Space Elevator vs Wildlife

An anonymous reader writes "The longest test yet of the technology that might one day lead to space elevators has revealed some unusual problems. From the article: "There were several unexpected encounters with wildlife. More than a dozen insect egg colonies had been laid on the tether and curious bats flew around the balloons, apparently attracted by the sound made by the tether's vibrations. Late in the test, swallows were also seen swooping down on the balloons, possibly to sip the morning dew on their surfaces." Maybe all the critters just want to go to space too."

Comments

It's Probably a Valid Concern

[eldavojohn]

From an industry report I found sometime ago on Slashdot:

Among the small wonders produced by nanotechnology are carbon nanotubes, an advanced material as strong as diamond. These amazing carbon cylinders possess 100 times the tensile strength of steel and are 10,000 times finer than human hair. They are believed to conduct heat better than any other material, and they can also conduct electricity or function as semiconductors.

"Nanotubes are astonishingly promising, and I'm a realist, not an optimist," says Rod Ruoff, a mechanical engineering professor at Northwestern University. "It's a question of making the technology cheap enough." In 2001, only 3 kilograms of the highest quality carbon nanotubes--the single-walled variety--were produced worldwide, each gram worth $300, or 30 times as expensive as gold.

Now, full-scale production of carbon nanotubes is underway at the world's first ever large-scale nanotube factory, built outside Tokyo by the Carbon Nanotech Research Institute, a subsidiary of Japan's Mitsui & Co. The new facility is expected to churn out 10 tons of carbon nanotubes--albeit the lesser quality multi-walled type--a month, and CNRI anticipates the price will be a much more reasonable $80 a kilogram.

These multi-walled carbon nanotubes may not possess all the impressive properties of their single-walled brethren, but mixed with plastics, they make ultrastrong composites or microscale precision parts. Such carbon nanotube-filled plastics are already being used by automakers in fuel lines because they are conductive and can thus be grounded to release static electricity, which can ignite flammable gasoline.

But this LiftPort PDF states:

One issue brought up is the possibility of discharging the ionosphere. Our calculations based on the size and conductivity of the ribbon and the electrical properties exhibited in our upper atmosphere illustrate that a small area (square meters) around the ribbon could become discharged in the worst conditions. The magnitude of this discharging makes us believe with high confidence that no adverse local or global phenomenon will occur. It also shows that it is unlikely, without considerable effort, that any kind of usable power may be generated by this same method.

I think your concern is valid though for conduction through the ionoshpere or even on the surface of the nano tube/wire -- what would this huge antenna/conducter do to our atmosphere (if anything)?

Re:Time.....

[jimstapleton]

actually, they'd be able to travel faster because there would be more accelleration time. It would take just over ten seconds at 1G (2G force on the passangers) to get to a velocity of 100meters per second, at which point you have 360,000 seconds, or 100 hours. Now with a lower accelleration, but a longer acceleration, that could be cut down significantly. Once acceleration stops, you are back to 1G (minus the effects of your distance from earth).

Re:robot tests are dumb

[dfenstrate]

I think you mean two orders of magnitude off, not 100.

That being said, how far off were we when this idea was first concieved, or practical work began? A factor of 1000? 10,000 ?

Anyway, we do stuff like this because it's fun and achievable. Most people who follow this sort of thing know that material strength of tether is the current limiting factor, and there is ongoing research in this field.

But there are plenty of people who don't have the expertise to contribute to the material strength problem, but they can sure have fun screwing around with climbers, can't they? The work has to be done sometime anyway.