Slashdot Mirror
Neal Stephenson On Rockets and Innovation
Dr. Gamera writes "Science-fiction author Neal Stephenson gives us his perspective on the history of the development of rocketry. He uses that history to illustrate the phenomena of path dependence and lock-in."
For a moment I thought we were back in the 19th Century at Rainhill
What the hell is this: "we sing about them at every football game"
I'm not aware of this... I've been to quite a few Saskatchewan RoughRider games and I haven't heard anyone singing about rockets.
is this some sort of beer drinking song?
I suspect you've all seen this e-mail forward, but it was basically what this article reminded me of. http://www.astrodigital.org/space/stshorse.html
While it is kind of easy to look back along the history of nearly anything complex and cherry-pick things to support a given point, the article raised some interesting points.
It would be interesting to consider the development of the Internet in the same lines and the subsequent lock-in.
It's a neat article, as usual with Neal, but the ending is odd. He says the current state of rocketry is at a local maximum, it's not going to get appreciably better, and there may be other ways of putting stuff in orbit that are better, and then he says he doesn't know why we aren't trying those other better things. This, after spending the previous twenty paragraphs writing about how the US has spent four trillion dollars to get to the top of this local maximum, and the old USSR spent about the same, and in the process we've established a huge military-industrial complex based on the money still flowing into that development path, with lots of political inertia greased by manufacturing and administrative money going into congressional districts... and he wonders why we're not considering spending another trillion dollars on a different, unproven system that would probably involve taking money from the people who are now getting it? He's already answered his own question, and that's surprising because he's a very bright person and does a good job of analyzing the subject.
Nostalgia's not what it used to be.
Funny, that the article fails to define the two concepts that its supposed to illustrate. Bad (popular) scientific writing. I would not have expected this from someone who supposedly knows how to write (albeit fiction).
Really that was just really bad. Satellites have never been "limited" to the size and weight of Hydrogen bombs.
Frankly it was just some kind of odd ramble that had no real facts at all. The History was also just dumbed down to about the level of a fourth grade book report.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
Stepheson makes this point late in the article:
"There is no shortage of proposals for radically innovative space launch schemes that, if they worked, would get us across the valley to other hilltops considerably higher than the one we are standing on now—high enough to bring the cost and risk of space launch down to the point where fundamentally new things could begin happening in outer space. But we are not making any serious effort as a society to cross those valleys. It is not clear why."
It's somewhat clearer why, to me.
I want to buy a more fuel-efficient car, and keep my current, less-efficient car. My current car is useful for many things, but commuting to work could be done by another, more efficient one. Here, however, is the rub. Despite the improvement in fuel economy, it is still a net increase in cost to me for a fairly long time. Acquisition, insurance, and upkeep consume most of the fuel savings. Yes, it would be better for he environment also, but that doesn't immediately or directly impact my costs very much. So I put off buying that car.
Our current methods of delivering object into space work well enough, and the alternatives are both unproven and not sufficiently advantageous to warrant immediate adoption.
However, as we re-enter manned space exploration, we will be looking for heavy-lift options that don't actually exist today, and those present the opportunity to develop new methods. Avoiding the vertical portion of a rocket launch also avoids the need for massive thrust to overcome gravity that directly. Stephenson alludes to this, and 'space planes' are the current focus, along with some multi-mode concepts. NASA'a failing Ares program is a fair example of lock-in that Stephenson is writing about. Being more open to the development of ultra-high-speed vehicles and their engines might offer both better alternatives and true advances. But that takes ingenuity and a willingness to risk that NASA doesn't seem to possess right now. Bad climate to propose trillion-dollar space programs, though we've been willing to propose trillion-dollar stimulus packages for more mundane projects, such as propping up failed financial institutions.
Imagine the impact of a trillion-dollar space plane project. Would US students consider a career in engineering if they saw both the opportunity to be part of a cool new future, and the employment options as well? Would this give US aerospace companies something else to sell instead of weapons systems, and is that a good thing? Would it spur international competition, and is that good? Would it divert China's resources into something besides crushing the world's manufacturing competitors? Does that matter? Would a trillion dollars given to this project do more good than giving it to the bankers? Will the bankers also flourish in the glow of this project?
deleting the extra space after periods so i can stay relevant, yeah.
I think he should stick to sci-fi instead of writing bad journalism with a poor story of rocketry.
He has many points wrong, he thinks he has guessed how it went and why but failed to it.
At least he should have read Von Braun book about rocket science, but obviously he didn't.
I stoped reading his "perspective" here :
centrifugal force counteracts gravity
One word, "Fuel Depots". Well that's two words, sorry.
See Rand Simberg's thread on this article here: http://www.transterrestrial.com/?p=31999
Stephenson really needs to go back and re-read the actual history of events, not the Cliffs Notes version. There are some embarrassing errors in there, including the mistaken idea that the hydrogen bomb was developed specifically for use with ICBMs. In fact, all of the H-bombs used in nuclear tests were either dropped by high-altitude bombers or placed (in the case of the thermonuclear prototypes in the Ivy Mike and Castle Bravo shots) in specialized installations on the ground. None of them were delivered by ICBM.
In short, the effectiveness of the ICBM is a fallacy that started with Robert MacNamara and has been perpetuated by ill-informed historians ever since.
What a bad article! I am not even sure what the point of writing it was. There was neither a useful proposal for an alternate approach, nor even a clear call to action of any sort.
