What you are saying is that those birds cost that much precisely because it's so difficult to launch them. So you have to amortize the large launch cost over as long an operational period as possible in an extreme environment. If launch costs were much lower, then you could make satellites much cheaper. You could launch more of them to achieve redundancy. And you have a much more affordable fall-back position of just launching another one. Also, economies of scale will start to kick in.
And I thought what they said to the FedEx founders, was that 1) there was already mail and 2) not enough people wanted to to overnight things badly enough. But if this is a misunderstanding, please correct me.
That's too cool! If you built your launch tower to give significant lateral velocity, then so much the better. In fact, it may be possible to design the trajectory so that you can skim off the top of the atmosphere and aerobrake any excess velocity. (You'll need some thermal protection for the craft anyhow, as it will be blazing through the atmosphere at only 35,000 feet at Mach 3.) Then all you're left with is a small burn for circularizing your orbit.
Unfortunately, you are probably leaving out a big chunk of energy for losses due to air friction. This is why rockets need something like 8600 m/s delta-v to get to LEO, while orbital velocity is actually a bit less than that. Still, a rocket firing as a velocity sustainer through the atmosphere is a lot easier than trying to get it going that fast from a standstill in one stage.
If we can build such a tower for 4 to 5 billion, then a much longer ramp reaching 11km but at a 30 degree incline might be feasible for under 15 billion. (Especially if it were built suspension-bridge style.) If we did this instead of a moon-base or manned Mars exploration, it would make those two things a heck of a lot cheaper!
The world's governments should get together and build this somewhere like Ecuador. I'm also hoping the Chinese will build something like this.
11 km towers are well established as feasible with conventional construction techniques. (It would be damned expensive, however!)
If we can manage atmospheric friction during hypersonic re-entry, then we can manage it during launch as well. Since we are partially freed from the tyranny of the Rocket Equation, we could afford the additional mass to do something like carry along some water to evaporatively cool the launch vehicle while it was blazing through the remaining 1/5th of the atmosphere.
Pratt & Whitney RL-10s! Linear electromagnetic accelerators. Lasers. We already have the tools to get into space. Let's go already!
The developers of launch technologies were (until recently) doing so almost solely at the behest of the government. And demand for space access is strongly shaped by the economics of the current launch vehicles. It's a classic chicken and egg problem.
I think there's demand that's invisible simply because the capability isn't there. I think that if companies could launch 5,000 pound communications platforms for only 5 million dollars, you'd have things like ubiquitous and cheap LEO satellite broadband. There is definitely a market for that. I suspect that the ability to transport goods and passengers around the globe in just a few hours would greatly open up demand once it became available, simply because people would get used to the idea that it's possible to begin with. (Remember, they said similar things to the guy who started FedEx.)
There has to be some up-front R&D investment. Otherwise, cultural inertia would stop all advance.
Well, if we use x = 1/2 at^2, and plug in 9*9.8 (m/s^2) (nine gravities) and 11,000 meters, we get t^2 = 249.43 (s^2). Take the square root, and you get 15.79 seconds. If you accelerate at 9 G's for that long, you only get to about 1393 (m/s). (Little over Mach 4.) Orbital velocity is something like 6900 meters per second. And 9 G's is pretty damn high for passengers. Most of them would black out, and you probably couldn't take elderly and infirm passengers without liability insurance problems.
What do you think reasonable G's are? I think 4 G's is what general cargo and passenger service needs to aim for.
I like the idea of towers, however. I don't think you need to avoid all of the atmosphere to get usable launch towers. And, as you point out, you don't need to accelerate all the way to orbital velocity. As I point out, TSTO is relatively easy, and replacing the first stage would be a great thing to do.
Unfortunately, 11km is far too short an acceleration distance for anything but unmanned cargoes. (Think of how far downrange the Shuttle gets, accelerating all the while. You'd need a structure with length on that scale!) Also, getting altitude is only a small part of the problem. It's getting up to orbital velocity which is the big sticking point.
That reminds me of another one. Apparently, some NASA researcher has determined that we could create super-strong cylindrical columns using Boron balloon tanks filled with super-pressurized gas. (A latex balloon is pretty flabby, but if one inflates one of the long skinny ones, one finds that it makes a usable column.) Such a structure would be super strong and super light, to the extent that we could build 100km tall towers. These would be incredibly costly, but a series of these could support an accelerator above the atmosphere. This would give us the same access to space as a basic space elevator.
