Startram — Maglev Train To Low Earth Orbit

Zothecula writes "Getting into space is one of the harder tasks to be taken on by humanity. The present cost of inserting a kilogram of cargo by rocket into Low Earth Orbit (LEO) is about US$10,000. A manned launch to LEO costs about $100,000 per kilogram of passenger. But who says we have to reach orbit by means of rocket propulsion alone? Instead, imagine sitting back in a comfortable magnetic levitation train and taking a train ride into orbit."

Comments

Fucking magnets

[ColdWetDog]

Now, how is this going to work?

Re:Fucking magnets

[busyqth]

200 million amperes of current running down a 1000 km long superconducting cable. In other words: it's child;s play.

Re:Fucking magnets

[Anonymous Coward]

If you bothered to read the article, you wouldn't look like such an idiot.

Re:Fucking magnets

[camperdave]

Do I want to know what the induced magnetic field capable of levitating 4 tons at a distance of 20km is going to do to my hemoglobin, or to my laptop?

Re:Fucking magnets

[atrain728]

Obviously we'll need some miracles.

Re:Fucking magnets

[Anonymous Coward]

I'm guessing accelerate it at 3gs for a period of 5 minutes.

If the craft is designed with any level of extraplanetary shielding in mind, it'll be able to reduce the EM bleedthrough to significantly below MRI levels, and 5 minutes in an MRI is generally not considered hazardous for a human. If they can't reasonably reduce the EM effect onboard low enough to be safe for electronics, you will probably have a secure faraday box to stow them in during launch.

Re:Fucking magnets

[mcgrew]

I know that a sample of one is insignifigant, but my dad was a lineman working with voltages up to 90k. He could not wear a wristwatch unless it was completely made of non-ferrous material, because when he put it on after work, an hour later it stopped. Apparently his hemoglobin was magnetized. Yet he's now 80 and still in good health.

I wouldn't worry about the magnetic fields. Apparently having your blood megnetized is harmless.

Of course, the fact that his uncle started smoking cigarettes at age 12, quit at age 82 and lived ten more years illustrates that a sample of one is indeed insignifigant and perhaps meaningless. Me, I'd risk magnetic blood for a chance to go to outer space anyway, as I have half of dad's genes.

Re:Fucking magnets

[Entropius]

Wow. That's pretty damn impressive -- that despite the fluid nature of blood the spins retained magnetic order over macroscopic distances *after* bouncing around through his arteries.

Re:Fucking magnets

[Anonymous Coward]

You can't use your laptop at take off because the rocket will fall out of the sky.

Re:Fucking magnets

[Baloroth]

Not when the launch tube is magnetically levitated, as suggested. TFA actually claims that the design is perfectly possible with existing technology, and they seem to have run the math. You need tethers to stop the tube from levitating too much, actually, but that is again perfectly possible.

Re:Fucking magnets

[eternaldoctorwho]

I disagree with everything everyone said in this thread, because I am a Slashdot poster! I am a bitter pile of negativity that always contradicts or attempts to out-do the parent post. All of your opinions are false, wrong, and stupid. I know everything about the topic at hand, and you know nothing!

Re:Fucking magnets

[WillDraven]

I think he was maybe referring to the people on the ground in the area of the launch tube. I would imagine that you would have to build this thing on the ocean or in the Sahara desert to keep it from playing havoc with nearby electronics.

Re:Fucking magnets

[Anonymous Coward]

He is talking about the 12 mile cables. They need to be able to carry the weight of a 12 mile cable. Get it?

Re:Fucking magnets

[fahrbot-bot]

Apparently his hemoglobin was magnetized. Yet he's now 80 and still in good health.

Another benefit is that when you're lost, you can just float your dad in a lake as a compass...

Re:Fucking magnets

[garyebickford]

The blood system does carry an electrical current, so it makes sense that there would be a related magnetic field. And (speculating) if a large number of individual cells had become weakly magnetized (acquired some magnetic alignment in materials in the cell), then it stands to reason that they would continue to maintain some small level of orientation for a while, as each one tends to encourage the neighbors to stay aligned.

Look up "Biologically Closed Electrical Circuits, by Björn Nordenström a very well-regarded pathologist, who was allowed in the 1960s to perform studies and experiments on terminally ill patients. He proved that there is an electrical current that flows through your blood stream, and that any inflammation involves a current flow as well. There's like a little fountain of current through that owie on your hand. Also through cancers, etc. In his experiments (on patients who were terminally ill of at least two different diseases, a requirement required to allow him to do the work), he was also able to show that many such diseases - cancerous lesions among others - could be shrunk and actually cured by reversing the current flow.

The original book of that title is oriented toward researchers in that field, is very technical and very expensive - IIRC $700? - but it is often available at college libraries, and there are several other books that are oriented more toward non-technical readers. There is also an association that has been supporting ongoing research, some of which has shown very encouraging results with localized tumors.

Dr. Nordenström was quite familiar with negative reactions from his colleagues. As his accomplishments grew, he became Head of Diagnostic Radiology at Karolinska Institute, Stockholm, Sweden. He also authored or co-authored more than 150 publications in radiology, electrobiology and pharmacology. He was a member of the Nobel Assembly from 1967 through 1986, and served as President of the Assembly in 1985. Even with these credentials, many of his ideas, such as needle biopsy and balloon catheterization were initially met with significant amounts of opposition by his peers.

Re:Fucking magnets

[PopeRatzo]

How will it work? Newt Gingrich says "With a big V8 and $2/gal gasoline."

Re:Fucking magnets

[busyqth]

And wives... lots of wives... don't forget that part.

Re:Fucking magnets

[CanHasDIY]

Whoever modded this down either has A) no sense of humor, B) a super-inflated sense of self worth, or C) both.

That's right funny shit.

Re:Fucking magnets

[CanHasDIY]

In fact... forget the V8 and $2/gal gasoline!

Re:Fucking magnets

[Cyberax]

Absolutely nothing at all. Magnetic field drops off according to inverse _cube_ law. So the field will be barely detectable at that distance.

Re:Fucking magnets

[Anonymous Coward]

*slap*

Could have had a V8!

Re:Fucking magnets

[Anonymous Coward]

Don't be so naive.

Just because the article claims all the technology to do this is known, doesn't mean it's true. Nobody has ever built a superconducting structure that suspends 12 miles in the air. Nobody has ever made a vacuum tube 1000 miles long. Nobody has made a maglev track 1000 miles long. I suspect hundreds or thousands of 'unknown unknowns' would crop up during the development of such a project. Not to mention cost overruns that would make the space shuttle look like a bargain.

Re:Fucking magnets

[Anonymous Coward]

If one can harness the power of the Sun effectively, it is child's play.

Unfortunately, we can only harness 5% of the sun's energy...

Re:Fucking magnets

[eternaldoctorwho]

You should read From the Earth to the Moon sometime.

Re:Fucking magnets

[BitZtream]

True, but it still has to be capable of carrying the weight AT that distance, that just means that while it has the power to carry 4 tons ... from a distance of 20km ... Regardless of how far away the train is, you still have to provide at least 4 tons of force at that point ... that means the further away it is, the ground station has to provide more energy at its location, squared by distance to the train in order for the train to get the required 4 tons of support.

The magnetic field that envelops the train will only get lower because the train is further away from the mass of the Earth, which will reduce the effect of gravity on it making it require less than 4tons of energy to support it, but FAR more energy at the base station to get that energy to the train at the distance it will be at.

So the field will be detectable at at least the distance from the base stations to 'orbit' or whereever you're going to be released from the maglev on your own if its got another form of propulsion.

Regardless of the distance, the magnetic field will still have to be significant enough to effect the amount of mass contained in the train at the trains location, including passengers, and no matter how you look at it, thats still one hell of a massively powerful magnetic field.

Re:Fucking magnets

[Grishnakh]

This is one of the big problems with our society as I see it, and a giant impediment to us actually making any real technological progress beyond building ourselves more handheld gadgets to entertain ourselves with, which aren't going to help us much with upcoming resource and energy shortages. We need to be building big superconducting structures, vacuum tubes, maglev tracks, etc. A space elevator or maglev train to orbit or undersea intercontinental vacuum tunnel or whatever is a monumental undertaking, yet the only experience we have with these technologies is very small-scale lab experiments, not any real-world production examples in the medium scale to refine our knowledge and techniques before we try building something really huge. And without any proven experience outside the lab, there's not going to be many investors willing to fund the megascale projects.

Re:Fucking magnets

[jandrese]

When someone proposes a gigantic megaproject like this and says that it would be technologically possible with todays materials, I always assume that they have oversimplified many parts of the design and that there are serious fundamental problems with the approach. This has been a pretty safe bet so far, and I don't think I'm going to be wrong here.

Here's a question: When you are accelerating a multi-ton mass at 3G up to the top of a tube that is 24 times higher than the highest skyscraper in the world, how do you keep it from buckling under the force? Don't assume that the designers have thought about stuff like this, because most of the time they have not. They just worked out the basics on the back of a cocktail napkin and got all excited.

Space elevator enthusiasts tend to be really bad about this. They're dreamers, not engineers.

Re:Fucking magnets

[Anonymous Coward]

Electrical power transmission lines carry about 1 or 2 kA of current in them, this system is talking about 200 MA, so a factor of 10^5 greater. I can put my tongue on a 9 V battery and get a nice little tingly feeling. I wonder what happens if I put my tongue on 900 kV?

Re:Fucking magnets

[evilviper]

technological progress beyond building ourselves more handheld gadgets to entertain ourselves with, which aren't going to help us much with upcoming resource and energy shortages.

These "handheld gadgets" gave us Li-Ion batteries, which made all-electric cars practical... That's pretty damn huge.

We need to be building big superconducting structures, vacuum tubes, maglev tracks, etc.

These kinds of things are called "prestige projects"... meaning, in-short, they're massively impractical, but SOUND impressive, and get lots of press.

Frankly, vocal proponents of maglevs are also preventing us from just developing traditional high-speed rail, which France has shown to be imminently practical, and still very fast. Instead, we've got more and more cars on the road, because a practical solution isn't flashy enough for people like you.

We don't NEED maglevs to space. Materials have reached the strengths needed for a space elevator, they just need more R&D, and THAT kind of fundamental materials research is where we should be putting our money. I guarantee you'll get more bang from it than you would building a maglev track.

Re:Fucking magnets

[multi io]

Absolutely nothing at all. Magnetic field drops off according to inverse _cube_ law.

The magnetic field strength (B) around an (infinitely long) conductor with constant current drops off with 1/R.

Re:Fucking magnets

[Anonymous Coward]

Unobtanium. Seriously, these guys need a hybrid launch concept. Short sleds that can have rocket boosters would be perfect. The engineering challenge would be supporting a structure several miles high. I propose that any ideas of going beyond 3000 feet off the ground for a support structure of any kind be abandoned in favor of horizontal maglev to at least 50% of orbital velocity, then rockets for the rest. Just what does superheated plasma (lightning) and 200 mph wind (hurricanes/tornadoes/cyclones) do to something suspended in the stratosphere? The real win of this concept is an external energy source to get to orbit. How else can you use hydro, solar, wind, geothermal, nuclear, oil, and even coal as a fuel to launch a spacecraft?

Re:Fucking magnets

[Baloroth]

From TFA:

Sandia National Laboratories has carried out a '"murder-squad" investigation of the Startram concept, whose purpose is to find any flaw in a proposed project. They gave Startram a clean bill of health.

Sandia, if you don't know, is a major Lockheed Martin-owned research lab that does research work for the DoE in nuclear science, materials research, etc. I have a high degree of confidence they know what they are talking about (more, TBH, than either the article or any arm-chair commentators on Slashdot). The designer has also been working on the design since at least 2002, so I imagine he has given at least some thought to the technical problems it possesses. So, slightly more than working out the basics on a cocktail napkin.

This isn't even close to the space-elevator. That is well known to be impossible with current materials research. There are several space-lift designs, however, that are very much possible (currently), and this looks like one of them. The problem is getting someone to front billions on a project that may well, half-way through, run into massive technical problems, and will, at best, take decades to complete, much less show a return on investment. Which, BTW, makes it a perfect project for the government, so long as they can dedicate themselves to actually finishing it (which I'm not naive enough to think will happen). So, any such system is unlikely to get built for a while.

Re:Fucking magnets

[Grishnakh]

These "handheld gadgets" gave us Li-Ion batteries, which made all-electric cars practical... That's pretty damn huge.

If we had had a bigger push for EVs earlier, more advanced batteries would have been researched and developed earlier, rather than waiting for handheld gadgets to drive the market.

Frankly, vocal proponents of maglevs are also preventing us from just developing traditional high-speed rail, which France has shown to be imminently practical, and still very fast.

You've got to be kidding. France is a tiny country, about the size of a few east coast states; there simply isn't much distance between any two points there. HSR may be practical there, but it hasn't shown itself to be very practical here in the US, aside from the Northeast Corridor. Things are just too far apart; there's too many people wanting to travel between FL and NY, NY and LA, LA and WA, etc. Besides, how can HSR travel ever get anywhere very fast when you're only allowed to travel 35mph anywhere near any populated area thanks to morons that try to "beat the train" at crossings? I have serious doubts HSR could ever work here even in limited deployments, because of too many legal issues; you'd need to either elevate the train well above the ground, or bury it in tunnels; the first is probably impractical and the latter too expensive.

A space elevator definitely sounds like a great idea, but again it needs more funding to develop the required materials and engineering knowledge, because right now it's pretty much just on the drawing board. No one's made a cable with the required strength and deployed it in the field for anything, they've just talked about how to make it. There's no telling what kind of issues will arise when trying to develop this stuff at a large scale.

Re:Fucking magnets

[Anonymous Coward]

Per NASA's science web site from 2000 (http://science.nasa.gov/science-news/science-at-nasa/2000/ast07sep_1/):

"Fiber materials such as graphite, alumina, and quartz have exhibited tensile strengths greater than 20 GPa (Giga-Pascals, a unit of measurement for tensile strength) during laboratory testing for cable tethers. The desired strength for the space elevator is about 62 GPa. Carbon nanotubes have exceeded all other materials and appear to have a theoretical strength far above the desired range for space elevator structures. "The development of carbon nanotubes shows real promise," said Smitherman. "They're lightweight materials that are 100 times stronger than steel.""

So apparently they moved past the cocktail napkin phase over 12 years ago. Of course, they also don't think it'll actually be feasible to build until at least the end of this century (if then).

Re:Fucking magnets

[Cyberax]

But we're not talking about an infinitely long conductor. We're talking about lots and lots of fairly small magnets, each of which is a simple dipole magnet.

Re:Fucking magnets

[ceoyoyo]

Hm... 60 billion over twenty years. That's well within the military budget of Iran, and would be child's play for China. You could use this thing to put stuff in orbit, quickly, which obviously has military uses, and it would double as an awesome artillery piece that could reach nearly anywhere in the world. Iraq tried to build a mega-gun once. It would be an excellent demonstration of Chinese superiority.

Re:Fucking magnets

[ceoyoyo]

I'd suggest not standing too close to the 100 million amp cable, actually, regardless of the magnetic field.

Re:Fucking magnets

[tragedy]

Here's a question: When you are accelerating a multi-ton mass at 3G up to the top of a tube that is 24 times higher than the highest skyscraper in the world, how do you keep it from buckling under the force?

By designing the structure to withstand the forces involved? If this is meant to be a trick question, it's not a very good one. A 10 metric ton mass at 1 G is about 9807 newtons. At 3G it's about 29,421 newtons. There's also the actual force of gravity, although it's acting in a different direction (at a rough guess I'd say the slope on this thing is 1 over 10 based on the concept art, so it's almost perpendicular to the 3 Gs) but we'll ignore that and just add it to the 3 G, so it's 39288 newtons. That's really not such an incredible force. Your comment sort of reminds me of people who criticize the concept of simulated centrifugal gravity on space stations who start to go on about the "incredible" stresses involved, not realizing that they're talking about the exact same magnitude of stress that terrestrial bridge-builders need to deal with.

The scale of such a structure would certainly be a big deal. But the masses, forces, pressures, and energies (although I will grant not the speeds) of such a system are miniscule compared to those dealt with on a regular, daily basis by all kinds of engineering that people interact with and take for granted.

Re:Fucking magnets

[shilly]

France isn't that small. Paris to marseille is about 800 klicks. New York to Orlando is about 1000.

The crossing point you raise is weird. It is inconceivable you'd build an hsr line with crossings!

Similarly, tunnels or elevated tracks are hardly a requirement for a complete track, a
Though both are likely needed at points. Cuttings are a much cheaper way of reducing noise etc.

The issues aren't about engineering, they're about politics and will

Re:Fucking magnets

[Anonymous Coward]

building stationary EM shielding is easy without the need to keep weight down. we know how to do that today.

Re:Fucking magnets

[Baloroth]

The launch-line also has to be about 1600km in length by present designs. A few neighbors might take objection to Iran attempting to build one over the top of them. Ideally, it should be close to the equator, and while it can be over water, hurricanes would be a serious issue. Pretty much makes the US, China, and possibly Russia the only countries large enough to build one (I mean physically large enough). Others might, of course, be able to negotiate with neighbors to build it over their heads: but anyone trying to use it militarily will probably run into issues with that.

Re:Fucking magnets

[Grishnakh]

The issues aren't about engineering, they're about politics and will

Exactly my point. This is the USA. You don't really think we could possibly build HSR in a sensible way, do you? And you make a comparison with France, a country that gets most of its power from nuclear plants (and exports a shitload of nuclear power to other European nations too) and manages to do so without meltdowns and catastrophes and the entire population jumping on an anti-nuclear-power bandwagon because of an accident in a country where they stupidly put a nuclear reactor right next to the ocean in an area where there's lots of earthquakes and tsunamis.

Intercontinental tunnels or elevated tracks would be a requirement here in the USA; if they didn't do that, people would be getting hit by the trains left and right, even if they have to go into these "cuttings" to do so. We're talking about people who elected Bush, twice, and then elected Obama on some vague promises of "change", and who constantly are trying to "beat the train" at crossings, getting hit by trains (traveling a measly 35mph), and then suing the train company! Don't underestimate the stupidity here.

Re:Fucking magnets

[tragedy]

A. There are plenty of materials that can support their own weight at those lengths. Even plain old steel, aluminium and titanium cables have breaking lengths of about 20-30 km, which meets or exceeds the requirements for most or all of the length of the elevated part of the structure (some of the cables are sloped so would be longer than 12 miles/20 km near the end, but it's a slope, so only the cables at the very end actually need to be that long). Materials like fibreglass and kevlar can reach 5 times that or more (and also aren't ferromagnetic like steel cable which would probably be a bit of a problem around a maglev system like this).

B. There's no actual need for the cables to support their entire length. This is only meant to reach up 12 miles. That's only a little bit above the cruising altitude of the Concorde. It's inside the atmosphere where aircraft, including lighter than air ones can work. There's no reason that the cable couldn't be supported at various points along its length with balloons, blimps or dirigibles.

C. The plans call for cables for stabilization of an actively supported structure. It may turn out that the design can be tweaked so that it can be actively stabilized as well. Maybe magnetically in a system with more than one ground cable. Maybe using gas jets (high pressure exhaust from the cooling system that chills the superconductors maybe?) or some other system. Heck, maybe using propellers (not sure about how practical that would be 20 km up) or jet engines.

Re:Fucking magnets

[Fastolfe]

Apparently his hemoglobin was magnetized.

Hemoglobin is paramagnetic (at best), not ferromagnetic. Paramagnetism doesn't work like that.

Re:Fucking magnets

[Jus10h]

Haha where do you live steam train/moron land , 35, cargo trains routinely go 55 to 65ish depending on load and number of trains here and i know passenger trains beat that.

Re:Fucking magnets

[tragedy]

Unobtanium doesn't seem to be necessary. Room temperature superconductors would be nice, but the kind we actually have would work just fine with an active cooling system. We have plenty of materials that can withstand the pressure and keep the tube evacuated of air. We have cables that can provide the necessary structural tension that high up. Stronger, lighter, more durable, more conductive, etc. materials would be nice, but they always would be for any project. This project does not require them.

As for the hybrid idea; I don't think you realize that this is a hybrid system. At least it is for anything you want to do outside LEO. If you want a payload to the Moon or Mars, etc. you use this system to put rocket engines, fuel and payloads in orbit, then assemble them there, then boost your way to your desired location at a significant savings compared to doing it from the surface of the Earth.

Doing what you suggest and accelerating on the surface ignores the little problem of air pressure, which is far higher at the surface than it is 12 miles up. If you're going to accelerate something to those kinds of velocities in an evacuated tube on the surface then eject it into the atmosphere you're basically going to be building yourself an explosion machine. Consider what happens to spacecraft when they aerobrake in the _upper_ atmosphere. Consider what happens when you try that at ground level. Maybe you could do what you suggest from a very, very tall ramp structure built to launch off the top of a very, very tall mountain.

As for what lightning does to such a structure suspended in the stratosphere, I assume that it grounds out through the lightning rods and earths through the conductive (or superconductive) parts of the structure. As for the winds, they may be high, but they're in a very sparse atmosphere so they're proportionately less energetic.

There are a lot of other ways to use hydro, solar, wind, geothermal, nuclear, oil and coal to launch a spacecraft than just building a rocket as you point out. Concepts like this are interesting, but you always want to get things right the first time if you can and use the best method. The idea in the article, for example, has some things in common with a launch loop, which is kinetically supported structure (basically a maglev system continuously hurls a cable, connected into a loop, into the sky at both ends) which implements the same maglev launch vehicle concept as this plan, but does away with the evacuated tube by having all the acceleration happen in the part of the loop that's outside the atmosphere. Then there are space fountains, which are kinetically supported structures like launch loops but using loose pellets and magnetic levitation to hold up an otherwise impossibly large structure. Then there's the space elevator concept, which you can make practical with modern materials if you support it along its length at strategic points with every technology you can think of: balloons, dirigibles in atmosphere, then maybe laser supported sails ( I suppose with the lasers mounted on the top-most balloons) outside the atmosphere, in the ranges where Earth blocks the light from the sun at night, then a network of tether-rigged solar sails out where they can avoid the shadow of the Earth. Actively supported like that, we might be able to get a space elevator to work without needing ridiculously strong materials. Then there's simply launching a payload using an earth-based laser to propel a craft with a light sail from the ground (or from a high balloon platform. Then there's this maglev system. Maybe we can find a way for it to work with just the ground cable and the train and skip the tunnel and track. Essentially magnetically levitate the payload and some sort of magnetic sled up to 12 miles and accelerate it there (would probably require a very long sled with a its own very powerful power supply if at all possible). Beyond those ideas, there are dozens or hundreds more ideas to skip the part where you use 50 times your payload's mass in fuel to get it up there. Some are more reasonable than others. Basically we just have to simulate the best we can, perform whatever scaled experiments we can afford, then pick one and then maybe we can re-kickstart the space age provided it actually works.

Re:Fucking magnets

[Grishnakh]

I'm pretty sure they usually have to slow down to 35mph in city limits or around other populated areas. 55-65 is also rather slow; I think the cargo trains go about 75 out here in Arizona/New Mexico in the unpopulated areas (like along I-40), but that's in places where there's absolutely nothing around for many miles except sand and rocks.

Re:Fucking magnets

[ceoyoyo]

A military one can be a lot shorter if you don't want to launch people. Iran even has some decent mountains, although if you were throwing rocks you wouldn't need to elevate it much.

Re:Fucking magnets

[evil mr. paws]

There's this wonderful idea called SIMULATION, one of the foundations of MODERN ENGINEERING. Posts like the OP I'm replying to just depress the hell out of me. Why? ==> THESE SIMULATIONS ALREADY EXIST http://en.wikipedia.org/wiki/Space_gun and in maybe 2-3 minutes your education might actually be catching up to your opinions.

Re:Fucking magnets

[tirerim]

HSR neither needs to be elevated nor completely buried; all you need are simple bridges over or under roads, which coincidentally we already have along almost the entire Northeast Corridor (at this point, there are only eleven remaining grade crossings, all in eastern Connecticut. HSR would be built with entirely new construction, so there would be no grade crossings at all. Then the legal issues are exactly the same as for regular trains, which is to say that the only people who get hit are trespassers. And a 60 mph train will kill you just as dead as a 180 mph one, with just as little chance of stopping before it hits you. Of course, you were right that maglev proponents are not the ones preventing us from developing traditional HSR -- naysayers like you are doing that.

Re:Fucking magnets

[Grishnakh]

A 180mph train hitting some moron on the tracks (or more accurately their car) will probably cause a derailment.

I'm not preventing anyone from developing HSR. I'm sure it'd work just fine in other countries like Canada, or France where it already exists. It's just not realistic here.

Re:Fucking magnets

[Anonymous Coward]

omg. They have a balloon at the top that holds everything up. duh.

Re:Fucking magnets

[theshowmecanuck]

Not sure but if you take a lot of iron supplements you might not need viagra. But maybe not.

Re:Fucking magnets

[theshowmecanuck]

I worked on a pilot system testing a direct current arc furnace that was designed to work at up to 6 MW (at about 3000 amps IIRC... hard to remember it was 20 years ago). It was the largest direct current arc furnace ever built up to that time and maybe still so, since arc furnaces are normally alternating current. The shell of the furnace was bout 25 or 30 feet tall and about 20 feet wide. The walls were around one or two inches thick of steel not included a good number of feet of refractory lining. Because it was direct current the steel shell and adjoining feed pipes became permanently magnetized. There were these around 15 inch steel pipes that raw material would slide down and one time someone working on a deck/floor just above them accidentally dropped an 18 inch crescent wrench through an opening in the deck. They yelled look out below and heard clanging as it fell, but no one ever found it for a couple months. It was stuck to one of the pipes about 40 feet up, hanging by the end... not even flat to the pipe... but from the end swinging. The induced magnetic field was that strong (and the furnace was off when they found it). And then there was the time our instrument tech went to check something on the furnace wall and pulled out a solenoid checker (looks similar to a continuity checker). He looked and saw it was broken because it was lit up already. So he walked away with it to go to the shop to replace it and when he got 30 or 40 feet from the furnace shell the light on the solenoid checker went out. He walked closer and it went on. The checker worked. It is supposed to light up when it senses a magnetic field. The shell was that magnetized. The welders had to wrap cables from a second arc welding rig around some 40 inch pipes leading from the shell when they were welding so they could set up some sort of counter phase to the field so the arcs on their welding sticks wouldn't just sputter/spall blow around because the field messed with the arc. When we ramped up power the monitors in the control room (about 60 or 70 feet away through double blast walls) would go all funky till we degaused them. Any monitor without a degausing switch we had to shield. If it wasn't like working in the myth busters shop every day, it would have been kind of scary. But I don't think it did us too much harm, except for the eye twitches and the strangelove hands (but then it just feels like someone else).

Re:Fucking magnets

[Hognoxious]

And (speculating) if a large number of individual cells had become weakly magnetized (acquired some magnetic alignment in materials in the cell), then it stands to reason that they would continue to maintain some small level of orientation for a while, as each one tends to encourage the neighbors to stay aligned.

In a moving fluid? Don't think so.

That would be like exposing nails to a magnet so they align along the field lines, sweeping them up & throwing them in the air and expecting them to land in the same pattern.

Re:Fucking magnets

[Intrepid imaginaut]

Bonus points: the Sahara is already being worked on as a location where gigantic solar panels can be based to supply the EU's future energy requirements. The energy to power this thing will be right at hand. :)

Re:Fucking magnets

[Anonymous Coward]

France is a tiny country, about the size of a few east coast states; there simply isn't much distance between any two points there.

Nah, you're just being stupid. That's why 213000 square miles looks small to you.

Besides, how can HSR travel ever get anywhere very fast when you're only allowed to travel 35mph anywhere near any populated area thanks to morons that try to "beat the train" at crossings?

French high speed rail does not do at-grade intersections. There are elevated passages and tunnels for road crossings, which lo and behold aren't all that expensive if you do a lot of 'em. There are fences all along the rail and extra-high, noise reducing fences in towns and villages it passes through or near.

Re:Fucking magnets

[Anonymous Coward]

being a pedant, but I wasn't aware of people in Louisiana (postal code LA) needing tons of transport to new york and washington.

I think a raised platform would be wiser for highspeed rail because people underestimate just how many roads are in the united states and how much of a pain dealing with crossings would be. Also, unlike france, we still have large wild fauna roaming about, and a train ramming into a bison would be a catastrophe. with environmental impact and other things put into the equation, raised rails may be the easiest. Also, we could double up the infrastructure by running natural gas, oil or power lines through the superstructure, which would help alemorate the cost and add some needed boost to those parts of the infrastructure.

Re:Fucking magnets

[garyebickford]

The interesting question WRT your example would be, (assuming they are close enough together for any effect), would the nails maintain any alignment _while they are in the air_? The impact with the ground would have a much more forceful randomizing effect that would overwhelm any slight magnetic alignment unless the magnetism was so strong that the nails glommed and stuck together . The blood stream is more or less continuous in that sense. I agree that the idea is unlikely, but it's an interesting concept to speculate on.

Re:Fucking magnets

[Anonymous Coward]

Why does the US not have proper barriers at crossing points, or I dunno, bridges?

Re:Fucking magnets

[tirerim]

Getting a car onto the tracks will be pretty difficult with no grade crossings. I'm not sure what's so hard to understand about that. Do you expect that people will cut down the fence just so they can get their car onto the tracks? And derailments do not happen just from hitting a human body on well-designed and maintained tracks.

Re:Fucking magnets

[Anonymous Coward]

Here's a question: When you are accelerating a multi-ton mass at 3G up to the top of a tube that is 24 times higher than the highest skyscraper in the world, how do you keep it from buckling under the force? Don't assume that the designers have thought about stuff like this, because most of the time they have not. They just worked out the basics on the back of a cocktail napkin and got all excited.

A legitimate question -- I don't know whether they've considered it, but I just took 7 minutes to do so...

There's no good reason the end section where it curves up (the main portion of the track is "flat", and can be rigidly secured to earth) should have any forward acceleration -- the centripetal acceleration doesn't cause buckling. As you say, buckling would be a massive problem if accelerating forward, and whether or not it's feasible to fix, it's guaranteed to be cheaper to tack on more flat acceleration run than to mess with it.

If you're willing to accept higher centripetal accelation for reduced structural loads, you can even replace the "obvious" constant-radius arc from the ground to 20km with one having a sharper radius at the start (where it can be supported with a compression structure, such as the side of a hill), and gentler radius for the elevated part. You could even leave the bulk of the elevated run completely straight, serving only to prevent atmospheric drag. (Technically, an elliptical segment, matching the orbit, would be needed for that. However, it will be nearly straight, so I'm rolling with that approximation for figures; even straight would work with dramatically reduced structural loads.)