Suppose you accept his premises that our current state of rocket technology evolved in part due to key improbable events. As a result, we've continued that technology, to "climb to the top of that hill" as he puts it. That doesn't, by itself, automatically mean there must be higher hills to climb. We may have purposefully or accidentally climbed the highest hill we are currently capable of climbing. Perhaps we would have been further along with some other technology if we hadn't climbed this hill, but it might not have been better overall. Right? I mean, it could have turned out like our quest for magnetically confined fusion.
Blind people develop superior hearing to sighted people. I'd still rather have my vision, and I don't think that's entirely due to path dependency.
Same mistake with the combustion engine. Yes, we are getting close to maxing out the technology. But it's not clear that, if we had not developed it in the first place, we would have come up with something more effective in its place. It's not even clear we would have come up with something *as* effective. It's not even clear we even have anything plausible *yet* that would be as effective.
The fundamental mistake in this article seems to be an assumption that the grass is greener in the counterfactual, but he presents no evidence to persuade us that this is actually true.
If you don't know where you are going, you will wind up somewhere else.
I think if he looks a bit more deeply it has very little to do with lock in and everything to do with the fact all the wonderful SF ideas out there simply can't be built with our current level of technology.
"Seven Deadly Sins? I thought it was a to-do list!"
That doesn't, by itself, automatically mean there must be higher hills to climb. We may have purposefully or accidentally climbed the highest hill we are currently capable of climbing. Perhaps we would have been further along with some other technology if we hadn't climbed this hill, but it might not have been better overall.
It might be actually slightly the other way around - did we already forget the absolute dominance of "spaceplanes" in scifi of 30s, 40s or 50s?! (even design attempts - Silbervogel, or early winged visions of von Braun) Flying saucers even, at some point...
... and we know how that ended, it didn't deliver on any of its main points as advertised; not a lot of flying boats around, too)
No doubt fueled by rapid advances in aircraft technology at the time. What almost everybody wished for. And we still do, it's easy to remember and relate common experiences of air travel, while forgetting how it's "supposed to" look like (airplanes from "our" times as envisioned ~130 years ago, no doubt influenced by rapid advanced in marine technology), when approached in the same style as "spaceplanes" (actually, I wonder how much the Shuttle was influenced by designers and decision-makers growing on spaceplane scifi
One that hath name thou can not otter
Oh you don't actually have a plan you just wanted to bitch. The space elevator is a great idea in theory but we need to build one hell of a rope and the material science aren't up to the task yet. A space plane? You mean a plane with rockets that would at best be a minor improvement if we could perfect it. So rocketry isn't exactly cheap or fuel efficient, but it does seem to get you out of one hell of a deep gravitational well.
Maybe we could build ionic craft in orbit they can hit higher speeds than rockets, but not fast enough to go anywhere interesting in a lifetime.
Truly interesting work in this field is going to be theoretical math and science for at least most of our lives.
But in the two areas he focuses his conclusion on - rocketry and energy - there are demonstrably higher hills to climb. There are other architectures and paradigms that, on paper or in experimentation, guarantee better efficiency, lowered risk, lower cost, etc. If we, collectively, only had the fortitude to start climbing again.
Don't forget the;
Roller Coaster Scramjet
Lighter than air or neutrally buoyant Space elevator
High Altitude Lighter than air Rocket Launch Platform
White Knight X carrying Giant rocket
A great article by Neal Stephenson, that I was lucky enough to stumble upon yesterday, after months of thinking over related difficulties in science, and particularly physics (in part, as Lee Smolin has written about.) I'm going to say that Jane Jacobs' argument in "Dark Age Ahead" subsumes Neal's, although Mr. Stephenson adds a great deal. She argued that what was exploratory science has now been replaced by a lot of people who look the same, since they still wear lab coats a lot[ but who are just spouting cant, merely copying previous “scientific” opinion, or just making it up on the spot; and are dreadfully reluctant to challenge whatever has previously been held to be “obviously true” - whether there was ever any evidence offered in support of that opinion or not. In other words, an academic priesthood that has a stunning degree of priestly inertia – the opposite of what science is supposed to be.
Lee Smolin argues much the same of physics in “The Trouble with Physics”, and I'd like to argue that the field of medicine is still worse for priestly nonsense. (I ask you, in what other field would the advocacy of something like “evidence-based medicine” be novel, and revolutionary?)
Jacob's argument easily extends to saying that only very large technological changes force the “science” priesthood to adapt and change occasionally, by revealing large new realms of incontrovertible evidence. But, ouch, now Neal Stephenson, using rockets as an example, argues that technology may be ossifying more than we suspect, too, making the logjam complete.
The historical extension of this argument is that progress slowly moves around the globe because every civilization can advance only so far until it lapses into immovable complacency headed by economic or academic special interests who are doing just fine as things are, thanks. Then the torch passes to another civilization; for example, China to India to Arabia to Europe, over the last few millenia. Yet today, globalization ties us together so closely that there is now nowhere left for that torch to go. Globalization means globalized lock-in, too.
In other words, to return to Neal's example: “Why did the Chinese invest in developing a rocket capability rather than try to skip ahead to a better technology, since they had no infrastructure or educational investment in the old tech? Why were they locked in?” Arguably, however, developing economies are often even more locked in to obsolete technologies, for which no alternative has yet emerged. The gains in capacity by copying are so great, for so little investment (starting buying rocket tech at a discount from Russia) and with such great political benefits, that the outcome is all too predictable, both in technology, education and science.
