")
Stephenson began by sharing his thoughts on a big idea that's underrated. Neal Stephenson: Desalination. It's an incredibly obvious, kind of simple process. Nothing is more basic than having water to drink, so it's kind of hiding in plain sight, but coupled with cheap energy from photovoltaics it's going to make big changes in the world. When you look at how much water, or a lack thereof, has shaped where people live and how people make food, the notion that we might be able to engineer ways to get fresh water in a new way could be revolutionary.
What's a technology you think is overhyped?
Stephenson: I'm going to go with an oldie: rockets. It's just a historical accident that chemical rockets became our only way of putting stuff into space, and if we had started at a different time we would have ended up doing something that works better.
One alternative would be beaming energy from the ground to vehicles, using lasers or microwaves. That seems like a doable project right now. There's nuclear propulsion, which I think is probably never going to happen at scale, because it's politically impossible, but even something as simple as constructing a very tall building or a tall tower and using that as a launch platform, or as a way to accelerate things up upward, could really change the economics of spaceflight.
Stephenson also says the book that most shaped his conception of the future was Robert Heinlein's 1958 novel Have Spacesuit, Will Travel. And the biggest surprise of 2022 was Ukraine's strong response after Russia's invasion. "Most people who are paying attention have understood that drones and other new technologies are going to change the way wars get fought, but we're seeing it unfold and mutate in real time in Ukraine.
"These guys are taking old Cold War grenades and disassembling them, and putting on homemade fuses and attaching 3D printed fins and dropping them out of consumer-grade drones, to a significant effect on the battlefield...."
In 2004 Neal Stephenson answered questions from Slashdot's readers.
Stephenson began by sharing his thoughts on a big idea that's underrated. Neal Stephenson: Desalination. It's an incredibly obvious, kind of simple process. Nothing is more basic than having water to drink, so it's kind of hiding in plain sight, but coupled with cheap energy from photovoltaics it's going to make big changes in the world. When you look at how much water, or a lack thereof, has shaped where people live and how people make food, the notion that we might be able to engineer ways to get fresh water in a new way could be revolutionary.
What's a technology you think is overhyped?
Stephenson: I'm going to go with an oldie: rockets. It's just a historical accident that chemical rockets became our only way of putting stuff into space, and if we had started at a different time we would have ended up doing something that works better.
One alternative would be beaming energy from the ground to vehicles, using lasers or microwaves. That seems like a doable project right now. There's nuclear propulsion, which I think is probably never going to happen at scale, because it's politically impossible, but even something as simple as constructing a very tall building or a tall tower and using that as a launch platform, or as a way to accelerate things up upward, could really change the economics of spaceflight.
Stephenson also says the book that most shaped his conception of the future was Robert Heinlein's 1958 novel Have Spacesuit, Will Travel. And the biggest surprise of 2022 was Ukraine's strong response after Russia's invasion. "Most people who are paying attention have understood that drones and other new technologies are going to change the way wars get fought, but we're seeing it unfold and mutate in real time in Ukraine.
"These guys are taking old Cold War grenades and disassembling them, and putting on homemade fuses and attaching 3D printed fins and dropping them out of consumer-grade drones, to a significant effect on the battlefield...."
In 2004 Neal Stephenson answered questions from Slashdot's readers.
Different time? (Score:5, Insightful)
"...if we had started at a different time we would have ended up doing something that works better."
Yeah, that applies to literally everything. So what's your point, Neal?
Re:Different time? (Score:5, Funny)
Yeah, that applies to literally everything. So what's your point, Neal?
As readers of his books will know...he struggles to get to the point, a lot.
Re: (Score:2, Interesting)
You're not getting the point, probably.
More likely than the idea that the most successful author of his generation in his genre is somehow struggling.
His readers, of course, often finish his works and wish he would "struggle" with the story some more! lol
Re:Different time? (Score:4, Funny)
Try to convince someone of that while he's in the Monday morning traffic jam.
job satisfaction (Score:2)
Given the levels of job satisfaction in this economy, the journey in a traffic jam may still be better than the destination at one's office.
