Les ascenseurs spatiaux pourraient bouleverser les choses en rendant les voyages spatiaux plus facile et moins coûteux que jamais auparavant. Imaginez éviter le coûteux carburant des fusées et simplement vous rendre dans l'espace en utilisant de l'électricité. Ce n'est pas seulement une question d'économie - cela pourrait conduire à une toute nouvelle ère d'exploration et d'industrie spatiale, avec plus de satellites, de stations spatiales, et même de vacances dans l'espace à l'horizon. De plus, c'est écologique comparé aux lancements de fusées traditionnelles, ce qui est un avantage pour la planète. Bien qu'il reste encore de gros obstacles à surmonter, comme la construction de matériaux super résistants, l'idée des ascenseurs spatiaux est excitante et pourrait changer la donne pour les aventures de l'humanité au-delà de la Terre. Animation créée par Sympa.
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Musique par Epidemic Sound https://www.epidemicsound.com
Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna
----------------------------------------------------------------------------------------
Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
Instagram: https://www.instagram.com/sympa.officiel/
Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
https://www.shutterstock.com
https://www.eastnews.ru
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Si tu en veux encore plus, fais un tour ici:
http://sympa-sympa.com
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FunTranscript
00:00If you want to travel in space, prepare to spend about 55 million dollars.
00:07But in the near future, you will probably be able to travel in space by simply pressing a button without ruining yourself.
00:14Because space elevators could come into play.
00:18While the idea of a galactic elevator seems to come out of a science fiction movie,
00:22it is a real possibility that could revolutionize space travel.
00:26With an estimated cost of 8 billion dollars,
00:29such an elevator could only represent a single investment that would last us forever.
00:37NASA alone spends about 2.7 million dollars on rocket fuel every minute of flight.
00:44To launch a rocket, they must spend up to 178 million dollars.
00:50These costs could be considerably reduced if we used elevators.
00:54Most of the tallest buildings on Earth have massive foundations to help balance their weight.
01:00The more you look up in the air, the smaller they get.
01:03Even the highest skyscraper in the world, Burj Khalifa, is thick at its base and thin at its top.
01:10If we wanted to build something that looked like a gigantic elevator,
01:15we would need a huge amount of concrete to build the foundations.
01:20Which goes against our original goal of saving money.
01:25Now, take a string, attach a ball to its end and start spinning it.
01:31The string in your hand will stay in place and the ball will spin around your hand.
01:35This is what is called centrifugal force.
01:38And the elevator will work the same way.
01:40The ball will be a base in space and the rope will pull towards the ground.
01:46The station through which we would enter the elevator would be located in the middle of the Atlantic Ocean
01:52and the cable would extend from there.
01:55For this to be possible, it must be perfectly synchronized with the rotation of the Earth.
02:01Otherwise, it will simply break or roll around the Earth like a whip.
02:06In addition, the orbit followed by the cable should form a perfect circle
02:11because the line could neither shorten nor extend.
02:14Many calculations have been made in order to find the ideal solution.
02:18Wait a minute.
02:19This is what algebra is for.
02:21Who would have thought?
02:23In the meantime, we will not bore you with more mathematics.
02:27Let's address directly the precise distance between the Atlantic Station
02:31and the one in space, which must be 36,000 km above the Earth,
02:36where the geosynchronous orbit begins.
02:40There, the four ascending forces are much stronger than the only descending force.
02:46This is why the station would remain in place.
02:49When you build a house or a building,
02:52you start from the bottom and progress upwards.
02:55But to create this marvel of engineering,
02:57we would need to go the other way around and start from the top.
03:02The main problem here would be the weight.
03:06If the line was too heavy, it would disturb the orbit
03:09and the lift would not work.
03:12We would therefore need to balance the space station
03:15to ensure a flawless operation.
03:20Steel is one of the most robust materials on Earth.
03:24The cable of each elevator is made of steel.
03:27But when you need a cable 36,000 km long,
03:31things can get a little complicated.
03:34Steel is difficult to break, but it is bulky.
03:37And when you have to use a lot of it,
03:40that's when problems start to arise.
03:43We use a lot of steel in construction,
03:46but we have lighter materials at our disposal
03:49that could exert less strain on the station
03:52and eliminate this problem.
