Scientist Sees Space Elevator in 15 Years

[hightime]

WASHINGTON - President Bush (news - web sites) wants to return to the moon and put a man on Mars. But scientist Bradley C. Edwards has an idea that's really out of this world: an elevator that climbs 62,000 miles into space.


Edwards thinks an initial version could be operating in 15 years, a year earlier than Bush's 2020 timetable for a return to the moon. He pegs the cost at $10 billion, a pittance compared with other space endeavors.


"It's not new physics — nothing new has to be discovered, nothing new has to be invented from scratch," he says. "If there are delays in budget or delays in whatever, it could stretch, but 15 years is a realistic estimate for when we could have one up."


Edwards is not just some guy with an idea. He's head of the space elevator project at the Institute for Scientific Research in Fairmont, W.Va. NASA (news - web sites) already has given it more than $500,000 to study the idea, and Congress has earmarked $2.5 million more.
http://news.yahoo.com/news?tmpl=story&cid=624&u=/ap/20040625/ap_on_sc/space_elevator_3&printer=1

[Love Bug]

1. Kim Stanley Robinson wrote about one of these...

... in his books Red Mars, Blue Mars and Green Mars. Interesting idea.

[Media_Lies_Daily]

22. He may have borrowed his idea from Arthur C. Clarke who introduced...

...the concept to the science-fiction community in 1978:

"Smitherman's paper credits Arthur C. Clarke with introducing the concept to a broader audience. In his 1978 novel, 'Fountains of Paradise', engineers construct a space elevator on top of a mountain peak in the mythical island of Taprobane (closely based on Sri Lanka, the country where Clarke now resides). The builders use advanced materials such as the carbon nanofibers now in laboratory study."

But wait! There were earlier thoughts on this idea:

"As early as 1895, a Russian scientist named Konstantin Tsiolkovsky suggested a fanciful 'Celestial Castle' in geosynchronous Earth orbit attached to a tower on the ground, not unlike Paris's Eiffel tower. Another Russian, a Leningrad engineer by the name of Yuri Artsutanov, wrote some of the first modern ideas about space elevators in 1960. Published as a non-technical story in Pravda, his story never caught the attention of the West. Science magazine ran a short article in 1966 by John Isaacs, an American oceanographer, about a pair of whisker-thin wires extending to a geostationary satellite. The article ran basically unnoticed. The concept finally came to the attention of the space flight engineering community through a technical paper written in 1975 by Jerome Pearson of the Air Force Research Laboratory. This paper was the inspiration for Clarke's novel."

Audacious & Outrageous: Space Elevators
<http://science.nasa.gov/headlines/y2000/ast07sep_1.htm>

[GoodSpud]

2. See also:

Arthur C. Clarke - The Fountains of Paradise

Interestingly the concept was originated by a Russian, Konstantin Tsiolkovsky, in the late 1800.

IMHO it is about time to do it.

T.D.P.

[Oggy]

3. Do you remember in Blue Mars

when it comes down?

[GoodSpud]

4. Just got to keep the free mars guys away.... n/t

nt

[Oggy]

5. I'm embarrassed to say

I'm getting mixed up with Total Recall :-)

Were Free Mars the Mars born?

[Oggy]

6. dupe

[lightbulb]

11. the result of a 'terrorist' attack

if I remember correctly. They detached it from it's orbiting anchor and the cable looped around the planet on fire as it fell, creating a huge trough-like crater. A very memorable scene.

[cjbuchanan]

7. This was the cover story of Discovery magazine this month

Very interesting possibility.

But I do fear that they would play "Stairway to Heaven" the whole trip.

[struggle4progress]

8. IMHO: this is a stupid idea and the thing will never be built.

But lots of money may go into it before it is abandoned.

[demoman123]

9. There is also something repugnant about it.

Like putting a TV antenna on a cathedral.

[Owsley]

12. I humbly disagree...

This thing may never get built in my lifetime, but it is far from a stupid idea. It is, in fact, the most effective means to exit the Earth's gravity well. Financially this makes complete sense in the long term if you are interested in helping any kind of space program, be it public or private, as it alleviates the bulk of the cost of launching something into space.

