Honestly one of the top five channels on UA-cam! There's nothing better than a channel that consistently puts out a ton of great content that you don't have to wait long for. Thank you for doing what you do
Not to mention the positive messaging of humanities future. If more people caught on to the idea it does not need to be terrible, we would have more people moving in the right direction.
True. Also this is one of the few channels that will be resistant to the inverse square law. Adding more people will only skew the poll results at first, but I dont see Issac straying too far from the spirit of the channel no matter how many people flood in.
Yes - I've seen the name Sun-Earth L2 en.wikipedia.org/wiki/List_of_objects_at_Lagrange_points Sun (primary) - Earth (secondary) L2 (second of the five Legrange points as the tertiary point)
There will still be a few humans who will push the "up" button repeatedly, thinking that will get them there faster. 😉 Can't thank you enough for this brain-stimulating content, Isaac! Excellent as always, Sir. 🌌
Learned new things in this one. Never thought about taking Earth's gravity into account when contemplating a Moon Space Elevator. Always learning on SFIA. Great work, Isaac.
Anybody who says the sentence “but let’s discuss the basic lunar elevator” officially out of my league. I still bite my tongue when I’m eating food I like.
I just want to say that i truly appreciate your channel a lot. It's one of the best channels out there and very educational and touches on one of my favorite subjects space and the technology coming with it thank you
just an idea: several lunar elevators (at least 4). make 2 towers (>10km)on the poles of the moon, one on each pole. and from each tower 2 elevators. one to L1, the other one to L2. the towers should be able to move a slight bit because they have to hold the elevators steady. these towers could then also be the anchor points of a lunar orbital ring that goes vertically from north to south. hopefully, there is an orbit similar to the sun synchronous orbit on earth. from there, they can send tethers down to many points on the surface, and it would make surface to surface transport very easy.
The mass driver would be first, because a killer ap for the Moon industrial park is volatiles for propellant and life support and construction materials for cislunar infrastructure, and you can build gobs of them for the price of a skyhook or space elevator, especially if you're trying to build the orbital stuff out of pre-mass-driver priced material. The mass driver makes elevators and skyhooks cheaper, so that's how you would bootstrap things: 1. ISRU extraction (volatiles for propellant, life support; agregate for mooncrete/moonmortar, moonbrick; metals, etc. 2. Start churning out mass drivers. 3. Use mostly Moon materials to build a rotating skyhook for Earth in the Lunar orbital plane. 4. Close the inner loop with an Earth-Moon L1 space elevator, mostly for traffic down to the Moon's surface. 5. Close the outer loop with an Earth-Moon L2 space elevator, mostly for traffic to the cislunar system from the rest of the Solar System. (You launch outbound traffic from mass drivers.) Of course, You'd be doing other things with the Lunar mining, manufacturing, fabrication, and construction in the meantime, but we're discussing transportation infrastructure on the Moon. The Moon becomes the rail and industrial hub.
I'm not a fan of lunar space elevators (rotovators make more sense, IMO), however you missed one of the lunar space elevator's party tricks: If you extend beyond L1 much more than is required for counter-weight, you can extend all the way into low Earth orbit. The "orbital" velocity, given the 29 day period, is tiny, allowing it to work in much the same way as the lower tip of a static orbital tether. Rockets from Earth require an order-of-magnitude less energy to dock with the tether-tip, compared to going into a proper orbit. There's a limit to how close you can get, since the moon's orbit is not circular, so the lower tip will drift closer and further from Earth each month. But theoretically, you could even use that to dip into the Earth's atmosphere once a month.
We will have mass drivers long before space elevators. I dimly remember an article in Analog probably 40 years ago that actually talked about the possibilty of a reverse mass driver for landing space craft on the lunar surface.
Thank you, Isaac. Tethers and sky-hooks have been concepts that fascinated me for a long time. "There's no such thing as a free lunch." ~ You haven't looked into tethers yet, have you? If you have the right mix of loads, you can actually generate energy with tethers, sell that off as electricity.... It would take a lot of energy to get them up there and working, but as long as you are mining on the moon, and shipping material back to Earth, that will provide energy to maintain the tether. Then you can use it to launch smaller loads from the middle to an upper atmosphere to a stable low earth orbit. The tricky part is it's like a plate-spinning act in a magic show, you've got to watch and manage a number of complicated dynamics at the same time. But as long as you can orchestrate the movements, it really is a free lunch.