03:54In addition, the cable should be fused
03:56because at the end the constraint would be practically non-existent.
04:00But it should always be thicker than necessary
04:03due to many safety factors.
04:06At first, the cable would be barely more than 1 mm thick.
04:10After a lot of complicated calculations,
04:12we can determine its size at the end of the race,
04:15which represents a number so long
04:17that we would be unable to pronounce it.
04:20But believe us, it is a very, very large number.
04:23So steel is out of the question.
04:25Another candidate is Kevlar,
04:27which is five times more resistant than steel.
04:30If we added materials such as carbon and titanium to this alloy,
04:33its resistance would still be doubled.
04:36The cable would then have a diameter between 80 and 170 m.
04:40It is much smaller than the diameter of a similar steel cable.
04:45The bad news is that it would cost too much.
04:49So, if we do not find the ideal material to build this cable,
04:54the very idea of a space elevator
04:56will never be more than a vast waste of time.
05:01If only we had a light, miraculous material at hand,
05:05capable of absorbing a pressure of 60 gigapascals,
05:09and which would also have a conicity ratio of 1.6.
05:13Oh, but wait, we do have such a material.
05:17These are called carbon nanotubes.
05:20They have a resistance of 130 gigapascals,
05:23which is much more than what we need.
05:27Nanotubes are made from carbon,
05:29and are 100,000 times thinner than human hair.
05:32This material is solid and has a good conduction capacity,
05:36which is made possible by its unique atomic structure.
05:40We use this innovation in many things,
05:43from batteries to optics,
05:45and they can be completely modified and adapted to many other uses.
05:50Bradley Edwards is the man responsible for this idea.
05:53NASA was looking for new innovations and told him,
05:56do not try anything too crazy
05:58and just start building a space shuttle.
06:01We suppose that Bradley had to take this as a challenge,
06:04because he started working on the elevator.
06:06Edwards therefore wrote an article on a galactic transporter.
06:10When he published it,
06:11he expected that many experts would wash away the flaws in his work.
06:15But surprisingly, no one did.
06:18His concept was irreproachable.
06:21He therefore had the idea of attaching a line of nanotubes to a rocket
06:25and propelling it into space.
06:27The other end of the cable would fall back on Earth,
06:30and robots would use the latter to climb it
06:33and lengthen it so that we could start building a space station.
06:37After that, the elevator could start moving everything and anything,
06:42from solar panels to tourists.
06:44In the future, space tourism could become accessible.
06:48Who knows, we could even go on vacation in space one day.
06:51Hey! Are you looking for an escape atmosphere?
06:54Well, don't come here, we don't have any.
06:57Oops, probably not the best advertising slogan, is it?
07:02A few years ago,
07:03we could only create microscopic carbon nanotubes.
07:07But over time, more research has been done to make them bigger.
07:12Today, they reach a few centimeters.
07:15In 20 years, they could be several kilometers long.
07:19Carbon costs $1 a gram.
07:21If we did the math,
07:23we would see that it would take us about $1 billion to build this elevator.
07:27Yes, it seems expensive,
07:29but it is a long-term solution for space travel,
07:32which could save us a lot of money.
07:35Everything looks perfect on paper.
07:37But the main reason why NASA chose not to pursue this project
07:42is that at the moment,
07:43there are probably more than 128 million debris floating in the Earth's orbit.
07:48And it could pose a real threat to this elevator.
07:52It could, of course,
07:54be designed to resist a few impacts from time to time.
07:58But being constantly bombed was not part of the equation.
08:01Nevertheless,
08:02Bradley supports that an armada of surveillance devices detects these spatial debris.
08:06Thus, the elevator could be able to avoid them all.
08:12If something hit the elevator,
08:15or if the cable broke in one way or another,
08:18the consequences would not be too severe.
08:20Finally, if there were no passengers on board, of course.
08:24If the line was cut,
08:26the elevator would simply drift into space
08:28and would not pose any threat to anyone.
08:31In Japan, engineers are trying to build a space elevator.
08:36This one could also be used for mining in space.
08:41We could easily cover the cost of this elevator
08:43by catching asteroids on the way,
08:45because some of them are made of precious metals.
08:48We could then exploit them
08:50and quickly repatriate them to Earth.