Comments on: Space elevator a real possibility

By: home made wind generators

home made wind generators — Sat, 27 Jun 2009 06:37:51 +0000

Engaging article,, will come back soon:D

By: home made wind generators

home made wind generators — Sat, 27 Jun 2009 05:56:53 +0000

Intelligent writing- will definitely come back again.

By: pyman

pyman — Wed, 10 Dec 2008 06:49:29 +0000

One thing I don’t understand about the concept is how do you just drop the cable from GEO orbit down to the surface? The only way I know how is to use a rocket the burn retrograde and decrease orbital energy. This will lower your PeA, but it would take a hell of a rocket to decrease Ecc to 1. Even at that the cable would be half way wrapped around the Earth by the time in hits the atmosphere, right? Also, the logistics of burning retrograde from GEO while towing a cable with you sounds insane. So, what is the tonnage payload capability of these elevators per run?

By: Hivemind

Hivemind — Thu, 30 Oct 2008 11:08:53 +0000

Actually the cable falling wouldn’t be at all dangerous, because of the incredible materials needed to build it, the cable would weigh the same as a sheet of paper for the same area, so it would just float down to earth.

There are a load of problems with it though, space junk IS a very large problem, even tiny flecks of paint colliding at such high speeds can have massive consequences. Another is radiation, parts of the cable would need to be heavily shielded to prevent them breaking down from a variety of effects.

By: Rivetgeek

Rivetgeek — Thu, 30 Oct 2008 00:09:06 +0000

@spinner

Think of it like this

[ ] <–counterweight
|
|
{ } <- hub/’rope’ factory (also cg) in geosync orbit
|
|
|
|
| <–cable
|
|
|
|
|
O <- Earth(probably not to scale)

By: spinner

spinner — Sat, 18 Oct 2008 08:14:35 +0000

Ooh! My mistake!
One assumes a “counterweight” to be on the “other side” or in this case, I thought the “other side” of earth.

So, to have an elevator going up and down to earth, one needs a counterweight going up further into space?
Now, you really need extra cable!

By: jaded

jaded — Sat, 18 Oct 2008 06:07:17 +0000

Oops, 27,000 miles, not 22,000. My mistake, sorry.

By: jaded

jaded — Sat, 18 Oct 2008 06:04:46 +0000

@spinner

Geostationary orbits are about 22,000 miles from earth — that’s just a fact of the mass of the earth and the length of a day. Every single geostationary satellite, from the DirecTV constellation to the Telstars and Echostars, is 22,000 miles from earth.

It’s important to note that the 22,000 mile distance is to the “Center of Gravity” (CG) of the satellite, not just to the nearest edge.

So the cable is just another satellite in a geostationary orbit. That means that the CG of the cable must be 22,000 miles up, too. With a traditional satellite, they’re only about 50 feet long, so the CG is right there with the rest of the satellite, and we don’t think about it much. The cable, however, has to be long enough to reach the ground, which is 22,000 miles away. That’s a heavy satellite. And if the cable was only 22,000 miles long, it’s center of gravity would be only 11,000 miles up — nowhere near the altitude required to stay in a geostationary orbit.

Something must be offsetting the mass of all that earthbound cable to keep the CG 22,000 miles up. Either you have an identical length and mass of cable reaching out further into space (that’s 44,000 total miles of cable), or you have a giant counterweight somewhere beyond 22,000 miles away. The cable won’t “stay put” on the earth end unless its CG remains in the precise geostationary orbit.

By: spinner

spinner — Tue, 14 Oct 2008 03:19:43 +0000

@barry99705 & @jaded
If there is “not enough mass” or “it’s not anchored…” why then the need for a counterweight?

By: k_aud_polymath

k_aud_polymath — Sat, 11 Oct 2008 18:48:35 +0000

I know that it won’t be physically anchored to the earth. Considering plate tectonics its just a bad idea. Again that’s why a lot of people advocate an ocean placed facility some where on the equator. I used the term “anchor” loosely to mean the earth end. I guess in the case of a space elevator the anchor is in space and the terminus in on earth.

And to all those that say it can’t be done, well the same thing was said about manned flight. Besides the shuttle is over 30 years old and is a prototype every time it flies because of the sheer number of modifications made between flights. Not to mention it costs 10k just to send up one pound of cargo.

As for the terrorists, well, nothing risked nothing gained. Also, I think the security will be a bit tighter than at airports. I mean have you been to a shuttle launch?!? They’ve got gunships flying around and inspecting anyone who even looks remotely suspicious.

By: Mr. McFeely

Mr. McFeely — Fri, 10 Oct 2008 03:43:35 +0000

Imagine though…reducing the per-pound cost to send things into space so drastically, that mankind could finally get out into the solar system…We could build solar plants above the clouds…We could build factories that make things that are impossible to make in a high gravity environment like that on the earth’s surface…. we could build more elevators at less cost than the first.. using the first.. we could build and assemble telescopes, using modern technology, that could see everything that’s out there waiting for us….We could stop squabbling amongst ourselves for the resources on this planet and devote our time to exploring the infinite resources that surround us just beyond this wonderful blue and green prison that has entrapped us since that fateful day when stinking bits of slime first crawled from the sea and shouted to the cold stars, “I am man.”

By: Mr. McFeely

Mr. McFeely — Fri, 10 Oct 2008 03:30:38 +0000

4 Mil won’t even buy you the tail of a boeing 747 (total cost of boeing 747 = 216 Mil). Human beings are too shortsighted for this kind of achievement, no matter how benificial it would be to mankind. Nobody is willing to take the risks, financial or otherwise, that are necessary for the success of a project of this magnitude. Hadron took forever, it took a small eternity for man to get to the moon (assuming that actually happened). If people are expecting an endeavor like this to succeed the first time… on 4 million dollars, then they would see much more benifit, paying me 2 Mil to kiss the fattest part of my black ass.

By: Almost_There

Almost_There — Thu, 09 Oct 2008 23:29:51 +0000

If my calculations are correct, a trebuchet with a 270.3 mile long boom and a 979.3 million ton counterweight should just barely get 300 pounds (a 150 pound human in a 150 pound space suit, or a small satellite) to reach escape Velocity.

It could be built rather inexpensively with parts bought on E-Bay (mostly the shipping costs for the counterweight.)

By: icefox

icefox — Thu, 09 Oct 2008 21:46:49 +0000

You people do realize that as convenient shuttles are, they are unsafe and very expensive right? They take too much fuel just to get into a low earth orbit. An orbital elevator may seem a bit extreme if you are just thinking about it like the ISS or a port to launch satellites, but consider how much easier it will become to go to the moon, mars, or anything else. More complex probes and ships can be built and launched from space.

I think that once one has been built here, we can move to mars and the asteroid belt. We use materials from the belt to make one over mars and begin colonizing.

By: offlinehacker

offlinehacker — Thu, 09 Oct 2008 20:23:47 +0000

Dear NASA,
I have just figured out how to go to space without rocket engine. I’ve started building my ladder to space(like in south park). Don’t worry it’s a great idea. I just need lots of some kind of cable(UTP would be great).
Thanks in advance.

Comment:
Idiots,
Isn’t space shuttle kind of an elevator to the space. What’s the point of having space in a tube. Why don’t they just thow the rope from the space(oh yeah, if you have tube, the equation E=MxGxH doesn’t exist, you need less energy or what) and lift space shuttle with it(joking).