53 replies to this topic

[Shirou]

I expect military bases in all directions monitoring a 50 mile radius around the thing, with jets standby to shoot down anything on a a collision course with the cable.

[Teron]

I wonder, how they will managed to prevent(?) meteorites and other space-trash flying around from hitting that tube :O

[Shirou]

The chances of a big meteorite hitting it are probably slim. It should be able to withstand cosmic dust impact though, but you are right that is also another issue.

Missiles on the space station perhaps

[Teron]

Well, wikipedia tells me that

Quote

"There are more than 600,000 objects larger than 1 cm in orbit (according to the ESA Meteoroid and Space Debris Terrestrial Environment Reference, the MASTER-2005 model)."

Thats much more than I expected. :O

EDIT: Link to Wiki

Edited by Teron, 25 September 2008 - 21:29.

[Dr. Strangelove]

Teron, on 25 Sep 2008, 22:27, said:

Well, wikipedia tells me that

Quote

"There are more than 600,000 objects larger than 1 cm in orbit (according to the ESA Meteoroid and Space Debris Terrestrial Environment Reference, the MASTER-2005 model)."

Thats much more than I expected. :O

EDIT: Link to Wiki

Those are the kind of problems I'm talking about.

[Rich19]

Well, most geostationary satellites seem to be okay for the moment, so why shouldn't this?

[Waris]

Geostationary can be achieved only at height ~35700km, with an orbit directly on top the Equator.

Edited by Waris, 26 September 2008 - 16:07.

[Rich19]

Correction - most satellites seem to be okay.

[markintellect]

This will become outdated when we get proper SSTO spacecraft, the kind that take off like an airliner, go up into space, and then come back down and land like an airliner. Once that happens (Soon, perhaps?...) we will look back and laugh. Anyway, maybe you want to get into a different bit of space than what is nearby the top of the elevator, or the cable breaks and the vehicle falls 4000km onto one of the most densely populated countries in the world, and with an impact force rivalling that of an asteroid.

[Code Monkey]

I guess going back on what JB said, this isn't much different from the imperial sky hooks in star wars (sci-fi I know, but isn't this? Yet they're trying to do it). The idea is pretty interesting I just dont see it as an effective way to get into space, not that launching 1000 gallon rocket into space is a better alternative, it's just been done. All in all this is going to take alot of time and alot of money, was of resources imo, aswell as the rest of the space programs (for the most part).

[CommanderJB]

markintellect, on 8 Oct 2008, 7:28, said:

This will become outdated when we get proper SSTO spacecraft, the kind that take off like an airliner, go up into space, and then come back down and land like an airliner. Once that happens (Soon, perhaps?...) we will look back and laugh.

I really hope you're not referring to the space elevator when you say it'll be made obsolete by SSTO craft. Do me a favour and read Fountains of Paradise by Arthur C. Clarke. Not only one of history's most visionary science fiction works, but also an amazing novel in its own right. Even if you took SSTO technology fifty years into the future you'd still be using heat shields, expensive fuel that is likely difficult and energy-intensive to produce, a very limited cargo capacity, unbeliveably huge support networks and limited airframe life. The launch costs for a space elevator capsule consist of paying people to load it and the cost of the power taken to send it up. Nothing more, nothing less. They can haul as much as you build them to, all without having to blast yourself out of Earth's orbit with thousands of kilograms of highly explosive substance burning bright behind you. There is no better bridge to the stars than these.

markintellect, on 8 Oct 2008, 7:28, said:

Anyway, maybe you want to get into a different bit of space than what is nearby the top of the elevator, or the cable breaks and the vehicle falls 4000km onto one of the most densely populated countries in the world, and with an impact force rivalling that of an asteroid.

Does this debris somehow not affect any other craft? Of course it would, and the reason carbon nanotubes are used is because their tensile strength is orders of magnitude higher than any other material. You may have to run up a replacement cable every year or so, but even then you are of course not adding at all to the problem (as you do with any ground-launched system) and can continue using it sustainably for as long as you like. The reason Earth's orbit has tens of thousands of pieces of space junk filling bands of it is because of all the casings, rings, thruster propellent, ASAT test debris and other such items left over from the multi-stage-to-orbit years of the 60s, 70s and 80s. Even SSTO leaves far more orbital debris than a space elevator.
As for crashing, as Mr. Clarke will no doubt clarify, it can't happen. It's simply a matter of physics. The end station for the elevator consists of a huge counterweight - people have suggested captuing an asteroid, which would be tricky to say the least, and is probably the major stumbling block when it comes to construction rather than manufacturing the cable - which keeps the cable taut. This is placed in a geosynchronous orbit some 36,000 or so kilometres away from the Earth. I'm going to give the classic 'whirling stone on a string' analogy - if the string snaps, what happens? The stone flys away. The effect would of course be far smaller on a space elevator thanks to the fact the system is kept in equilibrium, but it's literally physically impossible for the elevator station to hit the Earth. Ever.

