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There's a good answer to this question here.

Those where the 2005 results the 2006 results where nearly there one team allready claimed it.
I'm looking forward to the 2007 result as this is a yearly even chek out here

http://www.elevator2010.org/competition.html

So not that beaten after all

Spectra is a mere 3.5G GPa UTS and *950* kg per cubic meter. You converted g/cm to kg/m^3 wrong. It's not even within an order of magnitude of what is needed. Furthermore, you represented SWNTs wrong. They're SWNTs, not graphite; it's a completely different form that just happens to use the same SP2 bonding structure. Their density is about 1300 kg/m^3.

Furthermore, while it's possible to build a space elevator with a nanotube cable that's only 65 GPa tensile, it's not realistic. It's also possible to build a space elevator out of kevlar. Your taper factor is just preposterous. LiftPort's numbers call for a SWNT fiber with strength 100-120 GPa, yet a total system cost in the tens of billions. You really can't get much lower of a strength and still have a remotely feasible business plan.

Now, the sad truth that Laine refused to address. Early after the discovery of SWNTs, there were all sorts of wild numbers for their strength produced, most around 120 GPa. That's not the reality of the situation. Modern calculations are only for 50-60 GPa, and that matches well what has been tested by using microscopic probes to break nanotubes. But it gets worse! The tubes cluster into ropes by pi bonding and vdw, and these aren't some sort of "reverse-wrap" ropes. Their strengths are only 3.6 += 0.4 GPa. Now, this can probably be improved, but it's obviously never going to surpass, and probably never even approach, the strength of the individual tubes. However, even ropes aren't the end of the story -- then you have to produce an *affordable fabric of an indefinite length* out of them, which puts yet another strength bottleneck into play.

Come on, Laine -- why didn't you address this? It's not like it hasn't been raised.

I think Liftport's development process can best be summed up as:

"In other news, my Teleporation Shoes are performing extremely well in tests. The shoelaces have survived twelve straight tying tests, including one "bunny ears" test conducted by a young child. Sole durability tests are also holding up well. Teleporation will be tested at some time in the future."

The competition was for building a vehicle to climb the ribbon, not making the ribbon itself.

There is a seperate competition for designing/making the actual ribbon.

Ref: http://www.elevator2010.org/site/competition.html

=Smidge=

Space Elevator Primer has all the basic questions answered. The worst that could happen is a few grams of ribbon will be spread over every few square kilometers!

The top half always escapes. The lower half flutters down reaching a top speed of 0.5 m/s. If a long piece happened to drape itself over a very tall building it might put a small load on it. This is a (OMG) PowerPoint on the risks that is very good. http://www.mit.edu/people/gassend/spaceelevator/SE C2005/BrokenElevator.ppt

I don't think the elevator would be made of such elastic material that a "whip" effect would occur. I won't claim to understand the physics, so I'll just quote the FAQ:

What happens if it breaks?

The short answer is that (much like the string-and-weight example) the portion of the elevator above the break point flies outwards, whereas the portion below the break point falls down to earth. We have to remember that the whole ribbon weighs only about 1000 tons (about the same as a Saturn V rocket) and has the density and consistency of Saran Wrap, so if it falls, instead of crashing down in one place it is distributed evenly around the entire planet, with each square mile getting about an ounce of debris. The overall effect will be like a very disappointing global ticker-tape parade - hardly a ground-shattering event.

The cable is not in contact with any moving surface. It's anchored to the Earth in some way. It then extends out past geosynchronous orbit so that the center of mass is located at geosync distance. Climbers are expected to take a couple of weeks to make the full climb to the end of the tether at which point anything they release will actually be moving fast enough to escape Earths gravity.

There is a ton of good info about space elevators out there - check out http://www.elevator2010.org/site/primer.html for a decent primer.

I believe that a space elevator is going to be the best method to get lots of mass into orbit, or out to a space station, quickly and cheaply.

A few groups are already testing and/or holding competitions to expedite innovations:

Lift Port:
http://www.liftport.com/index.php?site=news&news_i d=3

Elevator2010.org:
http://www.elevator2010.org/site/index.html

I think these monetary incentives to innovate are great. Nothing like a little competition to get people thinking creatively and working hard to realize their dreams. It has done wonders for the autonomous vehicle and commercial space shuttle fields, hopefully that will extend to all these other proposed areas.

One other piece of "future tech" I am hoping it will pay off in is the development of the first space elevator. Another organization has set up an X-Prize style competition, one every year until 2010 when I suppose they're hoping to have something viable. Probably a little overly optimistic, but competition brings out the best in people and I think it's great they are harnessing that power for good.

Go check it out: http://www.elevator2010.org/site/index.html They held their first competition last year. You can check out the results and see the pictures in the "Photo Gallery". Hooray for progress!

