Another opinion of the Space elevator - Questioning the sanity of the Space Elev

Martian Republic · 2004-07-04 07:30:19

Another opinion of the space elevator.

http://www.rense.com/general54/wef.htm] … 54/wef.htm

Larry,

Ian Flint · 2004-07-04 08:04:36

I say we just take this as constructive criticism and learn to build a space elevator that will overcome all the problems he stated.

Since it may screw up our ionosphere, we should test one on Mars first.

How convenient...another reason to go to Mars.

dicktice · 2004-07-04 12:02:12

Well. that should put "finis" to any space elevator program for Earth. And to test the scheme on Mars you'd first have to take out Phobos--that satellite handed to us on a platter? That's poor value-engineering, to say the least. Tethered propulsion, based upon solutions to the problems posed, could and should be taken up right now, however.

DERF · 2004-07-04 14:26:53

Slighty off topic, but from the article:

"Current micrometeorite impacts on earth are in the millions every day. You can stretch a large plastic sheet outside, and over a month or so they will accumulate. Most of them have an iron content, about the size of a grain of sand, and are black. You can also use a magnet to collect them from the gutters on your home. Many can be found there. Micrometeorites are everywhere."

Does anyone know if this actually works or they have tried it? I think I want to try it myself.

On Phobos: In the Mars trilogy I believe they had the cable sort of wobble back and forth to avoid Phobos, so unless that causes fatigue I can't see that being a problem. If the cable gets too close though it could flex under the attraction to phobos or deimos, but I imagine that is pretty negligible at far enough distances. Bonus fact: In the Mars trilogy, the knowledge from the Martian space elevator helped build the ones on Earth...so there.

Martian Republic · 2004-07-04 14:46:34

Well. that should put "finis" to any space elevator program for Earth. And to test the scheme on Mars you'd first have to take out Phobos--that satellite handed to us on a platter? That's poor value-engineering, to say the least. Tethered propulsion, based upon solutions to the problems posed, could and should be taken up right now, however.

Then that would leave just the moon as the only really viable candidate for space elevator. You probably would not do that unless you would be building a city on the Moon, because it would not be cost effective. Beside you could build a three or four mile rail system on the Moon and catapult your occupants into space instead of building a sixty mile elevator.

Larry,

Josh Cryer · 2004-07-04 17:16:34

Heh. I'm taking his article with a grain of salt. But in the end I would maybe agree with him about 'TR3' being more viable (or what is "known" as TR3; just a blimp that can achieve spaceflight), I think his article lacks a really solid argument, the only thing that concerns me is the electrical conductivity.

Shaun Barrett · 2004-07-04 18:27:32

I think this Ted Twietmeyer is slightly flaky. His list of problems with the Space Elevator (SE) is full of red herrings and pseudo-science.
The cable hung from the shuttle developed a large current because it was a conductor moving very quickly in Low Earth Orbit through Earth's stationary magnetic field.
The SE will be essentially stationary with respect to Earth's magnetic field because it will move only at the same rate as Earth's rotation. Trying to equate the two situations is false science designed to impress people who don't understand basic physics.

As to the prospect of shorting out the entire ionosphere, I believe this shows a misunderstanding of the density of the atmosphere at these altitudes. While there may indeed be a major electrical potential between the ionosphere and Earth's surface, the number of ions per second that will impinge on the surface of the SE in the ionosphere will be totally insufficient to create the kind of massive electrical current Ted describes.
In addition, however good a conductor the SE may be, over distances of 100,000 km there will be significant electrical resistance. We can even introduce substances, if need be, to reduce the electrical conductivity.

Then Ted mentions massive ice build-up on the SE in the upper reaches of the troposphere. Well, which is it? An elevator frozen and heavy with ice? Or an elevator crackling and sizzling hot with mega-Amps of current causing it to glow like an incandescent lamp?!!

There are more holes in Ted's article than I have time to point out. The guy is a wild-eyed, Luddite, sensationalist with little grasp of the facts.
Don't lose any sleep over his nonsense.

C M Edwards · 2004-07-05 14:38:34

RE: _SPACE ELEVATOR INSANITY_!!!!!

Back when I was a student, one of my physics professors would let me look at incoming letters from all of the nutcases wanting him to help them get published or endorse their crackpot ideas.

AND I DISCOVERED SOMETHING ALL OF THEM HAD IN COMMON:

********INDISCRIMINATE USE OF FONTS and PUNCTUATION!!!!********

That right. Invariably, font and punctuation rather than narrative were used to indicate important points within each article/letter.

