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Space Elevators Could Be Lethal
Maggie McKee writes, "A new study reports that passengers on space elevators of current design could be killed by radiation. Even traveling at 200 kilometers per hour, passengers would spend several days in the Van Allen radiation belts, long enough to kill them." Looks like the elevator scientists will get this one solved before liftoff.
will tinfoil hats help?
One of the most popular (and massive) items that will need to be shipped to orbit will be water; and water makes a good shield against radiation. Just make your passenger cars with a living unit inside a larger freight unit, and fill the gap in between with water. If you used filtered fresh water you could even have windows on both walls and be able to look through.
From TA: "it's going to make things a little more complicated and a little more expensive"
Everybody panic! Apparently, "a little more expensive" == "potentially lethal"!
I guess people should buy from Wal Mart instead of Target, since the latter is "a little more expensive". Obviously making a purchase at Target will kill you. I love sensationalist headlines.
Mutant Freaks of Nature: "Frighteningly Addictive"
Seems like this would be simple to solve. Shield the passenger cabin. The extra weight of the shielding doesn't make a damn bit of difference if it costs a penny for a quintilliton of cargo to orbit. Plus, you get to re-use the shielding. Those passenger cars to orbit are going to be like victorian rail cars. They never wear out.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
I thought the main idea was to send equipment, not people? If we can get one in place (which doesn't seem particularly likely any time soon), it'd be far cheaper to send tons of heavy stuff into orbit via a tether than via a rocket.
$x='S24;r)>63/* h@<5+oZ)32"5cz';$me='phroggy'x$];
$x=~y+ -xz+\0-Tx+;print$_^chop$me for split'',$x;
This is why the First Amendment is so important- to expose Corporate Greed! Greed which led space elevator manufacturers to produce elevators without the neccesary safety precautions. How many people have to DIE in the name of profit? How long will it be before space elevator travel is actually made safe? It should have been done BEFORE the elevators were even built, damnit!!
Thank you Maggie McKee, for planting a seed for the grassroots "Space Elevator Safety" movement!!
How much thrust would a rocket need to zip you through those sections if you waited to fire it until reaching, say, 500 - 800km? Surely by then you'd be far enough away from Earth that a little bit of push would go a long ways, compared to firing a rocket from the ground?
Unpleasantries.
The article says that you may not want to add shielding because of the added mass. Wikipedia says that "an object satellite shielded by 3 mm of aluminum will receive about 2500 rem (25 Sv) per year." I don't know how this would translate for people going through the area, but 3 mm of aluminum doesn't weigh much.
This post climbed Mt. Washington.
Looks like the elevator scientists will get this one solved before liftoff.
You betcha they will. Compared to the problem of running a cable tens of thousands of miles straight up, and strong enough not to tear under its own weight, this sounds downright trivial. We're still a dozen orders of magnitude off.
So can regular ones. Your point?
In the same vein -- Always wondered how you'd pass an environmental "impact" review for one of these things. What happens when your 20,000 nmi long cable to geosynch breaks -- or is intentionally damaged by the "bad guys" -- halfway up and 10,000 nmi of cable falls down to earth-- a cable 10,000 nmi would stretch from the coast of Ecuador to somewhere on the island of Borneo.... even bigger mess if it falls over land...
The solution, of course, is more speed! With a mass driver, and 1000+ Gs acceleration, you too can zip right through that hazardous Van Allen belt in record time!
You quitting proves that the karma kap worked. The most annoying of the whores shut up. --CmdrTaco
Why do people even waste their time on this idea. WHY DO WE NEED SPACE ELEVATORS?
For all the engineers here: why would you want to build a cable tens of thousands of miles long out of currently UNAVAILABLE materials (unobtanium) to slowly ratchet up one payload at a time? It's a horrid idea, and it STILL takes just as much actual energy to put anything in orbit...just it does so pathetically slowly.
The plan is to use PHOTOVOLTAIC PANELS to receive the energy being beamed from the ground. That is a patheticaly slow method of energy conversion considering the payload still has to receive the equivalent energy of being accelerated to several miles/second!
There's a simple and really OBVIOUS idea that has been on the drawing board for at least a decade. It would involve a heck of a lot less work, be likely much simpler and cheaper, and be flat out cool.
Instead of building just a few lasers to beam the energy, lets make a whole bunch of them and use the latest electrically powered pulse laser technology being developed for the joint strike fighter. Our spacecraft is just a payload module with stabiliers BOLTED to a block of inert material. A very short and simple linear accelerator kicks the spacecraft about half a mile into the air, high enough for all the lasers spread across the industrial plant infrastructure to 'see' it.
Pulses of light vaporize the fuel in a sequence such that the shock wave of superheated vaporized gas is planar : basically a rocket engine without needing :
A nozzle pumps, combustion chambers, volatile fuel, electrical systems, elaborate control systems and sensors, just enormouse amounts of hardware gets taken out of the spacecraft and left sitting on the ground. Sure, there's a LOT more delicate hardware left sitting on the ground...WHERE IT BELONGS. The laser launch system would be designed for almost continuous duty, launching one capsule after another all day long. Spacecraft would be MUCH simpler, and with a lower cost of launch could be made MUCH more cheaply as well. After all, why bother with all the checks and cleanrooms if you can send 10-20 Mars probes for the price of what 1 costs today? No need to shave every gram if launches only cost about 20 bucks a kilogram instead of about 1-10 thousand.
