SPACE ELEVATOR

Have you ever wondered a large rope reaching from the surface of the Earth to distant Space ???completely insane right ?? ok check this one, what if a rope from the surface of earth to space do exist and an elevator carrying payloads and men ascents on it?? hmmmm...do u think its a science fiction....well check it out then... 

SPACE ELEVATOR:

A climber or an elevator ascend a ribbon or a rope, 100,000 km long, strung between an anchor on Earth and a counterweight in space. Connecting Earth and space in a way never before possible, the space elevator will enable us to inexpensively and completely expand our society into space.

The biggest drain of energy takes place when a vehicle or a rocket blasts off, pushing through Earth’s

gravitational pull.It requires great amounts of fuel, but once it get out of our atmosphere, the rest is easy.If you could cut out that blast off portion, space travel would be easier and much more fuel-efficient.

In a Space Elevator scenario, an elevator would ascend up the side of an exceedingly tall structure and reach a transfer point where they would then board a craft to the Moon, Mars, or any other distant destination.

A space elevator made of a carbon nanotubes composite ribbon(rope) anchored to an offshore sea platform would stretch to a small counterweight approximately 62,000 miles (100,000 km) into space. Mechanical lifters attached to the ribbon would then climb the ribbon, carrying cargo and humans into space, at a price of only about $100 to $400 per pound ($220 to $880 per kg).

Space elevator would consist a counterweight  attached at other end.The counter weight is generally past the geosynchronous orbit of earth.

For the construction of space elevator the following building units are important:

·         Base Station

·         Cable

·         Lifter

·         Counter Weight

·         Power Beam

BASE STATION: The base station designs typically fall into two categories—mobile and stationary. Mobile stations are typically large oceangoing vessels, though airborne stations have

been proposed as well. Stationary platforms would generally be located in high-altitude locations, such as on top of mountains, or even potentially on high towers.

Mobile platforms have the advantage of being able to maneuver to avoid high winds, storms, and space debris. While stationary platforms don't have these advantages, they typically would have access to cheaper and more reliable power sources, and require a shorter cable.

HOPE THERE TRAIL BRINGS SPACE ELEVATOR INTO REALITY WHICH THEY HAVE ALMOST ACHIEVED.....

SPACE ELEVATOR- A bridge between Earth and Space.....

SPACE ELEVATOR RIBBON OR CABLE:

As stated earlier the material for cable or rope or ribbon is carbon nanotube.

Carbon nanotubes have a potential to be 100 times stronger than steel and are as flexible as plastic. The strength of carbon nanotubes comes from their unique structure which resembles like a football.

LIFTER OR CLIMBER:

A climber is generally a robotic lifter which ascends on a stationary rope. In an ordinary elevator lifter is stationary and rope moves through pulleys. But in case of space elevator rope is stationary and lifter ascends by powering it up by powerind beam.





POWERING BEAM:

In general, a solid state laser or electron laser is used to power up the lifter. The lifter is attached with photo voltaic array. The flashed laser beam is made to focus on this photovoltaic array. This array transforms the energy bfrom the laser beam and gives it to motors which ascent the lifter.

COUNTER WEIGHT:Several solutions have been proposed to act as a counterweight:

·         a heavy, captured asteroid

·         a space dock, space station or spaceport positioned past geostationary orbit; or

·         an extension of the cable itself far beyond geostationary orbit.

The third idea has gained more support in recent years due to the relative simplicity of the task and the fact that a payload that went to the end of the counterweight-cable would acquire considerable velocity relative to the Earth, allowing it to be launched into interplanetary space.

FAILURE MODES,SAFETY ISSUESAND CONSTRUCTION DIFFICULTIES:

As with any structure, there are a number of ways in which things could go wrong. A space elevator would present a considerable navigational hazard both to aircraft and spacecraft. Aircraft could be dealt with by means of simple air-traffic control restriction but impacts by space objects pose a more difficult problem.

SATELLITES: In nothing were done, essentially all satellites with perigees below the top of the elevator would eventually collide with the elevator cable. Twice per day each orbital plane intersects the elevator, as the rotation of the Earth swings the cable around the equator.

CORROSION: Corrosion is a major risk to any thinly built tether (which most designs call for). In the upper atmospheres, atomic oxygen steadily eats away at most materials. A tether will consequently need to either be made from a corrosion-resistant material or have corrosion- resistant coating, adding to weight.

RADIATION: The effectiveness of the magnetosphere to deflect radiation emanating from the sun decreases dramatically after rising several earth radii above the surface. This ionizing radiation may cause damage to materials within both the tether and climbers.

OTHERS: A space elevator would present a navigational hazard, both to aircraft and spacecraft. Aircraft could be diverted by air-traffic control restrictions. All objects in stable orbits that have perigee below the maximum altitude of the cable that are not synchronous with the cable will impact the cable eventually, unless avoiding action is taken. Impacts by space objects such as meteoroids, micrometeorites and orbiting man-made debris, pose a more difficult problem

ECONOMICS:

With a space elevator, materials might be sent into orbit at a fraction of the current cost. As of 2000, conventional rocket designs cost about $11,000 per pound ($25,000 per kilogram) for transfer to geostationary orbit. Current proposals envision payload prices starting as low as $100 per pound ($220 per kilogram),similar to the $5–$300/kg estimates of the Launch loop, although nowhere near the $310/ton to 500 km orbit quote to Dr. Jerry Pournelle for an orbital airship system.

Philip Ragan, co-author of the book "Leaving the Planet by Space Elevator", states that "The first country to deploy a space elevator will have a 95 percent cost advantage and could potentially control all space activities.”

SCIENTISTS AT NASA ARE ALREADY ON A MISSION TO TURN THE SO CALLED SCIENCE FICTION INTO FACT.THEY HAVE CONDUCTED EXPERIMENTS BY BUILIDING UP A BABY SPACE ELEVATOR.

BABY SPACE ELEVATOR

 

If it all sounds like too much science fiction, take a look at the requirements for making the Space Elevator a reality. A new material has been developed, however, called carbon nanotubes that is 100 times as strong as steel but with only a fraction of the weight.
A carbon nanotube is an idea that makes this all sound much more achievable.
In this concept, which is very fuel efficient and which brings space tourism closer common man uses the newly added concept of nanotubes to light.

STRUCTURE OF SPACE ELEVATOR: