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« Strange Bedfellows | Main | Long Overdue »

Elevator To Nowhere?

Hey, I like space elevators, but if James Miller thinks that this idea will win the 2006 election for Republicans, he's...well...politically naive.

I can just imagine the Democrat commercials, were they to attempt such a thing. All they'd have to do is show the end of the Simpsons monorail episode, with the giant magnifying glass, the skyscraper made of popsickle sticks, and all of the people riding the escalator to nowhere and falling off the top.

"Millions go without health insurance, our soldiers are dying in Iraq, and the Republicans want to build an elevator to nowhere."

Sadly, in many ways (as I've noted previously), the human spaceflight program has in fact been building a metaphorical elevator to nowhere.

Posted by Rand Simberg at March 14, 2006 05:33 AM
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If the "alt.space" crowd is right about space transports being buildable and easier-than-the-conventional-wisdom thinks, then it would have to stand as a corrolary that government is particularly bad at space technology development.

Posted by Phil Fraering at March 14, 2006 06:38 AM

Halfway to anywhere - LEO - is indeed no-where particularly interesting, whether we get there by elevator or by shiny SSTO spaceplane.

Now, if we had lunar tourism and were mining platinum group metals from Dennis Wingo's asteroids (okay Ruzic wrote about this before Wingo) then there would be a reason to go to the moon and then getting halfway would be a great start to going all the way instead of going in endless circles, going no-where interesting (ISS).

MXER tethers are one example of a cheap method of making the 2nd half of the trip (at least for cargo) and = IF = lunar tourism and lunar PGM mining were started with obsolete expendable rockets, the demand would be created for bright people to spend even more time and money developing truly cheap Earth-to-LEO systems.

= = =

Once lunar mines and tourism have started, an elevator will be funded by private sector. But, until we have cheap access there will be no tourism or mining, or so some say.

As always, chickens and eggs.

Posted by Bill White at March 14, 2006 07:37 AM

Yeah, funding a space elevator through NASA is gonna just cause all us small-government conservatives to *rush* out to the polls. :)

I have to admit... I wouldn't necessarily object to some degree of government funding of a space eleator, but I would *not* want to see typical cost-plus mega-wasting garbage like we see today.

I *might* could go for increased funding of CNT research, which is the basis for not only this, but also ultralight rocket parts, bridges, skyscrapers, body armor... heck, I keep saying that plastics in the 50s has nothing on CNT in the 10s.

Posted by Big D at March 14, 2006 09:05 AM

I've always been curious. This whole space elevator thing, other than the global ring in 3001, how would this skyhook elevator thing work as a platform? aren't you talking about major transfer of force if you say, launch a rocket off of the side of it? wouldn't that rip the base off the planet, or knock the anchor off kilter which would then rip the base off of the planet?

Posted by wickedpinto at March 14, 2006 09:32 AM

At geosynchronous altitude, you can simply let go of the elevator and you'll be in geostationary orbit. From there you can light up the rocket and go anywhere you want without disturbing it at all.

Posted by Rand Simberg at March 14, 2006 09:34 AM

Agreement abounds (and thanks for the pointer to 'Escalator to Nowhere,' which I hadn't seen before and liked as well). Anyone interested in an Edwards-style "beanstalk" space elevator needs to understand two things:

First, all other questions are irrelevant if we can't make a CNT or CNT-composite material of adequate strength/lightness: at least 10x and preferably 20-25x stronger than the best fibers on the market (Spectra, Kevlar etc) and with a handful of other virtues. Below that strength, the ribbon (cable) mass goes up so fast that the Edwards deployment scenario quickly gets impractical. We do not currently know that such material is possible, and the obstacles are in basic science as well as technology -- i.e., at this time they demand more understanding rather than more money. No one is going to, or IMHO should, commit serious bucks (say 8 figures and up) to other elevator-specific R&D until that changes. Miller needs to relax and breathe deeply.

Second, there's lots of useful work to be done "on spec" at lower cost levels. A good deal of it overlaps with the interests of other space technology "constituencies": e.g. laser power beaming, debris avoidance, and tether dynamics in general. I'll be hosting a panel on these Friday May 5th in the Spaceward Foundation's track at the ISDC.

Posted by Monte Davis at March 14, 2006 10:40 AM

Given that a Terran elevator requires CNT (as Monte Davis points out) building a lunar elevator sure seems like a good way to spend our time and energy while CNT research continues. Much can be learned about how a tether will behave in space with a lunar elevator which can be built with available materials. MXER tethers might also be a test bed for some of the techniques that will be useful in building a genuine Terran space elevator.