And finally, after testing this laser launch system by actually launching thousands and thousands of missions to find out what the REAL failure rate is, and gradually scaling it up to launch bigger, but just as simple, spacecraft we use it for manned missions as well.
Seems like a no-brainer approach. I think the current planning for space travel is like trying to transport goods by horse and buggy across the continent on a massive scale when the same money could be used to install a railroad.
Additionally, the space elevator is expected to be very tall, taking riders several miles above the surface of the earth where, experts say, they could fall to a harrowing death. And if that's not bad enough -- it turns out that if the earth were to suddenly stop spinning, the entire space elevator could come crashing back down to the ground!!! I, for one, will from now on refer to them only as "Space Elevators of Death!" in order to raise awareness about this potentially leathal issue!
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Sure, just eat at McD's for a month, and you'll go through all your belts in that timeframe. Supersize me!
MadCow.
I used to have a sig, but I set it free and it never came back.
It's the high-speed rotation and length of the cable that keeps it upright and taut. If you don't anchor the bottom of the elevator the entire thing will go flinging off into space. Fun for a while, but eventually someone will get upset about it.
"Yeah - Like China will build a 4000 mile long wall."
"Yeah - We are going to build a tunnel under the English Channel."
"Yeah - We are going to dig a ditch to let boats cross America."
"Yeah - The Egyptians are going to build a gigantic pyramid that will still be standing in 4500 years."
"Yeah - We will propel a highly explosive cargo ship to the moon carrying people."
CS: It is all sink or swim...oh and did I mention there are sharks in that water?
Given that gravity won't be nearly as much of an issue at that altitude, a combination of shielding including water or metal (likely both) and increased speed seems to me to be the simplest route. All things being equal, that's probably the better solution.
We've made it through the Van Allens before, we'll figure out how to do it again.
And, anything can kill you, really, so long as it's an action. Space elevators aren't lethal in and of themselves. Organ failure due to blunt trauma, rapid depressurization, radiation poisoning; these can kill you. An elevator cannot. It's an inanimate object. Well, unless you're on acid. Then you're on your own, kid.
If all my base are belong to you and I attempt to retrieve my base, does that mean I'm freebasing?
Except no one mentions the giant sea monster that can come along and snap the cable at the anchor. Lethal radiation will be the least of your concerns.
While there might be some small benefit, it would not be as large as you think. Gravitational acceleration is still very significant at 500km up.
Acceleration toward an object due to gravity is given by g = GM/r^2, where G = 6.67e-11 is the gravitational constant, M is the mass of the object, and r is the distance from the center of mass of the object. The mass of the earth is about 5.97e24 kilograms, and its mean radius is about 6.37e6 meters. Thus, the acceleration due to gravity at the planet's surface is approximately (6.67e-11 * 5.97e24) / (6.37e6^2) = 9.81 m/s^2.
Go up another measly 500 kilometers, and your new acceleration is approximately (6.67e-11 * 5.97e24) / (6.87e6^2) = 8.44 m/s^2. That's only a 14% difference; a very noticeable reduction, but not enough to have significant savings. Your rocket fuel wouldn't go much farther at all, at least when the goal of the space elevator is to reduce cargo costs by orders of magnitude.
The cable needs to stretch beyond geosynchronous orbit. The center of mass of the cable will be in geosynchronous orbit. As for the sheilding, the article simply says what you say: we will need some. Three centimeters of aluminum should do it. This is absolutely not news to anyone who has seriously looked into space elevator technology.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
Actually, feces would probably be a huge commodity in space; it'd be invaluable as fertilizer for the farms.
And no, I'm not joking; if farms are at all feasible, you'd want them, not just to supplement the diet of the population in space, but also to regenerate oxygen from carbon dioxide.
Everyone knows exposure to this radiation is nearly always benign...in fact, 75% of the people exposed to this radiation found it to be beneficial. The remaining 25% were less pleased, apparently having super-strength and near invulnerability does not make up for the fact that one's body is covered with rocks and people call you a "Thing."
My other sig is extremely clever...
If you eat the pizza you destroy your shield!
And just where do you think you're going to get pizza for the return journey. No, my friend, these are critical protective pizzas, not for eating. In space, there are no wood-burning ovens. Or mozarella.
Order the pizzas frozen from Domino's so you won't be tempted to actually eat them.
the major advances in civilization are processes which all but wreck the societies in which they occur - A.N. White
Its already probably a trillion dollars give or take an order of magnitude -- what is another 2%? (But don't worry, kids, after we have it we'll find a way to get a trillion dollars out of it! I mean, we could sell tickets to the space hotel for like a billion dollars each! Then we'd only need to find a thousand sucker billionaires and a space hotel!)
