By Raquel Lima*
The project engineer Israeli is one of the futuristic ideas and seemingly crazy to take people and cargo to space.
Enter the lift, press the button “space” and enjoy a trip of up to 100 thousand kilometers by the cosmos.
To you that idea is just crazy or something from science fiction movie?
But for the Israeli space engineer living in the United States Ben Shelef the proposal is viable and yes invention may well be ready sooner than many people imagine: in 2020. But how is that the lift that will work?
In the exclusive interview Scenario XXI, Shelef explained that when we talk about space elevator, we can not think of the conventional lift that we used to use.
Their equipment and their operation are obviously more complex. In addition, there will be ascensorista in command (or pilots). The transaction will be made through a cabin of command.
Following Israel’s projects, the elevator is going up to space by a sliding cable, which will have 100 thousand kilometers long, which is more or less one third of the distance from Earth to moon.
This cable (which Shelef calls “ribbon”) will be made of carbon nanotubes (class of molecules discovered in 1991), highly resistant material.
The lift itself would be done with material regularly used in the aerospace industry, such as aluminum and titanium, and would be composed of a large photovoltaic panel to capture light and produce electrical energy, and electrical motors. Para voltar à Terra, o elevador usaria o mesmo cabo, mas sem precisar dos motores. To return to Earth, the elevator would use the same cable, but without the engines. The speed of the lift on cable will be constant, leaving around 200 km/ h.
However, its speed in the lateral direction (around the Earth) will increase to the extent that they depart. “As the lift will follow the rotation of the Earth, the higher it is, the faster it will move,” explained the engineer.
We understand? Then imagine a wheel spinning.One point that is at the outer rim will rotate faster than a point closer to the axis, because the two points give a full lap at the same time, but the length of the circle in the outer rim is larger than the circle next to the shaft.
Following the same principle, the tip top of the lift will be rotating with a speed greater than the Earth.
And where would be the starting point for the lift? Shelef said that a vessel will be located in the eastern equatorial Pacific Ocean.For several reasons: there, the tsunamis are less intense, no formation of hurricanes, is far from airports and creates certain degree of difficulty to a terrorist attack.
Initially, the space elevator is designed to carry only cargo (up to 20 tonnes per trip), such as satellites, for example. But the intention is that the invention can also lead people to a walk in space. Questionado on how long someone could travel by elevator, Shelef brincou: “To get hungry or wanting to go home.” When ready for tourism in the cosmos, the lift will have the entire structure of a space module, ensures the Israeli engineer.
To develop, build and operate the space elevator, Shelef estimates that it would take $ 10 billion. Think much? The engineer thinks not: “It’s much cheaper that the International Space Station (which consumed about R $ 220 billion) or develop a new type of aircraft,” he argued.
It is not yet possible to think what would be the price for a person traveling on the space elevator. “It is a calculation that involves other costs, such as insurance, life,” justifies Shelef.
If we succeed, the space elevator will present some advantages over the Rockets. One, and perhaps the main, is that by being fed the ground, the elevator not need fuel load. Already the rockets, which currently represent the only way to move people and material into space, traveling more fuel than payload.
The inventor said that, for now, laboratories engaged in production of the cable “ribbon”. At the same time, the engineer is involved in the Spaceward Foundation, the organization which is co-founder, dedicated to spreading the exchange of information on the subject.
If the space elevator in fact succeed, that old warning: “Make sure it is stopped this floor” should begin to be taken into account, does not it?
Technology of the Future
Anthony Bertachini Prado, professor of the National Institute of Space Research (Inpe), said:
“When considering the proposal as part of science, there is no absurdity in the design of the space elevator. But when we think technologically, it is extremely advanced. Just to give you an idea, the radius of the Earth is 6.7 thousand km in length and the cable suggests that the engineer is 100 thousand kilometers in length. They are almost 15 times more. Of course it is not possible to say that this will never exisitir, but difficult to think that by 2020 will be ready. There are many details that need to be analyzed. So, I think that would be a project for more than a hundred years. Being something bold, yet I see as a science fiction”.
Specialist says that everything is merely a delusion
More light and sturdy as the steel and wire thinner than a hair in about 100 thousand times, the nanotubo carbon is identified as one of the greatest discoveries to be applied in the area of information technology projects and more daring, as dreamed lift space. It is not for less: it is one of the harder material known and have a high mechanical strength, coupled with a high flexibility that supports without breaking even at high pressures.
However, the scientist Daniel Ugarte, the National Laboratory of Light Síncrotron (LNLS) and the State University of Campinas (Unicamp), considering that the production of carbon nanotubes currently is expensive, and energy consumption, and limited to centimeters. Remember that the draft Ben Shelef provides 100 thousand kilometers of cable. “This elevator is a delusion.A silly without size, “said Ugarte, who has achieved international recognition for his research with atoms and molecules of carbon and their strange properties.
“The production of a cable of nanotubo carbon to the elevator require a perfection of the material, a purity, which are not yet able to do,” said the expert.
The carbon nanotubes also can be drivers of electricity, insulating, semiconductors and superconductors until (if subjected to low temperatures).
This behavior of paradoxes can be explained by the geometry assume that the nanotubes: if the object presents a particular geometry, it is insulating, presents another geometry, it is driver. Scientists, however, still do not know how to control the forms assumed by the material accurately. Ugarte provides that this area occurs in the medium or long term.
* Raquel Lima, brazilian journalist of Egency Anhanguera, Brazil