Re: (Score:2)
Greater? Sure. Go around a block twice and it will be a greater journey than only doing that tour once.
Better? In the case of Neal Stephenson... I can't say that.
E.g. With Stephen King? Yeah... Sure.
Having recently gone through "It" and "The Shining" - it's obvious King was holding back with those newspaper clips in "The Shining".
Similar short "interludes" in "It" are not only fully fleshed-out standalone stories they also enrich the larger universe of the book (one literally connects "The Shining" to "It")
No, he didn't say "rockets" (Score:2)
He actually was referring to The Rockettes [wikipedia.org] - and I have to agree, the act hasn't aged well.
Houston Rockets Are Definitely Overhyped. (Score:3)
Go Spurs!
Ya, about that ... (Score:5, Funny)
It's just a historical accident that chemical rockets became our only way of putting stuff into space, and if we had started at a different time we would have ended up doing something that works better.
One alternative would be beaming energy from the ground to vehicles, using lasers or microwaves.
That seems like a doable project right now.
(a) How much laser/microwave energy would be required to lift a vehicle from the ground into orbit and how would that work?
(b) I tried microwaving a Falcon 9, but I couldn't get the door closed on the oven.
Re:Ya, about that ... (Score:5, Informative)
The rule of thumb that is usually quoted is that it takes a megawatt of power beamed to a vehicle per kg of payload while it is being accelerated to permit it to reach low earth orbit. [wikipedia.org]
SpaceX is talking about 100-150 (metric?) tons to orbit [wikipedia.org], so that suggests a 100 to 150 Gigawatt beamed power source (not sure for what duration) for an equivalent launch to a Starship
Re: (Score:2, Interesting)
Most of that 100-150 tons is fuel plus rockets just to put something like 1 ton of payload into orbit.
In theory, it should only take 9.8J to lift 1 kg by 1 meter, so 1 ton (907 kg) to 100 miles (161,000 meters) should take 1.43GJ or 397 kWh, about $48 at 12 cents per kWh.
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Read up on SpaceX Starship [wikipedia.org], it is being designed to put 100 to 150 tons of payload into orbit, with 5000 tons total vehicle weight including fuel
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Read up on SpaceX Starship [wikipedia.org], it is being designed to put 100 to 150 tons of payload into orbit, with 5000 tons total vehicle weight including fuel
It was originally supposed to have a 300 ton launch capacity which was then cut in half.
so now it's 100-150 tons? let's see if it manages to keep the low end of that range
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I don't recall hearing 300 tons proposed for Starship. Possibly for its much larger conceptual predecessor - but even when they were talking the initial carbon fiber
Starship plan I think 150-200t was the aspirational goal.
Last I heard the stainless steel Starship should carry 100-150t to orbit once it starts flying commercially - and if Falcon 9 is any indicator we can expect that number to increase as the design matures.
Re:Ya, about that ... (Score:5, Insightful)
> In theory, it should only take 9.8J to lift 1 kg by 1 meter, so 1 ton (907 kg) to 100 miles (161,000 meters) should take 1.43GJ or 397 kWh
And if you want it to stay up there, you need to accelerate it to orbital speeds as well; at 161km altitude the orbital velocity is 7,814 m/s. So a 907kg payload to LEO would need an additional 27.7 GJ on top of the 1.4GJ from altitude.
Air resistance is going to be a major factor as well of course, but I have no idea where to begin calculating that.
Then figure that it would be an amazing feat of engineering to get an energy beam that powerful that's more than like 5% efficient (you're definitely in MASER territory) so take whatever value you come up with and multiply it by at least 20.
TL;DR: It's a stupid fucking idea, just build a normal rocket.
=Smidge=
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I didn't think about the insertion cost. So just under $1,000 in energy costs, theoretically, to put 907 kg into low earth orbit--about $1 per kg.
In comparison, the actual cost today is about $2,700 per kg.