Help poke pirates in the eyepatch, arr.
And the downward trip is easy - drop capsules with parachutes are a lot simpler and more reliable than fancier rockets like the space shuttle, and you'd want to keep a bunch of them around for emergencies anyway.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
To low earth orbit, yes. But remember that the cable is stationary above the Earth, so one orbit is exactly 24 hours (it's more like 90 minutes in LEO). Thus, to move fast enough to actually be in orbit, rather than just falling back down to Earth, the elevator must go all the way to geosynchronous orbit, which is more like 24,000 miles out.
If you don't understand any of my sayings, come to me in private and I shall take you in my German mouth.
Seriously, why humans? Get your fix riding your local space tower / space needle ride.
The problem it solves is CHEAP transport into space for cargo. NOT people. robots will be better than humans for nearly all space work. It will be a long time before we NEED human space transport.
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"375,984,751,127th floor: Menswear, sportswear, and lethal doses of radiation."
You forgot:
"Yeah - And I'm a Chinese jet pilot."
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This however assumes that one is allways going to "the top floor" so to sepak. Nothing should prevent the elvator from stopping a LEO and letting people off......
If it just lets people off, they're going to fall straight back down to earth unless they have some way of accelerating to an extra 20,000km/h fairly quicky.
When the posters fear their moderators, there is tyranny; when the moderators fears the posters, there is liberty.
Actually, unlike other get-rich-in-space-schemes like tourism, a Space Elevator would be a major revenue generator, and not just a novelty. With the ability to safely lift tons of material into space on a daily basis, a lot of industries would become viable: mining, solar power satellites, regular interplanetary travel, zero-gravity factories, non-trivial space stations, etc. Oh yeah, tourism too.
Space right now is like the Wild West before the invention of the train. You can send a few people out there, sure, but it'll never really be settled in any non-trivial way until there is a bulk-shipping infrastructure in place.
I don't care if it's 90,000 hectares. That lake was not my doing.
Ionizing radiation is just awful on chemical bonds and crystal structures. After all, it works by knocking electrons or whole atoms loose from the nice, bound states they were in. That's how the radiation damages you, too -- it's just that biological systems are a whole lot more sensitive to being scrambled, than are bulk objects like bricks or (to pick a not-so-random example) bundles of carbon nanotubes.
High doses of radiation do strange things to materials -- increase cross-links, damage coherent structure, add skillions of crystal defects. If you lower a nice flexible, white piece of polyethelene plastic into a nuclear reactor for a while, you are liable to pull out a yellow, harder, brittle, fragile piece that has the same overall shape.
If I understand the nature of the space elevator right, each particle "hit" would tear apart a carbon nanotube, gradually shortening the average tube length and weakening the whole bulk structure. I'm sure someone has thought of this effect, but we haven't seen much of it in the space elevator press packets.
Why would I travel at only 200KPH? How about 2000Km:h, on an engineered track, through the near-vacuum past 100-200Km out? Space is an acceleration game, so really I'm concerned only with how long I have to spend under the crush. At 1G, I could get to 2Mm:h (Megameters per hour) in under 1 minute. 15 minutes through the atmosphere, another minute up to 2Mm:h, then a couple of hours to the top (another 1.5G deceleration for a minute) once friction is immaterial. At 1.5G all the way up halfway, then slowing 1.5G the rest of the way, that's 2 minutes to the top. I don't know if I'd want to fry on a daily commute, but why live with Earth limits when we're leaving the Earth?
The other solution they're not considering in that article is to engineer the elevator car to travel inside the cable, rather than outside. Use the mass necessary for tensile strength for radiation shielding, too.
These are 30 second solutions. I'm sure the next decades before we actually deploy the spacehooks will find lots of better solutions.
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... Or given SUPERPOWERS!
You guys can't fool me, I saw that documentary about those people on the space station. I wanna be the one who can be all stretchy!
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What's to stop space stations etc being tethered to the cable?
Actually, the giant counterweight at the top of it would be actually beyond geosynchronous orbit, and the center of mass of the cable would be in geosynchronous orbit, but the cable itself would not be in any kind of orbit.
Saying the cable is in geosynchronous orbit is analogous to saying that the cables on a suspension bridge are "flying".
Random and weird software I've written.
Reading that, I realize we're all insane. Quite insane.
All rites reversed 2010
Next hurdle to overcome: how to keep from going batshit insane while riding in an elevator for 7.5 days.
I Am My Own Worst Enemy
They better have a state-of-the-art air purification system in this elevator. And make sure there are no Taco Bells anywhere within a 500km radius of the base station. I love Taco Bell and I have to ride an elevator to the 24th floor to work every day. I have first-hand knowledge of potential problems in such a situation.
Perhaps if they played light, pleasant music continuously in the background, it would calm the passengers and make them think tranquil thoughts.
"I've got more toys than Teruhisa Kitahara."
"Yeah - We will propel a highly explosive cargo ship to the moon carrying people." ... "and bring them back safely to earth"... which was the hardest part.
snarkd
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