Also, a lunar elevator combines with MXER tethers from LEO to Luna will lower the transportation costs from Earth to Luna very substantially whether or not alt-space delivers low cost Earth-to-LEO in the immediate future.

Right now we need (about) 5 tons in LEO to get 1 ton to the moon or Mars. Go with tethers and maybe we need 1 1/2 or 2 tons in LEO to place a ton on the moon. Same net effect as cutting Earth-to-LEO launch costs by 60% to 70%.

Once we create a destination on the moon the incentive will be there to invest billions in low cost Earth-to-LEO

Posted by Bill White at March 14, 2006 11:41 AM

At geosynchronous altitude, you can simply let go of the elevator and you'll be in geostationary orbit. From there you can light up the rocket and go anywhere you want without disturbing it at all.

So like a drop launch? Okay, that gets rid of most of the questions, but the very transfer of mass would interrupt the orbit/stability of the space hook wouldn't it?

and I like that term, I don't know why, I've attached myself to skyhook/spacehook instead of space elevator. just a random personal desire to exert my free will.

Posted by wickedpinto at March 14, 2006 11:59 AM

Miller needs to relax and breathe deeply.

Second that notion. The last thing a technology that doesn't even work quite yet needs is to be associated with 'the other side' in a political fracas.

Posted by Brian at March 14, 2006 12:00 PM

You know what? I have SO many questions about how this might work as a static platform. . . .is there any chance that since this has hit political terms in the post that inspired your response, can you . . . . um. . .

I know it's selfish, but kinda create a. . . um "complete retard's guid to space elevators!" FAQ sort of linkfest?

I'll keep looking, but the more alphabet after the name, the less interesting the alphabet when explaining a topic, it's hard for us mundanes to pick up on why certain things don't effect other things.

Thanks just for letting me post, and I can get you a pretty decent working over thanks to a friend of a friend, if you are willing to overlook that whole hetero thing, next time you find yourself in the City. as a greater form of thanks.(thats a joke)

Posted by wickedpinto at March 14, 2006 12:04 PM

...the very transfer of mass would interrupt the orbit/stability of the space hook wouldn't it?

Not really. Lifting it in the first place would slow down the earth's rotation (almost immeasurably) if one didn't send stuff back down to compensate, but the disturbance to the elevator from a geo departure would be minimal. For other questions, try liftport.com.

Posted by Rand Simberg at March 14, 2006 12:09 PM

I know it's selfish, but kinda create a. . . um "complete retard's guid to space elevators!" FAQ sort of linkfest?

it's still the 'old style' but the Liftport FAQ page is not-so bad.

http://www.liftport.com/faq.php

Posted by Brian at March 14, 2006 12:27 PM

http://en.wikipedia.org/wiki/Space_elevator

Somebody did a good job with this entry.

One thing... please remember that elevators and skyhooks are completely different things. One stands straight up and cars move up and down it using their own propulsion (powered externally). The other moves at high velocity (well, the tips, which are the important bits) and performs direct momentum transfer.

IMHO, the elevator is easier to use, while the exoatmospheric skyhook is probably easier to build.

I'm a little nervous about skyhooks in general, because of the precision required and the result of being off by a few meters, as well as the huge swathe low-orbit ones cut through the spacelanes. I'd just as soon they stuck to L-points.

Posted by Big D at March 14, 2006 03:57 PM

"Halfway to anywhere - LEO - is indeed no-where particularly interesting, whether we get there by elevator or by shiny SSTO spaceplane."

As Edwards designed it, the elevator is over 60,000 miles long. Once an upward-bound climber passes geostationary orbit, it "falls" toward the end of the cable, faster and faster, until it leaves the end (or some intermediate point). Escape velocity is reached well before the end of the cable, so you could go anywhere in the solar system from the elevator, not just LEO.

wickedpinto, I suggest you try to find a copy of Bradley Edwards' book (interlibrary lo@n?) or google his articles/interviews for the best handle on the concept.

Posted by Patrick at March 14, 2006 04:59 PM

I bought Bradley Edwards' book, and it is a good description of the concept, and I would also recommend it. Having said that, ever since I first heard of the space elevator idea, it was obvious that the crucial item is the "ribbon" that supports it. And Mr. Edwards spends one fairly thin chapter on this. Neither he or anyone else has convinced me that we can make this ribbon in the forseeable future. Without that ribbon, all discussions of other problems and possible benefits is moot. I like the idea, I really do, but until someone convinces me that we can really make this ribbon I don't want my tax dollars spent on any space elevator program. I might support a limited research program on whether the ribbon is feasible, but please not a full blown NASA elevator program.

Posted by Ray_g at March 14, 2006 06:31 PM


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