Air re
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Most of that 100-150 tons is fuel plus rockets just to put something like 1 ton of payload into orbit.
In theory, it should only take 9.8J to lift 1 kg by 1 meter, so 1 ton (907 kg) to 100 miles (161,000 meters) should take 1.43GJ or 397 kWh, about $48 at 12 cents per kWh.
I am not a rocket scientist. So here's my question:
Assuming you had a 1kg device 10cm x 10cm x 10cm that could produce an effectively infinite amount of electricity, how do you use that to actually get a payload into orbit?
I mean, sure, plenty of science fiction shows things like antigravity shuttles. But we don't have anything even vaguely similar. I'm not aware of anything our understanding of physics and material science would suggest such a thing would be available to us if only we hadn't got stu
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You use it to power a linear accelerator. See "Moon is a Harsh Mistress" by RAH. Theoretically possible, but it would take some MAJOR engineering to actually build it, and it would take a metric-fuckton of power to use it. Think major engineering project powered by multiple nuclear power plants running up to the top of Everest...
Re: Ya, about that ... (Score:2)
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Power a huge laser on the ground pointed up with adaptive optics and aim it at your space craft's bell shaped nozzle which is very ablative and use pulses from the laser to make small explosions in the bell for thrust is one idea.
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You use it to heat up some kind of reaction mass, probably via microwaves, and let it blow out the back end.
Energy isn't really the issue with launches from the surface. Mass is. Our chemical rockets are the same thing, they just store the energy in the reaction mass.
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Most of that 100-150 tons is fuel
Thermal rocket schemes require a reaction mass so you can't just zero out the mass of "fuel." The "lightcraft" concept can only operate in the atmosphere unless it, too, has some reaction mass, in addition to the mass of the reflector. So again, you can't zero out the mass on your napkin.
to 100 miles
At which point it falls back to Earth. Getting into space means getting into orbit, not just clearing the atmosphere.
This all assumes technology that can safely and cost effectively concentrate staggering amounts of po
Re: Ya, about that ... (Score:2)
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But maybe they don't need it to get to orbit just assist the takeoff and landing if the additional parts don't add a lot of mass, like say the laser was aimed at the existing heat shield tiles.
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Yeah, this seems a dumb solution. The normal go to, is using an airplane up to the thin atmosphere, and only then a specialized rocket from there.
Re:Ya, about that ... (Score:5, Informative)
The problem is, it's not about going high up to get into orbital altitude. The problem is going fast enough to reach orbital speed.
https://what-if.xkcd.com/58/ [xkcd.com]
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Yes, but that is easier in thinner atmosphere, and rockets have to be constructed compromised to work in both ground level and near space atmosphere, you can get much better efficiency if you can optimize for only thin to none atmosphere. The problem is carrying that much weight up there, and getter a reliable separation and angle.
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There's no "compromise" needed for atmospheric thickness, and no gain in effectiveness achieved by starting from further up. You still need to reach 8 km/sec, and that still takes just as much energy.
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The advantage of both beamed power and nuclear thermal is that you can use anything for reaction mass. You can use air on your way up, then switch to a small internal tank of pretty much whatever is convenient for the last kick into orbit. You can actually use air much longer than with combusion engines too, because you don't have to worry about keeping the combustion going.
Re:Ya, about that ... (Score:5, Insightful)
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Ummm.... (Score:5, Insightful)
I know he's a respected speculative fiction author, and that he worked at Blue Origin for a few years thinking up zany alternative propulsion methods, but his statements sound like somebody who knows little to nothing about the physics involved in getting stuff into orbit. We use chemical rockets because nobody has figured out a better alternative. Even nuclear propulsion, even without all the political roadblocks, was only ever suitable for upper stages. Ultimately it was still going to be launched by a chemical first stage. And... launching from a tall building? The only thing altitude gets you is less atmospheric pressure, and while that's helpful, the absurd cost of building a structure tall enough to get above a meaningful portion of the atmosphere would be far more than just building a bigger rocket. And we've already tried equivalent systems, like air-launched rockets, and they end up being just not worth it.