I ran some quick numbers, and at 9km/s, a centripetal acceleration of 3g (which is actually 4g total, counting gravity, but would be acceptable; it's a suitable vector for reclined couches, and only for 40s), we're talking 2800km radius of track, which means 20km elevation is reached after 330km for a constant-radius arc.

Say we want to do all acceleration below 2km, so we can just lay the tube in a cut in some hills, and assume we can permit an excursion to 6g (+grav = 7g) for this <10s burst: now we've got a radius of 1400km, so the arc to 2km has a 74km run; this is followed by a 330km straight/elliptical run to 20km. Total is 400km. So basically, you increase the ramp section length by 25% in exchange for completely eliminating acceleration forces on the flying section -- no-brainer, eh.

And yes, space elevator guys are really bad at this. I'm a launch-loop/ram accelerator/startram (as of now) guy, and... well, we're less bad about it, anyway. ;)

Re:Fucking magnets

[kurzweilfreak]

You instantly cease to have a tongue or anything else that might be attached to that tongue, and you will be gone too quickly to have any kind of feeling whatsoever, tingly or not. It would be an impressive visual though.

Or you could instantly be transformed into an energy being and make your way through the planet's electrical system and take over the world Lawnmower Man-style.

Re:Fucking magnets

[justforgetme]

100Mamps? I think they are going to need the desert and a couple nuclear reactors

Re:Fucking magnets

[Grishnakh]

There are elevated passages and tunnels for road crossings, which lo and behold aren't all that expensive if you do a lot of 'em.

Wrong, you're looking at tens of millions of dollars for each one, at the low end. Moving earth around is incredibly expensive; just look at how much it costs to make one mile of roadway here in the US. Maybe it's cheaper in France, but here in the US, road construction costs a fortune, thanks to the construction companies giving generous "campaign donations" to the politicians to choose their company for the construction project.

Re:Fucking magnets

[Grishnakh]

Because there's lots of very small roads that cross railroad tracks, and it'd be very expensive to build bridges for every one of them.

Re:Fucking magnets

[Grishnakh]

With no grade crossings, where is the train going to go? In a tunnel? Or on some kind of raised platform? Either one will be ridiculously expensive, and it'll have to cross a bunch of small and large roads at some point. Just look at how much it costs to build one mile of regular road here, let alone one mile of interstate highway.

Re:Fucking magnets

[Anonymous Coward]

Fuck the people on the ground. I'm goin to space, bitches!

Re:Fucking magnets

[Intrepid imaginaut]

Covering about two percent of the uninhabited bits of the Sahara with solar panels would supply enough energy for the entire world's needs.

Re:Fucking magnets

[shilly]

You don't really know what a cutting is, do you? Hint: it's not a solution to track crossing, it's an alternative to tunnels and bridges.

Maybe you should have a look on the interwebs.

Train romance

[Tangy]

Every step towards "Galaxy Express 999" is a step in the right direction.

Re:Train romance

[nhat11]

lol I love that movie. Definitely a classic and a must watch.

Re:Train romance

[RevSpaminator]

Except the cyborgs killing loved ones.. that part would suck.

Space-elevator meets rail-gun

[Anonymous Coward]

What could possibly go wrong

Re:Space-elevator meets rail-gun

[Anonymous Coward]

What could possibly go *splat*

FTFY

I can imagine quite a bit

[elrous0]

If I'm going to fantasize about shit that will never be built, I'd rather dream of the sexbot. Oh perfect robotic woman---who is always horny, cooks and cleans, never wants diamonds, has no parents, never drones about about some bitch at work, never cheats, never complains about wanting a bigger house or nicer car---how I dream of thee.

Re:I can imagine quite a bit

[grimmjeeper]

...never complains about wanting a bigger... "dork"

Re:I can imagine quite a bit

[Anonymous Coward]

That will be built, and if it's made well enough then it will eliminate our species (except perhaps the Amish).

Re:I can imagine quite a bit

[busyqth]

If I'm going to fantasize about shit that will never be built, I'd rather dream of the sexbot. Oh perfect robotic woman---who is always horny, cooks and cleans, never wants diamonds, has no parents, never drones about about some bitch at work, never cheats, never complains about wanting a bigger house or nicer car...

...doesn't care if you're a neckbeard. seems turned on by the fact that you're a fat slob who hasn't bathed in three days, etc. etc.

Re:I can imagine quite a bit

[vux984]

She sounds dreadfully boring. You'd probably hate her within a few months.

Re:I can imagine quite a bit

[Oswald McWeany]

A robot like that would never settle for a slash dotter.

Re:I can imagine quite a bit

[na1led]

Buy yourself a Furby

Re:I can imagine quite a bit

[busyqth]

Does this happen to you often?
Never happens to me. *shrug*

Re:I can imagine quite a bit

[grimmjeeper]

Does this happen to you often? Never happens to me. *shrug*

Re:I can imagine quite a bit

[Anonymous Coward]

Does this happen to you often?

Never happens to me. *shrug*

Of course not, if you're on Slashdot you don't have a wife!

Re:I can imagine quite a bit

[PolygamousRanchKid]

Imagine no more: http://en.wikipedia.org/wiki/Cherry_2000

. . . now about that memory chip necessary . . .

Re:I can imagine quite a bit

[Anonymous Coward]

My God! He never took middle school hygiene. He never saw the propaganda film.

DON'T DATE ROBOTS!!!

Re:I can imagine quite a bit

[camperdave]

"Oh elrous0... I love you more than the moon and the stars and the *POETIC IMAGE NUMBER 37 NOT FOUND*"

Re:I can imagine quite a bit

[elrous0]

She will when we find a way to jailbreak her.

Re:I can imagine quite a bit

[elrous0]

Then I just flash her with a new personality.

Re:I can imagine quite a bit

[ViperOrel]

always horny, cooks and cleans, never wants diamonds, has no parents, never drones about about some bitch at work, never cheats, never complains about wanting a bigger house or nicer car

Um... your hand does not qualify as a robot... :/

Re:I can imagine quite a bit

[elrous0]

Robosexuals are people too! And also robots!

Re:I can imagine quite a bit

[busyqth]

No, it's more like:

Neckbeard: "Come on, let's go into the bedroom and get comfortable..."
Robot: "This function is available for only $29.99. Please enter Apple ID password."

Re:I can imagine quite a bit

[NatasRevol]

PMS once a quarter, just for the entertainment.

Re:I can imagine quite a bit

[Anonymous Coward]

She will when we find a way to jailbreak her.

Unless she is a young jailbait model. You break her jail, you go to jail.

Re:I can imagine quite a bit

[WillDraven]

"sudo let's go into the bedroom and get comfortable."

Re:I can imagine quite a bit

[Pope]

Did you just call him a romosexual?

Re:I can imagine quite a bit

[superdave80]

What if it's a robotic hand?!?!

Re:I can imagine quite a bit

[Bob the Super Hamste]

... never complains about your member

Re:I can imagine quite a bit

[mcgrew]

Oswald, you really should read a lot less science fiction and a lot more nonfiction. If you're going for "funny" you failed miserably.

That goes for the idiots that modded you "insightful" as well. A robot does not have emotions. A robot can not think. It's a mindless machine, and the only thing that makes it look like it's intelligent or sentient or having emotions is clever programming and anthropomorphism.

That sex bot wouldn't care if you were President Obama, a movie star, or a fat alcoholic who hadn't bathed in a month. It wouldn't care. It's incapable of caring.

Sheesh, doesn't anybody here understand how computers work?

Re:I can imagine quite a bit

[Anonymous Coward]

Cherry 2000.

Re:I can imagine quite a bit

[Aryden]

You'd have to jailbreak her for that and violate the TOS. The Apple gestapo would raid your house, take your robot and then try to have you tossed in jail. Then the RIAA will get involved because the voice was copyrighted by SONY or Universal.

On the other hand, if could be an android running Android and you would have half a billion custom roms to choose from, but i'd be damned if I were a bug tester for that shit.

Re:I can imagine quite a bit

[TuringCheck]

Does anyone understand how brains work?

Re:I can imagine quite a bit

[idontgno]

F that. I'd settle for understanding how magnets work.

<deftly bringing the thread almost back on-topic.>

Re:I can imagine quite a bit

[Grishnakh]

There's plenty of women who don't want diamonds out there, you just have to look for the ones who aren't selfish and shallow and understand that participating in the diamond trade is not only utterly stupid (as these are utterly common rocks with no rarity and thus little real value, and only cost a lot due to a monopoly and a lot of marketing), but fuels a lot of violence. Plus, CZ looks better and has superior crystal structure, in addition to being dirt-cheap.

Re:I can imagine quite a bit

[Em Adespoton]

Is that you, Daneel?

Re:I can imagine quite a bit

[Anonymous Coward]

That will be built, and if it's made well enough then it will eliminate our species (except perhaps the Amish).

Yeah, the /.-ers species at serious risk of extinction.

Re:I can imagine quite a bit

[iggymanz]

lighten up, Francis. Quit being a dill-hole and quit belabouring the obvious.

Re:I can imagine quite a bit

[mcgrew]

http://en.wikipedia.org/wiki/Magnetism

Re:I can imagine quite a bit

[TheTurtlesMoves]

http://www.youtube.com/watch?v=WLtaVmqkEEQ

Re:I can imagine quite a bit

[Anonymous Coward]

Stoopid muggle! Everyone knows magnets are magic! They even start with the same three letters!

Re:I can imagine quite a bit

[Anonymous Coward]

That word, it requires no quote marks.

now it's just a minor matter of engineering

[Thud457]

I'm assuming the weather control satellites will steer hurricanes away from this monstrous sitting duck?

Re:now it's just a minor matter of engineering

[elrous0]

All they need is a trillion $ and a bunch of technology that hasn't been invented yet. Easy Peasy.

Re:now it's just a minor matter of engineering

[Anonymous Coward]

Build it in the middle of Africa. No hurricanes there. This would need to be pretty close to the equator to work anyway.

Re:now it's just a minor matter of engineering

[Thud457]

There are two proposed configurations of Startram, Generation-1 and Generation-2. Gen-1 Startram is a cargo-only version which does not require levitated tubes (but instead is built up the flank of a tall mountain) and could be built within ten years at a cost of $20 Billion. Gen-2 Startram is a people-capable version which does require levitated tubes and could be built within twenty years at a cost of $60 Billion.

[citation]

ohmygod. I want some of whatever they're smoking. At those low, low prices, everybody can have one.

Re:now it's just a minor matter of engineering

[Entropius]

$20 billion is 1% of the cost of the Iraq war. We piss away mountains of money on things far less useful (and far more harmful) than shooting bunnies into space.

Re:now it's just a minor matter of engineering

[NatasRevol]

Would they be ski bunnies?

(Side of a mountain joke.)

Re:now it's just a minor matter of engineering

[Patch86]

$20 billion is only a shade more expensive than the 2012 Olympic Games. Sod it, build one every 4 years!

Re:now it's just a minor matter of engineering

[mosb1000]

$20 Billion is approximately NASA's yearly budget. Much more apt comparison.

Re:now it's just a minor matter of engineering

[0111 1110]

Isn't that gen-1 system similar to the railgun system proposed in The Moon is a Harsh Mistress?

Re:now it's just a minor matter of engineering

[wagnerrp]

Considering you're talking about achieving orbital velocities in just a few miles up the side of mountain, it may as well be a railgun with the kind of acceleration you're going to have. Rough estimate puts a 5km diagonal launch ramp at 2000Gs, and you're still going to need a decent orbital insertion motor once you get out of the atmosphere.

Re:now it's just a minor matter of engineering

[Anonymous Coward]

We can have one every 2 years! We'll call them the 2018 summer startram, the 2020 winter startram and so on.

Re:now it's just a minor matter of engineering

[camperdave]

Because there is effectively no atmosphere on the moon, you don't need to build it up a mountain. It can run along level ground. As long as it reaches lunar escape velocity, you're golden.

Re:now it's just a minor matter of engineering

[Grishnakh]

Exactly, when you compare the projected cost of this thing to the Iraq War, the Afghanistan War, the TSA budget, the Olympic Games (as another poster noted), the cost of enforcing marijuana laws, the budget for Federal prisons, and how much we gave out with no strings attached to mismanaged companies to bail them out, this amount is really quite cheap, and a tiny fraction of the US's budget.

Re:now it's just a minor matter of engineering

[ceoyoyo]

"ohmygod. I want some of whatever they're smoking. At those low, low prices, everybody can have one."

That's kind of the point. We spend more than an order of magnitude more than that on rockets NOW. IIRC Americans spend more than that on cosmetics, every year. It's also such a tiny fraction of the US defence budget that it probably wouldn't even be missed (literally).

Re:now it's just a minor matter of engineering

[Anguirel]

Couldn't they just turn off the super-conductor providing the magnetic lift and strap down to survive serious weather conditions?

Re:now it's just a minor matter of engineering

[tragedy]

Except of course that you haven't read the article. The payload would accelerate along a very long evacuated tunnel, following the curve of the earth. The mountain (or magnetically levitated tunnel section) would be a small part of that at the very end. You would pull some heavy G's for a short period of time from the change in direction, but it wouldn't be anywhere near 2000. It would probably be more than humans could take, but not more than all kinds of non-living payloads could take.

Re:now it's just a minor matter of engineering

[Anonymous Coward]

the California train-to-nowhere is estimated at $80 billion, up from its original $40 billion, and they have not broken ground yet. Lets use the Boston Big Dig model to estimate the project trajectory... if it gets finished.

Sodor

[Oswald McWeany]

So will the spaceport will be built at Sodor?

Re:Sodor

[jdgeorge]

Tidmouth. Obviously.

Re:Sodor

[Anonymous Coward]

One does not simply walk into Sodor...

(Always thought there was something a little odd about that island - the way the fat controller always had his "Muscle" following him around like a Mob boss. Tall, skinny, androgynous goons at that - could easily have been elf extras from the Peter Jackson films.)

Re:Sodor

[tragedy]

With the abysmal safety record on Sodor? You'd have to be crazy to let those people (and sentient trains) operate their railroad, let alone a space program. Somewhere in their office they have a full-time employee devoted entirely to flipping the "minutes since last accident" sign back to 0.

Alternatives

[gmuslera]

Looks that the investment, time, resources, etc should be orders above of the ones needed for a space elevator, and even that one is pretty hard to ever happen.

Re:Alternatives

[MozeeToby]

35756 Km of cable is going to weigh quite a bit no matter what you make it out of, multiply that by $10,000 per Kg and you've got one heck of a problem to solve right there when it comes to building a space elevator. Several non-rocket launch technologies, the star tram included, can be build from the ground, you could build the whole thing without a single rocket launch. The same can be said about space fountains and (my personal non-rocket launch technology) launch loops.

Re:Alternatives

[Patch86]

They're promising a "first gen" Startram for $20 billion on their website. Which is almost absurdly low. The London Olympics are set to cost only a little shy of that- you could build a new one every four years at that price.

You won't get much of a Space Elevator for $20 billion, either.

Re:Alternatives

[ChromaticDragon]

There are many unsolved issues with regards to a Space Elevator, but lifting 36,000 km of cable isn't necessarily one of the most significant problems. Most projections or descriptions I've come across describe things such that we would manufacture and lower the cable from orbit. Now granted, this itself presents many problems since you would have to create all that infrastructure "up there" and then find/capture source material. But you also need to do that for the counterweight. You're certainly not going to lift THAT into space.

Re:Alternatives

[jandrese]

There's also the slight problem of building a material that is considerably stronger than any known material today.