I wish there were some way to convince the Chinese that no society is rich until it can afford to fund research efforts that fail frequently, publicly, and thoroughly. Then again, I wish I could convince us! Here in the U.S., centrally planned science funding that is ultimately supervised by an easily embarrassed Congress has everything to do with lock in, since innovation at the margins is the only reliable way of obtaining research funds, period, end of sentence, end of marked innovation.
The key for that new state would be to keep their developments a closely guarded secret, purely to increase the time advantage they had until every other spacefaring nation could work it out for themselves. The question then becomes, do the other states try to play catch-up and slavishly emulate what the new guy is doing, or do they try to leapfrog them onto the hill after that?
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
The main problem to advancement is horizons. His solutions are looking at horizons that take generations to come to fruit. But, political horizons are two years apart. The status quo is the safer bet. The future belongs to someone else.
At the start of the space program they couldn't build rockets that would reliably not explode. Over the coarse of it they developed a wide range of new materials and technologies (ceramic tiles on the shuttle, velcro, hydrogen fuel cells, and any number of polymers for example), which made what was impossible with the technology of the day common enough that people think it's boring.
The point of the article is that alternative launch methods may be beyond today's technology, but developing the technology of tomorrow would be a more worthwhile use of the resources that would otherwise go towards milking that last couple tenths of a percent of efficiency out of the technology of yesterday.
I've always wondered why to get to space you HAVE to start on earth with rockets. Air breathing engines can get us up to almost 100,000 feet in one or two stages. A large 'first stage' could use a combination of turbine engines to get up to around 50,000 feet at sub-sonic speed, then switch to scram-jets to get to hyper-sonic speed and 100K+ feet. Then a rocket powered second stage would go the rest of the way into space while the first stage glided back to earth (or flew under it's own power if there was still fuel left).
IIRC the original plans for the space shuttle were along these lines.
I think the article is ignoring some basic physics that has driven us to these outcomes, both his rocket and his oil dependency example.
To get anything into orbit needs a very good weight/energy ratio. The only thing that can provide this itself are your typical rocket fuels. There's two other options:
- Atomic: this usually goes out the window when you consider manned vehicules due to the weight of shielding, and for unmanned vehicules the environmental effects.
- Cheat by leaving a significant part of your mechanism on the ground. Space cannons, magnetic rails and the like. The problem here might indeed be one of technology. even a very fast car (Thrust SC2), might go about at the speed of sound. Sounds pretty fast? It's still nowhere near enough what you'd need. The escape velocity is about 11 km/s, the speed of sound about 300 m/s. Now we need to think in energy, so we need to use E = 1/2 mV^2. Or in other words we need to compare the square of the velocities. 300^2/11000^2 = 0.00074 or about 0.075% of the energy required.
Going much faster and the friction with the atmophere melt your vehicule.
So to get anywhere with a space cannon type system, it needs to be on a very high platform, probably 10km or more, and then be big enough to accellerate a payload to 10-20 times the speed of sound.
When you look at the basic physics, you very quickly end up with rocket-like devices.
A similar thing holds true for our dependency on oil. It again boils down to weight/energy ratio, but with much bigger safety, usability and logistics constraints.
The math is not as straigthforeward, as it's mostly economics, but only rocket fuels give much more power to weight ratio then the conventional fossile fuels.
RogerWilco the Adventurous Janitor
Arthur C. Clarke, who'd been pushing space travel for decades via the British Interplanetary Society and his SF works, was interviewed during the runup to one of the Apollo launches. He said "If we'd have known this was going to cost twenty billion dollars, we would have given up and gone home." Before Sputnik, space travel was a hobbyist thing.
Chemical rockets to oribt just barely work. Most of the mass is fuel. For a single-stage-to-orbit rocket, with the fuels with the best possible energy density (LOH and LOX), 97% of launch weight must be fuel. With two stages, it gets better, but not much better. So rocketry is about weight reduction, which is why everything is so fragile and failure rates are so high. If the mass ratio were better, rockets would be built with aircraft-type weight budgets and would work much more reliably. But, launching from a 1G planet, we're stuck with those numbers. That's why Richard van der Riet Wooley, Astronomer Royal in the 1950s, said "Space travel is utter bilge".
Many alternatives have been tried. Launching from an aircraft works; Pegasus is launched that way, as is the Virgin craft. But it's not a big win. Big guns? Feasible, but only for stuff that can handle a few hundred Gs, like water or air shipments.
Takeoff with a suborbital spaceplane? That was Ronald Reagan's idea in the 1980s. Ben Rich, head of Lockheed's Skunk Works and designer of the SR-71 propulsion system, decided that Lockheed wouldn't bid on that. The materials problem was too hard. "We used titanium. You know something stronger?".
Atomic rockets are feasible, and have been ground-tested. Early plans for Apollo had a nuclear powered second stage and a Nuclear Assembly Building at Canaveral. It's messy, but it would work. The cost back then was calculated as half a human life per launch from cancer, amortized over a large population. That might not stop China.
Fusion would be great if we could do fusion power. (The "helium-3" enthusiasts tend to gloss over that fact. He3 fusion is harder than Dt-Dt fusion, which we can't do either.)