Spinlaunch is another attempt at an alternative, but the payload will face a peak acceleration of 10,000g, so it's extremely limited in the sorts of payload it can launch.
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Really, really big guns have been used as well
imo, we do need the occasional curmudgeon to smack us upside the head and get us out of a mental rut
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After Putin wrestled bear, he threw defeated creature into orbit!
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There is a company looking at yeeting stuff into orbit as well.
The problem is we live in a deep gravity well, the escape velocity of which is around 11,000 m/s (about 420,000 mph, or 660,000 kph). Basically you have to accelerate to that speed at which point you are falling into the earth and miss, i.e., orbiting.
So somehow you have to accelerate an object to that
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Nuclear propulsion would be neat, except for one tidbit: It's heavy and bulky. Two properties that are pretty much the opposite of what you need in rocket design.
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Well, an Orion can use fission to put a huge load into orbit from the Earth's surface.
You have a huge dome, with huge shocks above it and a huge craft on top of the shocks then you let of a nuke under the dome, those million tons will move, then you keep exploding nukes under the dome.
A super Orion could put 8 million tons into orbit, would take about 1080 nukes each about 3 tons including polythene or such. Smaller would be more practicable but you want some size to even out the nuclear pulses.
https://en.w [wikipedia.org]
Accelerated launch platform? (Score:2)
Stephenson seems to be losing the focus of his speculations in his recent books?
"The focus is strong in this one" seems more descriptive of the younger Stephenson's books?
("The focus is weak in this one" is too descriptive of yours truly.)
However, I've been speculating on this topic quite a bit, so I was disappointed with the shallowness of the quoted bit on the tower. My current belief is that the best way to put lots of mass into orbit would be with an accelerated launch platform, and it would be crazy to
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> We use chemical rockets because nobody has figured out a better alternative.
I speak as a "rocket scientist" (space systems engineer) who worked for Boeing and NASA. We *have* figured out better alternatives, but modified ballistic missiles got us to orbit first and have dominated the market.
Hypersonic gas guns can reach Mach 5-13, depending how many g's you can tolerate, and guns are pretty reusable, but you want a *lot* of traffic to justify the cost of building them. Such guns already exist in sm
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Hint: he graduated with degree in geography and a minor in physics.
Well, based on TFA, he knows bugger-all about space travel. It is really hard to beat rockets for getting to orbit, unless doing it on a massive scale that we have no reason for. He dismisses nuclear rockets, but they are best used in space (after getting to orbit) where NIMBY politics is less of a problem.
And how is desalination under-rated? It is widely used all over the world. Half of my own water supply comes from desal plants (W. Australia) .
Maybe he means it is not talked about much because it is
Re: Ummm.... (Score:2)
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Hint: he graduated with degree in geography and a minor in physics.
And people really wonder why the world laughs about US degrees?
Re:Ummm.... (Score:4, Insightful)
Hint: he graduated with degree in geography and a minor in physics.
And people really wonder why the world laughs about US degrees?
Which explains why people come from all over the globe to obtain them, right?
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Doesn't much matter what he graduated with when he spouts garbage. Appeal to authority is at best ugly, at worst enabling religious rulers. Don't do it. It makes you look like a zealot.
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It would be easier to build a 300 km high ring around the planet and drop mini space elevators from it. It's called an orbital ring, and it's surprisingly practical. We could probably build one today if we really wanted to.
Re: Ummm.... (Score:2)
Kalideoscope vision (Score:3)
I'm going to have to push back on the future vision of a guy who cannot even explain how one of his favorite characters, Enos Root, could possibly exist.
And, correct me if I'm wrong, but "nuclear propulsion" is still a type of rocket.