Re:Alternatives

[Deathmoo]

There are actually lots of mass in orbit. It is mostly in the form of disposed rocket stages and old satellites. Additive manufacturing, advanced robotics, nuclear power and a few small captured asteroids later and we're in business.

Of course, we could just waste all of our money on senseless wars and litigating ourselves into extinction too if we wanted. Either way. (Sorry... It's a cynical day here..)

No thanks

[Anonymous Coward]

No thanks. I'll ride my unicorn. They will have invented it at about the same time they invent this.

Need to mag-lev a megastructure to 20km

[GameboyRMH]

I can't see anything impractical or horrifically energy-intensive about this system.

Re:Need to mag-lev a megastructure to 20km

[Oswald McWeany]

I can't see anything impractical or horrifically energy-intensive about this system.

That's because the article doesn't fill you in on all the important facts:

- it would be built by British Rail.

In 20 years

[Anonymous Coward]

It is doubful that the cost per pound to orbit with rockets will be as high as it is now.

Re:In 20 years

[Anonymous Coward]

Why?

Re:In 20 years

[NatasRevol]

Which direction do you think fuel costs are going to go over the next 20 years?

Re:In 20 years

[camperdave]

Thing is, everyone is focussing on the launch as the costly part; as if all the expense of the entire spaceflight was tied up in the first eight minutes of the journey. What about the re-entry? What about the on-orbit operations (communications, station keeping, life support (if applicable))? There is no toll booth in space where you pay one fee to go up, and another to go down. Practically all of the costs for the entire mission are up front costs. Fuel is so cheap that it is a rounding error three digits to the right compared to other components of the costs.

Re:In 20 years

[ceoyoyo]

The shuttle cost about half a billion dollars to launch. Satellites that can do most of those things can be built as class projects in high school.

Rentry and human rated space capsules are a little harder, but still cheap compared to the infrastructure, design and effort (yes, fuel is not the only part, but all those launch costs go away) of actually launching anything.

A better idea that a space elevator

[ShooterNeo]

1. Requires no materials we don't already have
2. Would allow for continuous launches. This tube could be used every 15 minutes or so for another payload
3. Fairly massively spaceships could be launched this way
4. Once you get into LEO, getting around in space is relatively easy and cheap.

Downsides : the forces involved here are extreme. There's enormous magnetic fields, the whole structure is suspended in the air, it's over 1000 miles long, and depends on various complex pieces of tech to not rip itself apart. If the vacuum leaks or the plasma window fails or a magnet gets too much current, a chunk or even the whole damn launcher could spectacularly fail.

In addition, the estimated costs have got to be a factor of 10 too optimistic. 60 billion dollars? For something constructed of tens of thousands of miles of superconducting cable and a structure made to aerospace engineering tolerances that is 1000 miles long? Even 600 billion sounds optimistic for something that large.

Re:A better idea that a space elevator

[Truekaiser]

umm where do i go and buy a plasma window? or the materials that can handle the strain of this? nothing this thing is made of can be made by modern materials...

Re:A better idea that a space elevator

[RogueLeaderX]

1. Requires no materials we don't already have 2. Would allow for continuous launches. This tube could be used every 15 minutes or so for another payload 3. Fairly massively spaceships could be launched this way 4. Once you get into LEO, getting around in space is relatively easy and cheap.

Downsides : the forces involved here are extreme. There's enormous magnetic fields, the whole structure is suspended in the air, it's over 1000 miles long, and depends on various complex pieces of tech to not rip itself apart. If the vacuum leaks or the plasma window fails or a magnet gets too much current, a chunk or even the whole damn launcher could spectacularly fail.

In addition, the estimated costs have got to be a factor of 10 too optimistic. 60 billion dollars? For something constructed of tens of thousands of miles of superconducting cable and a structure made to aerospace engineering tolerances that is 1000 miles long? Even 600 billion sounds optimistic for something that large.

The Gizmag author forgot to read these guys web-page apparently.

Whitepaper
FAQ

The version the 'requires no materials we don't have today' is built into the side of a mountain and would kill any person you tried to launch using it. Basically a massive rail-gun for getting payloads to orbit. They're especially interested in space based solar power generation. (Because launching solar panels into space and beaming the power down to a receiving station near population centers is better than putting solar panels in the desert and running power to city centers via cables?)

Re:A better idea that a space elevator

[RogueLeaderX]

Ok, URL tagging doesn't work ...
https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxzdGFydHJhbXByb2plY3R8Z3g6NDI1YjVjZmMwZmRjY2VlMg
https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxzdGFydHJhbXByb2plY3R8Z3g6NjBhZmQ1YTE3MzY2MTA0Mg&pli=1

Re:A better idea that a space elevator

[busyqth]

They're especially interested in space based solar power generation. (Because launching solar panels into space and beaming the power down to a receiving station near population centers is better than putting solar panels in the desert and running power to city centers via cables?)

Putting solar panels in the desert isn't feasible because you'd need a 1000km long superconducting cable to carry the power to the cities...

Re:A better idea that a space elevator

[suomynonAyletamitlU]

In addition, the estimated costs have got to be a factor of 10 too optimistic. 60 billion dollars? For something constructed of tens of thousands of miles of superconducting cable and a structure made to aerospace engineering tolerances that is 1000 miles long? Even 600 billion sounds optimistic for something that large.

Not to mention that the idea is that the entire tube holds a vacuum, which buoys it up, and it's held DOWN with tethers. How do you even construct that? There are no cranes to LEO. Even if you put them in place, and empty out the gas slowly so that it rises (without coming to a sudden stop at the end that breaks a tether), each segment is probably hundreds of pounds of metal. Imagine being miles in the air, wrestling with an enormous hunk of metal that's tied to the earth in what you can only hope is the right position, in order to get the end to line up with the last piece...

Well, okay, it sounds like a heck of an exciting job. But it also sounds like it could go wrong so terribly easily...

Re:A better idea that a space elevator

[HiThere]

I wouldn't say it's a factor of 10 too expensive. Instead I'd say that a lot of development work needs to be done on simpler projects...like mag-lev trains for cross-continental travel, and a few other sub-components. Each one of the needed technologies can be developed in the process of constructing something useful, so you don't need to charge the developmental work against the launch device.

As for magnetic problems, Faraday cages are old technology that still works, and anything built out of steel can become one without much effort. If you build it out of aluminum, then you need to line it with iron foil, and take a few other steps. But it's still easy.

I'm less convinced that it will be able to launch things of arbitrary size. I suspect that the sizes that any particular launcher will launch will be rather restricted. So there is likely to be a lot of assembly required in orbit for anything sizable, and small things will probably need to be grouped together into modules of about the correct size. I also believe that the packaging will need to be, itself, a space vehicle.

I'd rate this as much easier than a space elevator (on earth), but not quite as useful (cost / kilo to orbit will be higher). And I still prefer a Pinwheel, but this, if it is built, will have definite advantages over a pinwheel. E.g., a pinwheel requires attaching to a moving cable high in the air. (How high varies depend on various system configuration choices, but several miles up, anyway.) OTOH, a pinwheel must both raise and lower freight & passenger modules. But it also requires about as much freight coming down as going up. The mag-lev doesn't have that problem. And my guess is that the cost of a pound to orbit would be about the same.

Still, a track 1000 km long? At hypersonic velocities? Not going to be easy. The pinwheel would probably be easier to build
AND maintain. Neither has an obvious failure mode that is very destructive (outside of a local area). But the mag-lev would be easier to sabotage.

OTOH, the smaller, freight only version of the mag-lev has definitely attractive features. And that's the only one we should even consider building right now. And it could be used to launch equipment to allow the building in orbit of a preferred alternative.

Re:A better idea that a space elevator

[Anonymous Coward]

Not to mention that the idea is that the entire tube holds a vacuum, which buoys it up, and it's held DOWN with tethers. How do you even construct that? There are no cranes to LEO. Even if you put them in place, and empty out the gas slowly so that it rises (without coming to a sudden stop at the end that breaks a tether)

Yeah, you're totally right, that's the big complicated piece of technology that's going to give us all the trouble.

Re:A better idea that a space elevator

[Patch86]

Their "First Gen" model, which would be cargo only, would allegedly be built on a mountain side (therefore eliminating the need for a levitating vacuum tube 1000 miles long) and only cost $20 billion.

If only I could believe that for even the tiniest of moments, I'd weep with joy.

Re:A better idea that a space elevator

[jamstar7]

Also, Earth-based solar power reception is extremely inefficient. There's this thing called 'night' that means the cells won't generate a lick of power for periods between 8 and 23 hours, depending on where the array is set up. (In the subarctic, for example, you get plenty of sunlight during the summer, practically none during the winters when you need it). Better to put the cells on a satellite where you can get sunlight 23+ hours a day and microwave the power down.

Hell, hang a couple good-sized SPSes and beam the power to a laser launching system in Baja for shipping cargo to orbit.

Re:A better idea that a space elevator

[Anonymous Coward]

They mentioned in TFA that it would be built with multiple redundancies so that the chance of a catastrophic failure would be reduced to almost nothing. If a vent/pump/whatever or 3 fail there should be plenty more to pick up the slack. The malfunctioning one could feasibly be fixed by a tele-operated robot/drone on an outside track of the tube. If it's on the inside, there could be repair tracks as well (though this could delay a few launches). You could even designate a maintenance window every couple days where there are no launches and you just send in a fleet of tele-operated and/or automated repair/maintenance drones.

I also enjoy the idea of the Space Cannon that I remember seeing somewhere for launching fuel/cargo pods into orbit cheaply every few minutes.

Re:A better idea that a space elevator

[shemyazaz]

In addition, the estimated costs have got to be a factor of 10 too optimistic. 60 billion dollars? For something constructed of tens of thousands of miles of superconducting cable and a structure made to aerospace engineering tolerances that is 1000 miles long? Even 600 billion sounds optimistic for something that large.

Not to mention that the idea is that the entire tube holds a vacuum, which buoys it up, and it's held DOWN with tethers. How do you even construct that? There are no cranes to LEO. Even if you put them in place, and empty out the gas slowly so that it rises (without coming to a sudden stop at the end that breaks a tether), each segment is probably hundreds of pounds of metal. Imagine being miles in the air, wrestling with an enormous hunk of metal that's tied to the earth in what you can only hope is the right position, in order to get the end to line up with the last piece...

Well, okay, it sounds like a heck of an exciting job. But it also sounds like it could go wrong so terribly easily...

I don't think you quite understood this. the tube is not elevated because of the vac. Its elevated by magnetic levitation. the vac is to avoid all the problems associated with going 25,000mph inside a tube filled with air.

Re:A better idea that a space elevator

[pavon]

Slashdot uses HTML syntax to format posts, not bbcode like some other sites.
So instead of [url=https://mysite.com]description[/url]
You can use <a href="https://mysite.com">description</a>

They used to have a list of the allowed tags below the comment box. Don't know why they got rid of it.

Re:A better idea that a space elevator

[Anonymous Coward]

Well, TFA doesn't suggest the buoyancy would be enough (which is frankly an incredible notion, not sure where you got it), it says it would be maglevved 20km into the air. So I suspect it would be built flat (with flex joints to accomodate the slight difference in curvature), and levitated by gradually ramping up the current while paying out the cables until the desired profile is reached.

Still an amazing, and scary, proposition.

Re:A better idea that a space elevator

[Fned]

umm where do i go and buy a plasma window?

Here.

nothing this thing is made of can be made by modern materials...

Everything in this thing can be made by modern materials, that's the whole point of it.

Re:A better idea that a space elevator

[jacerie]

I remember reading a while back about a Naval research program looking into creating a vacuum bubble in front of torpedoes to increase speed, accuracy, and reduce drag. Makes me wonder if that same research couldn't be adapted with this to make the project even more feasible.

Re:A better idea that a space elevator

[camperdave]

The tube isn't held up by vacuum buoyancy. It is held up by magnetic repulsion between superconductive cables on the tube, and similar ones on the ground. (They don't actually go so far as to how to generate the current needed, or how the current is dealt with at the end of the tube.)

Re:A better idea that a space elevator

[recharged95]

"aerospace engineering tolerances" ...

"optimistic for something that large"...?

Well, unless the robots build it... likely after we have them complete the Matrix.

Re:A better idea that a space elevator

[Deathmoo]

I've always wondered why we boost so much shit into orbit, and spend so much money generating electricity, when we could just do this ^^^. Orbital power collection stations beaming power where it's needed? What could be simpler? Sure it has a few small drawbacks, but what doesn't? At least this is renewable, and hugely efficient, which is more than can be said for most other things.

Re:A better idea that a space elevator

[tragedy]

I think you're overestimating the forces involved and some of the logistics. It's over 1000 miles long, but the whole structure is not suspended in the air. Maybe the last 100 miles is suspended in the air. The rest is a tunnel sitting on (or under) the ground. So, 90% of it can basically be a thick-walled iron pipe with some concrete around it. The forces involved (unless there's an accident) are fairly small by engineering standards. Take whatever your payload weighs and multiply by four to get an estimate. As for the aerospace engineering tolerances, for that last 100 miles, you'll want to keep the weight down while withstanding atmospheric pressure (although it will reduce with height) and some decently high stratospheric winds, but it doesn't have all the other aerodynamic demands of a jet planes hull. It's just a re-enforced, airtight tube. It certainly could spectacularly fail, of course, but a leak should be detectable instantaneously and would only be catastrophic if it were perfectly timed, otherwise a payload in transit would be able to be braked.

Re:A better idea that a space elevator

[tragedy]

It's not buoyed up by the internal vacuum (ok the vacuum will add some buoyancy, but will by no means keep it up. They mean for it to be magnetically suspended.

Re:A better idea that a space elevator

[jwdb]

Because launching solar panels into space and beaming the power down to a receiving station near population centers is better than putting solar panels in the desert and running power to city centers via cables?

Yep! No clouds in space, nor any sunsets. Plenty of room, as well.

Re:A better idea that a space elevator

[Anonymous Coward]

I am happy to see this article. Since I read about launch loops I am not dreaming about a space elevator. If we can build half a loop with the current materials, even better !

Re:A better idea that a space elevator

[Intrepid imaginaut]

That's already being done with HVDC cables, and longer distances too.

Re:A better idea that a space elevator

[busyqth]

*sigh*

Re:A better idea that a space elevator

[infinitelink]

(Because launching solar panels into space and beaming the power down to a receiving station near population centers is better than putting solar panels in the desert and running power to city centers via cables?)

Freeman Dyson, see.

cost, $60 billion?

[Ardeaem]

From the article:

"Estimates suggest that building a passenger-capable Startram would require 20 years and a construction budget (ignoring inflation and overoptimism) of about $60 billion."

So, triple it for a realistic estimate: $180 billion. Now, that sounds like a lot of money, but when you consider that the total amount of money flushed down the toilet for the Iraq war will probably be an order of magnitude above that, it's play money. We just have to convince people that there's oil in LEO.

Re:cost, $60 billion?

[busyqth]

Well Apple has been "thinking hard" about what to do with 100 billion dollars recently.

Re:cost, $60 billion?

[Anonymous Coward]

Well, I'll let you take the first ride on the iTrain.

Re:cost, $60 billion?

[TheRaven64]

To put $180 billion in perspective, that's about the same cost 400 shuttle launches.

Re:cost, $60 billion?

[subreality]

I'm skeptical of the cost. $60B 2010 dollars is the estimated cost for high speed rail from SF and Sacramento to LA and San Diego. You're telling me I can get a maglev to fucking space for that much? Please do it if it's true, but I don't believe it.