I couldn't believe it when I saw it laid out in front of me, but there it was.

"Great Scott!" I thought at the time:

(damn! where's the FLASHING TEXT font when I need it!)

I've discovered a new characteristic symptom of Paranoid Schizophenia!!!

!!!!!!!!

However, I was wrong. It turns out that there is an entire school of "business-oriented" technical writing that teaches that getting attention is more important that what the writer has to say. Unfortunately, it's advertised very heavily outside of academic circles, and a good many of the so-called instructional books available to the lay public today are selling this philosophy to make money. The people sending those goofy letters learned to write them from books like these, and were not displaying some sort of delusional hypergraphia.

This particular writing style is, however, a sign of lack of formal training. (Or should be. IMHO, no self respecting teacher of composition, MBA or otherwise, should pass a student out of his classroom being as unable to convey information as this particularly limited writing style will leave them.) It's not a red flag, but it's definitely a call for time out.

Twietmeyer uses this writing style, making me immediately suspicious of everything he has to say.

Some of it, like charging of the tether by the ionosphere, sounds like legitimate concerns. Having studied the problems inherent in high altitude tethered ballooning, I can say that problems from charging of the tether have to be considered even if it does not conduct electricity at all. However, since attention is more important than information to Twietmeyer, no detailed discussion -- or even rational perspective -- is forthcoming from this source.

I still think space tethers are a possibility. I think Edwards, et al. are doing an adequate job planning for any expected current in the tether. This poorly written article has not persuaded me otherwise, I certainly have no fear for the ionosphere, and I wish the HighLift team godspeed.

P.S. Yes, you can collect micrometeoritic material from the roof of your house. However, the rate of collection is so low that if you live somewhere dry where there's any amount of local dust on a regular basis, or even have iron roofing nails that could rust, the influx of particles is completely swamped by terestrial sources. That's a great attention grabber, if you don't give out the rest of the information.

Shaun Barrett · 2004-07-05 17:59:15

Ha-ha!! :laugh:

Thanks for that, CM. "Delusional hypergraphia" .. nicely put. I do enjoy your input here at New Mars; both the well-reasoned serious posts and the amusing asides.
Long may you continue to grace our pages.

Timeslicer · 2004-07-05 20:16:47

Sigh - 5 seconds with google yielded this:
http://www.isr.us/Downloads/niac_pdf/ch … ter10.html
It even addresses the ionosphere issue, which obviously 'Ted' thought was his strong suit, since he led with it. He should spend 5 minutes on that site, then drop the issue and go back to perusing his usual UFO sites/conspiracy theory sites.

I took part in a discussion forum Edwards previously helped organize - disbanded when Edwards got a new position with potential to support his work. All of Ted's "problems" were raised and dismissed along with many more - including a few that Edwards found interesting, but ultimately was able to dismiss.

BTW - the moon isn't a very good candidate for a space elevator - it rotates far slower, so the cable would have to be much longer even though it's gravity is much lower. There are much better launch options for the moon.

Mars is technically a pretty good candidate - lower gravity, almost the same angular velocity as earth. Phobos could be dodged relatively easily - it's just a more extreme form of the "space debris" issue. But until we decide we're going there to stay it won't make economic sense.

The biggest problem with a space elevator is making it economically viable. You need a lot of modest sized cargos worth hauling into space. But if a government footed the bill for the first elevator (for the military) it'd make building additional elevators and doing anything in space far less expensive.

While I don't advocate this, my guess is that - if feasible - the first elevator will be built by some government-military-industry collaboration to support military/intelligence applications, but offering commercial orbiting services as well.

Timeslicer · 2004-07-05 20:51:03

BTW - if you want something with a REALLY high giggle factor (i.e., FAR less analysis than the space elevator) :

http://www.halfbakery.com/idea/polar_5f … r_5fbeanie

This would be a good complement to using space elevators to launch cargo to orbit, as it is more suitable for launching human beings (shorter time to orbit, less time spent in the van Allen radiation belts, no need for laser power to the out-going vehicles).

I used to have a link to a more serious site by someone else, but now I can't find it.

dicktice · 2004-07-06 09:14:03

Phobos would NOT be easy to dodge, and I challenge anyone to prove otherwise, Arthur C. Clarke to the contrary, with his "synchronous solution." Not failsafe, not to mention idiotproof.

TwinBeam · 2004-07-06 16:21:08

Phobos would NOT be easy to dodge

Ok - why? With a combination of swinging the elevator at the half of phobos' orbital period, and making small computer controlled adjustments over time to keep it synchronized, what do you see as being the big problem?

