# Universe In a Nutshell, Space Elevator – Science Fiction or the Future of Mankind?

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 billionare

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

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 billionare

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

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