Re:cost, $60 billion?

[JoeMerchant]

Another form of accounting put the cost of 135 shuttle launches at $170B - you do need to include program startup and shutdown costs.

Re:cost, $60 billion?

[busyqth]

We're talking about the difference between California money and real money.

Re:cost, $60 billion?

[WillDraven]

Well, I'm no expert on the issue, but I will say that this maglev only needs a single station instead of several along the line.

Personally I'm in favor of using a launch loop instead however.

Re:cost, $60 billion?

[Bob the Super Hamste]

How much do you think a train line the same length in the middle of Arizona, Nevada, Montana, Wyoming, or Utah would cost where there is lots of open land that is dirt cheap. The problem is California is expensive and there are tons of costs because everyone and their brother will be suing to stop the train if it negatively affects them. I am sure the California rail project is mired in as much red tape as the Stillwater Bridge project here in Minnesota is.

Re:cost, $60 billion?

[maxwells_deamon]

Also does not need right of way through some of the most expensive real estate on the planet. that is a big chunk of the costs

Re:cost, $60 billion?

[Aryden]

I wonder if that statement counts as prior art...

Re:cost, $60 billion?

[ceoyoyo]

Presumably you'd build this thing in a desert somewhere. Real estate is a lot cheaper.

Re:cost, $60 billion?

[forkazoo]

I'm skeptical of the cost. $60B 2010 dollars is the estimated cost for high speed rail from SF and Sacramento to LA and San Diego. You're telling me I can get a maglev to fucking space for that much? Please do it if it's true, but I don't believe it.

Fair point, but when you look at how much cheaper-per-mile the LA-San Diego line will be compared to the LA expo line expansion, it's clear that these things scale very non-linearly, and cost more when you have to deal with existing infrastructure and population. Stick a megastructure in the middle of some accessible but vacant desert, and you will get a lot more bang for the buck than if you tried to stick it near extremely desirable California coastline.

Re:cost, $60 billion?

[Intrepid imaginaut]

This could do more than 400 launches a month.

Re:cost, $60 billion?

[c6gunner]

The estimates assumes Ugandan labor, Chinese materials, and Pakistani tech-support.

2 week train ride up to space.

[Colin Smith]

Yeah! Looking forward to it. I take it there are baths/showers en-suite?

Re:2 week train ride up to space.

[badboy_tw2002]

A little shorter than that. At the acceleration they're talking about you're in space in 5 minutes. You'd probably need a shower/bath after shitting yourself on the ride up considering you hit some atmosphere head on after exiting a tube going 25,000 mph.

Re:2 week train ride up to space.

[Grishnakh]

Why would anyone shit themselves on the ride up? According to TFA, when they hit the atmosphere, there'll be a 3g acceleration force felt. 3g isn't much to humans; that's like an amusement park ride.

If you're talking about the acceleration the train undergoes before exiting the launch tube and hitting the atmosphere 12 miles up, that's probably quite a bit less. 5 minutes to space is a pretty long time compared to the time a rocket does it in, and humans are able to withstand those forces with no trouble.

Re:2 week train ride up to space.

[ceoyoyo]

They said 3 g forward on the way up, 3 g backward when you hit the atmosphere. So on the way up you're in the tightest turn you've ever felt on a roller coaster for 5 minutes straight, then you suddenly get to experience it in exactly the opposite direction.

It would be a pretty wild ride. Nothing a reasonably healthy person couldn't take, but it would scare the hell out of most of the population.

The space shuttle, for comparison, had a maximum acceleration of about 3 g. So it would be like a shuttle ride, except for that 6 g switch when you slam into the atmosphere.

Re:2 week train ride up to space.

[Grishnakh]

The space shuttle, for comparison, had a maximum acceleration of about 3 g

You sure about that? Because the Space Shuttle reached orbit much faster than 5 minutes, so it seems like the acceleration should be somewhat more than this train (of course, the train is also traveling laterally some distance, so that would probably account for it).

Anyway, exactly how many people are going to be taking the space train anyway? Anyone who can't handle a roller coaster ride for 5 minutes straight probably shouldn't be going to space. Anyone too scared should definitely not be going to space, where they're going to go out of their mind when they experience weightlessness.

Still, it seems to me the space elevator makes more sense than this thing, though it relies on some advanced materials technology. With the SE, you don't have to worry about a giant catastrophe if the power fails, whereas this thing will have its launch tube fall 12 miles back to the earth (maybe parachutes could help here), not to mention the enormous power consumption for making the tube levitate.

Re:2 week train ride up to space.

[ceoyoyo]

"You sure about that? Because the Space Shuttle reached orbit much faster than 5 minutes, so it seems like the acceleration should be somewhat more than this train (of course, the train is also traveling laterally some distance, so that would probably account for it)."

Yes. And no, the space shuttle took longer than 5 minutes to reach orbit, and took a big shortcut by going straight up for the first bit. Haven't you ever watched a launch?

http://en.wikipedia.org/wiki/Orders_of_magnitude_(acceleration)
http://en.wikipedia.org/wiki/Space_Shuttle#Launch

No, the proposal for this thing is as big as it is specifically so that people can ride it. But it very well might make the average person "shit his pants" as the OP said. As for space elevators, they are currently impossible, whereas this thing is probably possible to build. Also, a ride up a space elevator might take a couple of weeks, while this thing gets you there in 5 minutes. As for energy, it's levitated with superconductors, so there is no ongoing energy cost except for the cryogenics, and if the power fails, well, nothing happens.

Re:2 week train ride up to space.

[the_other_chewey]

5 minutes to space is a pretty long time compared to the time a rocket does it in

It isn't. For a Space Shuttle launch, MECO (main engine cut-off) was about 8 minutes after lift-off.

Re:2 week train ride up to space.

[Grishnakh]

Hmm, that's odd. I saw a video a while ago taken from a rocket (Titan, I think, launching a satellite), and it was amazing how fast it went from the ground up to space. Maybe they sped it up, or maybe those unmanned rockets rise faster?

Re:2 week train ride up to space.

[the_other_chewey]

Yep, unmanned rockets can and often do accelerate quite a bit faster.
However, humans are not able to withstand those foces without trouble,
so if you want to ride along, 5-8 minutes will have to do.

Quantum levitation

[Anonymous Coward]

Why don't they use those quantum levitation things they recently invented, that could go straight up!

so...

[tscheez]

a rail gun you can ride?

Re:so...

[Chelloveck]

A-yup. But I'm betting that "riding a train" tested better with the focus group than "being shot out of a really long cannon".

Energy requirements are the same

[Anonymous Coward]

The energy requirements to get into orbit are practically the same no matter what method you use. Yes there is some savings from air resistance if you do it at a slower speed but it's not that much.

The only savings will be from a safety standpoint or similar. The energy costs will still be enormous.

Re:Energy requirements are the same

[Anonymous Coward]

Posting Anon to save my mods. Don't the savings come in not accelerating your fuel?

Re:Energy requirements are the same

[i kan reed]

Yeah, that's true, except in as much that it's not. This system would save you all the fuel it takes to launch all your fuel. The air resistance is anything but negligible at 7 times the speed of sound. That's disregarding the propulsion inefficiency of rocket fuel compared to magnetic force. Not to mention the risk/preparation costs for a launch. All estimates I've seen of the differences are measured in orders of magnitude. While a space elevator is generally considered impossible at this time, it really would be worth the cost.

Re:Energy requirements are the same

[TheRaven64]

The energy requirements to get into orbit are practically the same no matter what method you use.

True, but very misleading. If you are in a rocket, the energy cost for the cargo is the same, but there is also the energy cost of getting all of the fuel that you need. A typical rocket getting to LEO or GEO is over 90% fuel, so under 10% of the energy cost of the launch is the cost of something that is not required if you are providing the impulse from the ground.

Re:Energy requirements are the same

[HiThere]

It makes a big difference whether or not you need to lift part way up the fuel to take you the rest of the way up. That's the basic reason that rockets are so much less efficient than jet engines. (Jets only need to lift half their fuel.) With this approach you need to lift hardly any of the fuel you would use to get to orbit. Only enough to allow maneuvering. Of course, you still need the fuel that you're going to use while in space, but for that you can use one variety or another of electric rocket, and eject your fuel at relativistic velocities. Not much impulse, but great for propulsive efficiency.

Re:Energy requirements are the same

[MozeeToby]

10 megajoules of electricity is a lot easier to come by than 10 megajoules of rocket fuel, especially once I get up to a few 10's of km.

Re:Energy requirements are the same

[Baloroth]

The actual energy requirements to get into orbit are pretty small, when you run the math. A couple hundred kg at standard kWh costs would be a couple hundred USD (don't remember the exact numbers and don't feel like doing them again. I actually ran the math to get from Earth surface to infinity: LEO would be much cheaper). You also need to accelerate to get orbital velocity, but again that actually doesn't take that much energy. The problem is, rockets are extremely inefficient. Hence why people want space elevators: technically, you could get to space, personally, for 50-60 dollars using that method. Now, this is pure physics: the actual energy cost is much higher, but even assuming only decent energy efficiency, it still wouldn't cost more than a thousand or so after you get the system set up.

Re:Energy requirements are the same

[gtbritishskull]

The amount of energy required to get a kilogram into geosynchronous orbit is around 15kWh. Assuming 10c per kWh (a pessimistic number since I pay ~5c/kWh to my utility company for my house), it should cost ~$1.50/kg to get something into geosynchronous orbit. I am pretty sure the space shuttle uses a lot more than 15kWh/kg to launch, considering that gasoline has 36kWh/gal (US). So, you are wrong unless you have some evidence that "no matter what method you use" you will get ~0.015% efficiency.

Re:Energy requirements are the same

[Baloroth]

For those who are curious, I ran some quick numbers on WolframAlpha. Using U=mgh as an accurate-enough measure, for a 100kg human to travel to LEO (300km) from Earth gravity (9.8 m/s) would be an energy cost of 294MJ. In kWh that is 82, or about $9 where I live. Technically, g diminishes as you go up, so it will be slightly less than that, but you get the point: the actual energy cost of getting to orbit isn't the problem. Moving upwards through 300km of mostly nothingness, is.

Re:Energy requirements are the same

[Anonymous Coward]

E = mgh + 1/2mv^2

There's a lower limit as the speed approaches zero, but speed is the dominant factor in the energy required right now.

Not even getting into the issue with rockets propelling themselves forward with their own energy source, so a significant amount of 'm' is also essentially wasted energy.

Space Elevators, Rail and Gauss guns promise to improve matters, by reducing 'm' and/or 'v'.

Re:Energy requirements are the same

[Overzeetop]

Actually, the problem isn't getting up, it's staying up. It may only take 294MJ to get there, but in order to stay in orbit you have to be moving at 7-8km/s to do it. 1/2mV^2 = (0.5x100kgx8000m/s^2) if I got my units right = 3200MJ, which is an orders of magnitude larger, not accounting for any losses in friction or energy transfer, so it may be off by at least a factor of four more, likely more like 10. Not bad for materials with a 0.5 payload to casing ratio, but still expensive if you want to keep that flesh alive once you get there, and have a way to get back down uncooked. ;-)

Re:Energy requirements are the same

[DerekLyons]

The energy costs will still be enormous.

Not really. Filling the Shuttle's external tank cost (last time I looked) around a million bucks or so. Fuel (energy) is cheap... the expensive part is all the hardware.

Re:Energy requirements are the same

[nusuth]

It is more like $43 (where you live, I can't be bothered to look up electricity costs) once you factor in required KE for orbital insertation. Using Gemini figures, you need 1500 kgs for three days of supplies and a space capsule capable of reentry per person. So actually, it is around $700 in energy costs per person.

Re:Energy requirements are the same

[Anonymous Coward]

Nobody is curious about anything as technically illiterate as the rubbish you just spewed.

There's a reason they call it an "orbit"; you've just described the energy needed to convert a 100kg human into a gravitational bombardment projectile -- drop from 300km and watch him splat! I guess, since you already mentioned accelerating to orbital velocity in your previous post, you just assumed that part was negligible? Perhaps based on "gut feel"?

The kinetic energy is roughly 10x the potential energy for LEO. Please find find somebody to punch you repeatedly in your gut, as that's clearly the only thing it's any good at feeling.

Re:Energy requirements are the same

[Baloroth]

That is true. And of course you need to factor in costs of getting the train/ship/elevator/whatever up as well. Helpfully, the earth is spinning at nearly half a km/s near the equator, which does help somewhat, but of course the actual costs are, even in the best case, going to be in the thousands of dollars to get a human up (alive). I wouldn't mind paying a few thousands dollars to go to orbit, though.

Re:Energy requirements are the same

[Overzeetop]

Paying for getting there is all well and good; I'd be more concerned about the costs of getting back down!

Re:Energy requirements are the same

[nusuth]

I got my units mixed up. Actually it is about $130 going up naked and around $2100 if you intend stick around a few days and return alive.
But returning a profit after spending 60 billion dwarfs every other cost by a very comfortable margin. Tens of millions of space tourists and fully reusable spacecrafts are needed for energy costs to even matter.

Re:Energy requirements are the same

[Anonymous Coward]

Today the primary costs of space travel are:

- The ground crew
- The rocket.

Space-X which is cheap not long ago published numbers that indicate that of their $50million launch cost, most of that is the rocket. The fuel cost is $200,000.

Which means that their is enormous potential to reduce launch costs in a rocket that can be launched more than once for less than the cost of building a new rocket.

Re:Energy requirements are the same

[Anonymous Coward]

Holy crap, have you even taken high school physics?
Try adding the kinetic energy required to maintain orbit and not fall back down.
Darn, you're off by a factor of 10.

Re:Energy requirements are the same

[Anonymous Coward]

The bigger problem of rockets isn't moving the payload, it's moving the fuel to move the payload, and then moving that additional fuel, etc. rocket fuel is heavy, and all that has to be lifted along with the humans.

Re:Energy requirements are the same

[CtownNighrider]

For reference the Saturn 5 burned something like 20 tons of fuel PER SECOND.

Re:Energy requirements are the same

[CtownNighrider]

Depending how high you are, a short burn such that you intersect with the atmosphere and let friction bleed off the rest of your energy.

Robert Heinlein was here first!

[Anonymous Coward]

And I'm not at all sure it was original with him. The Moon is a Harsh Mistress

Re:Robert Heinlein was here first!

[steveg]

Even before that. The Man Who Sold the Moon.

Re:Robert Heinlein was here first!

[gatzke]

Great book. One of my favorites.

For high g cargo it makes total sense, nothing too crazy required.

They assume 3g as a max. I bet you could do 6 pretty easy. Reading up, looks like if you are reclined it could be 10+ even for untrained folks.

Re:Robert Heinlein was here first!

[WillDraven]

On the other hand if you CAN do 3g you might as well. Sure, MOST people could handle 5 or 10, but practically EVEYBODY can do 3. And if you're trying to convince all the 80 year old rich dudes to invest in this thing, you better be sure they can ride on it without breaking a rib or having their heart give out.

Re:Robert Heinlein was here first!

[gatzke]

If my math is close, if you double the g you cut the length required in half.

Still, a 500 mile long tube 20 miles in the air seems a bit silly.

10-20 miles long seems more reasonable, but the g forces get a little nutty.

Re:Robert Heinlein was here first!

[Anonymous Coward]

You make the vehicles ridiculously complicated to make sure you are reclined for the forward acceleration, then gimbal all the fucking chairs around for the backwards acceleration when it hits air, then back around for the orbital insertion...