I think this is by far the best way to handle the problem :

http://www.elevator2010.org/site/competitionClimbe r2005.html

What I want to know is how a 2x4 is going to get out to the center of the pacific where they would build an elevator. Any elevater would be built close to the equator, most likely at sea. The bottom of the elevator would be tethered to a mobile platform that can be moved whenever there are major storms approaching. The information about this and how it would be accomplished can be found here

from http://www.elevator2010.org/site/primer.html
What happens if it breaks?
The short answer is that (much like the string-and-weight example) the portion of the elevator above the break point flies outwards, whereas the portion below the break point falls down to earth. We have to remember that the whole ribbon weighs only about 1000 tons (about the same as a Saturn V rocket) and has the density and consistency of Saran Wrap, so if it falls, instead of crashing down in one place it is distributed evenly around the entire planet, with each square mile getting about an ounce of debris. The overall effect will be like a very disappointing global ticker-tape parade - hardly a ground-shattering event.

They certainly do talk this one down... You have 1000 tons of cling film falling to earth. about 60 thousand miles of it, 3 feet wide, is a billion square feet of material. That is one hell of a ticker tape parade that would cling film a city.

What about turtles/manatees/(wont somebody please think of the children!) eating this stuff...

And will it be conductive? there is ordinace designed to take out power grids in just this fashion...

just thinking out loud...

Actually, the design for one of the ribbons was so thin and wide that the wind resistance alone meant that it fell at about the speed of a cardboard box.

See http://www.elevator2010.org/site/primer.html and http://www.liftport.com/faq2.php#science2 for starters, Google for more.

What really makes sense is an infrastructure that makes getting people and payloads in particular to and from space cheap and reliable, even ordinary. The only chance for that right now is a space elevator.

You have a 3% chance of death flying on a space shuttle. That's an incredibly poor record, and incredibly expensive.

http://www.elevator2010.org/site/ Has TONS of information on this. It is a contest site that has been mentioned here before a few times (I'm too lazy to look up previous articles). All of the materials are currently available to construct one. The movie on the site explains a space elevator in simple terms. I recommend watching it.

Ideally, mass would go up in our new sexy space elavator and people would go up in very safe and small rockets, and then rendezvous up in orbit.

Why do they say they're going to enter the material into some space elevator competition at the end of the article then?

For this year's space elevator tether competition (a collaboration between the Spaceward Foundation and NASA's Centennial Challenges), I think the tether doesn't have to actually be space elevator strength, it just needs to be stronger than everyone else's. As for following years, it needs to be the previous year's winner by 50%.

If at all plausible from a technical standpont, space elevators are probably the most sensible way for sending humans or loads to space. If you can't beat gravity, use it. Armchair engineers can send in their entries.

Actually, for the competition, We are only aiming for 1 m/s for 50m up a tether. Power will be supplied by a 1300W (or so) searchlight. Most groups will likely be using sattellite solar panels. In future competitions these are expected to be increased, and presumeably power will eventually be supplied using a laser. The winner will be determined by some combination of climbing speed and payload.

I expect that any groups that can meet the requirements specification (PDF) [http://www.elevator2010.org/site/documents/climbe r_rulebook.current.pdf ] will be in a good position, regardless of speed or payload.

BTW, I'm actually part of a UBC team building a climber, our website is here: http://www.physics.ubc.ca/~climber/index.html

According to the site linked from TFA: "What about space junk? ... the ribbon structure is resilient to hits from small debris." If one grain of sand would bring it down, it's doomed anyway. Also, a normal ballistic missile doesn't put a payload in orbit, just takes it up but without the velocity to stay there, so it falls back to earth in a few minutes.

Here is some money that NASA could "invest" in another x-prize like compitition.

They already are.

NASA's Centennial Challenges Program

2005 Tether Challenge

2005 Beam Power Challenge

Slashdot article from a few months ago

Granted, it'd be nice to see them offer more money, but Congress is currently keeping them from awarding prizes larger than a certain amount.

Here is some money that NASA could "invest" in another x-prize like compitition.

They already are.

NASA's Centennial Challenges Program

2005 Tether Challenge

2005 Beam Power Challenge

Slashdot article from a few months ago

Granted, it'd be nice to see them offer more money, but Congress is currently keeping them from awarding prizes larger than a certain amount.

from the site: http://www.elevator2010.org/site/primer.html
"# The ribbon is 62,000 miles long, about 3 feet wide, and is thinner than a sheet of paper. It is made out a material called Carbon Nanotube Composite. # The climbers travel at a steady 200 miles per hour, do not undergo accelerations and vibrations, can carry large and fragile payloads, and have no propellant stored onboard."
so lets see . . . 62,000/200 = 310 hours! how many times do i have to listen to Kraftwerk?

The Space Elevator is in fact such a case: think about the absolute nightmare a cable cut would be. I mean, all that has to happen is a plane goes the wrong way, or a meteor happens through the wrong area, or bad weather, or lightning, or god knows what. That cable is going to be seriously heavy - half a ton per mile, maybe more, even designed to be as light as possible - and it's flexible so it won't get brittle, and it's, well, long. So it starts falling to earth, right?

A space elevator that had the linear density you quote wouldn't be able to support it's own weight, let alone the weight of any climbers. Most estimates of the total mass of the elevator's ribbon are on the order of 1000 metric tons.