There are several things we could be doing to dramatically lower launch costs.
Two Stage To Orbit - If done correctly, we can build one of these to operate like an airplane, instead of a munition. (See The Rocket Company for details. Single Stage To Orbit (SSTO) is right at the bleeding edge of our capabilities. But if we're willing to build big and build robustly, TSTO is doable with off-the shelf technology. (The fuel to get into space is not that much more expensive than the fuel to get a 747 over the Atlantic.)
Modular Laser Launch - You can develop a laser module to launch a small unmanned test vehicle, then scale it up to launch useful payloads (5000 lbs) by building and combining multiple modules. When economies of scale kick in, you get launch costs that start to rival those hypothetical beanstalks.
Rotovators that rendevous with a High Altitude Airplane - Again, it's hard to imagine a robust and reliable SSTO, but a Mach 12 high-altitude aircraft is much more reasonable. Also, a rotating tether that reaches only partly into the atmosphere and cancels only about half of orbital velocity can be built from materials that exist today! (Not unobtanium or carbon nanotubes.)
A Lofstrom Loop - would also enable cheap access to space, and could be built with materials we have today. This is an arc that reaches above the atmosphere, suspended by the momentum of electromagnetically accelerated iron links. Vehicles would be launched into orbit by "stealing" a bit of the loop's momentum.
If we were really serious about lowering launch costs, we would be pouring money into researching these. But we're not. (Too easy to make money off the government doing what we're doing now.)
Not a blog troll! I have no association with Technovelgy. I was just cleaning up my less-used bookmarks, and happened on this post on goold ole Technovelgy, and thought it was neat. (So did the editor, and lots of readers!)
I posted the blog entries about the Starfish Robot because it was a good and useful summary. If you don't think so, then that's fine. Just don't go falsely ascribing motivations and intentions!
I've been a Slashdot reader and commenter for many years now. (Lost count. Over 5?) This account was not nor ever will be eBayed. I also have this username on Reddit, Digg, k5, and Halfbakery where I am the same persnickety OO and hard SF purist I have always been. (Oh, but I love a good "space opry" now and then!)
My head, not yours. Look at you, standing there, being WRONG!
Re:Started with Perl-CGI, went to OO
on
GWT in Action
·
· Score: 1
There's a lot of so-so OO in academia. (A lot of what I see is downright horrific!) And just because you've been doing Java, doesn't mean you've been exposed to good OO. Heck, I've seen plenty of procedural programming in Smalltalk. (I even saw guys who tried to use a Smalltalk image build process like they'd use make and a compiler. Just wrong!)
If, as you say, there are *times* Perl had a better object model, and *times* where delimited strings and hashmaps reach their limits, then you are on the right track. Trust me, there is more!
What is "good OO" in the wrong context can be pernicious, just like good procedural programming in an OO project can be. Just about the only good way to learn good OO is to be mentored in a project where it is being practiced. Again, trust me, there is more. Go and search. Read the beginning of Martin Fowler's Refactoring book and go through the video store example. That's one of the things that made the light bulb go off for me.
Started with Perl-CGI, went to OO
on
GWT in Action
·
· Score: 1
I started with Perl CGI. Take a look at Django or Rails. The Java implementations have been way too heavy.
My guess is that you have been polluted by bloated Java implementations, and still only have a foggy idea of what OO is. True, OO is just a set of ways to organize and think about code along with its data. But if done right, it increases the effectiveness of your organization a lot. And like procedural programming, it can also be done wrong and cause misery. If you want to investigate something, you need to find the best examples of it. And to do that in OO, you can't *just* look in the Java world. There is much fine OO in the Java world. But it is only one slice of a larger pie. This is especially true for Web Apps.
They are always the de-facto pioneers for commercializing new media technology. It would make sense. Unfortunately, even all of them worldwide probably can't afford the 4.6 billion price tag.
A tablet PC with Dasher might be the thing. Dasher is designed to enable 1 finger text entry at reasonable speed. My girlfriend uses it because of her repetitive stress injury.
Damnit, it's a paradigm shift that Linus is talking about. True distributed source code management brings an entirely new way of working. It enables very fast merging at a very fine granularity, which lets you use casually use this information (about what changed and when) in a way that changes the nature of how you work! It's the same sort of difference that code completion or Google search made. Once a certain kind of very useful information -- that has always been available, but a bit inconveniently -- becomes like running water out of the tap, it enables ways of working that just wouldn't have been practical before.