Seems better to invest more in a longer/higher track (which you build once) to save that complexity, mass, and failure risk on every single vehicle.

Re:Robert Heinlein was here first!

[Anonymous Coward]

3g is all the millionaires paying off the development costs will tolerate while taking their girlfriends on a day-trip to space.

Nothing to see...This is nothing new....

[Anonymous Coward]

This is nothing new...

Linear magnetic launchers have long since been considered...I read papers about then in the 80's...and there were a number of tests and prototypes that were looked at for this, and a number of sci-fi books have written about the device.

The engineering did not appear to be impossible just a large expensive project that no one wanted to fund, and there were concerns about it being used as a weapon as you just don't quite put the projectile/"train" in orbit and make sure it drops on the desired target with a high suborbital velocity.

I have never seen it called a mag-lev train...but it is more or less a standard magnetic linear accelerator and has been considered many times before.

Love love LOVE the artwork

[jeffmeden]

Image 4 looks way too much like an 1850's Toile pattern for this to possibly be a serious attempt to devise a way to get to space.

Re:Love love LOVE the artwork

[WillDraven]

Yeah, that picture looks like it was pressed from a wood carving, scanned in, reprinted in a book at 1/32 scale, and then scanned in and blown up 10x for the article. The author could have done better copying the image by hand with a Wacom tablet.

Really interesting idea

[gurps_npc]

Better than the space tether crap which requires manufacturing capabilities we don't have.

I like the idea of building it on the ground then mag lev'ing it up. Makes building it a lot easier....

20 years is in my lifetime and 60 billion is less than 4 years of NASA's current budget. So 20 years of NASA's budget should easily be able to pay for this AND still have money for other stuff.

Re:Really interesting idea

[demonbug]

Better than the space tether crap which requires manufacturing capabilities we don't have.

I like the idea of building it on the ground then mag lev'ing it up. Makes building it a lot easier....

20 years is in my lifetime and 60 billion is less than 4 years of NASA's current budget. So 20 years of NASA's budget should easily be able to pay for this AND still have money for other stuff.

That might be the case if the estimate had any basis in reality whatsoever.
Hell, a high-speed rail system of similar length to the launch track using conventional, proven technology is expected to cost around $100 billion; evolutionary development of a new airliner is running about $30 billion; somehow I think it is extremely unlikely they could come anywhere near their cost estimate given the scale and number of unknowns here. It would probably take 50% of the budget just to design and build the launch vehicle, never mind designing and building the enormous launch structure.

Re:Really interesting idea

[Entropius]

The trouble is that it is impossible for the US government to accomplish any project of large enough size to be political and which will take more than four years.

Well, unless it involves the military -- they've bamboozled the electorate into pretty consistently fellating them regardless of the wisdom of whatever it is they are doing.

Re:Really interesting idea

[Bob the Super Hamste]

The CA rail project cost is more a product of it being CA. I would be willing to bet a similar length line in an area that people were going to sue and didn't have such high property values would cost quite a bit less. Do you really think it would cost $100 billion to build in the middle of Nevada, Arizona, or any of the other large relatively empty western non coastal states on all that empty government land?

Re:Really interesting idea

[Thud457]

It's ~850 miles from Reno to Tuscon. I really hope they build this thing up on pylons, or else you just walled off three states off from each other. I guess you could lay it out between Tijuana and Matamoros while building it. Benefits - cheap, available workforce, keeps them Mesckimins out. Down side - not sure if the workforce is skilled enough for the job.

Hmmm, 1600 km of superconductors...

[hbar squared]

" there is a superconducting cable on the ground carrying 200 million amperes, and a superconducting cable in the launch tube carrying 20 million amperes, at an altitude of 20 km there will be a levitating force of about 4 tons per meter of cable length"

That works out to an energy density of (mgh)=1.5e9 J/m. Multiply that by 1600 km, and you get 2.5e15 J, or half a megaton, equivalent to the yield of a small hydrogen bomb. Anyone ever see a superconducting magnet quench?

Re:Hmmm, 1600 km of superconductors...

[FTWinston]

Presumably they first need to either invent a cheap room-temperature superconductor that can be mass-produced, or have this thing be very vulnerable to power cuts.

Re:Hmmm, 1600 km of superconductors...

[Anonymous Coward]

the yield of a small hydrogen bomb, spread over 1600km. not quite as dramatic.

Re:Hmmm, 1600 km of superconductors...

[Anonymous Coward]

Anyone ever see a superconducting magnet quench?

Not with my remaining eye, thank you very much.

Re:Hmmm, 1600 km of superconductors...

[Anonymous Coward]

I'm not sure what you mean about vulnerable to power cuts. Modern HTSes are above LN temps, so you bathe it in LN. If you run out of power, you truck more LN in.

Space junk, meteorites, and terrorist.

[C_Kode]

Falling space junk, meteorites, and terrorist. Which one takes out the $60B elevator first?

Re:Space junk, meteorites, and terrorist.

[Anonymous Coward]

I'm going to say either reality or politics are going to get there first.

Re:Space junk, meteorites, and terrorist.

[fiannaFailMan]

Falling space junk, meteorites, and terrorist. Which one takes out the $60B elevator first?

Oh will you people give it a fucking rest about terr'sts? I see this "oh but the Jihadists might try to attack it" on almost every single major engineering post on /. these days and it's getting on my wick. Why don't you demolish the Golden Gate Bridge and Hoover Dam before they get to those landmarks, hmm? Why don't you sit in the house and don't move in case anything bad happens?

Christ, you'd think terrorism was invented in 2001 to listen to you. What do you think the people of Israel and Palestine have been living with since the 60s? What do you think the people of Northern Ireland and later Britain were putting up with during the Northern Ireland Troubles? What do you think Londoners had to put up with during the Blitz? They had a 9/11 scale death toll every week.

Re:Space junk, meteorites, and terrorist.

[C_Kode]

Falling space junk, meteorites, and terrorist. Which one takes out the $60B elevator first?

Oh will you people give it a fucking rest about terr'sts? I see this "oh but the Jihadists might try to attack it" on almost every single major engineering post on /. these days and it's getting on my wick.

I don't recall saying "a jihadist" you freaking asshat. A terrorist is a terrorist no matter what their religious beliefs are.

btw, if you don't like it take your uppity ass to a different site.

Re:Space junk, meteorites, and terrorist.

[busyqth]

Uh oh... fiannaFailMan is a negro and you called him "uppity".

Re:Space junk, meteorites, and terrorist.

[fiannaFailMan]

Oh please! Did you think the Basque sepratists were going to attack this thing?

Uses already available technology

[Oswald McWeany]

Uses already available technology?

What like teleportation? If we're using already existing technology- why not teleport stuff up into space.

OK- OK- so we have no Star Trek like teleportation yet... we also don't have space-trains yet either.

Don't get me wrong sounds neat- if you ignore that it's an easy terrorist target/war target; vulnerable to natural disasters (cannot be moved); we have no concept of what it would realistically cost to build something like this- and you have the whole concept of NIMBY- where my back yard is a 500 mile radius- because if one of these things comes and shoots out at high velocity and isn't shooting straight (yeah, I know she said that) - no prediction on where this will go.

I don't want to be a downer- think it sounds fine- I just hope the negatives have been explored. Interesting idea really.

Re:Uses already available technology

[Oswald McWeany]

Ooops- forgot to link my Wikipedia link to teleportation

Re:Uses already available technology

[Chris Burke]

OK- OK- so we have no Star Trek like teleportation yet... we also don't have space-trains yet either.

But a space train could theoretically be built with things that exist today, and that's what they mean.

A space elevator could not be built with things that exist today. It requires hypothetical advancements in material technology to create something that could be used to build a space elevator.

A teleporter is even farther out there.

Kinda obvious, right? I mean you wouldn't have said that an iPad could not be made using existing technology because iPads didn't already exist, right? It would imply that the iPad could never be built.

Re:Uses already available technology

[Anonymous Coward]

They just don't want a terrorist organization to take a space elevator down just to get at Friday.

Re:Uses already available technology

[Intrepid imaginaut]

a) Don't go round invading other countries, terrorist problem solved b) its already been examined by Lockheed Martin and found to be sound, c) build it in the Sahara desert.

cargo version much more practical

[bcrowell]

The thing that makes this such a ridiculous engineering project is the requirement to carry humans, who can't be subjected to more than about 3 g's. The length of the track is inversely proportional to the acceleration, so if you're sending up steel I-beams that can withstand 3000 g's, you can shorten the track to 1 mile rather than 1000 miles. Tanks of water and rocket fuel can also be subjected to a lot more than 3 g's.

Re:cargo version much more practical

[badboy_tw2002]

Agreed, but there is still the problem of the exit door needing to be at a sufficiently high altitude to avoid tearing the thing apart when it leaves the vacuum. But a circular acceleration track with an exit ramp that goes on for 10 miles at a 45 degree angle certainly seems more doable than a 1000 mile long train kept at vacuum. We can't even build a 500 mile long train in CA without spending $40bln, and that's just tracks, no enclosing vacuum tunnel to speak of.

Re:cargo version much more practical

[Chuckstar]

This thing needs to be going at over 10,000 miles per hour. The g-forces would be ridiculous at those speeds in a circle. And you'd have a really, really hard time keeping the vehicle from impacting against the track.

Re:cargo version much more practical

[goodmanj]

steel I-beams

I worked it out: the magnetic fields in the vicinity of the spacecraft are in the ballpark of 0.2 Tesla. This is a bit less than your average MRI machine. If you try to carry *anything* ferromagnetic in your launch vehicle, or build it out of ferrous metals, it will run your whole day.

Re:cargo version much more practical

[Anonymous Coward]

True, but the idea isn't bad. You could have a circular track for the first part, and a long exit ramp for the rest. I don't feel like doing the math right now, but let's say a 100 mile circumference circle and 800 mile launch tunnel; that would cut the total track size by 100 miles. And that's only going around the circle twice.

Re:cargo version much more practical

[khallow]

We can't even build a 500 mile long train in CA without spending $40bln, and that's just tracks, no enclosing vacuum tunnel to speak of.

I would suggest then that we keep California out of this particular business.

Re:cargo version much more practical

[Intrepid imaginaut]

There are two versions proposed, one for cargo, one for humans.

How is this possible?

[Karmashock]

I was reading through it and initially thought it was just flinging the train from the ground up... but apparently it needs a TWELVE MILE HIGH RAMP!... that is not practical. If you used Mount Everest to get a head start it would help but it wouldn't get it near enough to that mark to matter. How the hell does anyone think building this would be possible?

the space elevator ideas are less crazy and they're kookoo for cocopuffs...

Re:How is this possible?

[MozeeToby]

You're imagining a 12 mile high roller coaster. They're proposing a pair of superconducting cables, one on the 'ramp' and one on the ground, that would repel each other, lifting the ramp into the air (stabilized by cables). Obviously there's some difficulties there, but they aren't talking about building a compressive structure 12 miles high. Personally I prefer the launch loop idea, which uses kinetic energy to hold the ramp and transfer power to the launch vehicle, since I feel there's less unknowns there. But there's no reason a magnetic system couldn't, in theory, work.

Re:How is this possible?

[Karmashock]

I'm not grasping how it works.

Be patient with me here...

Yes, I am imagining a 12 mile high roller coaster.

You're saying the cables are able to support this tube that is strong enough to keep a partial vacuum inside it and the weight of this train? How exactly are you going to hold up all that weight at 12 miles?

You're not saying magnets will hold it up right? Because... how? Magnets couldn't hold it up from the ground at that range.

Just give me the fisherprice answer here because it sounds beyond fishy... it sounds rotten fishy.

Re:How is this possible?

[MozeeToby]

Magnets couldn't hold it up from the ground at that range.

You're just not thinking big enough. They're talking about running hundreds of mega-amps along wires in the ground and dozens of mega-amps through wires in the ramp. The magnetic field will be massive in size, and massive in strength, enough to provide 4 tons of levitating force for each meter of rail (2x the weight of the system per meter). There will be problems; lots and lots of problems, which is why I prefer the launch loop idea, but there's no reason their theory isn't sound.

Re:How is this possible?

[busyqth]

Yes. The magnets hold it up.

Re:How is this possible?

[Karmashock]

I'm sure you could hold all that up at a range of a few feet. But a magnetic field strong enough to hold it up 12 miles?

Maybe I'm not understanding this properly. Are you saying a giant magnetic field at the ground and another one on the wire? Or are we building some kind of super structure out of magnets somehow? Like a spiderweb of self supporting magnetic fields?

I'm trying hard to see what you're talking about.

If you're talking about a huge magnetic field on the ground then I don't see how that could work. The intensity of the field reduces exponentially with distance. To be strong enough to support a structure 12 miles high it would have to be too large to be practical. But if you're taking about thousands of smaller fields all interlaced with each other... maybe.

Re:How is this possible?

[Karmashock]

how though? Magnets don't have that sort of range unless they're insanely powerful... I mean... more powerful then the magnetic fields around planets. We've never built magnets a billion times as strong as what this would need if it were holding it up from the ground.

The strength of a magnetic field falls off geometrically from it's source. So a magnet that can lift a car at 2 inches can't lift a paper clip at 10 feet.

For a magnetic field to be so powerful that it can lift this crazy thing at 12 miles... I mean... there are magnetic fields that strong and stronger in the sun... but... I can't think of anywhere else you're going to run into force like that outside a star.

or am I just wrong about everything? I have enough humility to know I'm sometimes full of crap. Tell me if I'm wrong. This is just my understanding of the science.

Re:How is this possible?

[Ibiwan]

Yes, magnets. They did the math already.

How are you defining "practical"? Remember we're already talking about a $60,000,000,000 project

Re:How is this possible?

[camperdave]

If they've got enough repulsive force at the top end, and the superconductive cables come closer together (one along the ground and one on the ramp), then how do they overcome the repulsive forces at the bottom end of the ramp?

Re:How is this possible?

[ceoyoyo]

Yes, a big magnet on the ground repelling a big magnet in the air. Since the magnets are actually very long superconducting wires the intensity of the field reduces more or less linearly.

Re:How is this possible?

[Karmashock]

really? Superconducting magnets have linear magnetic fields?

If so that would be pretty amazing...

Re:How is this possible?

[ceoyoyo]

Not superconducting magnets. Any magnet that is shaped like a very long wire. Technically to have linear falloff it has to be infinitely long, but if you're 20 km above one that's 1600 km long it's going to be closer to linear than cubic.

Re:How is this possible?

[Karmashock]

I didn't know the shape of the magnet mattered. I thought magnetic fields acted like electromagnetic fields in that they lose ins tensity with distance geometrically.

I mean, if I'm twice as far from the sun the sun will be less then half as bright. The sun is huge... the size of the light source doesn't matter. I didn't realize magnetic fields allowed for linear falloff... If so... then that's pretty amazing.

Re:How is this possible?

[ceoyoyo]

Electric fields and EM waves do the same thing, except it's a little harder to make an electric field that shape.

The size of the light source does matter. If you're very close to the sun the falloff in intensity is NOT inverse squared. Think about it. As you get further away, the falloff of light from the points directly beneath you is inverse squared. But as you move higher, your horizon expands, so you're illuminated by more of the sun's surface. Technically the falloff isn't inverse squared even at Earth because the sun still shows a disk, but it's close enough not to matter. If you've got an omnidirectional light meter and you're careful, you can probably demonstrate it with a big computer monitor or TV.

There is no decrease in intensity from an infinite plane by the way. Demonstrating that (and the infinite line case) are usually problems in first or second year calculus and/or electromagnetics.