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Enoch Root is obviously coming from outside the simulation, as demonstrated by his detached interest in the human effort to create its own simulation in Fall or Dodge in Hell
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Yer rong. Now look up what a "rocket" is (for the first time in your life)
Your spelling is on par with your understanding of rockets. How ironic that you talk about Dunning-Kruger with no self-awareness.
Be it nuclear-thermal, nuclear electric ion drive, or Project Orion, they are all rockets.
Laser rocket (Score:2)
I almost went to RPI (Rensselaer Polytechnic Institute) back in the early 90s cause I heard of a professor there who was working on a laser propelled rocket.
Reference: https://www.youtube.com/watch?... [youtube.com]
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How did they plan to deal with atmospheric attenuation of the laser?
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I can imagine that a lot of money has been spent on that issue for high energy weapons, maybe some mature technology could trickle down to the commercial world.
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I can imagine that a lot of money has been spent on that issue for high energy weapons
Yeah. Specifically it's why high energy weapons don't have very good range, and also why they wanted to put lasers in space to shoot down ICBMs.
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Here is an article from January of this year, they seem to be focused on taking drones down from a distance and driving off small motorboats.
Also, they make no mention of the power involved but it seems low considering their targets
Summary:
The Department of Defense (DOD) is not alone in its efforts to field HPM weapons, as potential peer-state competitors are actively pursuing them as well. They still remain one of the murkier areas of military research, however, and a high degree of confusion and misinform
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The coolest active laser weapon in my opinion is currently Iron Beam [wikipedia.org], used for rocket defense. All of these weapons (as far as I know) have a range of less than 10 miles. The Iron Beam have a 5 mile range. Still useful.
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You don't necessarily have to "deal with" it at all outside of the predicting how much power to use, when.
Mostly you choose an appropriate frequency based on charts that are in any optics engineering book.
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There's moisture/dust/etc in the air that blocks radiation. You can't get any kind of focused beam at a frequency that doesn't lose power when it hits air and its contents.
Re: Laser rocket (Score:2)
I remember that. As I recall, the really insurmountable problem is that atmospheric attenuation, refraction, and scattering makes it basically impossible, or at least you get efficiencies approaching zero, whether you're talking lasers or microwaves.
And of course there's that whole problem with horizons and line-of-sight, which would necessitate multiple transmission stations around the globe. Not a small ask when 70% of the planet is ocean and you need megawatts of essentially instantaneous power deliver
Re: Laser rocket (Score:2)
Does not mean SpaceX cannot use something like that for the takeoff and last part of the landing if it can save fuel. As long as they do not have to add a ton of extra stuff to make it happen.
He is just wrong. (Score:5, Insightful)
Yes, in principal you could beam GW of microwaves at a rocket that is using say hydrogen for reaction mass. But how is that better. The microwave transmitter is both expensive and inefficient and you need to worry about the scattered microwaves causing a hazard on the ground. You need multiple stations as the rocket accelerates horizontally out of range of the first one. Yes, the rocket mass might be lighter, but what has this actuatly improved?
Nulear works but even an ardent nuclear proponent like me is uneasy about a GW, barely shielded rocket flying overhead. The reactor is so heavy that againg you aren't winning a lot on payload, but have an extremely complex and dangerous reactor to deal with.
Tall towers? Rockets aren't normally launched from mountains because stating from a higher altitude doesn't help much. Even if you built a 200 mile tall tower, you haven't decreased the delta_V very much (its almost all in horizontal velocity). Launching from an aircraft isn't crazy, and that is done a little, but so far ground launch is less expensive.
Rail guns, spin launch, slingatron etc all expose the payload to very high G's The problem is that once you launch up, you need a lot of horizontal delta-V. If you launch horizontally you are going through a lot of atmosphere at Mach 20. Since there are high launch G-'s the uper stage needs to be extremely strong which makes it extremely heavy, so the mass ratio is terrible for the horizontal delta-V.
Space elevator requires extreme materials, and has problems with power and throughput if you want to launch a lot of material. The capital cost seems extremely high.