Launch lasers are a neat idea, but it takes a gigawatt to launch a metric ton. That's not impossible; one could in theory have a huge collection of lasers at Mojave, and, launching late at night, could use all 6GW from Hoover Dam, plus extra power brought in from the LA area. The Apollo lunar module was about 10 metric tons. The biggest continuous laser ever built, though, produced a megawatt for 70 seconds, So we need 4 more orders of magnitude, or 10,000 such lasers, to do a launch.
I recently had this discussion with someone who's entering the X-Prize competition. He's a bright young guy with an interest in space. But he can't see any new ideas working, other than even more clever weight reduction.
Liquid fuel rocket research did not start in NAZI Germany. It is very likely in my opinion the technology would have been used to launch payloads to orbit initially no matter the course of history. It's inventor specifically imagined using the technology for launching payloads to orbit, and it was the only technology even remotely capable of achieving that at the time. H.G. Wells imagined shooting a payload out of a giant cannon, but the Germans were working on that too. Even today, the imagined alternatives (Scramjets, space elevators among others) may prove to be impossible, infeasible, or more expensive. Irregardless, research on such alternatives is ongoing, and it disingenuous to imply that it somehow is not.
You seem to have missed the part about how our current level of technology is the result of 60 years and 4 trillion dollars of rocket technology innovation. Of course other ideas are a long way off, but before WW2 our current technology was just as intimidating.
Strange, then, that he didn't present these in his argument, don't you think? I just disagree that this is about "fortitude." It is about being sensible. The way to develop emerging technologies is *incrementally,* by exploring possibilities and slowly increasing the funding of the ones that show promise, as long as they continue to show promise. We have in fact been doing this, but none of the competing technologies have *in reality* shown much promise yet. Many of them are still at early stages of basic feasibility, because ancillary technologies (like materials) have only recently become sufficiently developed.
If you don't know where you are going, you will wind up somewhere else.
Ironically none of your examples are correct.
- The heat shield tiles were originally developed for ICBM warheads (using composites technology developed in other fields)
- Velcro was a commerical invention having nothing to do with the space program
- Hydrogen fuel cells were invented in 1838. The ones used by NASA were invented by a commercial company, G.E., in 1959.
So it really is more of a case that increasing technological development enabled the space program, not the other way around.
If you don't know where you are going, you will wind up somewhere else.
I like how one of the things Stephenson blames in his article for the rocket lock-in is, "engineering culture," that is resistant to change. I often find that nontechnical folk (and no, sci-fi writing does not count as a technical pursuit) use terms like, "engineering culture," or "scientific elitism," to describe phenomena brought about by actual technical details. In other words, that engineering culture doesn't develop simply because we engineers are resistant to change. It develops because we engineers crunch the numbers and have to deal with reality.
Anyone who thinks that engineers working in the space launch industry are resistant to change just for the shits is pretty misinformed. When it comes right down to it, we're the ones who would love to find a new Pandora's box technology that could get us into space faster, cheaper, and safer. Hell, we have devoted our lives to pursuing the development of the space industry. If anyone wants to see men and women living on Mars, manufacturing in orbit, and fucking onboard inter-galactic colony ships, it's us. Unfortunately, we don't have the luxury that sci-fi authors have of writing about some great new idea and just assuming it will work. We have to test material strengths. We have to plot thermal loads. We have to damp harmonic oscillations. We have to produce enough energy to overcome gravity. Those aren't trivial tasks. And we don't get to defy the laws of thermodynamics and gravity with some hand-wavy bullshit about, "couldn't this idea totally work in theory?!"
So yeah, there are lots of proposed theories and ideas on how to get to orbit. Great, congratulations Mr. Stephenson, you have an imagination. And, awesome, you can see sunnier hilltops across the valley that reach higher than the one we are standing on now. That's a great fantasy land. I hope you enjoy living in it. But while you draft up clever metaphors based on cherry-picked "facts" and unrealistic assumptions, those of us working in the industry, you know, the ones doing the math, actually have to look at the numbers. And those distant, high hilltops you see, well they might not be as high as you think. And all those, "innovations," on how to get to space, well they might not be as Earth-shatteringly ingenious as you think.
I'm not saying there's not room for improvement, there definitely is. But until someone shows me some numbers that prove a space-elevator, a launch loop, or a space fountain can be built, today, without unobtainium (in the form of some material, or some epic power source), I am going to delegate those ideas strictly to fantasy-land for now. And as for things like space planes, hypersonics, multi-propulsion-type vehicles, and so on, we are trying them, to an extent. And, believe it or not, just like rockets, they are still fucking difficult to get right. That's why it takes a long time to develop them. In the end, chucking something out of our gravity well is no easy task, no matter what method you take. And it is expensive, in both time and energy, no matter what technology you utilize. So stop lamenting about how poor off we are compared to where we could be. We're doing everything we can with what we've got. If that's not good enough for you, vote to give us more money or design a small, portable power-plant that can produce a proper metric fuckton of thrust.
In the end, engineering culture is just a term being used to say, "technical shit that I don't understand well enough so I'lll use it as a scapegoat to justify my preconceived notions"
Motorcycles, Robots, Space Gossip and More!
You have just described Nietzsche's "Last Man".
I also agree with your "demonstrably." It's more like, we're standing on a hilltop. We think we can see - barely - higher hilltops through the mist. But we can't be sure it's not just a cloud.
If you don't know where you are going, you will wind up somewhere else.
Rockets are no nearly perfect - given new fuel http://nextbigfuture.com/2010/12/swedish-researchers-have-discover.html shuttles could have 4-8 times more payload. And this is actually huge step. Next - launch could be performed from towers few kilometers hight or even mountains - it will take money - but still will make quite a change. There are other possibilities such as quad airship launch (walrus was designed for 500 -1000 tonnes - so the rocket could be 4000 tonnes of weight and could be launched, say from 15000 meters hight ), there are other, non rocket ways to launch things into space - but even rockets could be times more effective, than now.
A couple of decades before WW2, Robert Goddard suggested all of the rocket propulsion ideas to the US military, and they decided not to pursue it because they didn't believe the basic science which underlay his work. The Germans realized that he had, in fact, proven some basic concepts and expanded on his work.
$4T has mostly gone into production and reuse of a great deal of the original innovation, not the innovation itself, and it's still dicey to send a person into orbit, all things considered.
Technology has advanced an many areas surrounding the "other" options far more than rocket technology in the past 40 years. The problem is that there are limits to what we can do without radical advances which - based on our current knowledge - would likely violate some basic physical principles.
Is it just my observation, or are there way too many stupid people in the world?
Actually a launch loop seems pretty do-able to me, it just required a tremendous amount of investment. It would make access to space almost "free" as a result. This is the kind of thing he is referring to as prohibited less by physics and more by accounting.
The point of the article is that alternative launch methods may be beyond today's technology, but developing the technology of tomorrow would be a more worthwhile use of the resources that would otherwise go towards milking that last couple tenths of a percent of efficiency out of the technology of yesterday.
See the funny part is that we are developing the technology of tomorrow. NASA is throwing money into contests designed to lay the groundwork for building a space elevator. The Air Force is currently testing hypersonic propulsion methods that could one day be utilized on an alternative launch platform. NASA and the Navy are both dumping money into tech like rail guns and mass accelerator cannons to see what can and cannot be achieved with them. Virgin, SpaceDev, and half a dozen other companies are looking into building space planes, eventually.
Anyone who says that we aren't attempting to develop alternative space access methods currently is not looking hard enough. We are working, across the globe, to lower the cost of access to space by whatever means necessary. The problem is, getting out of our gravity well is hard. So developing this technology takes time, decades even, like rockets. Do we have space elevators, space planes, and orbital cannons? No. Are we working to get there one day? Yes. So I really don't understand what the complaint is, other than impatience.
Motorcycles, Robots, Space Gossip and More!
I thought the "space balloon" idea was pretty cool. The idea is to use a series of balloons to lift very large payloads to the edge of space. The final balloon would be very fragile and huge (to handle the super-thin atmosphere) and shaped as a lifting body. Ion thrusters would slowly accelerate the craft (and payload) to orbital speed. I don't know how much unobtainium is involved in the construction of the balloons, but it sounds pretty cool any way. I don't know that anyone has ever spent any real money on testing the idea.
Said article is based upon bunk proposal of somebody who wishes for current working systems to be replaced by his system. Do you expect us to grant every such wish (when looking closer at engineering, even at physics, tells us they can't work...)
... what is indeed the normal state for our species (interspersed with very few short bursts of progress). At the least, logic dictates that wishful thinking has limits.
From what I see, some people also tend to belittle all of current science and scientists mostly when too many of its aspects run counter to some "opinions" of said people... while the humanity is doing quite good (there is nothing wrong with "inertia" in such case). You can't know if we're not approaching relative stability of practically possible technology
(medicine has social problems BTW - people, the patients care about their lives too much to simply trust evidence)
One that hath name thou can not otter
There is an alternative technology that Neal is probably thinking of. All studies of it done to date suggest it is better in every possible respect than rockets. Interestingly, it requires technology that was not developed until the 1990s - which means that even if history had gone differently we might not have it today.
It's called laser launch. The vehicle still works like a rocket - there's propellant on board, and it gets superheated and escaping propellant generates thrust. However, since the energy source and nearly all of the technical complexity of the launch system stays ON THE GROUND where it can be as big and cheap and redundant as it needs to be, it reduces the cost of the system by orders of magnitude. The easiest and simplest laser launch system is a spacecraft with a block of metal bolted to the bottom.
The lasers fire in pulses that create planar shockwaves acting like a rocket nozzle without the nozzle. Spacecraft lifts off. Technically the spacecraft could work without any onboard electronics or control systems of any sort. That is to say, no aerospace hardware AT ALL. Nothing made in a cleanroom with reams of paperwork speccing every part. Independent laser moduules would be made by whichver cut rate contractor offers the best price this week...a few errant beams or failed modules would not affect the launch.
Since concentrated light can increase the temperature of the exhaust more, the rocket would be much more efficient and need less propellant for the same payload.
Everyone in the rocket business thinks of the alternatives all the time.
And then looks at the laws of physics, and the laws of economics, and goes for the solution that gets the job done with minimal waste and effort.
This isn't to say there's no waste or extraneous effort, but the main theme of the project isn't based on a fantastic boondoggle.
And if there's more than one way to skin a cat, it will get tried eventually as someone realizes they do have the resources to attempt it.
But while it may work for a niche, eventually you come back to the science of rocketry and the equations of motion and you decide that your rocket is going to look and act like a lot of others before it.
I was going to write a snarky comment myself, but I decided to just do an obligatory snarky reference to a comic instead:
http://xkcd.com/123/
tried to follow a different path and innovate using polar bears as rocket fuel, but as it turns out harvesting the critters is a really technical problem.
