Can We Build A Space Elevator? | Earth Science
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- Опубликовано: 4 авг 2013
- Getting to space in a rocket is expensive! One of the most popular alternative ideas is the space elevator, but is it really possible?
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Развлечения
Sorry elevators broken, take the stairs
ShadowVyrus
Damn you... Damn you all to hell
Imagine hearing that 3 days into your trip up the elevator...
NOOOOOOOOOOOOOOOOO 😢😢😢
Stair time: 10 weeks
ShadowVyrus. 😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂
Im just here because I miss Top Gear
Sander Salumets I'm here because I miss the grand tour
252Scooby we still dont even have a trailer for season 2 yet
I come from the future to tell you that season 2 is live and seasons 3 will begin shortly.
I’m here because I miss top gear, and have watch all the grand tour episodes till fridays next. Which you all need to watch if you don’t.
Fel Hammer
And sadly season 3 is almost done probably.
I'm getting flashbacks of the New Mombasa Space Elevator from Halo
I also have flashbacks to that day
Same here
Same i came here from halo
Mmmm we're working on it!
Really!!
make a nightclub in orbit with a space elevator. partying in zero gravity hell yeah.
Funny enough as I watch this video I am reading (yet again) Arthur C Clarke's "Fountains of Paradise" which is about this very concept.
I don't know about balloons, but there have been some companies that have used jet aircraft (typically old strategic bombers like the B-52 or airliners with special modifications) to lift rockets to about 40 000 feet before launching them.
Upsides: "Re-usable 1st stage" i.e. the jet platform > lower costs
Caveats: 1000lb payload capacity
Examples: Orbital Sciences, which has the Pegasus platform
Weave the Kevlar strands into long cables. Then weave the cables together. Use the moon as a counter weight. Construct tracks on both the moon and earth so as the moon rotates it doesn't snap the cables. Also construct carbon nanotube sheilding to stop the space debris.
It baffles me that most people seem to ignore the fact that geostationary orbits happen at approx. 3Km/second speed. Climbing (or descending) such a structure (even if it could be built) is no "trivial task". You still have to gain that orbital speed and it ain't free. Newton's laws still apply (ie: F=ma). So supposing such an elevator were built and the climb began, where would that force come from ? If viewed from the rotating earth/elevator's frame of reference, the climbing elevator would experience a HUGE Coriolis force "pulling" in the direction opposite the rotation, and this force would have to be "countered". Of course Coriolis is an "apparent force", and can be explained by plain inertia if the system is observed from an "outside" inetrtial frame of reference. But either way, the elevator still has to reach orbital speed, which is why "ordinary" rockets need so much fuel to begin with. It's not so much about the "hight".
Im not fully confident i understood the concept but i think that at the point you reach geostationary altitude you are moving with orbital velocity (3km/s) in reference to the earth. In other words, if the earth had a 35k radius, its surfacevelocity would be 3km/s. Correct me if im wrong
Something I've always wondered why they've never tried: using electromagnetic mass drivers to assist the rockets during the initial phase of their acceleration so that less of their payload has to be fuel. If I remember right, these large railguns can't achieve escape velocity on their own, but we could significantly reduce the required fuel. Also, if you miniaturized it enough, you could install it in a 747 and launch stuff from 10,000 ft to cut that distance out as well; useful for small stuff
Haven't been "Squozen" since it became Brit Lab. Used to tune in because of vids like this from Capt. Slow. Space Lift is a fun "May" look at things. His humor still resonates.
"oh no, we've become tangled in the space rope"
Valued food for thought there. However what about electro magnetic propulsion?
It makes it sound like one of those platform games. You have to go to the further away bit, before you can even think about jumping on the nearer stuff.
James shirt looks absolutely mesmerizing when you press the POW! button!