You could simply attach the space elevator maybe 300km off the equator (which requires a slightly stronger elevator - easy since Mars has less gravity and it is only about half a degree tilted). According to my rough calculations, phobos should never come near it.

If you assume the technology to get to Mars and build a space elevator there - no mean feat in itself - is arranging to not hit an ~3x/day orbiting moonlet 13km wide really so tough?

dicktice · 2004-07-07 16:39:39

Nice try, TwinBeam, but Phobos is evey space elevator's nightmare..
First case: Not failsafe. Wish it were, but it won't work "forever" without active supervision of some kind.
Second case: All satellites must lie within, or cross the equatorial plane twice each time round. S'fact.
Third case: This is not roulette, it's orbital mechanics. Phobos is bound to collide with the elevator at least once, or maybe more glancing blows, but sooner or later . . . it's a goner.
Last case: You can just forget any hanky-panky with our little Phobos in future, because Mars Society plans to claim it on the 2nd Mars trip. (You mean, they didn't they tell you that, when you joined up?)

TwinBeam · 2004-07-08 09:30:33

First case: Not failsafe. Wish it were, but it won't work "forever" without active supervision of some kind.
Second case: All satellites must lie within, or cross the equatorial plane twice each time round. S'fact.

If you toss in "forever", everything eventually fails. But if it went a century without a collision, that's plenty of time to get good value from it and build several more elevators. The ribbon is more likely to be cut by a meteor than it is to collide with a big, obvious and avoidable obstacle like Phobos.

And WRT your second point - yes, all free-falling satellites must cross the equator - but as I was trying to say, the space elevator ribbon need not be attached to Mars at the equator. It can be attached at a higher latitude so that the ribbon does not cross the equatorial plane inside the orbit of Phobos. It just puts a bit more strain on the ribbon. This was discussed at some length in that forum I mentioned.

Here's a link explaining the idea:

http://www.mit.edu/people/gassend/space … quatorial/

TwinBeam · 2004-07-08 14:15:13

I posted before about the high giggle factor "polar space beanie" (PSB - http://www.halfbakery.com/idea/polar_5f … r_5fbeanie ). I've been thinking about it a bit more.

The biggest advantage of the PSB is that it would not have to be built down from orbit. Use a large balloon to loft components up to about 50km or higher - fairly near vacuum conditions, at 1/1000th sea level air pressure. You don't even need to carry up all the starter ribbon - you can feed it up from spools on a rotating platform on the ground.

Beam power up to two or more very large "blades" - like helicopter blades, except these would be to impart spin, not lift, using an induced ionic wind drive. The blades might be balloons themselves - similar to the JP Aerospace "zeppelins to space" plan.

As the blades spin, begin feeding out counter-weighted ribbon. It doesn't need to spin faster and faster - in fact just the opposite. But they do have to be able to impart enough force to keep adding angular momentum while overcoming the residual air drag as the ribbon gets longer and longer. (It might be necessary to put a solar power collection unit out at the counter-weight, and use a current in the ribbon interacting with the Earth's magnetic field to induce motion, if the blades can't do the job alone.)

Eventually the ribbons extend out far enough in both directions, and the spin has slowed to a halt. You now have two ribbons in displaced GEOsynch orbits. Build up the ribbon for a while, then simply cut the cable about 1 earth radius up on both sides. Two new space elevators will fall into place at the equator. No rockets needed!

I know this still sounds wacky - but like the space elevator it also sounds very promising, if all the problems can be worked out.

TwinBeam · 2004-07-08 14:27:45

New Mars Forums

Announcement

#1 2004-07-04 07:30:19

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#2 2004-07-04 08:04:36

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#3 2004-07-04 12:02:12

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#4 2004-07-04 14:26:53

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#5 2004-07-04 14:46:34

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#6 2004-07-04 17:16:34

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#7 2004-07-04 18:27:32

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#8 2004-07-05 14:38:34

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#9 2004-07-05 17:59:15

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#10 2004-07-05 20:16:47

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#11 2004-07-05 20:51:03

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#12 2004-07-06 09:14:03

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#13 2004-07-06 16:21:08

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#14 2004-07-07 16:39:39

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#15 2004-07-08 09:30:33

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#16 2004-07-08 14:15:13

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#17 2004-07-08 14:27:45

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

#18 2004-07-09 11:31:56

Re: Another opinion of the Space elevator - Questioning the sanity of the Space Elev

Board footer