@@isaacarthurSFIA ~ It has been a while, I'm rusty, but I think you can do a pure kinetic rotivator right down to the moon surface and off it, as long as you balance the loads. You need as much going down as you have coming up, or you need some external thrust for your tether. You can't drive it by electro-magnetism either, as you say. If it gets a bit out of whack, you have to apply thrust to correct and you have to do it pretty fast. Like I said, it's like spinning plates. But unlike on Earth, you can operate the thing right down to stationary pick-up / drop-off right on the surface. On the down-side, if you get the sums wrong, imagine 5,ooo miles of the cables that hold up the Golden Gate, falling down across that city, first parts going fairly slowly, but the later parts moving at 34,ooo km/h or so .... Exactly how far along the surface that could spread out and wreck stuff, I don't know, but I think it would rival SFO's big Earthquake that's coming. You could do a mind-boggling amount of damage with that. Have you read DiskWorld, and the shade squares come down and so do their cables?
Could you catch an aluminium spacecraft on lunar elevator with a magnet? Similar to the trick where you try swing an aluminium sheet through a horse show magnet which makes it stop.
You can, but it isn't optimal. Using aluminum limits decel speed by how much eddy current waste heat you can radiate away & the MP of aluminum. Also using a magnet, especially the superconducting variety, let's u do regenerative braking to recover almost all of the kknetic energy of the payload. Fine for a first go, but probably not what u stick with for any length of time
The more i think about it, it seems Mars should be very secondary to a lunar base in many ways. It seems like we have a much better chance of getting a lunar base up and running thrn moving out to mars and the Jovian moons.
mars is so dumb as a first step. Grav wells are for suckers &, other than a small base, most people who live in the mars system will probably live on/in/near it's moons for the near to medium future(next several hundred years at least)
If you thought a regular space elevator's dynamics were hard to manage... That would be doable, but would be a pretty absurd megaproject. If you plan on moving vast quantities of material it is a great idea, and doesn't need any exotic materials. The issue is that it doesn't scale down particularly well. It really wants to be as close to symmetric around the planet as possible. Any failure to distribute the loads will result in flexing, and that would be bad. It really wants to have base stations distributed around the planet, and thousands of them. It is probably how you would go about dismantling an entire planet, but up to that point I don't see it having upsides that make up for the complications it brings. On the plus side, you might actually be able to build it without putting anything into space. Imagine you have a hyperloop setup that has a continuous ribbon of magnetic tape running through it, suspended by superconductors. You could accelerate this to ~20km/s, and then gradually raise the whole thing on tethers. If you can build a near enough frictionless pipe this could be extremely useful, because you stop caring about material properties at all. That makes it a viable structure even in the atmosphere of Jupiter (though then you are talking more like 200km/s, and having that much mass going at speeds where the speed of light becomes relevant means it could go very badly wrong, but it could work in theory with materials we have now!). While a space elevator is a megaproject because it requires a complete covering of a 1 dimensional line between the surface and geostationary, such a project does not really function without a complete covering of a 2 dimensional plane. It is vastly larger than project than a single elevator, though in theory much simpler. It would also fail even worse than an elevator; if it does the entire structure fails! That would be bad.
L1 isn't the anchor. It's better to think of it as the mid-point: you need a whole other tether beyond L1 to counter the weight of the mass of the tether between L1 and the moon. Same as you need the same weight of tether/anchor beyond GEO for a space elevator to Earth.
well clearly L1 moves as the lunar orbit isn't circular. I'm aware of the mass needed earthside of L1. I am surprised that there will be significant slack at periapsis that must be taken in at the base!
I dont know if this is appropriate or not to say but i've become so used to Isaacs speech impediment that i see it almost like just another accent. Just like a british accent i now associate it with intelligence. Keep up the great work.
Same! I NEVER struggle to understand him anymore. Probably his friends and family do not either. I wonder if he has become clearer, or we have become more attuned?
Near the end of this universe, if there's no barrier or one that "we" can pass through, can we go start over in another younger universe carrying the knowledge and skills that we would have before the exit? Head start?
I firmly believe that a Lunar Space Elevator is more practical than an Earth version. The Earth-bound version is a huge risk if it goes wrong, whereas a Lunar version is safer.
Since the Lagrange points are for the Earth Moon system, which other uses might the Earth want for Lagrange 1? You need development on multiple faces of the moon, and the lunar speed rails need to carry both people and materials or finished goods to the equator. I'd still focus on idustrializing the moon first and once the moon has operations throughout, it probably gains the support to build. It's actually my same strategy for trying to justify building one in Equador. Once the trade throughout Latin America is all lawfull and there are secure property rights and you have other trains and activities occuring throughout the land funneling resource to Quito, you can have one for Earth as well if they are possible.