Rockets can use H2/O2, and once we have clear energy, that means rockets can be non-polluting. Then its all about cost and I don't see any reason to think these other technologies are cheaper. Fuel is only a tiny fraction of launch costs, so trading fuel consumption for far higher capital costs is not a win.
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Anything removing fuel/oxydizer from the rocket is a win. Most of the mass and volume of rockets are both, the payload is tiny. Power beaming, however inefficient, would still be more efficient than carrying whatever your replacing.
The idea of towers is missing the point, it's not the distance but the fact that the atmosphere is thicker the lower in altitude you go, a lot of power, and thus reaction mass, is used just getting out of the troposphere versus the rest of the way. The real reason
Re:He is just wrong. (Score:5, Informative)
Anything removing fuel/oxydizer from the rocket is a win. Most of the mass and volume of rockets are both, the payload is tiny.
Sorry, but you don't seem to understand the first thing about rockets.
That fuel/oxidiser doubles as propellant, which is what really counts.
You could have a nuclear reactor to remove most of the need for "fuel", but still need mass to throw out the back.
Power beaming, however inefficient, would still be more efficient than carrying whatever your replacing.
Really? Please show us your maths, because actual engineers think you are talking total horse-shit.
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> He is visionary - but he lacks strong science, critical thinking, and research skills. I like him - but he âoeshoots from the hipâ.
A visionary who "lacks strong science, critical thinking, and research skills" is called a crackpot.
He should stick to speculative fiction where being fundamentally wrong doesn't matter so much.
=Smidge=
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Rockets can use H2/O2, and once we have clear energy, that means rockets can be non-polluting.
The upper atmosphere is very dry, polluting it with large amounts of H2O, a very potent greenhouse gas, might have unintended consequences.
Currently not a worry but in a future with hundreds of launches a day...
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Maybe the high tower thng is to allow accelerating without needing reaction mass ? I don't think it would work with realistically sized towers, but it might with your 200 miles one :)
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Drag forces go as V^2 and power as V^3, so we are talking 160X the drag force and 500X radiated power of present generation hypersonic missiles. You could imagine a structure to put the launch rail at 20 miles altitude to avoid most of the atmospheric drag, but that is a pretty heroic engineering project.
If you limit to say 10G's. (100M/s^2) and want 8000M/s, that is an 80 second launch and co
I'm not sure about overhyped. (Score:2)
Got one thing wrong (Score:2)
I'm under the opinion that this will never be 'doable', the efficiencies are dismal, and those are for fixed systems.
"Politically impossible?" (Score:2)
Calling nuclear-powered spacecraft "politically impossible" is kind of a cop-out. What it is, is one of the highest risk/reward ratios of all possible propulsion technologies. Potentially making a huge swath of land uninhabitable for generations because a bird flew into your spacecraft is not a great risk profile. It's Russian roulette on an intercontinental scale. So... maybe politically impossible, but also reckless and irrational.
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My points are:
1. It is not "impossible" to launch a reactor as they have already done it
2. A lost of orbit by a reactor does not result in "making a huge swath of land uninhabitable for generations"
Just chipping away at the hyperbole, but thanks for your input
In the meantime, out here in reality (Score:5, Funny)
The world thinks the metaverse and Web3 are overhyped technologies, so I guess it evens out.
Rockets think Neal is over-hyped (Score:2)
and so do I. If there were a promising alternative it would have been pursued already.
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And if there was at least some sort of weird pipe dream, Elon would have tried it by now.
Why are you dissing Stephenson? (Score:2)
now a Web3 entrepreneur
Did he kill your dog or why are you doing that to him?
Just a matter of one's personal taste in futures. (Score:3)
Personally, I'm just not that interested in futures where people are lost in entertainment and other cryptological metaphors. The answer to the faux-deep questions those stories always pose is painfully simple: Crawl out of your ass and go explore reality, which I assure you cannot be destroyed or compromised by electronic mirages, math voodoo, or tiresome "neon lights through rain" Blade Runner effrontery.
