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  • It's hard to get to space

  • As much as we all wish there were an easy,

  • and affordable way to see our planet floating in the dark

  • Right now, the only way is to become an astronaut or a billionaire

  • But there is a concept that might make it possible

  • -while serving as the starting point for the exploration of the universe-

  • The space elevator

  • How exactly does it work?

  • To understand how a space elevator will get us into space

  • We must first understand what an orbit is

  • Being in orbit basically means falling towards something,

  • but moving fast enough to miss

  • If you throw a ball on earth it makes an arch through the air,

  • and then hits the ground

  • In space, gravity makes you move much the same way,

  • but if you move sideways fast enough

  • the curvature of the earth makes the ground fall away beneath you

  • as fast as gravity pulls you towards it

  • So, to enter Earth's orbit rockets have to go up

  • and sideways fast

  • By contrast, a space elevator taps into energy from Earth's rotation

  • to get the cargo going fast

  • Imagine a child spinning a toy on a rope with an ant on the child's hand

  • As the ant climbs out along the rope

  • it starts to move faster and faster as it ascends

  • Compared to rockets, with cargo launched on an elevator

  • you only need to provide the energy to go up

  • Fast sideways movement comes free with the Earth's rotation

  • But the space elevator would without a doubt

  • be the single largest and most expensive structure ever built by humans

  • So, is it worth it?

  • It all comes down to costs

  • Rockets burn a huge amount of rocket fuel

  • just to get a small amount of cargo into space

  • At current prices, it costs about $20,000 to put one kilogram of payload into space

  • that's $1.3 million dollars for the average human

  • $40 million dollars for your car

  • billions for an international space station

  • This immense cost is one of the major limitations of human spaceflight

  • Even with advancing technology,

  • this cost isn't likely to be comparable with the price of an airline ticket anytime soon

  • A space elevator would solve this problem

  • After construction,

  • a space elevator is projected to reduce the cost one hundredfold to $200 per kilogram

  • If an inexpensive space elevator costs 20 billion dollars,

  • then we'll recoup our losses after launching only one million tons

  • Close to the weight of two international space stations

  • So what would a space elevator look like in real life?

  • A space elevator has four major components:

  • the tether, anchor, counterweight and climber

  • The elevator part of the space elevator is the tether and the climber

  • It extends from the surface of the Earth to space

  • The climber is like a conventional elevator carriage

  • A chamber that works its way up and down the tether

  • At the base would be an anchor

  • pinning the tether to the Earth along with a port for climbers

  • At the top is the counterweight which holds up the tether

  • The tether is held tight like a rope

  • and supported from above by the tension from the counterweight

  • Located higher than 36,000 kilometers above the Earth's surface

  • At the counterweight could be a space station,

  • a launching point for all missions from the spaceport elevator

  • But can we actually build one?

  • It's hard to say

  • The biggest challenge is the tether

  • It needs to be light, affordable

  • and more stable than any material we can produce right now

  • There are promising materials like graphene and diamond nanothreads,

  • but even they may not be strong enough

  • And aside from being incredibly strong,

  • the tether would also have to withstand atmospheric corrosion, radiation

  • and micrometeorite and debris impacts

  • Additionally, it takes several days to climb the elevator

  • How do we power the climber?

  • It requires a lot of energy to go up

  • Do we need a nuclear reactor on our elevator carriage?

  • Or do we beam it power from the ground with a super powered laser?

  • And where do we get the raw materials for a 36,000-kilometer-long tether?

  • Do we make it on Earth and launch it into space?

  • Or do we make it in space and lower it down to the Earth?

  • Could asteroid mining be the answer?

  • Put simply, there are still some major technological hurdles to overcome

  • And a space elevator is not without risk

  • Should the tether break, it would collapse in spectacular style

  • If it breaks near the anchor

  • the force exerted by the counterweight will cause the entire elevator to rise up

  • ascending into space

  • Should it break near the counterweight

  • the tether will fall,

  • wrapping around the world and whipping the end off

  • The resulting debris in orbit could pose serious problems to future spaceflight

  • If we build a space elevator on Earth, we have to do it right the first time

  • For these reasons some experts have proposed first building

  • a space elevator on the Moon

  • The Moon's gravity is much weaker than the Earth's

  • so a flimsier but existing material like kevlar

  • could serve as a tether

  • Even with all these challenges,

  • the payoff of having a working space elevator would be immense

  • It might be the first step to truly becoming a space-faring civilization

  • Maybe we will never build a space elevator,

  • but in trying to do so we might learn an awful lot

  • And when it comes to the exploration of the universe,

  • there can't be too many dreams of a glorious future

  • Subtitles by the Amara.org community

It's hard to get to space

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Space Elevator – Science Fiction or the Future of Mankind?

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    mommy posted on 2016/04/12
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