Edited by CommanderJB, 08 October 2008 - 03:10.

[The Wandering Jew]

I am currently working for an elevator company (hint: starts with a letter M).

After I read the link, I almost burst my head off laughing. In the first place, why would they create such an expensive and unfeasible thing? Oh, I know. To get their names in the What's Hot news. :chillpill2:

Here are my simple reasons why they should not continue with the project:
1. Expensive (the amount they'll expend could feed millions of hungry people in the world and provide them with ample livelihood)
2. Not feasible (Remember the "Mech Thread"? How 'bout the "Mammoth Tank Thread"? Basically it's just the same, albeit on a grander scale!)
3. If ever they do successfully create one, they only have given the terrorists a new structure to demolish. C4, anyone?
4. Labor and capital extensive
5. Do we have the technology? I honestly do not see any current technology that could accomplish this project.
6. (see No.1)

Remember the movie Doom (starred by Karl Urban and The Rock)? That teletransporter thingy really looked cool.

[CommanderJB]

The Wandering Jew, on 8 Oct 2008, 15:47, said:

1. Expensive (the amount they'll expend could feed millions of hungry people in the world and provide them with ample livelihood)

Oh, for god's sakes, not this again. If you want to go funding hungry people do it out of a military budget. They're hundreds of times larger, non-peaceful and don't tend to bestow a wealth of benefits on human advancement. Or at least do so much less readily. The space programmes of this world have yielded untold dreams and technologies that have enriched our race beyond belief. To quote Carl Sagan (he has so many good quotes it's not funny):

Quote

A scientific colleague tells me about a recent trip to the New Guinea highlands where she visited a stone age culture hardly contacted by Western civilization. They were ignorant of wristwatches, soft drinks, and frozen food. But they knew about Apollo 11. They knew that humans had walked on the Moon. They knew the names of Armstrong and Aldrin and Collins. They wanted to know who was visiting the Moon these days.

Tell me that pushing the 'final frontier' is less worthwhile than the plethora of other things you could fund it from.

The Wandering Jew, on 8 Oct 2008, 15:47, said:

2. Not feasible (Remember the "Mech Thread"? How 'bout the "Mammoth Tank Thread"? Basically it's just the same, albeit on a grander scale!)

The technology is almost there and would take a decade at most to get to the prototype stage. Those familiar with the idea have estimated that we would be technologically ready to build a space elevator by 2040. Within a half century at the latest. The only true problems are the cable material (the technology exists, they just need to get it to the right stage and then make it ready for mass-production) and the counterweight. The rest of it was easily covered in the Space Race.

The Wandering Jew, on 8 Oct 2008, 15:47, said:

3. If ever they do successfully create one, they only have given the terrorists a new structure to demolish. C4, anyone?

Ever heard of 'security'? Ever heard of any terrorist attacks on space facilities ever, at all, in history, for that matter? No offence but I think you've been watching too much Contact (you know, that one with Jodie Foster).

The Wandering Jew, on 8 Oct 2008, 15:47, said:

4. Labor and capital extensive

No kidding. Name me something as worthwhile that isn't. But it would bring untold financial windfalls on the country that managed to corner it; the cost per kilo to orbit currently sits around about $10,000 IIRC. For a space elevator it would be a fraction of that. No-one would want to use rockets any more and they'd pay through the nose to go for this instead.

The Wandering Jew, on 8 Oct 2008, 15:47, said:

5. Do we have the technology? I honestly do not see any current technology that could accomplish this project.

Already answered.

The Wandering Jew, on 8 Oct 2008, 15:47, said:

6. (see No.1)

Already answered.

Edited by CommanderJB, 08 October 2008 - 10:53.

[partyzanpaulzy]

I remember first time this idea has been used by Arthur C. Clarke in one his novel (1950's ?) where 4 space elevators are used to send material and people to large ring space station going around the equator. Many of his visions (satellites) have become true, many of his visions are becaming true. Most of his visions are feasible.
He said: "50 years from the moment people stop laughing about this and start thinking about this, it will become reality. " The reasons for space elevator: better safety, lower cost (rockets needs plenty of the fuel), more material would be sent to the space. Space elevator could carry material to some 100 kms and from this point space rocket could be sent more far with lower cost than rocket launched from the Earth surface. Also it could be much easier to construct large interplanetar ship! And it's hard to tell of if mammoth or bipedal mech will be feasible in the 2nd half of the 21st century (new materials, many military experts want mechs), but if there will be no big mistake, the space elevator will be made, materials (carbid fibres) are almost done (even though long fulerens could be dangerous like asbestos). There was a documentary film in TV The world after 50 years: Global strategy where such space elevator is used.

[The Wandering Jew]

I do not want to throw cold water on the subject, but I believe that it shall never be built.

[Rai]

Why exactly?

[Shirou]

The Wandering Jew, on 9 Oct 2008, 11:59, said:

I do not want to throw cold water on the subject, but I believe that it shall never be built.