Couldn't a space tether also be a power generator in Earth Orbit, power is obtained via electromagnetic induction of the elevator crossing the Earth's magnetic field. Remember an unsuccessful Italian experiment, facilitated by NASA space shuttle mission researching such an option.
Every time people talk about time travel I cannot avoid thinking- earth rotates on it's own axis at around 1000 miles per hour (at the equator), also oscilates a bit and it's also affected by the movements of the moon. It rotates around the sun, in what we know as a solar year at around 67000 miles per hour. The sun does a galactic rotation every 225-250 years around the galaxy at around 490000 miles per hour. We also know that the solar system is moving towards the Leo constellation at around 242 miles per second and the whole galaxy is moving towards the Great Attractor at about 621 miles per second. Obviously those are only the most noticeable movements, but the position of earth, the solar system, the galaxy, local group, etc. are affected by any strong enough gravities, giving them additional movements to take in to consideration. So, my point is, (and by all means, I understand the fun part of futurism might be the "science fiction" part) before we talk about time travel, we need to talk about the mastery of space, not only as in "space travel", but pretty much as a part of reality we can trivialize. Pretty much instant teleportation if we think about it.
I would think that since the space between Earth and the Moon is essentially "weightless," having a continuous bridge between them seems massively pointless, even if you have the means to do it easily. It seems much more practical to just have a system where an Earth elevator moves a craft to an ideal distance into space, and then "flings" it toward the moon at a particular speed, and then a complementary elevator from the moon will "catch" that pod, with all the relative speeds being balanced so that from the perspective of the pod, it would feel no change in acceleration at any point in the journey, and would be internally identical to if it had been a continuous elevator, and require zero fuel (aside from some back-up fuel for emergencies). It would be similar to those devices that launch a ball bearing off a roller-coast style rig, and then the bearing flies through the air and lands on a similar roller coaster style rig, with no significant impact when it lands, because the angles are calculated out.
One fun thought is the way you could launch large space ships is using a space fountain to lift them off the surface of the moon in either earths orbit or from the backside of the moon to set the ship into solar orbit and then accelerate to a faster speed
sorry to call you out, but at 11:45 you said the JWST was at the Earth-Moon L2 point, ~200,000 miles beyond the moon. Isnt it actually at the Earth-Sun L2 point, about 1.5 million miles beyond Earth's orbit?
I think that the best option for a rocketless launch assist system on the moon is actually a launch loop. A system that doesn't support launching and landing on the moon is far less useful than one that does. Also if the payload has to be a certain shape makes it even less useful. My option would be to use starship to establish industrial capacity on the moon and constructing a launch loop, on the equator, raising up to 20km from the surface where it would avoid any craters (saving you the pain of building multiple Km long supporting towers),launching you straight to orbit with no orbit raising required and ships could dip their periapsis and match speed with the platform and be caught by tethers. They would then apply regenerative breaking to slow down. The reverse for launching. At one G accel,it would need to be about 285km long (including safety margins). At 3 G's,you could get away with 120km. And i would prefer to be capable to have about 150 tons of payload capacity,the mass of a starship or its payload. If you got that then you go for an orbital ring,which straight up beats any space elevetor in every scenario i can think of. Orbital rings get far too little attention,and more episodes about them would be very welcomed.
All this makes me wonder. What will industrialization look like in space? Transformation and refining of in-situ materials. Metal forging, machining, 3D printing? Solar powered forges? Laser ray casting? Construction from raw materials in space is an interesting topic in itself as well. And also the collection and transformation of useful materials for space agriculture and generation of living organic matter. Nitrogen, oxygen, carbon dioxide, phosphorus, calcium...
Hi Mr Arthur, could you cover exotic weaponry some day? Like the monopole cannons and cosmic strings from the xeelee sequence, or other similar spacetime-messing weapons. Cheers, and keep up the quality content!
Because the moon is tidally locked with Earth, space elevators will only function on the side of the moon which faces away from Earth. any point, from limb to limb, as long as there's clean access to the elevator's intended altitude, the elevator should be able to have enough centrifugally induced tension for the tether to work. Any attempts to fly the tether toward Earth will result in the tether not being able to achieve centrifugal tension, resulting the tether's collapse. All tethers must extend parallel to the line of centrifugal force, along the Earth/moon tidally locked line.
No, an L-1 elevator has the same requirement as an L-2 elevator. You need enough of a net counterweight Earthward of L-1 to tension an L-1 elevator, just as you need enough of a net counterweight outward of L-2 to tension an L-2 elevator. The engineering case of the L-1 elevator is tensioned by an overbalance of Earth gravity, whereas the L-2 case is tensioned by an overbalance of centrifugal force. The libration points are DEFINED as the balance points where the vector sums of both gravity fields and inertia allows a trajectory motionless with respect to the Moon. Inward (Earthward) from L-1 at the same radial velocity (Moon's "RPM" around the Earth) an object will immediately tend to bend it's trajectory toward the Earth more sharply than L-1s path, because inward from L-1 (the balance point between Earth gravity on the one hand and the sum of Moon gravity and centrifugal force on the other hand), the balance is tilted in favor of Earth gravity. It's not orbiting fast enough in that place to maintain a concentric trajectory with the Moon unless pulled Moonward by the rest of the structure anchored on the Moon, which it is in turn tensioning Earthward. An L-1 elevator is slightly EASIER, in fact, than an L-2 one because L-1 is close to the Moon than L-2, making a shorter construct for a given capacity.
What is the feasibility of lunar balloons like zeppelins going from the Venusian surface up to a balloon that would go up higher to where it could be winched up to high balloon height, relatively close to orbit? Could that allow a Venusian mining operation?
Assuming you had a hypothetical supermaterial that could support a space elevator to geostationary orbit, at what point would you stop feeling gravity? In orbit you don't feel gravity because you're in freefall (you just have enough tangential momentum to keep you from hitting the earth so your ballistic arc "misses"). Just because there's a whole elevator connecting the top at geo-stationary to the surface of the earth doesn't mean it's not experiencing those same forces but obviously you would feel gravity on the surface. So at what point would you start to feel weightless? Or over what range would you gradually feel lighter? Would it be from the surface where you'd weigh 100% of your normal weight at 1g, to 0 at geostationary since the speed at every point closer to the earth than geostationary would be moving slower than the necessary orbital velocity at its given altitude?
Its like they said "How are we getting into space?" And the answer was 'trucks'. Cause we used trucks, uh rockets. Those things for fireworks? Yes that's exactly what we used! So, now elevators.
If using the lunar mass driver to land incoming spaceships is so dangerous, wouldn't that imply that using orbital ring mass driver to slow and land arriving to earth will be equally or greater danger? This time not just to the ship and mass driver but also earth itself?
Depending on the setup, it doesn't seem any worse conceptually than landing on an aircraft carrier. That used to be dangerous, but is highly automated these days.
It depends on whether you're building a compression/active support tower or a equator through GSO "beanstalk" in tension. The latter type of structure has to be built space down to maintain tension. A compression or active support structure has to be built bottom up to maintain support. You can't lay a course of brick top down because as soon as the mason releases the bricks they fall to the ground faster than he can lay the lower courses to connect it to the ground. Since a space tower is supposed to extend beyond the atmosphere, you could build the top in orbit, but it would be going sideways at orbital speed, so how do you connect it to the ground?
2:24 - I wish people would use relative numbers, rather than exact like this ... This gives me no no idea, and only overwhelms my brain ... something like X is 3.4 times the lunar speed, and 8 times the length .... etc. (made up numbers) - That would be much more insightful! - I wish everyone well.
Has anybody ever suggested that smaller planets are more likely to create space faring civilizations, due to space elevators? Surely a planet with low enough gravity would make space elevators a possibility, pretty much immediately upon reaching the space age, because they wouldn't need to invent crazy strong materials? Should we expect to find most space faring species are smaller and weaker than us, because lower gravity makes space more accessible by definition? If there is something to this idea, then does that imply that humans actually are space orcs? Maybe most space travelling species only ever used rockets in the void of space. The idea of strong, large, borderline indestructible monkeys firing themselves out of a massive gravity well on rockets.... Terrifying.
Higher gravity would likely decrease species size depending on food sources and overall calorie intake. If the calorie sources and oxidizers are similar to Earth they would have to be smaller or starve to death if they don't dedicate much more time to food. We can do space travel because we have 3% of our population concerned with food sourcing in our most developed countries. Also, too low a gravity and things like atmosphere start to disappear without either a Venus level magnetosphere or a very small and dense planet which would increase gravity. It's a sensitive balancing act when talking about planet size and life sustaining.