He's right about desalination though. It's a no-brainer. There's no excuse for water scarcity on a planet like this.
Why Do We Care (Score:3)
This is like asking your flight attendant about jet propulsion.
Build it and they will come (Score:2)
So build it. My guess is nuclear will become more prevalent when we don't need to build and test them on our own planet risking everything. When we have a much more reliable methods of putting and/or building equipment in space is when we will see perceived riskier technologies take shape.
Rockets are primitive, but they are what we have and they will serve as bridge to the future.
CSP is better than PV for desalination (Score:2)
A book I am currently reading ("Solar Trillions" by Tony Seba) suggests that Concentrated Solar Power (CSP) is a better technology for desalination than photovoltaic panels. The logic is as follows... CSP is more efficient than PV in converting sunlight into electricity. In addition, a side product of CSP is a massive amount of waste heat, and this waste heat can be used for desalination.
A benefit of PV is that the technology can scale up/down to suit whatever the intended application is. For example, a d
Let's create the space-age (Score:2)
...by listening to English-Majors.
Desalinization (Score:4, Interesting)
Yeah, it's great, and using solar power (surprisingly convenient in most places arid enough to benefit from desalinization) can be done with little pollution on the energy-intensive parts.
The problem is, what do you do with the waste salt? There will be a lot/b of it. Too much to use for the things we use salt for, though we could certainly stop mining salt. Too much to bury, even to fill up old mines, even open-pit mines, not that that's necessarily a good idea, since you don't want it getting into aquifers and such. Dumping highly saline brine out to sea sounds good, but it is a pollutant that can kill already-stressed marine ecosystems, which can only tolerate so much salinity. And you don't want to break it down into its constituent elements, since they're way harder to deal with than salt is.
So I'd enjoy hearing his solution. Perhaps waste salt is what he's blasting into space.
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The problem is, what do you do with the waste salt?
Dump it into the ocean. Dilute it if necessary to prevent localized ecosystem damage. But eventually all the water you desalinated returns there as well. Mixing with that salt you dumped and returning to the original salinity.
Hold back the brine and release it slowly into treated waste/storm water which you are dumping back into the ocean already. Although as waste treatment improves, we may just recycle it and reduce the desalinization demand (and waste salt production).
"Works Better" (Score:2)
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We need some way to build the nanotube fiber space elevator, and we are fortunate that our gravity is low enough to allow use of chemical rockets into orbit to accomplish that
Nanotube production tech is getting better and new materials like amorphous diamond may make this possible in a decade or two (not really sure about the tall-tower idea).
I suspect Earth based laser powered launch may work for bulk materials, but I am not sure if it is low enough G for for people to use it
Even for cargo, have to wonder
Re:Rockets are more primitive than a Model T (Score:4, Insightful)
The space elevator won't happen in our lifetime. It'll be bogged down by insurance problems and the tiny problem that nobody wants to take responsibility in case the whole thing turns into a giant whip. No, I'm not talking about the technical problem, but the fact that our culture has evolved to the point where "taking responsibility" isn't a thing anymore, and AVOIDING responsibility is what matters. The entire economic system is built on that (the main purpose of corporations is to let people hide behind the corporate shield).
No, don't look at China, they're half capitalists now.
No, I don't mean communists would've accomplished it, they have other fails.
Re:Rockets are more primitive than a Model T (Score:5, Interesting)
In the interview, Stephenson rues that environmental laws passed in the 70's, for good reason, are so frequently used as a stall tactic against mega projects, some of which he says will be needed to reduce carbon in atmosphere
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It'll be bogged down by insurance problems
What insurance problems are there if there won't be anyone left on Earth to deal with the consequences of its failure?
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Or probably ever, since to have an adequate safety margin on Earth (like you'd expect normal elevators to have to avoid killing people on a daily basis) we'd need to mass produce materials on an unprecedented scale, with a considerably stronger strength to weight ratio than anything we have in the lab.
And sadly we have reason to believe those are approaching the theoretical strength-to-weight limits for atomic matter.
