Space Elevator: High Hopes, Lofty Goals

Yahoo! News ^ | 9/17/03 | Leonard David

[MalcolmS]

>>>(26000 miles)*(3 feet)*(1/1000 inch)* (1.7 gm/cc) = 3067 tons. <<<

Including counterbalance, that's 40,000/26,000 *3067=4718 tons

At $10,000 per lb to orbit = $94.36 Billion

[PatrickHenry]

You'd eventually want something the weight of the Cheops pyramid at the ground end.

I wish you hadn't said that. Now the crazies will come into the thread claiming that the pyramids were ancient anchor points for Egyptian space elevators.

[Diddle E. Squat]

Say it can be built, how does it work as an elevator? Seems like lifting anything up it would require a tremendous boost to get past the earth's gravity(basically an attached rocket) and what if something goes wrong early on the lift? The load comes crashing back due to gravity at such force as to destroy the base. Could run it as a loop, like an escalator, but now you've doubled the length, and it seems the amount of friction at the bottom wheel to pull through 44,000+ miles of loop would be huge, plus anything pliable enough to bend around the end wheels wouldn't be strong enough to hold for 22,000 miles.

[Brett66]

The elevator they're proposing is designed for payloads of twenty tons or less. How many tons of tension on the cable would that require? By the looks of the size of that platform, it might come close to the weight of a pyramid.

[Diddle E. Squat]

You're thinking of Machu Picchu...

[Diddle E. Squat]

Sounds like a job for the Otis-Babel Elevator Company...

[RightWhale]

Now the crazies will come into the thread claiming that the pyramids were ancient anchor points for Egyptian space elevators.

We don't know what was attached to the Cheops pyramid, do we. It's missing its cap. Hmm

[Brett66]

Here's a good article from Spacereview that goes into a little more detail about their concept:

The space elevator: going up?

[RightWhale]

If this elevator idea is going to work out economically it will need to move significant mass. 20 tons is okay, but how long will it take to crawl all the way up, it's 22,000 miles, after all. A city bus is about 6-7 tons. Can't see many people waiting for the next bus unless they come every 20 minutes.

[r9etb]

Thus, the anchor could be in Nebraska, which is not near the equator, and the geosynch crossing of the cable would be near the equatorial plane 22,000 miles up.

OK, I think I understand what you're saying.

So now let's look at what that means.

For this scenario to work, you're going to need the center of mass of the system to be at GEO on the equator. If we use Nebraska, the cable is going to be at a latitude of 40 degrees, more or less.

Gravity is going to want to pull the cable south, toward the equator, so that it hangs straight down. If I'm not mistaken, this will exert a combination of radially inward and out-of-plane forces on the center of mass, which will cause the orbit to change.

[RightWhale]

Yes, that appears to be a good picture. The cable will remain stationary, but offset from the equatorial plane with a slight arc toward the equatorial plane and being closer to the equatorial plane the higher you go.

[KevinDavis]

At first I was against the space elevator idea, now I'm for it after the Columbia accident. I did talk to some people who is developing the space elevator, they will place it away from a populated area and I'm sure there will be some protections against the terrorist.

Space Ping! This is the space ping list! Let me know if you want on or off this list!

[slimer]

If they are so worried about space debris then why not build a space vacumn cleaner to remove all the junk? Hell if they can build a space elevator they surely could build a vacumn cleaner. ;>)

[Rocky]

Conversations heard on the elevator:

1) "Maintenance? Yeah, I'm stuck on the 10,000th floor. Can you send someone up to help me?"

2) "Anyone got a match?" (Below sign reading, "No Smoking on Carbon Elevator, by Order of the Management")

3) "Anyone heard lately where that hurricane is headed?"

[Brett66]

how long will it take to crawl all the way up, it's 22,000 miles

Their proposal uses a magnetoplasmadynamic (MPD) engine for transit. I don't know how fast that could be and presently it's a device that hasn't been out of the lab. It's one of those "pacing items" :) that will have to be developed.

[RightWhale]

why not build a space vacumn cleaner to remove all the junk?

It's being worked on. Something along the lines of micro-rockets that would go to each piece of junk and de-orbit them individually. One thing about low earth orbit, which is where most space junk is, all that naturally comes back to earth in a few months on its own. The problem is that we are creating space junk faster than it is disposing of itself.

[Brett66]

4) Who f@rted?

I pity the poor midget that rides one of these. :)

[irv]

It really looks foolproof, folks.

You didn't mean to say that, did you? I'd make a comment about "famous last words" but in the case, I think the famous last words would be (It's [the ground's] coming right at us!!!"

(Not meaning to sound negative - I actually like the space elevator idea - but there are plenty of opportunities for failure here.)

[tophat9000]

While I find the idea intriguing.... I dread to think what would happen if something in low earth orbit hit it....

[norraad]

Good point, however the smarty pants space admnistrators need homegrown toolbox common sense or "accidents" will continue on schedule.

i.e. 1. Shuttles, how about just not flying when it's too cold?

if we didn't fly during Jan. & Feb. guess how many shuttles we'd still have?

2. if good old freon r12 based adhesive was used on the wing foam (as per spec. design) instead of new enviro-wacko library paste, we'd still have at least one more, even though they flew in the winter.