08-16-2017, 10:55 PM
INTRODUCTION
The story of Jack and the Beanstalk is starting to sound more and more plausible every day. A huge, tall structure comes out of the ground and goes straight up through the clouds; at the end is a wonderful, mysterious castle. Experts agree that the biggest drain of energy takes place when a vehicle blasts off, pushing through Earth's gravitational pull requires great amounts of fuel, but once they 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, a Maglev vehicle would zoom up the side of an exceedingly tall structure and end up at a transfer point where they'd then board a craft to the Moon, Mars, or any other distant destination. 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.
CHALLENGES FACED BY SPACE ELEVATOR
The major challenges faced for bringing this concept to light are
2.1 Atmospheric issues
Lightening, clouds, winds. Historic data maps shows lightening occurs a land masses ,less on mountains and least along equator, further experimental cables don't attract lightening ,winds aren't a factor since it is capable of withstanding wind spend of 71m/hr and hurricanes not a problem since they form and travel outside the equatorial region.
2.2 Impact or Collision
Big issues requiring more study .Debris is monitored using radar. Stud between Debris and meteors indicate space debris to be more hazardous .It must be noted number of impacts on ribbon, not as important as degradation cost due to impact.
2.3 Health issues
Fiber health focuses on three things, dose, dimension and durability .The bigger ones can't be integrated and smaller ones appear to dissolve quickly.
DIFFERENT CONCEPTS
3.1 LOW EARTH ORBIT CONCEPT
The LEO space elevator is an intermediate version of the Earth surface to GEO space elevator concept, and appears to be feasible today using existing high-strength materials and space technology. It works by placing the system's midpoint station, and center of gravity, in a relatively low-Earth orbit and extending one cable down so that it points toward the center of the Earth and a second cable up so that it points away from the Earth. The bottom end of the lower cable hangs down to just above the Earth's atmosphere such that a future space plane flying up from the Earth's surface would require 2.5 km/sec less change in velocity than a single-stage-to-orbit (SSTO) vehicle launched directly to LEO. The space plane and LEO space elevator combination would likely be able to carry 10 to 12 times the payload as an equivalent-sized SSTO launch vehicle without the LEO space elevator. The length of the upper cable is chosen so that its endpoint is traveling at slightly less than Earth escape velocity for its altitude. This is done so that a spacecraft headed for higher orbit, the Moon, or beyond, can be placed in the proper orbit with only minimal use of its onboard propellant.
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