We then figured out that we could piggy back arms on other space programs and did that instead.
We were experiencing some problems shutting down our submarine thermal generator we used to limit the polar bear habitat, making them easier to catch, but we just blamed it in "Climate Change" and that seems to have solved the problem.
Our scientists are off shoveling their driveways now and are unavailable for comment at this time.
Seeing "Stephenson" and "Rocket" in the same headline, I couldn't help assuming it's about a steam locomotive...
That's called a "rockoon". First tried in 1949. Works OK, payload rather limited.
Back in 2004, JP Aerospace was pushing the idea of a permanent station at the edge of space which was really a balloon.They're still sending up balloons, but they're basically repeating what the USAF did in the late 1940s.
Accelerating a fragile airship to orbital velocity at the edge of the atmosphere is a fantasy. If there's enough air to get lift, there's enough air to get drag.
Aha, that's simply because your gun isn't big enough. Consider an 11km high pylon tower, quite doable, with maglev tunnels in them to accelerate a vessel at 7g, quite acceptable again. The savings you make in fuel consumption and atmospheric density/turbulence are quite significant enough to lower the cost of launches to LEO to justify the initial expenditure, assuming you had a long term path to profitability in mind, like siting medical facilities in orbit for the rapid drop of transplant organs or something.
This is the crux of it, I think:
I don't agree that Hitler choice of rocketry for the V2 was random. I think he went to his not-yet-rocket scientists and said, "How do I deliver X kilograms of payload to England with such and such circular error probability, and oh yeah, it can't be intercepted?" And rockets were the answer. And for good reasons. I'm not sure what other technologies of the 1930s and 1940s could have performed the task: submarines with huge artillery built-in (susceptible to torpedo planes unless you could do some kind of shoot and scoot); they did try the bomber thing but that wasn't a winner; balloons don't seem like a possibility. We *still* don't have something better than rockets and missiles for mass producing corpses (whether you agree its a good idea or not): perhaps the Navy's upcoming railguns are different enough to be considered a "change".
This argument is and always has been horse shit, informed only by the view of those who are too myopic or narrow minded to see the quickening pace of technological advancements beyond their own limited world views.
Nice to see Randy and Avi back with a little conversation about rocketry:
Avi: We could make a preposterous amount of money from communications satellites.
Randy: It will be expensive to build those, but even so, nothing compared to the cost of building the machines needed to launch them into orbit.
Avi: Funny you should mention that. It so happens that our government has already put $4 trillion into building the rockets and supporting technology we need. There's only one catch.
Randy: OK, I'll bite. What is the catch?
Avi: Your communications satellite has to be the size, shape, and weight of a hydrogen bomb.
There is a post above yours that says in order to launch an Apollo-type mission with lasers it would take all the power of the Hoover dam and then some, plus they would have to burn much longer than the 70 milliseconds or so they currently do.
A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
It was an interesting article, but there were a couple of parts that I thought were really weak. One problem area:
What? Surely step 2 was more or less a direct result of step 1 - there's nothing improbable about that at all. I omitted the rest of the list, but the sequence didn't seem all that improbable to me. In fact, I really can't even figure out how the concept of probability even applies to historical events. They're all unique.
Another problem:
*crickets*
Ok, Neal, care to explain to us what these radically innovative schemes might be? In addition to the parent's theory that institutional inertia is the reason (which is probably a big part of the answer), there's also the very real possibility that none of these other "radically innovative" schemes have any chance of competing with rockets on the basis of cost-effectiveness - because all the R&D on rockets is essentially done and paid for, whereas to "cross those valleys" would be simply enormously expensive. And there's no guarantee your radical new technology would work. I think the risk factor here is even more important than the problems of inertia.
Big gun sounds pretty good to me. Especially at two dollars a pound.
Good lord, imagine all the incredible things you could do with just the ability to send cheap loads of water into space. Let alone massive quantities of reflective foil!
Of course this incredibly cheap technology would make it real easy for our enemies to launch stuff at us. I guess that's why it had never been developed, aside from one they pointed at the ground and one that was dismantled in the first gulf war without ever being used. (maybe I should use some of that foil to make a hat)
How about a maglev train in a large circular vaccuum tunnel, accelerated to very high speed,... and then shot out horizontally into orbit? (how fast would it have to be shot out for it to leave earth orbit, irrelevant of air resistance---can't maglev get it to that speed in a vaccuum tunnel?)
or... how large would a trebouchet have to be to launch a capsule into orbit?
or... how about a huge slingshot (with a whole lot of rubberbands?).
or... how about launching rockets from air balloons, e.g. if amateurs can get a camera up 30miles for $500 to take pictures... why not get the whole rocket 30miles up... and avoid wasting energy in fighting densest 30 miles of atmosphere? (also can accelerate much slower---due to vastly reduced air resistance).
or... how about launching off a high flying airplane (sorta like in that new superman movie?)
or... how about using small nukes to propel things? ... a gazillion of such ideas are unworkable, but some of them, if given enough thought and research, might just be practical, and long term, cheaper than current methods. So... who knows what the alternatives are...
"If anything can go wrong, it will." - Murphy
Yeah, except your numbers are backwards. Rockets are nearly perfected technology - making little tweaks to them is not very expensive, and all the basic R&D is already paid off. However, developing entirely new technologies from scratch is very, very expensive. And you run the risk of them not working at all.