If you really want to know what Linus is talking about from the man himself, watch this Google Tech Talk. It's over an hour, but there's nothing like hearing it straight from the horse's mouth.
Most people don't get new forms of elegance, actually. They usually need a little nudge to get something that's genuinely new. Once something has entered the mainstream, then people can use social cues to direct their attention. Most of us are used to being told what is good.
But besides that, people are conditioned by what they see over and over again. Back in the stone age, we constantly came in contact with physics in our everyday lives in ways that were much more vibrant. Everyone made their living interacting with the outdoors. Today, we have much more experience with often badly simulated (faked) physics in movies and video games. And yes, I have seen that this has taken a toll. I saw a couple of kids who couldn't figure out how to get the maximum bounce out of a trampoline. I actually had to tell them. I saw a grade school girl (about 4th grade) who couldn't figure out how to get her bicycle over the lip of a driveway. She actually stood there on her bike and asked her mom to help her. And the number of people who are deficient in the intuitive geometry they need for driving! (Creeping towards the inside of the lane or even over the edge on a turn. Unable to make a left turn without cutting across the right lane of the street they're turning onto. Unable to parallel park.)
I think this is also connected to the scads of people who are unable to reason critically. We're all becoming a mob disconnected from actual reality, hypnotized by Hollywood's version of it. (How convenient for our elitist masters in our broken democracy!)
Awwww. When I first saw "Spore to Ship..." I was thinking the endgame now involved evolving your planetary ecosystem into a giant interstellar spacecraft. (Sort of like the ships in Octavia Butler's Xenogenesis books.)
Microwave Rectennas would enable the transport of power back to the Earth's surface just fine. The radiation is relatively diffuse, non-ionizing, and would do no more to birds flying overhead than heat them up.
What about Line-Kill Spirits? The idea that you have to take panty shots of your foe to keep her from regenerating is just...bad. Cheesy bad. Yet somehow fun to think about in a it's so ridiculous it's funny sort of way.
When that becomes widespread, then someone will start building 'fake' hardware. In fact, this hardware will probably be an emulator running on top of a general purpose computer.
Slashdot Mirror
What you are saying is that those birds cost that much precisely because it's so difficult to launch them. So you have to amortize the large launch cost over as long an operational period as possible in an extreme environment. If launch costs were much lower, then you could make satellites much cheaper. You could launch more of them to achieve redundancy. And you have a much more affordable fall-back position of just launching another one. Also, economies of scale will start to kick in.
And I thought what they said to the FedEx founders, was that 1) there was already mail and 2) not enough people wanted to to overnight things badly enough. But if this is a misunderstanding, please correct me.
That's too cool! If you built your launch tower to give significant lateral velocity, then so much the better. In fact, it may be possible to design the trajectory so that you can skim off the top of the atmosphere and aerobrake any excess velocity. (You'll need some thermal protection for the craft anyhow, as it will be blazing through the atmosphere at only 35,000 feet at Mach 3.) Then all you're left with is a small burn for circularizing your orbit.
Unfortunately, you are probably leaving out a big chunk of energy for losses due to air friction. This is why rockets need something like 8600 m/s delta-v to get to LEO, while orbital velocity is actually a bit less than that. Still, a rocket firing as a velocity sustainer through the atmosphere is a lot easier than trying to get it going that fast from a standstill in one stage.
If we can build such a tower for 4 to 5 billion, then a much longer ramp reaching 11km but at a 30 degree incline might be feasible for under 15 billion. (Especially if it were built suspension-bridge style.) If we did this instead of a moon-base or manned Mars exploration, it would make those two things a heck of a lot cheaper!
The world's governments should get together and build this somewhere like Ecuador. I'm also hoping the Chinese will build something like this.
11 km towers are well established as feasible with conventional construction techniques. (It would be damned expensive, however!)
If we can manage atmospheric friction during hypersonic re-entry, then we can manage it during launch as well. Since we are partially freed from the tyranny of the Rocket Equation, we could afford the additional mass to do something like carry along some water to evaporatively cool the launch vehicle while it was blazing through the remaining 1/5th of the atmosphere.
Pratt & Whitney RL-10s! Linear electromagnetic accelerators. Lasers. We already have the tools to get into space. Let's go already!
