NASA Report: Only 50 Years Away
This August, NASA scientists put the concept on paper for the first time in a report designed to assess if building an elevator to space is possible and what technologies would be needed to make it possible. The verdict? In a little over 50 years, with a little bit of luck and a lot of research, people could be paying the future equivalent of $5 a pound to take the longest, most exciting elevator ride of their lives.
Scientists estimate the journey to literally the beyond would take just over 24 hours.
The idea is to work on intermediate concepts and then in 50 years well hopefully start working on building this thing, says David Smitherman, a scientist working in the Advanced Projects office of NASAs Marshall Space Flight Center in Alabama.
Smitherman admits his 50-year prediction is a little optimistic. The scope of the proposal is unprecedented and daunting. Construction would entail extending a 22,000-mile-long cable from a 20-mile-high or higher tower at the Earths equator to a level in space known as geosynchronous orbit.
Objects at geosynchronous orbit travel at a speed that matches the spin rate of the Earth. That means the orbital station astronauts would construct at the far end of the space elevator would hover in a straight line over its base on Earth.
To keep the extremely long cable from tumbling to Earth, a large weight possibly an asteroid would be attached to the far end. The pull of that object trying to spin off into deep space would counter the pull of gravity that would tug the cable at increasing levels closer to Earth. Both forces would keep the connecting cable taut and allow it to escort electromagnetic cars that would shuttle back and forth through tunnels in the cable.
Its like building a skyscraper in reverse, explains Pearson. At the top you have the thickest point and below theres a cable hanging.
Feasible or Farfetched?
If this idea sounds like science fiction, thats because it has been. Arthur C. Clarke wrote about the concept in his 1979 book Fountains of Paradise after reading the technical paper Pearson finally managed to publish in a physics journal in 1975. The book captivated the imagination of hundreds of thousands of readers and some believe the idea will be limited to peoples imagination for many more than 50 years.
Its fun to talk about, says John Pike, director of space policy at the Federation of American Scientists. But I would put this whole thing strictly in the category of conjecture.
There are countless problems to overcome, including finding ways to construct such a long structure in space and then maintain and protect it from passing space debris. But one of the first concerns is creating a material that would be strong enough to withstand the extreme pulling forces at either end of the elevator line. Pike jokingly calls this substance unobtainium.
But Richard Smalley, who won the 1996 Nobel prize for chemistry for his co-discovery of carbon nanotubes, claims creating a strong cable to space is, in fact, possible.
I dont think its unrealistic at all, he says. He explains that carbon nanotubes, which are elongated configurations of carbon atoms, now have nearly 200 times the strength of steel. Although they are prohibitively expensive to create at this point (as Pike says, Carbon nanotube is a polite way of saying diamond), Smalley predicts in 10 to 20 years, new methods will make it affordable to build enough for a 22,000-mile connector to space.
I believe it is quite likely that ways will be found to produce such cable cheaply, and in quite adequate amounts, Smalley says.
Space Tethers and 20-Mile-High Towers
Smitherman further adds that scientists are already working on many of the technologies a space elevator would need for other innovations. For example, NASA and the U.S. Air Force have been experimenting with long tethers that generate their own power by using the Earths magnetic field. These tethers are intended for reboosting a space station like Mir or the International Space Station, or for directing a satellite in orbit. The same tether technology could be used in the space elevator concept.
NASA engineers have also spent time designing a so-called launch arch that would provide a 10-mile perch from which space vehicles could bolt into space. Although the tallest freestanding tower today is just over a quarter-mile-high (the CN Tower in Toronto is 1,814 feet high), Smitherman says current construction materials are already good enough to build a tower several miles high. By adding ultra- strong and -light materials to those designs, he says, those heights could easily be extended to offer a launch arch or a space elevators 20-mile-high perch.
Of course, none of this technology comes cheaply. And one of the looming questions surrounding the space elevator proposal is would it really be worth the trouble?
If it works, Smitherman and Pearson argue that it would be worth the trouble because moving people and cargo in a space elevator would cost drastically less than blasting them off in a fueled spaceship. The innovation could lead to an entirely new way of life, they say.
In fact, Pearson is fond of thinking about the return of the pioneer family. Just as families packed their belongings in covered wagons and ventured into the American West in the mid-1800s, Pearson imagines the space elevator could allow a similar group of daring settlers to pack themselves into an elevator car and create a new society in the final frontier.
Id like to see the modern-day pioneer be able to settle into space for a years salary, he says. Sure, its in the far future, but its possible.