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Space Elevator – Science Fiction or the Future of Mankind?

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    It's hard to get to space
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    As much as we all wish there were an easy,
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    and affordable way to see our planet
    floating in the dark
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    Right now, the only way is to become
    an astronaut or a billionare
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    But there is a concept
    that might make it possible
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    -while serving as the starting point
    for the exploration of the universe-
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    The space elevator
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    How exactly does it work?
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    To understand how a space elevator
    will get us into space
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    We must first understand
    what an orbit is
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    Being in orbit basically means
    falling towards something,
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    but moving fast enough to miss
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    If you throw a ball on earth
    it makes an arch through the air,
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    and then hits the ground
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    In space, gravity makes you move
    much the same way,
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    but if you move sideways fast enough
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    the curvature of the earth makes the ground
    fall away beneath you
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    as fast as gravity pulls you towards it
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    So, to enter Earth's orbit
    rockets have to go up
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    and sideways fast
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    By contrast, a space elevator
    taps into energy from Earth's rotation
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    to get the cargo going fast
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    Imagine a child spinning a toy on a rope
    with an ant on the child's hand
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    As the ant climbs out along the rope
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    it starts to move faster and faster
    as it ascends
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    Compared to rockets,
    with cargo launched on an elevator
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    you only need to provide
    the energy to go up
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    Fast sideways movement comes free
    with the Earth's rotation
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    But the space elevator would without a doubt
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    be the single largest and most expensive
    structure ever built by humans
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    So, is it worth it?
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    It all comes down to costs
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    Rockets burn a huge amount of rocket fuel
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    just to get a small
    amount of cargo into space
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    At current prices, it costs about $20,000
    to put one kilogram of payload into space
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    that's $1.3 million dollars
    for the average human
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    $40 million dollars for your car
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    billions for
    an international space station
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    This immense cost is one of the major
    limitations of human spaceflight
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    Even with advancing technology,
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    this cost isn't likely to be comparable with the
    price of an airline ticket anytime soon
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    A space elevator would solve this problem
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    After construction,
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    a space elevator is projected to reduce the cost
    one hundredfold to $200 per kilogram
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    If an inexpensive space elevator
    costs 20 billion dollars,
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    then we'll recoup our losses
    after launching only one million tons
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    Close to the weight
    of two international space stations
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    So what would a space elevator look like
    in real life?
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    A space elevator has four major components:
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    the tether, anchor, counterweight
    and climber
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    The elevator part of the space elevator
    is the tether and the climber
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    It extends from the surface of the Earth to space
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    The climber is like a conventional
    elevator carriage
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    A chamber that works its way
    up and down the tether
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    At the base would be an anchor
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    pinning the tether to the Earth
    along with a port for climbers
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    At the top is the counterweight
    which holds up the tether
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    The tether is held tight like a rope
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    and supported from above
    by the tension from the counterweight
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    Located higher than 36,000 kilometers
    above the Earth's surface
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    At the counterweight
    could be a space station,
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    a launching point for all missions
    from the spaceport elevator
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    But can we actually build one?
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    It's hard to say
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    The biggest challenge is the tether
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    It needs to be light, affordable
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    and more stable than any material
    we can produce right now
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    There are promising materials
    like graphene and diamond nanothreads,
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    but even they may not be strong enough
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    And aside from being incredibly strong,
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    the tether would also have to withstand
    atmospheric corrosion, radiation
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    and micrometeorite and debris impacts
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    Additionally, it takes several days
    to climb the elevator
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    How do we power the climber?
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    It requires a lot of energy to go up
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    Do we need a nuclear reactor
    on our elevator carriage?
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    Or do we beam it power from the ground
    with a super powered laser?
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    And where do we get the raw materials
    for a 36,000-kilometer-long tether?
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    Do we make it on Earth
    and launch it into space?
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    Or do we make it in space
    and lower it down to the Earth?
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    Could asteroid mining be the answer?
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    Put simply, there are still some major
    technological hurdles to overcome
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    And a space elevator is not without risk
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    Should the tether break,
    it would collapse in spectacular style
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    If it breaks near the anchor
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    the force exerted by the counterweight
    will cause the entire elevator to rise up
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    ascending into space
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    Should it break near the counterweight
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    the tether will fall,
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    wrapping around the world
    and whipping the end off
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    The resulting debris in orbit could pose
    serious problems to future spaceflight
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    If we build a space elevator on Earth,
    we have to do it right the first time
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    For these reasons some experts
    have proposed first building
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    a space elevator on the Moon
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    The Moon's gravity
    is much weaker than the Earth's
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    so a flimsier but existing material
    like kevlar
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    could serve as a tether
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    Even with all these challenges,
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    the payoff of having a working
    space elevator would be immense
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    It might be the first step to truly becoming
    a space-faring civilization
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    Maybe we will never build
    a space elevator,
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    but in trying to do so
    we might learn an awful lot
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    And when it comes
    to the exploration of the universe,
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    there can't be too many dreams
    of a glorious future
Title:
Space Elevator – Science Fiction or the Future of Mankind?
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Space Elevator – Science Fiction or the Future of Mankind?

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Video Language:
English
Duration:
06:32

English subtitles

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