The developers of launch technologies were (until recently) doing so almost solely at the behest of the government. And demand for space access is strongly shaped by the economics of the current launch vehicles. It's a classic chicken and egg problem.
I think there's demand that's invisible simply because the capability isn't there. I think that if companies could launch 5,000 pound communications platforms for only 5 million dollars, you'd have things like ubiquitous and cheap LEO satellite broadband. There is definitely a market for that. I suspect that the ability to transport goods and passengers around the globe in just a few hours would greatly open up demand once it became available, simply because people would get used to the idea that it's possible to begin with. (Remember, they said similar things to the guy who started FedEx.)
There has to be some up-front R&D investment. Otherwise, cultural inertia would stop all advance.
Well, if we use x = 1/2 at^2, and plug in 9*9.8 (m/s^2) (nine gravities) and 11,000 meters, we get t^2 = 249.43 (s^2). Take the square root, and you get 15.79 seconds. If you accelerate at 9 G's for that long, you only get to about 1393 (m/s). (Little over Mach 4.) Orbital velocity is something like 6900 meters per second. And 9 G's is pretty damn high for passengers. Most of them would black out, and you probably couldn't take elderly and infirm passengers without liability insurance problems.
What do you think reasonable G's are? I think 4 G's is what general cargo and passenger service needs to aim for.
I like the idea of towers, however. I don't think you need to avoid all of the atmosphere to get usable launch towers. And, as you point out, you don't need to accelerate all the way to orbital velocity. As I point out, TSTO is relatively easy, and replacing the first stage would be a great thing to do.
Unfortunately, 11km is far too short an acceleration distance for anything but unmanned cargoes. (Think of how far downrange the Shuttle gets, accelerating all the while. You'd need a structure with length on that scale!) Also, getting altitude is only a small part of the problem. It's getting up to orbital velocity which is the big sticking point.
That reminds me of another one. Apparently, some NASA researcher has determined that we could create super-strong cylindrical columns using Boron balloon tanks filled with super-pressurized gas. (A latex balloon is pretty flabby, but if one inflates one of the long skinny ones, one finds that it makes a usable column.) Such a structure would be super strong and super light, to the extent that we could build 100km tall towers. These would be incredibly costly, but a series of these could support an accelerator above the atmosphere. This would give us the same access to space as a basic space elevator.
A "Null Prize" if you can find that one.
If we were really serious about lowering launch costs, we would be pouring money into researching these. But we're not. (Too easy to make money off the government doing what we're doing now.)
Not a blog troll! I have no association with Technovelgy. I was just cleaning up my less-used bookmarks, and happened on this post on goold ole Technovelgy, and thought it was neat. (So did the editor, and lots of readers!)
I posted the blog entries about the Starfish Robot because it was a good and useful summary. If you don't think so, then that's fine. Just don't go falsely ascribing motivations and intentions!
I've been a Slashdot reader and commenter for many years now. (Lost count. Over 5?) This account was not nor ever will be eBayed. I also have this username on Reddit, Digg, k5, and Halfbakery where I am the same persnickety OO and hard SF purist I have always been. (Oh, but I love a good "space opry" now and then!)
My head, not yours. Look at you, standing there, being WRONG!
There's a lot of so-so OO in academia. (A lot of what I see is downright horrific!) And just because you've been doing Java, doesn't mean you've been exposed to good OO. Heck, I've seen plenty of procedural programming in Smalltalk. (I even saw guys who tried to use a Smalltalk image build process like they'd use make and a compiler. Just wrong!)
http://www.geocities.com/tablizer/oopbad.htm -- this guy is a bit of a nutter. Seen his stuff and traded posts with him before.
If, as you say, there are *times* Perl had a better object model, and *times* where delimited strings and hashmaps reach their limits, then you are on the right track. Trust me, there is more!
What is "good OO" in the wrong context can be pernicious, just like good procedural programming in an OO project can be. Just about the only good way to learn good OO is to be mentored in a project where it is being practiced. Again, trust me, there is more. Go and search. Read the beginning of Martin Fowler's Refactoring book and go through the video store example. That's one of the things that made the light bulb go off for me.
That's that sticking out of the 19" monitor? It looks like a little black hand.
If we can make new ones that can replace the ones that are already there with broken-down mtDNA, then this brings us closer to extended lifespans!
e =mitosens
http://methuselahfoundation.org/index.php?pagenam
I started with Perl CGI. Take a look at Django or Rails. The Java implementations have been way too heavy.