Robinson's books were brilliant, by the way. I recommend them to anyone.

Owsley

[lanparty]

13. Carbon Nanotubes ...

They've found the material that will make it happen. It's only a matter of time now until they figure out how to make really long filaments.

The applications for carbon nanotubes are limitless. It's not a technology that needs to be funded by NASA. One of it's first applications will be bullet proof shirts that appear no different than a fruit of the loom T. Anything that's currently made with carbon fiber or fiberglass can be made lighter and tougher used carbon nanotube fabrics combined with some epoxy.

The money is definitely there to build a space elevator. At 10,000 per pound to orbit, you have a LOT of funding there.

Regarding space travel, it could revolutionize it. You see, most of the fuel necessary for an interplanetary voyage is just getting into orbit. A space elevator changes this COMPLETELY. A ship could be ferried up the elevator followed by fuel modules.

Finally, a cable that fell would be little or no danger to the earth population. The stuff has to be so light that hitting a building with a space ribbon would be like hitting you or me with a common sewing thread. Most of it would fall into the ocean, that's where the tether platform would be located.

The way we do space right now is a collosal waste of money. A space elevator will make space exploration practical.

[struggle4progress]

16. I want to see some calculation about the cable weight.

Yeah, something carbon nanotubules might provide a "lightweight" material -- but it needs to be miles long, and the weight will add up.

You claim "most of the fuel necessary for an interplanetary voyage is just getting into orbit. A space elevator changes this COMPLETELY."

The only thing I can see that changes is that you don't need to lift the fuel used to put the object in orbit, if you lift with a motor based on the ground. There may be an efficiency there, but I think it is offset somewhat by the following issue: rocket motors are rather efficient at turning energy into work; mechanical motors, in comparison, are likely to be much less efficient. So you skip lifting the blast-off fuel, but you lose in the hoisting engine.

[lanparty]

19. Rockets in atmosphere are horribly inefficient ...

I'm not competent enough to do the calculations. The people who ARE say that carbon nanotubes have the right weight to strength ratio so that they could be strung for THOUSANDS of miles without breaking under their own weight and the tension of the ballast.


A rocket must carry enough fuel to carry enough fuel to carry enough fuel etc.....

That is if I want to get 100m off the ground, I have to have x amount of fuel. To get 200m off the ground, I need MORE that 2x fuel because the fuel must be carried straight up. The fuel requirements end up being computed using exponents.

An elevator bypasses this colossal waste of energy. You get into this recursive fuel requirement. The vehicles position is supported by the cable. The cable is effectively supported by the rotation of the earth.

Under current proposals, the vehicle itself would carry no fuel. On the way up, it would get it's energy from a laser based on the tether station (likely nuclear powered). On the way down, a vehicle would get power from gravity.

Once in space, burning rockets becomes pretty efficient. All navigation is circular, no energy is wasted.


BTW, the space elevator folks aren't the only one's who think that rockets launched from the ground are a collosal waste of energy. Some of the X-Prize entries use launch vehicles that fly into the upper atmosphere on kerosene. Flying this way is a LOT more efficient than fighting gravity head on in a ballistic trajectory.

Once in the upper atmosphere, the orbital vehicle separates from the "launch plane" and burns it's rockets where it's most effective in an orbital trajectory.

An elevator concept could be much more efficient in delivering fuel into orbit for an interplanetary vehicle. Robots could fuel the vehicle in orbit using disposable "gas tanks".

Another concept being explored is "shooting" cargo into orbit. Basicallly, you pick out a nice mountain and build a mag-lev launcher on it. You give it enough speed to get into the upper atmosphere. Once there, it sheds a ballistic shell and a booster takes it into orbit.

Either way, rockets from the ground are a collosal waste of fuel and largely responsible for the astronomic launch costs of satellites.

[LastDemocratInSC]

21. The mass adds up but is balanced by centripetal force

The cable will extend to 62,000 miles and have an anchor mass at the end. The centripetal force of this arrangement will balance the mass.

Electrical motors will be used to lift payloads but the motors will be on "lifters" that traverse the cable and are powered by ground-based lasers that beam energy to the lifters. The laser energy used won't be high enough to be a hazard in any way.