I suppose that in the event that the cable was somehow snapped, we could design a complex rocket powered (yes, rockets) system to automatically put the counterweight into orbit with the earth, thereby avoiding it's fond farewell into the cosmos and giving us a chance to budge it back into place and repair the cable. :)
Something like that IS actually possible at this point in time; and with only one power station at that. The concept was actually fairly well flushed out in a game called "Ace Combat 5" and people are still debating it. The theory, as I understand it, would use large capacitors to store electricity over time. Once a sufficient amount of energy was stored, it was channeled into an electromagnetic mass driver, like a rail gun, to propel a single stage craft into orbit.
Time to start harvesting the 5000 tons of debris & junk already in orbit. Smelt it down for counterweight or materials for the waypoint.
That baby crab thing freaked me out. Kinda like the initial vampire scene in From Dusk Till Dawn...
When in the UK did we start using Dollars James?
+WhitwellMike B Soon, baby!
lol
+WhitwellMike B The US dollar is the standard international measurement for 'money'
WhitwellMike B they will after Brexit LOL
Why Saber?
thank you for support
Whenever James speaks, it's as though Shakespeare has reincarnated himself into the body of Mr. May.
6:34 if the cable snapped, the counterweight wouldn't be in a hurry to "fly off" into eternity. It's in geo-stationary orbit, it would (more or less) sit there waiting to be re-attached to a new cable.
You forgot to mention Sir Arthur C. Clarke, who in 1979 wrote a Sci-Fi novel about a space elevator rising from Sri Lanka to a satellite in geosync orbit.
Wonderful series Mr. May, thank you. Have you read red mars trilogy? The Marian colonies use a space elevator in the novels.
Building a space elevator is what the Tower of Babel was meant to accomplish. We could greatly increase the efficiency of launching things into orbit by building a very large gun, I don't know if a magnetic rail gun a few miles long could ever safely put humans into orbit. But we could launch all the necessary equipment for constructing an elevator for fractions of the cost of traditional rocket powered vehicles.
Imagine when we've figured it out. We have our Graphene cables that can be magnetized for power (or the solar lift version). Then we take this technology to another planet and eventually have these systems running from local planets to each other. Like a Solar system train route. Amazing thought.
Imagine the delays on those bad boys.
That... wouldn't exactly... work... at all.
Tying a rope to two planets is impossible because all the planets have their own orbital periods which are different from earth's, and in addition, different rotational periods. Even if their rotational periods were the same... it still wouldn't work because both objects being tethered would rip the rope/structure apart once either object turns around.
Also there would be the theoretical time it would take to get there. A space elevator or whatever, doesn't make the trip any faster, it just makes it easier to get into space more cost effectively. You'd be on that space train for years getting to another planet, or months to the moon.
Not to mention all the debris that would bombard it all to hell.
HOWEVER! It would be pretty sick if there was a train to Mars or something, but it would only work if all the planets didn't rotate, and if they all orbited the sun at exactly the same pace (wrong choice of word, they all need to be in a straight line, so their speeds would have to be at a pace that each planet orbits the sun in the same number of days), and if the elevator went straight through the core of each planet as a short cut of going around them :P
@@johnmichaelchase8530 Four years late I know, but it would kind of work. If you can get to escape velocity on an elevator it would then take relatively little energy in a conventional rocket to go from the top of one elevator to another, even if that second elevator is another planet, since in open space you need energy only to accelerate and decelerate. So your "affordable" interplanetary public transport network is just elevator up, rocket between planets, elevator down. Simple!
@@georgebateman3876 well sure, that all makes sense, but the original comment must've seemed to me back then to imply making a space elevator ALL the way to a different planetary body. For obvious reasons, that just wouldn't work lol
I don’t know why, but I laughed out loud at the idea of dropping a rope from space. That would either be a disaster if it fell into a populated area. Or the craziest amusement park ride if it worked.
He would be at geostationary orbit HEIGHT, but to be "in orbit" (in any orbit, not only the geostationary one) he would also need some speed perpendicular to the geodetic. Otherwise, like already said, he would fall down.
In the video it is clearly specified that to 'escape' gravity w/o entering a stable orbit you would need to go much higher (6:55)
The main challenge in building tall buildings is not how much weight the base has to support but rather the shear modulus of the building. For any cylindrical or cone shaped building, whether the building will topple over can be determined by whether (density * height^3)/(shear modulus * diameter^2) exceeds a certain amount. That amount is larger for cone shaped buildings than cylindrical buildings.
THANK YOU FOR DOING THIS!
I have always wondered this...Thanks for answering.
:)
2:11 if you didn't know, those building blocks are called "KEVA Planks". they're lightweight but very strong and well-balanced. you can't build into orbit with them, but if you're careful, you can actually build them to massive heights.
You're more than welcome. I also think the method proposed in Big Ideas was decent. That solar powered lift would be great if we can develop a newer carbon-based strength material similar to carbon fiber to act as the chain.
- Loyal Top Gear, Man Lab, Big Ideas, and Head Squeeze fan. And Redditor.
6:33 WRONG! The counterweight will only raise to a higher orbit. It will still be locked to Earth's gravity as a rotation per day at that altitude is not fast enough to escape earth's gravity; it will stay in geostationary orbit, just higher. We could just grab it again without much trouble.
Love your videos. Sure wish they were captioned for us who have hearing loss.
If you didn't know, those building blocks are called "JENGA Blocks". they're lightweight but not well-balanced. you can't build into orbit with them because they are simply blocks of wood used to play a game for amusement.
Anybody Viewing this from Ace Combat 7: Skies Unknown?
ah yes. ISEV
A man of culture
The "space elevator" actualized in a novel...
Arthur C. Clarke: "The Fountains of Paradise"
By climbing the cable you are actually doing that already. Think of it like holding a rope with a rock and the end and spinning, and a spider walking along the rope as its spinning toward the rock.
GEO, or gestational orbit, is important because it is the distance away the the orbital velocity is exactly the same as the spinning of the earth. (which is why people put satellites there because they can constantly be above the same spot on earth). So there is no work to be done once you get there,
I love how he always finds a way to tell us to subscribe!
The same side of the moon is always facing us, anchor the space elevator to the moon. I heard something about the number of plastic bottles that we use and so I'm sure we can make enough material to get to the moon and leave it. And we only need to have it reach down far enough to where those giant Red Bull balloons can reach. Remember Red Bull Stratos and the dude jumping from the edge of space? Have a balloon powered vehicle reach up and 'dock' with the space cable.
At the end I think you have it. Rockets are round why not a rail gun. (You might need 3 power plants at the site, but it should cut weight, then again why a cylinder you could shape a shuttle to fit a rail gun launch, does job, lands, refit, launch.). then use Buzz Aldrin's idea of using planetary slingshots to direct movement and orbits. or maybe instead of a oversized craft we can have small shells with a payload that once in orbit releases the shell and sends the payload in its like direction
Alright, my supervillainous plan to destroy humanity's first space elevator is possible! I just need to get people to Mars and build a space elevator there.
There is a solution which solves vitually all of these problems. It is called an orbital ring. Basically it's a ring constructed just a few hundred kilometers up (so out of the way of 99.9% of meteorites and junk), wouldn't need a super strong cable, and, by my calculations, could be contructed in such a way that it lifts itself into space. It would be nothing more complecated than a lightweight pipeline with magnetic particles inside and two meglev engines on either end with cables attached.
Centrifugal means center-fleeing, or pointing away from. Centripetal is center-seeking; meaning the rope always points towards the center.
One of the most interesting channels on youtube!
Damn james may saluting redditors, im surprised he isn't with the keanu chungus wholesome 100 gang
if the rope ever snaps, then the space counter gets flinged across like a discus being thrown. Throwing a high speed projective over space that probably wont stop until it hit something is always fun. It may even smash into some alien ships that are really really far away, and start a intergalactic war.
Uh no the rope would fall back to earth. The counter weight would be in geostationary orbit and won't be affected. When in geostationary orbit you are orbiting earth every 24hours, from the ground it would look like the satellite is stationary. The satellite would of course be in zero g while falling even while attached to a huge space elevator.
The earth is a rotating mass, and as such, the tower rotates with it. The farther away from the centre of rotation, the faster the rotation is. At that height, the speed that the tower rotates at the top is equal to an object's orbital speed at that altitude, so that's why stepping off the tower would be suffice to enter orbit.
You're right there is no centrifugal force (or a normal force in this situation). If you construct the freebody (a force) diagram in this case you just have two forces - the centripetal force provided by the cable tension and the weight of the elevator. Both these forces are directed towards the centre of rotation. I jump on my students for labelling a centrifugal force on a freebody diagram
Only Jeremy can build a space elevator
Fantastic episode.
Many years ago I read Arthur C Clarke's book The Fountains of Paradise. It's about space elevators. Clever man Mr Clarke
It should have been mentioned in this video! His detailed depiction of the space elevator is pretty much blueprint how it would be build. A must read for people who are interested!
Small maneuver rockets could be attached to the projectile to stabilize its orbit, but they would be much lighter than what is needed to punch from the ground through the atmosphere, and a supercomputer could compute the necessary muzzle velocity so that the payload is only a little bit off from the trajectory it needs.
If you're talking about the guy on the Jenga blocks, at that height, he would indeed be in orbit.
Excellent!
how about this; a cylindrical tower with cables fastened at the base running up the interior in cyclone pattern fastened to the interior walls to maintain the pattern but allowing the cable to converge until at geo stationary orbit, where the cables will meet some sort of space buoy the entire structure will act as an anchor and the weight on the base would be countered by the cable's upward pull.
I can see the collecting part being a big issue, but all you need is some sand paper to weld everything together.
I once had a looong discussion with a very experienced NASA engineer on the prospect of building space elevators. He saw no future in the concept at all because of the difficulties in engineering such a device.
James is definitely my favorite Top Gear host. Probably my favorite television host in general.
The materials for a six stage progressive diameter rotorvator exists already. It's not quite as cheap as a space elevator, but it's in the same ballpark.
spider webs for cables: its the strongest material on earth
simple physics. go iceskating and start spinning, like the earth, then extend one arm, like the space rope and the weight, and you will slow down.
if we model the rope as an ideal rope we will have two bodies orbiting each other and, ignoring every other body in the universe, using the equation of universal gravitation we can find the the speed of earth+weight will be a bit smaller than the speed of only the earth, and the rotation axis will be shifted a bit towards the weight
Unmanned drone balloons could dock and send up supplies, and manned balloon can bring astronauts. Relay, not one way.
This was fun!
Meteorite is a meteor that makes it to the surface of the earth so tieing a rope to it would be useless
Well there's a bit of a compromise solution. An Earth based mass driver, built into a mountain could launch a payload at fairly high speed and altitude. But it wouldn't get into space on its own, it would still need a rocket. But on the plus side, the construction would be cheaper than a space elevator (still enormous, on the scale of the LHC), cost less than rockets, use existing tech, and it would need significantly less fuel than a conventional rocket launch.
How will the elevator rotate earth? In order to secure it well enough, the support has to be very strong, and that would mean it'll have to be stationary. We can't really put a strong enough guiderail around earth either, because of tectonic plates, oceans and seasons. That means that there will be a pull on one side of the earth all the time using the earth's rotation. I can only assume that'll slow it down to a standstill, and that will be bad for us all.
The biggest hurdle to space elevator construction is that we don't have a material strong and light enough to build something that's several hundred or thousand kilometres tall. Carbon nanotubes or some modified grafite material could work well. Though we've yet to make something more than a meter long with carbon nanotubes and similar materials.
You don't have to launch all 5000 tons of the counterweight via rocket. You can launch a skinnier ribbon with a smaller counterweight via rockets (say, two launches of the Falcon Heavy), then have climbers add to the ribbon and counterweight in a bootstrapping process.
The quest for the necessary material is quite a challenge. It's driven me into a career in materials engineering so I can help in the creation of such a material and therefore make the space elevator a reality.