At least assuming you're talking about a beanstalk style elevator - pinwheels, etc. are via
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The space elevator won't happen in our lifetime. It'll be bogged down by insurance problems and the tiny problem that nobody wants to take responsibility in case the whole thing turns into a giant whip
There are some pretty big problems with the space elevator, such as the fact that climbing it is ridiculously slow, however it's never seemed to me like wrapping around the Earth destructively should be considered one of them. Has anyone every actually fully modeled that failure mode? It seems to me that, unless it's incredibly thick and resistant to both heat and burning in an oxygen atmosphere (carbon is incredibly heat resistant, but it also burns really well) it would just burn up. After the lower parts
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China is capitalism, with dictators skimming off the top and making sure nobody is powerful enough to depose them. Sort of like organized crime where one gang won. Russia *is* organized crime, but the criminals don't know how to manage a modern economy. The Chinese leadership at least are technocrats who have a clue.
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Sadly a space elevator (beanstalk style, which is what most people mean) is probably impossible on Earth.
Multiwall carbon nanotubes have *barely* enough strength-to-weight ratio to do the job, in theory. I think diamond thread promises to be a little better, and is likely approaching the theoretical limits of the strongest material possible using chemical bonds, but I believe still nowhere near providing the 10x "overstrength" safety factor you really want in any situation where human lives are at stake.
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> "Should the accelerating launch platform end its runs at the top of Everest or Kilimanjaro?"
Mt. Cayambe in Ecuador. It is the highest point on the Equator. Since the Earth has an equatorial bulge, it is the farthest point from the center of the Earth and thus the nearest to space. You also get the maximum benefit of the Earth's rotation. Lastly, the mountain has reasonable slopes for both short (2 km) high acceleration (1000 g's) systems, and long (15 km) lower g systems that can carry people and
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I've done work on space elevators for Boeing and NASA. Although the *theoretical* strength of carbon nanotubes is high enough for a space elevator, real materials are nowhere near the theoretical strength. That requires no defects at an atomic level, which never happens.
Fortunately, a newer design than space elevators (1894), the "skyhook" (1986) can accomplish most of the benefits with 50 times less cable, and today's materials. It doesn't reach all the way to the ground, but it doesn't have to. A sing
Re:Rockets are more primitive than a Model T (Score:4, Funny)
Magic 8-ball sez, Space Elevator more likely [wikipedia.org] than your unexplained "harmonic" "esonating" electrostatic thingies
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Magic 8-ball sez, Space Elevator more likely than your unexplained "harmonic" "esonating" electrostatic thingies
You're both wrong. The future is spin-launching nuclear power stations into LEO, hooking them up together - basically building a huge nuclear propulsion system in orbit. Then it's fuck the Moon, we're on to Mars and the asteroid belt.
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Spin launching is the winner.
Question. Since entering the atmosphere at the very top, where it's so thin it's basically vacuum, at orbital speeds means a giant fireball requiring extensive heat sheilding, how does transitioning from vacuum to close to 1 atmosphere of pressure at much higher than orbital speed (since you're going to bleed off a lot of velocity on the way up) work? The result has to be an enormous fireball, all the way up through the atmosphere. Also, there's so much oxygen, you're not just dealing with heat of friction
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That's a lot of words for "FACT! Believe me!"
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Basically all of this is pure nonsense. Up to and including a handful of consumer drones making a real difference in Ukraine.
I could explain in detail why all of this is nonsense but this has been done so often and Iâ(TM)m so tired of doing this over and over.
A) It's not a "handful" of consumer drones. Ukraine has hundreds of off-the-shelf drones supplemented by military grade ones they've been given. These drones have allowed for faster, easier, real-time reconnoitering and spotting than would be possible otherwise. If you don't think these drones are having an effect, go ask the wounded [youtube.com] and dead [youtube.com] Russian soldiers who thought the same thing.
B) These drones are having so much no real difference in warfare that every nation on the planet is now taking notes on