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

Channel: Kurzgesagt – In a Nutshell

Views: 4,612,579

Rating: 4.9689107 out of 5

Keywords: space elevator, space, science fiction, mankind, death, universe, space travel, space ship, star, sun, earth, future, far future, star wars, nasa, space x, rocket, rocket science, physics, elevator, tether, anchor, counterweight, kurzgesagt, in a nutshell, science, fantasy

Id: qPQQwqGWktE

Length: 6min 32sec (392 seconds)

Published: Fri Apr 08 2016

Reddit Comments

[u/VeryLittle]

This is definitely my favorite Kurzgesagt video yet. I'm about to hang up that "ANTERING HYPERSPACE" frame in my office.

[u/snuffybox]

Question, would moving things up the tether cause a loss in rotational energy for the earth? Similar to a figure skater moving their arms out to slow down. Would this be a significant amount?

[u/MIllawls]

Not even a minute since upload and it's already on Reddit.

[u/BoogsterSU2]

If we build a Space elevator, we should board all the flat-earthers as their first customers.

[u/uzingniga]

People here are talking about costs, but are ignoring the fact that there is no material with enough strength capable of being used as a cable. From a material science standpoint, a "space elevator" is impossible with current technology, let alone cost.

[u/PM_ME_HEALTH_TIPS]

If you can figure out the tether you could also look into things like space solar power because it would be easier to get the energy back to earth.

[u/iSlacker]

That Starcraft reference tho.

[u/UScossie]

They overlooked one of the biggest problems with the concept, the Van Allen belt. Due to the speed limitations of the climber it will spend a long time in the Van Allen belt exposing it to enormous amount of radiation, far more than what is considered safe for humans, thus it could be used to transport goods, but not people.

[u/Evilchickens]

There are huge problems with a space elevator design. Firstly low orbiting objects will impact the tether damaging it or more likely completely destroying a section. It also takes a over a week to ascend to GEO in which time you will have spent a lot of time in the Van Allen belts, areas of high radiation. The dangers, cost, complexity and general difficulty in construction of a space elevator make it all but useless for earth (Although the moon and mars are far easier).

There are other options. Laser launchers increase the 'effective' energy density of a rockets propeller by transmitting it from the ground. Space fountains use materials and technologies that exist right now, but is maybe a little on the crazy side. Also several others.