So if your object is to get something into space in the relatively near future, are you going to go with a) the system that's already been extensively tested, has pretty good capability, and a known price? Or b) a system that hasn't even had basic R&D done (meaning you'll need to pay for that), might have either extremely good capability, about the same capability, or worse capability, and you have no idea what it will cost?
I think the question answers itself.
... is to be taken quite literally for the first couple of attempts to launch an entirely new system! ;-/
I was quite impressed that you can actually get launch insurance (but only for rocket launches, of course!).
Paul B.
He didn't so much as mention what these alternative technologies might be, and the only things I've seen have been pretty much pie-in-the-sky. It's far from a sure thing that there ARE any higher hills to climb, and even if there were, there's a good chance that getting from here to there would be cost-prohibitive.
If it requires a "tremendous amount of investment", then it can't be "almost 'free'". That investment would have to be paid off, and all the while, it would be competing with rocket technology that's ALREADY been paid off. Net result: rockets would be cheaper, so no one invests in the launch loop.
... dude, we've ALREADY SPENT the 4 trillion and ALREADY HAVE the rockets. What you're proposing is that we just dump all of that and spend another $4 trillion in the (not guaranteed) hope that you'll come up with something better? The GP is exactly right here.
And amortized development costs for that will OBVIOUSLY be cheaper than our already paid for rocket technology.
Your investment ideas intrigue me and I'd like a copy of your prospectus.
The article illustrates why we don't love Stephenson for his engineering.
These rockets, which were known as V-2s, were worse than useless from a military standpoint
True enough, but rocket development doesn't depend on the V-2 alone. On the other side of Europe, for instance, we have the Russians hurling Katyushas. The V-2 was a direct development of German Army experience with rocket artillery.
Atomic bombs turned out to be expensive, dirty, controversial, and of limited military use
Really? There's no military use for an explosion in the kiloton range? How about, just as an example, dropping it on an enemy army headquarters?
The rockets of the 1950s and 1960s were so expensive, and yet so inaccurate, that their only effective military use was lobbing bombs of inconceivably vast destructive power in the general direction of large urban areas.
Katyusha again.
because those bombs were so destructive (making it tricky to drop them out of a manned aircraft without killing the crew)
Again, preposterous. Piston-engined propeller planes dropped atomic bombs without serious issue. Turbojets and turbofans just made it even easier.
I love a lot of what Stephenson does, but societal and technological reasonableness isn't his focus. This article reads a lot like his books.
Lofstrom Loops and Space Fountains don't require unobtainium.
A. There's a big gap between finding a new molecule and producing giant amounts of rocket fuel. They've only found tiny little bits of your magic fuel.
B. Tall towers are structural nightmares. Tall towers meant to hold a massive beast of potential energy that will throw itself into orbit - lots more structural issues. Mountain locations are of limited use - you get more effective launches by moving closer to the equator. But moving closer to the equator means major political issues (noted in the article).
C. Airship launch: possible, but complicated. More complicated = more ways to go wrong. There are several programs going on hybrid air-breathing/rocket combinations, Space Ship 2, etc for example.
The article made a good point about us being near to the top of the conventional rocket curve, plus the amount of funding it takes to get new technologies built, scaled, certified, and commercialized.
I don't have planet busters until my scientists invent Orbital Spaceflight, and then that gets me these wonderful weapons deliverable only by rockets, never by needlejet or any other technology. And likewise, I don't have any other space tech until I have these rockets. Rockets are the key. You can't have planet busters or spaceflight without them.
And trust me, no matter how hard you try to get along, there's always some pro-war nutcase who wants a vendetta. You must arm. That doesn't mean you have to nuke anyone, but you damn well better at least be trying to get the technology. He is so right about the evil genocidal leaders. Stuff just doesn't ever get done without these kind of people.
One thing I was shocked to see Stephenson miss, though, is that you also need Pre-Sentient Algorithms. Orbital Spaceflight can't exist without it; it's a path dependency. (This is why, in the pseudo-reality (Earth simulations often played on the computers at the University) outside the true reality of SMACX, computer Science basically starts in the 1940s after you build something called Bletchley Park.) I cannot imagine how the author of Cryptonomicon, of all people, missed this.
I think the most realistic alternative launch technique is a rail gun like the one the navy recently demonstrated. You could use it at first to launch a scramjet vehicle up to the supersonic speeds it needs to begin working. Later as the technology develops you might be able to launch payloads at orbital velocities directly from the railgun. This would reduce the weight and size of the vehicles, and hopefully their cost along with it.
In 1987 I was on the opposite side of the earth to Florida looking at a NASA funded scramjet that was being prepared to go into a NASA funded shock tunnel to be tested at mach 6. That team went to to do the Hyshot test a couple of years ago and the more recent US military scramjet test was also based on this work.
I'm sure there are other promising leads that NASA is funding or others are working on elsewhere.
This article is factually incorrect.
First, rockets were developed by the USSR before and during the war. http://en.wikipedia.org/wiki/Katyusha_rocket_launcher rocket launchers were used quite devastatingly on the Axis forces.
Before the war USSR was experimenting with liquid rocket engines ( http://en.wikipedia.org/wiki/GIRD ) and later proceeded to develop the R-7 rocket which was used to launch the famous Sputnik-1. And no, it was done without significant contributions from the German engineers.