Re:How is this possible?

[Karmashock]

thank you. This has been enlightening. You've expanded my understanding of physical laws and the nature of the universe.

I've perhaps made that easy through my ignorance but know that I truly do appreciate the insight you've provided me here.

Applying what you've just said back to the idea of a magnetically suspended railgun (basically what the train is), would a thin line of magnets or a track be sufficient to sustain a field at that distance? Or would you need a massive plane? Because a track is only just possible. But a plane would require far too much to be reasonable.

Re:How is this possible?

[ceoyoyo]

Thanks. I'm in academia and, unlike some (definitely not all) of my colleagues I get a lot of satisfaction from sharing all the bits of esoteric knowledge I've gathered over the years. Seriously, the idea of measuring the light intensity at different distances from an all-white LCD occurred to me while I was replying to you. If you try it, let me know what result you get.

So what they refer to in the article is basically a long, thin superconducting wire 1600 km long, which is quite possible. There's one under New York right now. IIRC it's only about 7 miles long, but there really is no reason it shouldn't scale up. I think if they used a long line of individual coils the effect would be the same. Of course, in either case, the Earth is curved and the track isn't actually infinite (especially the part that needs the higher field to levitate the track) so your actual falloff will be worse than linear, but probably significantly better than inverse squared. If you did build a plane (which would be impractical) there would be no falloff (until you got high enough that the finite size of your plane came into play).

I'm sure this particular part got a lot of attention from the team at Sandia Labs who studied the proposal, and they must have checked the numbers pretty thoroughly. The article does give the proposed current through the wire though, so using that, some guesses about the mass of the track, and the height, you could make a rough estimate of what kind of falloff they're expecting.

Re:How is this possible?

[Karmashock]

Does the position on the earth matter? I ask because a cable that long will use up a lot of real estate and you're going to want to put it someplace where the land is cheap.

As to the fall off... I'm picturing the fall off from an infinite plane and I can see the fall off is linear. But now I'm picturing a strip of light 12 miles away and when looking down at the earth I'm going to guess that most of what I see won't be that strip of light. So the fall off while not inverse squared will have to be pretty savage. To a certain extent the strip will probably have to get wider as the pipe gets farther from the ground.

It would be manageable if the whole thing fit into a 20 mile square area. We can find a stretch of nowhere to put something like this... especially if we can shut it off when we're not using it without destroying it.

We should be able to slowly reduce the field and "land" the track right? We're just not going to need this thing 24/7... at least not until we have used it enough to get a really strong space economy going.

Re:How is this possible?

[ceoyoyo]

Nope, it shouldn't matter, although for putting things in orbit it's better to have it nearer the equator. The Sahara desert would be a good place.

Yes, the falloff from a long thing conductor is roughly linear. Making it wider probably wouldn't be as practical as adding more wires alongside the existing one to add more force.

Yes, you could theoretically land the track, but it would cost you a lot in electricity. Since it's a superconductor, once you get the thing up there, it only costs you energy to keep the wire cool. If you want to land the track you have to pull the power out of the superconducting wire, and then charge it up when you next want to fly. Unless you're going to be idle for a long time, it would probably be cheaper just to leave it charged. If it really can launch things to orbit for $100/kg or less, I think we'd quickly find it utilized to 100%.

Re:How is this possible?

[Karmashock]

As to the location, it will have to be in a very stable region of the world. No one is building something like that in a place where it will be vulnerable to attack. Africa and south america are off limits for that reason. If it could be built in the US south west, east asia, Siberia, or Australia that would be fine. I don't know if temperature matters but if cold weather conditions are useful then we have lots of space in Canada, Alaska, and Siberia.

As to adding more force and making it wider... my understanding is that you'd have to do both. I'm just conceptualizing this in my mind... but the force should start dropping off exponentially if it's just a strip. I think you'd need a plane to sustain the force linearly.

As to charging up the super conductors... I was thinking about weather and emergencies. We could even use the conductors sans magnets to store power from the grid. Like a giant capacitor. So it wouldn't go to waste.

Re:How is this possible?

[ceoyoyo]

We build things all the time in unstable parts of the world. It might even be easier in less developed countries - just grease a few palms and no civil liberties or freedom of movement to worry about. Someone you don't like gets too close to your expensive space launcher and you just disappear them.

No, the magnetic field from a long conductor falls of linearly. If you don't believe me, do the math, do the experiment or here's a web page that gives the formula (note, no exponents): http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/wirfor.html. The magnetic force from a plane does not decrease with distance: http://en.wikipedia.org/wiki/Current_sheet#Magnetic_field_of_an_infinite_current_sheet

In an emergency, yes, you could quench the superconductors and lower the track. You'd want to build somewhere where weather isn't much of a problem though (another vote for the desert). There's no such thing as a conductor carrying current sans magnet. It is a magnet.

Re:How is this possible?

[Karmashock]

ah... I understand that better now. Thank you.

I'd still avoid unstable regions. It would be okay if we buried the cable and there were nothing above ground to remind the locals that there is a multi billion dollar installation below their feet. But that will be hard with the startram reaching into the sky.

Also the people you have to bribe or disapear... it's just more trouble then it's worth most of the time.

I'd much rather it be in Arizona or Nevada. Ever seen Nevada? It's flat, dry and dead.

We could put the magnets well below the ground right? It wouldn't matter if they were 20 feet or so below the surface?

Re:How is this possible?

[ceoyoyo]

I've been to Nevada. As I recall it's somewhat less than 1600 km across.

You could bury the magnets, but you probably wouldn't want to walk, and especially not drive or fly anywhere near them.

You could theoretically build the launcher track across the US starting around New York and ending in New Mexico, with the elevated part in the foothills of the mountains. Only the elevated part would be really dangerous. But you'd have to buy a lot of decently expensive real estate. On the other hand, you could build it through the Sahara on land that some of the countries care so little about they don't even bother defining accurate borders. You'd also have a nice source of power there. As for locals... there aren't any.

Re:How is this possible?

[Karmashock]

No idea it had to be that big. I thought the track itself was only going 12 miles up? I assumed it wasn't going to be more then 12 miles long... so you have a track at a 45 degree angle. And then maybe make the magnet trail twice as long so 24 miles or something. That we could bury in Nevada no problem. But if it has to be a thousand miles long then it has to be in Canada or Siberia. Ideally canada because I have no interest in giving the Russians bargaining chips. The Canadians are reasonable... the Russians are frequently irrationally stubborn.

Re:How is this possible?

[Karmashock]

Question since you seem to be knowledgeable.

The cable must be kept cool to be super conducting. I'm assuming we have to do that with some very cold compressed or chilled gas. Is it possible to place the cable in a pressurized chamber, fill it with liquid nitrogen, and then keep the gas cool by keeping the chamber under pressure?

That is, are there passive ways to keep the cable cool? Or must the cable(s) be actively cooled? I'm hoping you can simply keep them in a chamber under so much pressure that nitrogen can't evaporate and is thus kept in a liquid state... and that that state assuming good insulation and pressure can maintain a very low temperature almost indefinitely with little or no maintenance.

Simple!

[metrometro]

It only has to be 1000 miles long and 12 miles tall!

Can we go back to making more cost effective wind turbines, please?

Re:Simple!

[MozeeToby]

All the equations that say what is and isn't 'possible' in space are really describing what is and isn't economical. If you cut the cost of LEO by 2 or 3 orders of magnitude, lots of things that sound ridiculously impractical now become feasible. If you can cut the cost of LEO from $10,000 / kg to $100 / kg, space based solar becomes practical. If you drop it to $10 / kg it becomes the cheapest energy source available. And that's ignoring all the other benefits that cheap LEO travel would bring.

wtf?

[jafac]

Did I accidentally browse to "Popular Science Online"?

Re:wtf?

[Anonymous Coward]

Seems so, this is ridiculous, in a lot of ways.... who even cares if the train is a maglev of diesel engine, the structure is completely impossible......

One problem with developing these

[Anonymous Coward]

Aside from the massive materials cost that it looks like this would involve, there's another problem.

Rockets have a thriving amateur community, and commercial projects at all levels of thrust. It's generally recognized and accepted that rockets are dual-purpose military tech. It's cool that an amateur can launch some pretty fantastic rockets with the proper permits, and little ones with no permit at all.

OTOH anything that hurls a projectile out of a tube looks like a "gun". All the experimental models built at smaller scale are essentially Howitzers. Just *try* getting a permit for HowitzerCon in Nevada. Ain't gonna happen.

Something like this is corporate only, which is a shame. Amateurs might even have something cool to contribute. Also, I'm sick and tired of seeing balloon launches that get to 100,000 ft. at zero velocity and amateur rockets that spin. Amateur tech has hit a brick wall of sorts. This kind of tech could get us some real cheap amateur suborbital launches which is... well...

Cheap ballistic missiles for every joe sixpack who might have a grudge. I don't think you have to be a fascist to be concerned about that. Not sure what the best answer is...

Nice pictures. Never happen.

[sl4shd0rk]

In the US at least, we can't even get funding for maglev trains ON THE GROUND. Until the economy is better (in, oh in another 500 years or so) nobody is going to fund something like this.

Re:Nice pictures. Never happen.

[0111 1110]

The Chinese have the money. And the manpower.

Re:Nice pictures. Never happen.

[Anonymous Coward]

They also have the ability to book it as GDP growth even if it just sits there and does nothing. It's a win-win situation!

Re:Nice pictures. Never happen.

[tirerim]

And some convenient mountains.

Re:Nice pictures. Never happen.

[Intrepid imaginaut]

And the need for abundant raw materials which just happen to be sitting in space.

Space cannon?

[Anonymous Coward]

Anyone else reminded of the space cannon in Jules Verne's From Earth to the Moon?

Foolish Mortals

[Anonymous Coward]

[fundamentalist] Foolish Mortals! Have ye learned nothing from the tower of Babel? [/fundamentalist]

Though now that I think about it, having workers confounded with buzzwords, jargon, and bureaucracy seems like a rather legitimate explanation for the incident.

Captcha: uncouth

Re:Foolish Mortals

[infinitelink]

The incident with Babble occurred due to the hubris of man (don't kill me for using a Greek term). Maybe they touch on it here, http://ocw.mit.edu/courses/literature/21l-458-the-bible-spring-2007/ although I do not know. And yeah, I know you were attempting a joke, but it is not a very good one: maybe with delivery it could be--plenty of bad jokes are funny because of the joker, but I figure someone might be interested in the MIT link. Don't know how well an engineering institution will pull-off teaching on literature and biblical stuff (mesuspects that some traditionalist--though not fundamentalists, religious organizations would probably do a whole lot better, but again, don't know). Now that I have said all I don't know, I'll have to put that MIT course on my own to-do/listen/watch/whatever list, but it could take a while to get to (stupid priorities).

Railgun anyone?

[Anonymous Coward]

For this principle you need way too much space.
You need way to much components to be safe.

Why not build a railgun-like construction in some high mountain and still use rockets?

The first part of acceleration could be provided by the "railgun", while the rest of the journey could be done by rockets. This stands to spare a lot of fuel and is a lot less costly to build.

Only engineering feat could be to drill straight up (instead of down), because chances are the top of the mountain might be difficult to reach.

So basically...

[RPGillespie]

This 1000-mile long passenger-safe rail gun which has to be vacuum-sealed with one-way vents will be cheaper than conventional rockets in the long run? I wonder what the initial cost for this structure would be... probably more than the combined net worth of all the countries on earth.

Re:So basically...

[Fned]

This 1000-mile long passenger-safe rail gun which has to be vacuum-sealed with one-way vents will be cheaper than conventional rockets in the long run?

No, silly, it's a 1000-mile long passenger-safe coil gun which has to be vacuum-sealed with one-way vents will be cheaper than conventional rockets in the long run!

The train?

[koan]

I'll beat you there in my flying car.

A "free" ramp of 5 miles is available...

[DontScotty]

Mt. Everest !!

29,002 ft = 5 miles

Literary mentions

[sirdude]

Novel by Miyazawa Kenji: Night on the Galactic Railroad
Manga & Anime: Ginga Tetsudou 999

Re:Literary mentions

[virgnarus]

I love how you gave the english translated title for Kenji's novel, but failed to do so for Galaxy Express 999. Going otaku on us?

Re:Literary mentions

[sirdude]

I'm just breaking everyone in gently :D

Circle?

[Anonymous Coward]

Rather than a 1,000 mile linear accelerator why not a large circle that just builds up the speed over 5 minutes then exits into the levitated exit pipe?

Re:Circle?

[Overzeetop]

Centripetal forces.

Interesting concept...

[grasshoppa]

...but better suited for a sci-fi novel rather than any serious contemplation. Look at all the trouble we have with building tall buildings AND magnetic installations. We are no where NEAR ready to take on something like this.

Kind of like the space elevator. Another concept that's several hundred years away from practicality, if ever.

I'd rather see us spend some real effort in improving the tech we currently have and are stuck with for the foreseeable future.

you know it's inevitable...

[Thud457]

Whereas if you have a SPSS with a collimated high-power MASER beam with a range of 300 miles, you also can carve "CHA" onto the surface of the moon.

Re:How is this possible? A Helical Accelerator!

[BoRegardless]

Make the acceleration track a helix and see if you can keep the gs down to 3gs with a reasonable diameter on the helix. I don't know, but I am not going to take a ride on it in my lifetime.

railgun technology...

[Anonymous Coward]

Heinlein, The Moon Is A Harsh Mistress...
Navy research on railguns
another approved reactor or two
sub-contract the skunkworks
offer DC bureaucrats and congressmen a ride in the testing phase
yep - easy, peasey

Network Rail

[Kupfernigk]

British Rail doesn't exist any more. On topic, if a simple rail line from London to Birmingham (with a stop at Chipping Norton so Rupe can call in on Dave) will cost $50G before overruns, I suspect that $60G has a decimal point in the wrong place.

Underwater gun

[Anonymous Coward]

Would be far easier to build it in a tube submerged with start at bottom of challenger deep (-11km) and just take the hit on atmospheric losses. It is very easy to support the barrel and you don't need to worry about wind etc. Atmospheric losses are not that great if you have a sufficiently heavy vehicle (mass per frontal area being the important metric)

That also allows you to use a massively cheaper light gas gun (ie hot hydrogen) for most of the boosting, or use a ram-tube design (ramjet in a tube).

Humans can withstand up to 30g if submerged in a water bath, so it is possible to build a human launching gun of only about 100km long (less if you use a reasonable amount of rocket boosting to reduce the muzzle velocity).

Re:Underwater gun

[Overzeetop]

No, that's the same problem with just running the tube on the ground - when you exit, the pressure forces at orbital velocity will tear any vehicle apart. Build one tough enough to hold together and it will burn up from friction. Plus the losses at seal level will mean you would need far, far more speed than orbital velocity to "coast" to space.

That, of course, presumes you're willing to deal with the 16,000psi pressures, continuous immersion in salt water, and the enormous buoyant force that would come with an underwater tube.

Trebuchet

[fizzer06]

A really REALLY big trebuchet. That should do the trick.

ACME

[Rhacman]

Didn't Wile E. Coyote commission the construction of one of these to help propel himself so that he could catch the Road Runner? We could try asking him how that worked out before we commit to building our own.

Fun with magnets

[coppernicus]

I remember when I first learned how electromagnets work and built some of my own, some the experiments I conducted included the "levitation" by use of the magnetic field, one thing I ran into time and time again was, when the distance increased to a certain distance the levitating magnet would suddenly flip over and come crashing down on the bottom magnet with both gravity and magnetic attraction to accelerate it.... hmmm.... train on top of levitating magnet..... uh, no thanks!