[mike1963]

29. Beaming mega-horsepower by lasers? BWAHAHAHAHA

Come on, that sounds like the old 'beamcaster' thing from Heinlein's novella "Waldo". It ain't gonna happen. There seems to be a mini-epidemic of _myasthenia mentalis_ around here. No offense intended. ;-)

[LastDemocratInSC]

36. Who said mega horsepower?

The energy required to move the lifters would not be what you think. Adaptive optics, now being used in ground-based telescopes to achieve images that rival those of the Hubble telescope, would be employed to minimize the atmospheric scattering of the laser energy. This has already been tested and works beautifully.

[booley]

20. don't forget the environment

everytime we put a rocket up we are dumping tonnes of pollutants in the air. Not to mention the run off from rocket feul that pollutes the water around launch sites.

we actually do need to go inot space but we also need a way that we can afford.

Why not this?

[struggle4progress]

28. You say "a cable that fell would be little or no danger"

and further that "hitting a building with a space ribbon would be like hitting you or me with a common sewing thread." But the link indicates that the "ribbon" is over 60000 miles long. I'm guessing that 60000 miles of "ribbon" (being three feet wide) weighs rather more than 60000 miles of sewing thread, and I'd bet even 60000 miles of sewing thread has considerable heft.

So, in response to your kind offer to drop this large apparatus harmlessly onto me, I say "No thanks."

[LastDemocratInSC]

37. Please consider this ...

If a portion of a sewing thread a million miles long were to drape itself across your town tomorrow, the length that touches your house, your car, or you, would have no greater effect than a length of thread 100 yards long. It's still just a thread. Nobody is saying that it's going to bunch up and land on your roof in a big lump.

[struggle4progress]

38. Perhaps you are right regarding the thread.

But someone was speaking of an airfoil three feet wide ...

[LastDemocratInSC]

39. You're just trying to be testy, aren't you? (just kidding)

The plans that I've read call for having lifters going up to the breakage point on the Earth side and down to the breakage from the distal end to rendezvous with each other and repair the damage (more work needed here, obviously) before anything can enter the atmosphere.

The Earth-bound lifters would move mass out to the broken end and hopefully keep that portion of the cable out of the atmosphere. So, if everything failed and the Earth-bound portion of carbon nanotube fiber fell back into the atmosphere, what might happen? What would the entry velocities be? Might we have something like several thousand miles of airfoil stuff in the ocean east of Tahiti (probably) and onto the mainland of South America or would any of it burn up (probably not).

Well, I think we could expect to see a new, highly insulative line of Alpaca sweaters from the Inca natives in the mountains of Peru. I say you and I should invest now. Who needs lamas?

[struggle4progress]

41. In a way, I am just being testy. But I don't believe this will work ...

at any reasonable price, and I'm always leery of huge technical projects, which always seem to encounter unexpected problems, including cost overruns. The superconducting supercollider was going to be a bargain, and I guess the plug got pulled on it when it was costing ten times what was estimated. We heard long tales about the glorious space station fifteen years ago, but it seems to have produced essentially no meaningful science and its boosters now seem eager to abandon it in favor of an equally unimportant manned Mars mission. "Space elevator" looks to me like as much of a boondoggle as "Star Wars" missile defense.

I say: stick with smaller scale unmanned space exploration for the time being. We can learn so much from it, we're having trouble managing all the data.

[struggle4progress]

15. Unlikely to be the most effective way of launching anything ...

because in addition to the lifting of the object, you must also lift the weight of the cable or (if you produce something with offsetting weight, such as a continuous loop) overcome the continuous friction.

Unlikely to be practical for a number of reasons. First, there is the difficulty of fabricating a reliable cable of the desired length, as well as the problem of controlling the elastic behavior of such a long piece of film. Given the investments involved, there would be enormous pressure to hide any problems associated with the cable. Inspecting the cable for defects thoroughly and with any regularity would be extremely difficult and expensive, which means that corners will be cut, as has (unfortunately) so often been the case with large scale projects. There is also an enormous difficulty of protecting such a large structure against windshears and other weather-related forces; continual damage from rain and wind is likely, while in the upper reaches cosmic radiation and the solar wind will degrade the cable film. Moreover, weather forces will constantly tend to relocate the upper end of the "elevator," which therefore requires constant fuel expenditure to maintain its location; this means that there is a constant need to refuel thrusters at the upper end of the elevator, which certainly must offset any theoretical lift efficiency.