My guess is that you have been polluted by bloated Java implementations, and still only have a foggy idea of what OO is. True, OO is just a set of ways to organize and think about code along with its data. But if done right, it increases the effectiveness of your organization a lot. And like procedural programming, it can also be done wrong and cause misery. If you want to investigate something, you need to find the best examples of it. And to do that in OO, you can't *just* look in the Java world. There is much fine OO in the Java world. But it is only one slice of a larger pie. This is especially true for Web Apps.
Back in school, my bus was so short, it drove Backwards!
Why would Keanu be so bad? He has just about enough emotional range for the Robot.
They are always the de-facto pioneers for commercializing new media technology. It would make sense. Unfortunately, even all of them worldwide probably can't afford the 4.6 billion price tag.
A tablet PC with Dasher might be the thing. Dasher is designed to enable 1 finger text entry at reasonable speed. My girlfriend uses it because of her repetitive stress injury.
5 080674416&q=dasher+google+tech+talk&total=2&start= 0&num=10&so=0&type=search&plindex=0
http://en.wikipedia.org/wiki/Dasher
http://video.google.com/videoplay?docid=507833407
But if she can still write, that will be even better and faster.
Damnit, it's a paradigm shift that Linus is talking about. True distributed source code management brings an entirely new way of working. It enables very fast merging at a very fine granularity, which lets you use casually use this information (about what changed and when) in a way that changes the nature of how you work! It's the same sort of difference that code completion or Google search made. Once a certain kind of very useful information -- that has always been available, but a bit inconveniently -- becomes like running water out of the tap, it enables ways of working that just wouldn't have been practical before.
4 4603874737&q=git+google+tech+talk&total=3&start=0& num=10&so=3&type=search&plindex=1
If you really want to know what Linus is talking about from the man himself, watch this Google Tech Talk. It's over an hour, but there's nothing like hearing it straight from the horse's mouth.
http://video.google.com/videoplay?docid=-21993320
Or an art movement. Or a new scientific paradigm.
Most people don't get new forms of elegance, actually. They usually need a little nudge to get something that's genuinely new. Once something has entered the mainstream, then people can use social cues to direct their attention. Most of us are used to being told what is good.
A lot of people do live a sad static life.
But besides that, people are conditioned by what they see over and over again. Back in the stone age, we constantly came in contact with physics in our everyday lives in ways that were much more vibrant. Everyone made their living interacting with the outdoors. Today, we have much more experience with often badly simulated (faked) physics in movies and video games. And yes, I have seen that this has taken a toll. I saw a couple of kids who couldn't figure out how to get the maximum bounce out of a trampoline. I actually had to tell them. I saw a grade school girl (about 4th grade) who couldn't figure out how to get her bicycle over the lip of a driveway. She actually stood there on her bike and asked her mom to help her. And the number of people who are deficient in the intuitive geometry they need for driving! (Creeping towards the inside of the lane or even over the edge on a turn. Unable to make a left turn without cutting across the right lane of the street they're turning onto. Unable to parallel park.)
I think this is also connected to the scads of people who are unable to reason critically. We're all becoming a mob disconnected from actual reality, hypnotized by Hollywood's version of it. (How convenient for our elitist masters in our broken democracy!)
Awwww. When I first saw "Spore to Ship..." I was thinking the endgame now involved evolving your planetary ecosystem into a giant interstellar spacecraft. (Sort of like the ships in Octavia Butler's Xenogenesis books.)
Microwave Rectennas would enable the transport of power back to the Earth's surface just fine. The radiation is relatively diffuse, non-ionizing, and would do no more to birds flying overhead than heat them up.
e
http://en.wikipedia.org/wiki/Solar_power_satellit
Unlimited Solar Power, a burgeoning Space Program, and free cooked poultry falling from the sky! What more could you ask for?
What about Line-Kill Spirits? The idea that you have to take panty shots of your foe to keep her from regenerating is just...bad. Cheesy bad. Yet somehow fun to think about in a it's so ridiculous it's funny sort of way.
http://en.wikipedia.org/wiki/Line-Kill_Spirits
When that becomes widespread, then someone will start building 'fake' hardware. In fact, this hardware will probably be an emulator running on top of a general purpose computer.
So, you'll be able to make a phone call from Javascript? I shudder to think of this. Imagine pornsite pop-ups that dial 1-900 numbers for you!
It was realized, it just wasn't that high to begin with.