Power grid

[bigtrike]

The technology to send electricity long distances with low losses was invented by Tesla, it's not exactly new. You don't need 0 resistance, you just need it to be low enough to still be economical.

Easier to use a mountainside

[Catbeller]

It's an old idea - run the rails up a mountainside, and launch the craft from the end. It save a first stage.

Re:Easier to use a mountainside

[virgnarus]

I learned to do this with Roller Coaster Tycoon. The amount of lift garnered is second to none in that game.

All great science is challenging

[Overzeetop]

But the biggest challenges are mudane. I did not notice any safety configuration for when the current fails and the power is no longer available to support the magnetic separation. The unpowered mode of this structure is unstable.

I suppose you could lower it each time you finished a launch, but then you have to spend the power to raise the whole thing again. I would expect they would build it on the ground and the cables would have automatic takeup/retraction (that's a lot of cable!), so it could be lowered.

Re:All great science is challenging

[ceoyoyo]

It's a superconductor. You don't keep pumping power into it.

If your superconductor somehow quenched then you'd have all sorts of problems, which is why they propose using lots of independent, redundant ones.

Re:All great science is challenging

[Overzeetop]

And what will keep these superconductors at superconducting temperatures? Or have they solved the room temperature superconducting problem? May as well say you'll use super strong cable and make a space elevator at that point.

Re:All great science is challenging

[ceoyoyo]

We keep a lot of superconductors at superconducting temperature all the time. There are three of them within fifty feet of my office, for example.

If all they need is a wire, they can use high temperature superconductors. We've even built at least one reasonably large scale example.
http://en.wikipedia.org/wiki/Electric_power_transmission#Superconducting_cables

So no, nothing like a space elevator.

Hmm. Is there Pb in our drinking water DUMB IDEA!

[jerryjnormandin]

Think about the stresses that this structure will be under! Nevermind the power requirements for a MAGLEV. Maybe the people who dreamed this tried to beat alcoholism by taking LSD ? ->reference to other insane slashdot news posting.

What happened to the land-sharks with the....

[Anonymous Coward]

What happened to the land-sharks with the freakin "laser" beam attached to their heads to lift off an elevator without cables? It seemed reasonable.

Why so much?

[Virtucon]

Cripes in the 50s a cartoon character could get a cheap ACME rocket and get into orbit! Well, try that is. Is the fact that ACME is no longer in business the barrier? I mean what we need is more ACME products damnit! It's not that hard people!

What Could Possibly Go Worng?

[Anonymous Coward]

What Could Possibly Go Worng?

Re:How is this possible? A Helical Accelerator!

[Carnildo]

Do you consider 3200 kilometers a reasonable diameter for the helix?

funny because it's also true

[Thud457]

seal level

I think you just won malapropism of the week there.
That's the level seals are found on, nominally 0m altitude, right?

Unanswered questions?

[hurfy]

Does that tube stay in the air all the time?

If it does, then doesn't that take the output of a power plant (or more?) all it's own...plus add a plant (or 2) for maintenance/redundancy. That doesn't sound that cheap to operate unless it is sending a LOT of stuff to LEO. Their estimate seems to be the (additional) energy to launch something, not lifting the tube itself (and presumably keeping there)

If it doesn't, i am having a hard time imagining it going up/down gracefully EVERY time...Who gets to test it and how?

Have to wonder where this could be built that wouldn't mind the permanent no-fly zone 100 miles long or so. Plus no earthquakes, hurricanes, etc. No vandals trying to sell your cable for scrap (ok, disconnecting the cable and getting slingshot to orbit from the tension is a good mental image) ;p
How are lightning strikes going to affect operation? It seems inevitable. Perhaps you just get an extra g or 2 ;)

$60billion must be raw materials....
Batteries not included right? ... Maybe you have to buy the cables seperately!

Cargo model seems 'reasonable'

Perhaps some kind of hybrid using this to accellerate a rocket? Could save a lot of rocket fuel (and rocket) it you gave one a running start. Wonder if that could be incorporated into the cargo model...full power for cargo and partial plus rocket for people?

Re:Unanswered questions?

[ceoyoyo]

It's levitated using a superconductor. There are no power requirements once you have it powered up. Well, you need some power to keep the superconductor cold, but that's it.

Why so linear?

[jandrese]

One thing I don't understand: Why build a linear track that is 1000 km long when you could build a much much shorter loop instead? The lateral G force will be a problem, but it has to be cheaper to solve than building a track across most of Europe. You can then spit the train out on a shorter (and elevated) linear section for the last bit.

Floating superconducting tracks 25km up in the air is total lunacy however.

Murder Squad?

[jklovanc]

It looks like the "murder squad" missed a couple of details.

Tethers; The article says that UHMWPE will be fine for the tethers. There is one aspect of UHMWPE that makes it completely unsuitable for those tethers; it is called creep. As long as the tethers are under tension UHMWPE will permanently deform getting longer and longer. At some point they will get thin enough to break. This would mean they would have to be replaced on a regular basis. How often is a factor of tension and heat. It may be that the down time will be so great that there will be no up time and replacing a 20 kM cable is no easy task. This would also mean that every line would have to have a massive tensioner to continually take up the extra slack.

Linear Accelerator;
I just love this quote "Maglev passenger trains have carried passengers at nearly 600 kilometers per hour (373 mph) - spacecraft have to be some 50 times faster, but the physics and much of the engineering is the same." One can't just take some numbers, multiply by 50 and assume they will work. That is like saying that we can make a 100 story building so making a 5000 story building would be easy as the "physics and much of the engineering is the same".There is already a problem with going a bit faster that what we do now. There is so much energy in the coils that sparks are forming that are welding the shuttle to the rails. Try to go 50 time that and you have much bigger issues.

The "murder squad" needs to take a closer look.

Re:Murder Squad?

[ceoyoyo]

"How often is a factor of tension and heat."

In other words, you have no idea. It might be a problem, it might not. Replacing a 20 km line isn't that hard, especially when you can drive up and drop it off. Regardless of the material, suspending 4 tons doesn't sound so impossible.

"There is so much energy in the coils that sparks are forming that are welding the shuttle to the rails. "

There isn't any extra energy involved in going faster when you're in a vacuum. If you can produce the acceleration, that and the length of track is all that matters.

Re:Murder Squad?

[tragedy]

There is already a problem with going a bit faster that what we do now. There is so much energy in the coils that sparks are forming that are welding the shuttle to the rails. Try to go 50 time that and you have much bigger issues.

But is that a factor of the speed, or of the force that has to be applied to accelerate against air resistance?

Re:Murder Squad?

[Anonymous Coward]

For the tethers -- make it a loop with a pulley at the elevated tube, and pay it out at the rate it's consumed. So if the designed creep life is 100000h, and a 25km tether (50km loop), feed it at 0.5m/h

Re:Murder Squad?

[jklovanc]

Regardless of the material, suspending 4 tons doesn't sound so impossible.

I think that you need to read the article again The only place where 4 tons is mentioned is in "a levitating force of about 4 tons per meter of cable length". That is how much force the superconducting wires are repelling each other and has nothing to do with the force on the tethers. Note that the wiki article state "how often". That means it will happen if the tether is under tension. The only variable is how often the tethers need to be replaced.

I never said replacing a tether would be difficult but It would take time. If you are spending more time replacing tethers that launching you are using a lot of money.

There isn't any extra energy involved in going faster when you're in a vacuum

Have you never seen the equation F=MA. Force = mass* acceleration. One of the fastest maglev trains today, the Shaghai maglev train, accelerates at .25G. The article is talking about accelerating at 3G. That is over 10 times the train's acceleration. Also the vacuum is not there due to resistance but to prevent a solid wall of air from forming in the tube as it has nowhere to go.

Re:Murder Squad?

[jklovanc]

Both

Re:Murder Squad?

[ceoyoyo]

The only place where 4 tons is mentioned is in "a levitating force of about 4 tons per meter of cable length".

So the total force the cables need to support is less than this.

Have you never seen the equation F=MA.

I do have a certain familiarity with it, yes. Try as I might, I can't find a v in it anywhere. And you did specifically refer to speed in your post. You'll note that my post specifically said that the system needed to be designed for a sufficient acceleration.

Now that you mention it though, you also said there was a problem with sparks welding the shuttle to the rails. You know maglev trains don't use rails right? And sparks from superconducting coils? Maybe you've got some kind of link to back up that claim?

I'm getting the impression you're really not that solid on some of the basic ideas here. Certainly it would seem advisable to take a less smug know-it-all tone. Just on the off chance you might be wrong....

Re:Murder Squad?

[jklovanc]

So the total force the cables need to support is less than this.

It may be more as one has to support 20KM of cable as well as the repulsive force.

I was talking about acceleration and not top speed. I only referenced speed as an explanation why I picked the example to compare against.

Some maglevs use electromagnetic suspension which as this article states "In current electromagnetic suspension (EMS) systems, the train levitates above a steel rail while electromagnets, attached to the train, are oriented toward the rail from below. "

In electromagnetic suspension there are two sets of electromagnets very close together with very high potentials. At high enough potential insulation will be burnt through and sparks form. They may not be a weight bearing rail but the strips have the same issues.

It is strange how you accuse me of being "not that solid on some of the basic ideas here" when you think that accelerating at .25G will take the same power as accelerating at 3G.

The issue is that the article takes numbers that are much smaller adds a multiplier and says see it is easy. Many mechanical systems do not scale that easily.

Better to build this thing on moon.

[Anonymous Coward]

This thing would be far easier to build on Moon where gravitation is much lower and there is no atmosphere. The whole structure could be built underground.

This is why it is much more important to build Moon-base before we go to other places like Mars. We can build the space vehicles on moon and launch cargo and/or humans to other destinations (like Mars) from there.

The Moon-base should be built and "manned" by autonomous robots - because humans need a lot of extra things such as certain temperature, shelter, food, air water and I presume from time to time vacation back to Earth.

It looks to me we won't get further into space without developing autonomous robots first - which is huge challenge by itself.

Re:Better to build this thing on moon.

[ceoyoyo]

"This thing would be far easier to build on Moon where gravitation is much lower and there is no atmosphere."

You know, it would be even easier to build it in orbit. It could be much smaller too, because getting to orbit requires much less delta v when you're already in orbit!

Re:Hmm. Is there Pb in our drinking water DUMB IDE

[Grishnakh]

Don't know if it's usable for this application, but there's an unpowered version of maglev in existence called "Inductrack" which uses no power, coils of wire in the track and permanent magnets in the vehicle, though of course it relies on the forward motion of the vehicle to achieve levitation.

It seems to me the more worrying problem is the power requirements for making the launch tube levitate, and what would happen if there were a power failure. A space elevator seems to make a lot more sense here, as it doesn't require millions of amps of current to stay stable and safe.

Heinlein was here first

[Anonymous Coward]

Hasn't anybody read Robert Heinlein's The Moon Is A Harsh Mistress, or Starman Jones? Heinlein discussed the physics of magnetic catapults back in the Fifties.

Re:Heinlein was here first

[Jay Maynard]

Ja da, cobber!

balloons

[strack]

why cant they use balloons to keep the tube up? 20km is still in the atmosphere, and the highest balloon has gone to 34km. just have huge balloons all along the tube, with cables to the ground keeping it in line.

Balloons

[foniksonik]

Instead of a levitated tube use more conventional means, balloons filled with hydrogen or helium. Let the balloons float it up, tethers hold it down and on target.

That should take a huge challenge out of the requirements. Balloons are cheap to build and maintain. They have a very low failure rate and the failure mode is very controllable with redundancy eg two balloons for each support node with heavy weights on them that can be dropped.

Really the entire structure could be held above ground in this way. Floated and tethered means no earthquake fears, no need to claim right of way, less environmental impact, no digging or foundation work, etc etc. just build the tube, build a tower as its start point then extend it straight out into space with more tube/track. Would be a perfectly straight line that does not follow curvature of the planet.

Why not put the prop. magnets ONLY on the ground?

[wisebabo]

Ok, I took a brief look at TFA but I'm not sure about the configuration.

It seems like they accelerate the "train" MOSTLY on the ground but then continue accelerating the craft up the final 12 miles. That requires the vacuum proof "tube" for the 12 mile vertical lift to be heavy and carrying a lot of power hungry superconducting magnets (and the final plasma curtain). No wonder they have to use such ginormous magnets to keep it aloft!

Why not do ALL of the acceleration on the ground and then, sort of gently redirect the train up the tube taking it to space. Then the last leg of the tube need not be anything than a (thin) wall keeping the air out with possibly some minor magnets just to keep the vehicle centered. Of course this will require the train to be set on a parabolic(?) path by the final set of propulsion magnets and will require some sort of tall, gently sloped "ramp" in order to do so in a manner that won't cause excessive g-forces but I imagine this ramp would be a lot shorter than 12 miles!

By the way, if you wanted to accelerate the train up to an appreciable fraction of orbital velocity in a CIRCULAR track, how big a ring would it have to be to keep the centripedal acceleration under 3g's. Didn't they ALREADY COMPLETE that 50 MILE in circumference tunnel for the SCC (super conducting collider) in Texas before congress axed the budget? I mean, the thing is already practically designed and built (instead of accelerating tiny particles to a very high fraction of c, use it to send much heavier things much slower)! If the g-forces are too high for humans, it could still be used for cargo.

Re:What is it with nerds and their facination with

[maxwell demon]

with gigantic and impractical structures to tackle a problem that's already been solved with other techs?

Yeah, why should we build long lines of iron bars across the country when the problem of transportation has already been solved with horse carriages?

Biologically closed electric circuits and cancer

[Paul Fernhout]

Free Google Books preview of that book by Nordenstrom: http://books.google.com/books/about/Biologically_closed_electric_circuits.html?id=zb-3YzIn4ZcC

There might well be something to it, but please also look into vitamin D and vegetables as a way to prevent or minimize cancer:
http://www.vitamindcouncil.org/health-conditions/cancer/
http://www.drfuhrman.com/library/article24.aspx

Space Cannon

[Anonymous Coward]

Jules Verne would be pleased. What we have is a cannon for shooting stuff into space. Or closer to the point, this is the style of launcher Heinlein talked about in his books -- up the side of Pikes Peak or some other convenient place, powered, no doubt, by a reactor or a billion wind turbines... (sorry).

Re:F magnets

[Anonymous Coward]

Speaking as an Engineer, there are ways to dampen the vibrations that a long cable (what a Space elevator really is). This has been addressed in all of the serious design studies that I have seen.

The forces acting on the 'tube' will be mostly downward, but due to swaying by the 'tower' there will be a certain amount of side force as well. There should be both passive and active systems in place to dampen those forces.

I would imagine that there will be periodically boxes on the sides of the tube to house the dampeners. Pendulums in the proper locations with electronic actuators would do the trick. This is the approach that very tall buildings use. Left to themselves, structures over 120 stories sway by as much as a meter most times. This can cause seasickness and risks of falling. The ultimate cause is different winds at different elevations. It's a known and solved problem.

To resolve the problems, the first step is to determine the resonant frequencies. From there, you want to find how to induce canceling frequencies. Talk to any good Structural Engineer to find ways to deal with it.

There will be several years of design for the monster, but there are ways to deal with these problems.

The more likely killer problems are the ones no one has experienced yet. Think Jules Verne and the Cannon to the Moon. Acceleration limits weren't experienced yet.