Further, the idea, that one can reliably move such a large object in and out of satellite orbits, with one end tethered to some movable gizmos on the ground, is IMHO simply preposterous.

And there is of course the nasty question of what to do, part way through a launch, when the machinery stops working (say, the upper bearings fail), and one has an extremely heavy object suspended at some distance above the earth, rattling about in the wind.

[lanparty]

18. Website ...

http://www.americanantigravity.com/highlift.html

People have spent a LOT of time thinking about this. You only need enough ballast at the end of the cable. And that really is NOT a problem. All you need to do is park some of your climbers at the end of the top of the cable.

The ballast end would NOT need thrusters. Newton does the job just fine. The tether would be a floating "ship". And I would bet it will be fueled with a nuclear reactor. The larger the ballast, the larger the objects that can be lifted.

The momentum of the earth takes care of lifting the cable. In fact, the cable does't "need" lifting. They cable is being "dragged" by the earth. The ballast by nature will attempt to move up into a higher orbit due to increased speed, the cable will prevent it from doing so. That is where your "lift" comes from.

People have spent a LOT of time planning for this. Engineers have spent a LOT of time thinking about it. The only thing they lacked was a material appropriate for the job. Don't kid yourself, carbon nanotube materials will literally be bulletproof. There are pans for machines that will repair the ribbon when it's damaged. And it's certainly possible to engineer materials that are resilient to cosmic rays.

As far a machinery breaking, well all space vehicles are designed with double and triple redundancy. Given the importance of the ribbon, I doubt a vehicle would have single points of failure. Even so, they could have vehicles at the end of the ribbon that could come down and "disattach" stuck cargo allowing it to fall into the ocean.

I don't think the project will be easy. But altogether, I think it has less problems than rockets. And it will ultimately be a LOT cheaper.

[LastDemocratInSC]

23. The problems you cite are real but manageable

The mass of the cable will be balanced out by an anchor mass at the 62,000 mile termination point and by the centripetal force exerted along the entire length of the cable.

The fabrication is a problem but progress is moving forward quickly on this front.

The cable can be inspected each and every time a lifter traverses the cable to deliver a payload. This will be one of it's tasks (video and image analysis software).

The cable will be shaped like an airfoil so that it always follows the prevailing wind at any altitude. This will mitigate any wind issues. Atmospheric conditions will not degrade the carbon nanotubes, but atomic oxygen outside the sensible atmosphere will be an issue to be dealt with. It oxidizes everything. Some kind of coating must be made to the cable.

The cable is not composed of a film. Cabon nanotubes are much, much stronger in tensile strength than steel at a fraction of the weight. Is steel a film?

The upper end of the cable does not need constant relocation. The anchor mass and the length of the cable result in a constant relationship with the ground (or ocean) anchor point. Thrusters are, therefore, not required.

The concept of moving large masses from the Earth's surface into space along such a cable aren't preposterous if you understand physics.

The issue of a lifter failing in mid-deployment is an issue, as will be a thousand other things, but this is the single best idea regarding space transportation in 60 years. It will soon be practical and the nation that does it first will have dominance in the field. We should be that nation.

The difficulties of developing the technology and means of launching the manned Apollo missions in the 1960s-1970s were far greater than the issues confronting the development of a space elevator using carbon nanotubes.

[struggle4progress]

25. Hmmm.

You say "The cable will be shaped like an airfoil" and "The cable is not composed of a film" but the original link indicates "The cable would be about three feet wide and thinner than a piece of paper." Something with those dimensions sounds more like a piece of "film" than an "airfoil."

You say "The anchor mass and the length of the cable result in a constant relationship with the ground (or ocean) anchor point." But there is no anchor in space: there is a 62,000 mile sheet with its top end in free fall, and there are constant transverse forces on the sheet from weather, which must tend to relocate the top end. So active measures are required to PREVENT constant relocation of the top.