Naïve persons like y[..] will probably stop it because they think the idea is too stupid for their narrow minded brains to envelop.

That's the idea I get from your response above with your six reasons. Each and every one of them is non-argumented, impulsively thought up and easily dismissed. I'm not going to repeat that as JB did a wonderful job.

Now I would really like you to explain and specify exactly why this is unfeasible, after you are done reading through the entire topic of course. Start with that, please.

[Dr. Strangelove]

I've had a bit of a change of heart on this subject, the only thing keeping this from reality is the lack of a strong enough cable(carbon nanotubes just aren't strong enough).

[CommanderJB]

Not yet, anyway. The development of the right materials goes hand-in-hand with the development of nanotechnology, which is rapidly becoming another boom area at the moment. I don't think it will take them more than a decade or two to come up with the right material, then another couple of decades to come up with a way of mass-producing it. The trick is getting the resources in space to assemble it from; you either need an astronomically expensive stream of spacecraft, hopefully but by no means guaranteed to be SSTO, or the asteroid counterweight, which solves it quite nicely. The problem, as I said, is getting that asteroid there. The technical challenge alone would be supreme, though with the advent of ion engines I can easily see it happening, but the political problems such a scheme would create would likely be even larger.

Edited by CommanderJB, 15 October 2008 - 09:32.

[amazin]

(for the breaking length of the cables) they could just have many detached cables, and machinery that removes the elevator from one cable and attaches it to another?


the only thing im thinking of is what would they attach it to?

[General Kirkov]

Looks interesting but given the amount of time needed to research the tech and build the damn thing your looking at 40-50 years. I figure by then humanity as mentioned by a prior member will have space craft able to exit the atmosphere with ease. That and the Vulcans will be here in like 60 years or so.

[Major Fuckup]

Aftershock, on 24 Sep 2008, 1:57, said:

Now just think of the possibilities. An elevator like this is like a gateway to space. An elevator into space is absolutely not stupid. In comparison to this, hydrogen fueled rockets are what is stupid.

wtf kind of use would an elevator have lets take a 24hr trip into space and pull some hang time lol
a rocket would be more practical it could carry more equipment and is safer u only have to worry about being exploded unlike a elevator. with an elevator ud have to worry about weather/winds, snapping cables, earth quakes, fire, birds, rust, erosion, farting in a confined space and if built international and national air traffic would be rerouted around it and would make a big terror target. All that just seem impractical to me imagine a gust of wind bending it in the centre XD

[CommanderJB]

You really need to widen your view on this. The space elevator concept is far, far more practical than a rocket if it can be made to work, which, within a few decades, it should be. How on Earth (or off it for that matter) is strapping THREE PEOPLE to the top of a hundred-metre tall rocket that weighs as much as a battlecruiser, carries enough destructive potential to tear the CBD out of a city of your choice, can be detected on earthquake sensors on the other sides of the country and costs billions of dollars to build, fuel, support and launch in any way 'practical'?
Compare this to a system which will have greater start-up costs but, once it is running, requires nothing more than an electrical current. For every kilogram sent into space, at the moment it costs the owner tens of thousands of dollars. If you could start a space elevator, this could easily drop to hundreds before too long. The 24 hour time issue is hardly an issue at all for the civilian sector - since when do you need to get a rocket into space in a hurry, save for military carriers which will still use expendable launch vehicles?
Also your concept of its length is clearly flawed, though you can't really be faulted for that. There's minimal atmosphere at about 100km above the Earth's surface. The end station on a space elevator sits at an orbital distance of approximately forty-six thousand kilometres. The public depiction of space is flawed at best. So no real need to worry about wind. Or airspace diversions - hardly much of an inconvenience anyway.

[NergiZed]

I dunno, the amount of material needed for something like this is just so gargantuan. It's one thing to send a couple dudes to the moon or a rover to mars; that's compact technology. It's an entirely different thing to build something a quite a times bigger than anything we've ever even considered building; this is marco-technology and huge material costs. (just think about it: do we like to build small things? or big things?)

I don't doubt the fact that we could build it. But I would just have to ask why?

Something that makes much more sense is some catapult/mass driver rails, that would speed up the space delivery vehicle starting from a horizontal position steadily increasing in inclination and eventually launching the vehicle as it leaves the rails at a near 90% angle at around hypersonic speeds. Then booster rockets can fire to maintain that speed and escape the Earth's gravitational pull. This would essentially be some 100 story (more or less, whatev) structure that makes the initial acceleration portion of the flight 'reusable' (as opposed to burning rocket fuel). It'll still need to have rockets, but now far less than the current setup. I personally find that idea far more logical, economical, safe (both technically and in terms of terroristic threats) and just overall easier to do. although a project like that seems more like an 'American' type of project, since it requires vast amounts of land and experience in maintaining reusable space vehicles.

[Balizk]

Reading this topic remember me Gundam 00 lol

Anyway, i think it's possible to exist... but i can't say "IT WILL HAPPEN" or "IT WILL NOT HAPPEN" (obvious )