James did a segment on space elevators in Big Ideas. Worth checking out.
I have a question if its possible to answer. Rockets and other space equipment always go left or right after they leave Earth but if we launched a rocket into space and it had the fuel to keep going indefinitely so that the earth was always directly below the rocket (it went up in a straight line and didn't curve at all), how far straight up could it theoretically go? Same for the opposite, if we launched it into space and turned it straight down so it went below earth and kept going downwards.
Centrifugal force is an apparent force that causes an object to leave its centre of rotation. This is caused by inertia. In other words, centrifugal force is inertia, and in that sense, centrifugal force does exist (as inertia).
could we not acquire the counterweight material by mining rock off the moon? setting up a decent mining station on the moon may be costly and far off but it would be able to supply additional counterweights whenever needed.
Yay, I'm from SL too!
you could keep going straight up, but you would never reach orbit. only two outcomes are really possible if you launch straight up. either 1, you shut off the engines before reaching escape velocity, and your rocket goes up, then stops, then falls right back down. or 2, you keep firing until you reach escape velocity, at which point our trajectory would never bring us back to earth, and you fly of into space. all this is also true if you launch in the other direction as well.
Damn those rockets!
I remember seeing a concept design for electromagnetic slingshots to launch things into orbit. The g-forces meant it wouldn't work (yet) for humans, but for cargo it seemed feasible to my lamemind.
The majority of cost in a rocket launch is the hardware that you throw away when you drop a stage, the fuel for a average orbital launch is the same amount that you would have in a transatlantic flight in a 747. if we had only fuel costs it could be a mere 25 dollars per kilogram to low earth orbit.
No, in the case of the video, the centripetal force would be the earth's gravity curving the path of the object and thus keeping the object in orbit.
Centrifugal force does not exist as a force on its own, but is presented in this case as inertia, which would cause the object to fly out of orbit into space.
The guys at the Liftport Group are working on a Lunar Space Elevator that can be built with current technology before this decade is out.
Read Kenneth Oppel's 'Starclimber'!
I had the same basic idea several years ago as way to deal garbage. A giant mass if is sent up the tube, collected and when enough is collected, the mass is launched towards the sun and it burns up before it gets there. Problem is, New Jersey would run out of usefulness.
How would you change the orbital velocity of the items including the crawler as you raie or lower them along the cable?
Damn right.... the asteroid rodeo idea doesn't sound so silly now, does it?
Any time the word Centrifugal Force is used, what is really being described is a Lack of Centripetal Force. (from a mechanical engineering student)
Thanks so much guys
You'd think someone would come up with a good solution to two issues at once. Figure out a way to collect all that space debris and use IT as the counter-weight.
Amazing
Centrifugal is the normal force to a *centripetal force - it exists in so much as it's a name for a force.
Obviously, the ship itself would need to take some of the load about 2/3rds up the tower... and by then, the force of the launching system would be immense. The power of the rockets, with the power of the steam catapult from an aircraft carrier (multiple of them if possible), and the magnetic launch system, much like that currently found in a Mag-Lev train.
Creating spider webs in the lab and multiplying the diameter by several million would also create a strong enough material.
Liftport is working on Space elevator :)
the space elevator has tons of cameos in science fiction and popular culture...
Greek Week - Can we build a lift into space? - James May's Q&A (Ep 33) - Head Squeeze
That counterweight is going to ruin someone's day.
The only force acting on the mass would be the centripetal force going down towards the center of the earth. If you're going past earth's gravitational field, correct me if I'm wrong, the centripetal force would simply be the tension force in the rope.
it would produce tension, yes. My issue with this concept though is that the Earth is rotating on its axis, as well as revolving around the Sun. It's not as easy as James puts it.
So. The highest mountains have 8 km. We can surely add the 2km tall building to form 10km high structure. Maybe in the next century, we can get at least to the ISS.
I remember a Top Gear talking about a lift to space.. or maybe that was something you just did.. I forget.