You claim "The difficulties of developing the technology and means of launching the manned Apollo missions in the 1960s-1970s were far greater than the issues confronting the development of a space elevator using carbon nanotubes." It sounds great. But I don't believe a work of it.

[LastDemocratInSC]

31. Some more info for you

There are several competing ideas for the shape of the cable. One camp wants to spin the cable one strand at a time, sort of like how cables are spun on a suspension bridge, with the strand lifters becoming part of the termination mass at the end of the cable, but there are problems with a circular cable. Another camp wants to have an airfoil shape, for obvious reasons, and this always means greater thickness toward the leading edge than toward the trailing edge. A cable of this shape could probably be extruded somehow. In either case the cable must be considerably thicker at its midpoint than at its ends, hence it's not really going to be a "film" for a significant part of its length even if it is thin at the ends.

There will be an anchor mass at the distal end of the cable. This is required to balance out the mass of the cable and establish the correct conditions for centripetal force to keep the cable in a constant position with respect to the ground anchor. This mass can be modified by running masses up to, or away from, the anchor point with lifters. Fine tuning of this mass will surely be needed to accomodate conditions in and out of the atmosphere, such as when the sun reaches its maximum output again in a few years and the Earth's atmosphere reaches further out than it does now, introducing more drag on the cable.

If you read the history of the Apollo project (many great books on the subject) you'll learn that the methods of constructing the spacecraft, from the Saturn rocket stages, to the command module and lunar module, had to be invented after the construction contracts were let. The contractors literally had no idea how to make significant parts of the machines when they competed for the contracts. The methods employed by North American Aviation in building the second stage of the Saturn 5 rocket were radical advances in material engineering at the time. They stand alone even today in their brilliance. These tasks were every bit as difficult as those that will face space elevator designers.

Never say never when it comes to the dedication and brains of American engineering.

And don't believe me, for heaven's sake. Read about it yourself.

[Occulus]

44. It is a scientifically viable,

cheap, fast way to get into space... and you don't have to be riding a controlled explosion to do it.

This thing WILL be built eventually... it's only a matter of time.

[Thor_MN]

45. Better a space elevator than deploying a missle defense system

that doesn't work...

[Gregorian]

10. We can only hope they have better choice in music by then.

Oh goody, we can get on an elevator and go NOWHERE! Who'd have ever thought of something so useless. Let me guess- people who want to make money.

[lanparty]

14. Orbit isn't useless

A vast chunk of our communication infrastructure relies on orbit.

A space elevator will reduce the cost of getting things in orbit by a factor of ten or more. It may also make "space tourism" a practical reality. Tourists wouldn't be blasted off of the earth. The would be carried upwards on the elevator in their vessel. Than the vessel would carry them to the orbiting "resort".

[Gregorian]

34. Those ARE the very things I call useless

Food for starving humans? What about that. Communications and tourism- useless.

[belle]

42. !

[truthisfreedom]

17. will there be enough room for the surviving members of bushco?

maybe we'd be safer if we could simply put them in orbit somewhere, like so much space junk.

[mike1963]

24. I did read the whole thread. This is a very very old notion and a very

very impractical idea that will never happen. I'm not a Luddite, nor a tyro, I'm an aeronautical engineer and a realist. Whatever's at the end of this farcical 'tether' would have to be at the geosyncronous distance, about 23,000 miles and would have to be attached somewhere on the equator. And there's no way to "install" such a thing even if it could be constructed. Then there are the aerodynamic issues to consider, apart from meteorological anomalies, and the obvious vulnerability to impacts from earth and space-borne objects.

And there's the little problem of maintenance...how do you do repairs on something that's halfway "up"?

I wouldn't mind being proven wrong about this, but I'd bet everything I own it will never happen. It's in the same bag with time travel and teleportation. There really are some things that're impossible.
So sue me.
:eyes:

[rocketdem]

26. Exactly right.

It's a stupid idea.

I am all for considering new approaches and new ideas, but this one is so fraught with pseudo-science and impracticalities, it's not really worth even considering seriously.

IMHO, of course.

