Space elevator ? How can it work?

SpaceShaft

Hey Russ, thank for figures, please note this is just a quick reply, therefore my apologies for its qualitative nature.

Just a couple of points. Within the description we speak of kilometers and not of miles, although 100 miles is an altitude that can be reached, and is an altitude at which human made artifacts do operate it is not the (+/-) official boundary of space.
Second one of the proposed uses of a SpaceShaft is for the deployment of the CNT tether, the SpaceShaft on its own does not need a cable to operate.

Let me point out that the proposed tower with the name SpaceShaft is an extreme application example of what will become, hopefully, a more down to earth tool for other uses, such as in enveloping buildings for maintenance, etc..

What we are ultimately proposing is the infrastructure for others to develop other applications, we do not aim to provide a full package of solutions, just to find other partners.

Again my excuses for not dedicating more time, right now, to respond

DaveC426913

Sure. Am I on your team now?

No, the onus is on you to show that you've thought this through.


Everything else you posted simply restates your original claim, without addressing the problem that the bouyancy effect on your tower is limited to a small fraction of its height.

DaveC426913

I read this as:

We have a solution for which a problem does not yet exist.

russ_watters

I understand you used km, but it doesn't have any impact on the calculations I did this morning, so it doesn't have any impact on the issues.

In any case, I'm still not sure that you understand that a 100 km (or even 100 mi) high tower doesn't have a whole lot of value. More to the point, it doesn't satisfy the goal of a "space elevator", which is to lift a payload into orbit. It isn't' clear to me that you understand that just lifting a payload to 100 km doesn't mean that that payload is in orbit. Could you explain what you think the value of a 100 km tower is? What happens to the payload when it gets to the top of the tower?

DaveC426913

This is what I've been asking. Several times now. Strangely, answers are not forthcoming.

dr dodge

what happens at the top?
Momentum will carry it past its bouyancy point, then it will fall back down the hole, only to float back up with less velocity, and eventually come to a stop floating around in the air.
I feel we are wandering further and further from (reasonable) realities
and ya'll called some of my ideas "crackpot"

dr

DaveC426913

There is no momentum at that point. The rise is slow and, since there's vacuum, it's all dead-weight.

Gfellow

I agree with SpaceShaft. A very interesting thread.

SpaceShaft

russ_watters you state that:

"it doesn't satisfy the goal of a "space elevator", which is to lift a payload into orbit."

are you implying that a CNT tether based space elevator will put things in orbit?

if yes can you explain how? since I don't believe that will be the case.

russ_watters

The goal of a space elevator (whatever it is made of) is to lift objects to about 22,000 miles, where just by being there puts them in geostationary orbit.

Could you explain what you think the purpose of a space elevator is? By now, I'm pretty certain you have no idea, since after repeated requests, you have yet to explain what your idea's goal is/what it does.

The opening paragraph of your website says: This implies you think that "reaching orbital space" (presumably, you mean the height of a low-earth-orbit satellite: 110+ miles) accomplishes something useful. Tell me what you think it accomplishes!

One of your drawings appears to show a space shuttle docked with it...

SpaceShaft

I have discussed this matter with other participants at the conferences. Bringing up stuff up to the counterweight at GEO means only to pile stuff at that altitude. The CNT tether, just like the SpaceShaft only brings things to a certain altitude from where they have to be launched.

Only Rockets are capable of fulfilling both requirements. That is; bringing a payload up to an operational altitude and giving the object enough velocity to make of it a satellite capable of counteracting gravity.

I will like to point out that in the event that deployment of a CNT tether to GEO Is unfeasible the only “plan B” out there is the SpaceShaft. It may not be as sexy as the popular system but it will work.

To your question: Basically it accomplishes the same thing.

russ_watters

That's what I thought: You don't get it and you aren't listening. Here it is for the last time:

Bring an object up to 100 miles and it falls back to earth, accomplishing nothing (well - unless the goal is to dig a big hole).
Bring an object up to 22,000 miles and it is in orbit, which is very useful.

The idea that things "pile up" at the top of a space elevator is very silly, since it only takes very small thrusters to move objects around the globe once in orbit at the top of a space elevator. That's nothing compared to the massive rockets required just to achieve orbit after leaving the top of your tower.

Here is the wiki on space elevators, and you really should read it: http://en.wikipedia.org/wiki/Space_elevator

You've made other conceptual errors that you should want to correct ("Bringing up stuff up to the counterweight at GEO" is also wrong - read the wiki and learn for yourself what is wrong about it)and it willl help as a starting point for learning about space elevators. You need to start from scratch because what you think know now is worse than knowing nothing: what you think you know now is basically all wrong.

This thread has become all crackpot nonsense and is therefore locked.