It's roughly equivalent to a highway just sort of coming out of the sky one day. There's pretty much nowhere you can put the space elevator where, if it gets cut, it's not going to cross some urban areas; the Earth/Moon lagrange 1 point is about 200,000 miles above Earth - enough to wrap around the planet a little over eight times. That's how it would fall, too - it'd be dragged behind a planet moving forward, and would wrap around under its own momentum, like a whip.

So, you've got a highway coming down, in bands, around the Earth eight times. Right through the middles of cities. Over the ocean. Into parks, monuments, farmland. Cutting cities in half. Killing tens of millions.

This is one of the largest and most common misconceptions about a space elevator. A broken space elevator would not kill tens of millions of people. In fact, a severed space elevator would likely be a disappointing anti-climax, as the powerpoint file on TFA shows. Impact occurs at 0.5 m/s (that's the terminal velocity of the ribbon).

Following is a modified version of a submission from last month, relevant to this discussion. I believe Edwards' group is planning on competing in the competition. Hopefully congress will lift the $250K prize restriction, allowing NASA to award larger prizes and truly stimulate research in this area:

MSNBC, Space.com, and Wired report that NASA, in collaboration with the non-profit Spaceward Foundation, has announced its first two Centennial Challenges. The Centennial Challenges, inspired by the Ansari X Prize and DARPA Grand Challenge, are prize contests seeking to stimulate private industry development of technologies relevant to space exploration. One contest is the Tether Challenge, for building the sort of super-strong tether needed to make a space elevator feasible. The other is the Beam Power Challenge, for creating a wirelessly-powered ribbon-climbing robot capable of lifting as large a payload as possible within a limited timeframe. The initial set of challenges in 2005 will award $50K to the winners of each contest. A second set of challenges in 2006 will award first, second, and third place prizes worth $100K, $40K, and $10K. It's hoped that these contests will further space elevator technology and help eliminate the 'giggle factor' surrounding them. Additional contests will be announced in the coming weeks, although Congress currently restricts NASA from awarding prizes of more than $250K; the agency is lobbying to try to get this limit raised to $40 million for future prizes.

I submitted this story a couple of times yesterday, but it sadly wasn't accepted. Maybe it was too long or had too many links? In any case, here's a copy, which has a little additional info:

MSNBC, Space.com, and Wired report that NASA, in collaboration with the non-profit Spaceward Foundation, has announced its first two Centennial Challenges. The Centennial Challenges, inspired by the Ansari X Prize and DARPA Grand Challenge, are prize contests seeking to stimulate private industry development of technologies relevant to space exploration. One contest is the Tether Challenge, for building the sort of super-strong tether needed to make a space elevator feasible. The other is the Beam Power Challenge, for creating a wirelessly-powered ribbon-climbing robot capable of lifting as large a payload as possible within a limited timeframe. The initial set of challenges in 2005 will award $50K to the winners of each contest. A second set of challenges in 2006 will award first, second, and third place prizes worth $100K, $40K, and $10K. It's hoped that these contests will further space elevator technology and help eliminate the 'giggle factor' surrounding them. Additional contests will be announced in the coming weeks, although Congress currently restricts NASA from awarding prizes of more than $250K; the agency is lobbying to try to get this limit raised to $40 million for future prizes.

Thank you for posting the real link for this story.

To everyone who is positing various ways of transmitting power wirelessly, they already have a method in mind:

Showcasing the first representative prototypes of Space Elevator climbers, this event will re-define public perception of the Space Elevator project by taking the first step away from mathematical models and drawing boards and into the world of real working hardware. By participating, you get the opportunity to partner in writing this unique chapter of history.

The competition provides the race track, in the form of a crane-suspended vertical ribbon, and a strong light source to power the climbers. Competing teams provide climbers, which have to use the power beamed to them and scale the ribbon while carrying some amount of payload. Climbers will be rated according to their speed and the amount of payload they carried.

The climbers (unmanned, of course) will weigh 25-50 kg [50-100 lbs], and will ascend the ribbon at about 1 m/s. [3 feet per second or 2.5 MPH]

The beam source is a 10 kWatt Xenon search-light (80 cm beam diameter, about 25% efficient), which should yield a climber power budget of about 500 watts.

The ribbon is roughly 30cm (1 foot) wide by 1 mm thick, is about 60m (200 feet) long, and is tensioned to about 1 ton.

Building a climber is not an easy task. The designers have to juggle light weight structure, efficient photo-voltaic arrays, efficient motors and power electronics, low-loss traction mechanism, thermal management, and control systems.

Not a walk in the park, but we'll make it worth your while. We will be offering $50,000, $20,000 and $10,000 to the 3 best teams.

link:click here

The competition rules are at the bottom (pdf). Frankly, this sounds more like a college/high school technology building competition than an X-prize.

What's 'spaceaward'? "The Spaceward Foundation is a public-funds non-profit organization dedicated to furthering the cause of space access in educational curriculums and the public." [found in NASA's press release: M05-083]