[mike1963]

27. Thanks...I probably should have added that if some entrepreneur wants

to try, it's no problem for me but I would strenuously object to any of my tax money being spent on it. (Like Star Wars as well for many of the same reasons.)
;-)

[jdj]

32. Not to mention the 20,000 children that starve to death daily.

Wonder how many this 10 billion could feed.

Hmm, let's see, starving children vs. mental masturbation...

[rocketdem]

33. Wrong argument.

How many more children would starve to death each day without the advantages that technology development has wrought?

Yes, there always is and always must be a balance between advancing towards the future and taking care of our responsibilities today. But it's far too easy to simply sit back and take snide pot shots at those at those looking ahead.

The total annual budget for NASA, for example, is on the order of $15 billion. Yes, that could feed lots of children around the world. However, that's only a fraction of 1% of the total federal budget. Surely we as a forward-looking society can dedicate less than 1% of our public resources for technology development in the realm of aeronautics, astronautics, satellite communications, weather forecasting, and earth sciences, let alone the exploration of our universe and the advancement of our fundamental understandking of our origin.

Go ahead and bemoan our misguided priorities as a society. I'll join you in your fight, but aim your jibes where they'll be most effective and most profitable. Don't just take aim at that which you see as the easiest target.

Yes, I still believe that the space elevator concept is stupid. But I think that for technological reasons. However, I applaud those with the imagination to at least dream of such things.

[LastDemocratInSC]

35. I don't think this is much of an aeronautical engineering issue

I think it's more of a material engineering issue, given that less than one percent of the cable's length will be subject to aerodynamic forces. I believe those forces could be significant, especially in storms, but the corrosive effects of atomic oxygen on the far greater length of the cable that is beyond the sensible atmosphere will be a more serious worry.

Let's talk about what must be done.

Carbon nanotubes must be constructed in vast quantities and lengths. They are now being used for a variety of commercial purposes and it's likely that, given the promise of this material in all kinds of applications, that efficient methods of creating them will be developed. This is analogous to the material engineering advances made with semiconductor materials when the promise of these was recognized in the late 1940s. The cost of manufacturing a working transistor dropped from tens of dollars in the 1950s to thousandths of a dollar in the 1980s, and even far less today.

The distal end of the cable is not at geosynchonous distance but well beyond it, at 62,000 miles. This distance allows the centripetal force on the cable and its anchor mass to achieve a stable relationship with the ground (or ocean) anchor point. Adjusting this anchor mass to accomodate changing conditions in "space weather" associated with the 11 year solar cycle must be figured out.

Something must be done to deal with strikes by manmade and natural objects. If a break occurs, the ends of the tethers will separate and move in different directions. Perhaps lifters can move quickly to the break points from both directions, and by using mass adjustments or thrusters, rendezvous and stitch things back together.

You said that a space elevator is in the same bag with time travel and teleportation. I don't think they are in the same bag at all because all the components of a space elevator can be constructed today, although on a very small scale. It's a matter of scaling a material manufacturing method up, and I think this will be done sooner rather than later.

I think that a space elevator would be more appropriately compared to where aviation was one hundred years ago. All the components could be constructed then, it was just a matter of doing it in the right order and form factor, solving some engineering issues and scaling it up to a practical level.

[Dr Fate]

30. Suuure they will. I'm still waiting for flying cars & robot maids...

They will make more bombs & shit before they do any of those things.

[belle]

40. OMG! It's "Charlie and the Great Glass Elevator!"

If only Roald Dahl could see this now...

[daleo]

43. Wouldn't this thing be vulnerable to terrorism?

I mean, how do you guard 63000 miles of cable. Granted, you would probably effectively only have to guard the bottom 8 or 10 miles, but that is a lot anyway. And, if the private space vehicles that we are hearing about become commonplace, you would also have to guard the first 100 miles, maybe more, depending on how these vehicles pan out.

It seems like it would be awfully easy to sabotage a multi-billion dollar piece of equipment. We can't even effectively guard the oil pipelines of Iraq.

From this point of view, the mass driver notion built into the side of a mountain seems more reasonable.

[Mr.Green93]

46. There will never be a "Space Elevator"