"If anything can go wrong, it will." - Murphy
Very nice contrast between post and sig :)
And yet for NASA's "Breakthrough Propulsion Project", NASA was only willing to part with $10,000.00 per suggestion. Where did the rest of the $1.6 million go. Surely, the website was not that complex. The message: "This society does not value the contributions of scientists and engineers."
you would think so, but thats because you havent put any thought into it whatsoever. do you know how difficult it would be to keep a cable going at mach 25, inside a flexible sheath, without it touching the sides? fucking impossible.
Didn't Arthur C. Clarke write about tethered space elevators as a substitute technology. (I think the original idea came from a Russian physicist.). I'm guessing the necessary materials or construction technology isn't available yet, not to mention the massive amount of capital to fund the infrastructure.
we need a rail assisted ssto rocket. the rail should give the extra boost needed to make ssto feasible.
Orion thermonuclear-pulse rocket?
I saw a documentary of a guy using lasers and plasma.
The neat thing was that the engine, the laser, stayed on the ground, and kept shooting pulses at a metal cup. The result plasma pushed the cup higher and higher. He demonstrated it and it worked! Sure it was a small cup and the height was maybe 20m but the prinicple worked! Leave the heavy engine on the ground or in a low orbit, and you save the energy of having to launch it.
Bram Stolk http://stolk.org/tlctc/
modded down? really?
I was going to write a snarky comment myself, but I decided to just do an obligatory snarky reference to a comic instead:
http://xkcd.com/123/
This xkcd n123 is one of my favorites since a long time ! :D
By the way : why do you imagine that I said there's nothing like a "centrifugal force" in a rotating system coordinates ?
I kept it short but the long story is that :
- The "centrifugal force" is not a force due to interaction of objects or fields but a correction term introduced to compensate the non-inertial frame choosen.
- The author didn't mention any frame, he uses a non-inertial frame without thinking about it, and I'm not sure he knows what a non-inertial frame is and what using it implies.
- Using the terrestrial reference frame for rocketry is terrible, not only you need the centrifugal pseudo-force but also the Coriolis effect. Instead of making things simple you dive in a nightmare.
But this specific point isn't that much important, I think several other comments have pointed out what's wrong in his perspective, right from the begining of this /. story...
Hmmm, wonder if we can get to the stars with steam engine power?
Sure enough, the cow costume was hanging up next to the superhero outfit and sailors uniform. (S,Spud)
Sure Neal, the accountants are to be blamed! Considering all your books I read, I'm pretty unimpressed with the article.
Launch Loop.
Why isn't launching from an aircraft a big win? Rockets spend loads of fuel launching through the lower layers of atmosphere that planes can pass through with far less energy.
Cow Cube
According to this paper the specific impulse of this new fuel is actually lower than that of LOX and LH, and comparable to other rocket fuels, It is the density impulse which is 20-30% better. This means that the propellant mass wouldn't increase, although making a smaller, denser fuel source would lead to a smaller rocket overall, with mass and cost savings for the structure. Additionally it's lack of Chlorine would make it more environmentally (and worker) friendly than some of the propellant options, which is always nice. Unfortunately that paper doesn't go into production costs, or any possible issues with storing it (This paper looks like it may have more information along those lines, but I don't have a subscription). I don't know if it can sit in a tank at room temperature like Hydrazine, or needs special care like Oxygen (due to its molecular weight I'm guessing the former.) All in all it does seem like a nice stepping stone between the high functionality of LOX LH, and the economy and convenience of some of the other liquid fuels, but it doesn't appear to be a serious game changer in any way.
As far as your suggestion to launch from buildings, mountains, or balloons, that doesn't actually offer substantial benefits either. While launching from high up would result in lower drag losses, that helps less than you'd expect because a ground launched rocket travels through the densest part of the atmosphere at it's slowest speeds. By the time a rocket is going fast enough that drag would really start to slow it down it is already at a pretty high altitude. If you are trying to make a cheaper rocket you really want to increase it's starting speed much more than its height. The math works out this way because of the fact that our starting radius is 6378 km. As big and impressive at Mount Everest seems to us it's really just a tiny pimple compared to the radius of the earth (brings you to 6386 km), and our entire atmosphere isn't much better.
and our entire atmosphere isn't much better. no, practically low earth transfer orbit starts at 150 km at this altitude a satellite will not decay into atmosphere for quite a while. and while at space station orbit there is also atmosphere - it does not change much - they just fix orbit every few days with quite a few amount of fuel. As for higher altitude start - it is actually already exploited in air launch. and building launch from mount will increase payload several times ( just check for existing projects ). the things I describe are not money wise - they really would require too much money to be spent relative to possible outcome - so currently it just make no sense. but not only rocket system are proposed - there are about a dozen of different future space launch proposals,
few links for you http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20030022661_2003025516.pdf http://www.aerospaceweb.org/design/aerospike/compensation.shtml
Guns are an effective way to get things going, but not all the way to orbit, or escape velocity, as in his book. They are good for 50-75% of orbital speed, and the rest you do by some other method. Half orbital speed guns have already been built, decades ago, I got to visit several over the years. They just have not been built big enough to deliver useful payloads to space. That would require not trillions, not billions, but about the cost of one rocket launch (~100 M$).
One big reason the major aerospace companies have not pursued things like this is that nobody ever got promoted by developing a scheme to launch stuff for 90% cheaper, which would cut your revenues by 90%. It has to be done by someone outside the current crop of vested interests whose *current* launch business would be decimated.