@@aronlinde1723Hmm I hadn't thought about gravity impacting size in that way. Very interesting, so low gravity guys would be big, yet weak for their size. Yet low gravity specis would be small and compact but powerful? Thanks
A space elevator on a low gravity planet is feasible with the right materials on that said planet. Scientists even proposed on building a Space elevator on Mars using Kevlar, which is a known strong material. A alien civilization living on a low gravity planet would have an easier time to reach space faring capability due to less emphasis on using ... They could also use rockets as well since it would take it would less fuel to get to orbit. Spacecraft concepts like space planes are feasible in a low gravity world. Aliens living on a low gravity would infact be taller than on a normal 1g planet or a super earth. Gravity would put less stress on their bones and cardiovascular system. The brain wouldn't need to work hard to pump blood into the system. There are hypothetical depiction of what Martian humans will look like over the generations living there and one thing they point out is how tall they could be due to low g and environmental factors.
@GiordanoBruno42 there are other factors as well. Everyone likes to think about large planets like ours, but we seem to be a bit of an anomaly in that area. I personally think moons are a better option, such as the ones around Saturn and Jupiter. They are also protected by the magnetosphere of the giant they orbit, the main problem with them tends to be radiation from said planets as well though. If the right conditions are met though, it could be viable.
I am now slightly disappointed we arent tidally locked to the moon, otherwise we could build a literal bridge there. Theres always Pluto and Charon though
Arg. Ultra cheap freight of the moon? From a space elevator costing what compared to the ships it would replace? Would cost how much to maintain per year/ton? Would last how long before radiation etc trashes it?
@@TheEvilmooseofdoom What motive for higher cost, more limited transport? It’s like Space elevators from earth, even ignoring that no material can do it, it would be wildly more expensive and more limited. These are not result folks pay huge bucks to get.
@@KellyStarks The only way to generate a ROI is through a lot of use. There is little on the moon that needs to get off the moon in any quantity that would make it worth doing until we're building really large space based structure... like in a few hundred years from now.. If..
@@TheEvilmooseofdoom Even then skyhooks or space elevators can’t compete, since their carrying capacity is pretty load, over high fixed and operating costs. One group wanting to start a space elevator groups own numbers, assuming you could make pure (full cable length) carbon nanotube cables for the price per ton of Kevlar composites. Figured you’ld need billions of tons of cable (about $400 billion back than), to lift a thousand tons a year from earth. Assuming the cable would last 40 years in space (iffy), that’s $10 million a ton, ot $5,000 a pound assuming the cables maxed out for load, and is only including the cost of the cable. Compared with RLV’s like the DC-x with full costs with high launch markets a fifth that, and dev and up frount costs maybe 100 times less then the cable material costs….. new craft could be much cheaper to operate, especially in a big fleet to support a big lift/landing market. And if you consider the cost to build, and rebuild the space elevators (like shipping that much cable material to the assembly orbit point with other transports, construct its geosync launch port, cable crawlers, space tug fleet, etc…. There’s simply no scenario where things like space elevators and orbital rings could Handel a big market, or be capable of of competing with conventional launchers or RLV’s.
@@KellyStarks Where are you getting these high operating costs from? Using a cable system to move cars on a space elevator is ridiculous nonsense. That group is worthless.
As Neil DeGrasse Tyson pointed out, if one reduced everything to the size of a schoolroom Earth globe, the current space station would be about 3/8ths of an inch off the surface of the earth. Every picture I see of a space elevator shows a tower, or tether, much higher than that. In fact, the tether would have to be much taller than geostationary orbit because one has to account for the weight of the tether. The space station can get away with it's orbit because it is supporting only it's own weight. Add a few million tons of tether and the equation becomes a lot different.
The moon, mercury, venus, & mars do. Airless rocky moons get a layer of powdery inpact regolith, but they have a solid rocky surface underneath. For asteroids depends on the type but probably not. Then again putting an elevator on an asteroid is a waste of time, effort, & resources anyways. A beer can has enough delta-v to escape most of em.
At a certain depth, which the rather shallow Apollo core samples detected, the regolith begins to "vacuum cement" together, enough that the astronauts had a hard time pulling out the core sample. That should secure things if bedrock is not accessible at the site. Under Lunar gravity, ENOUGH of even loose material should secure a scoop anchor. (It works for ships anchoring on muddy sea bottoms.)
Thanks Isaac. I think orbital facilities at L1 through L5 should come first. However, I have a novel approach to 'mining' lunar regolith that doesn't require landing on the moon. I propose a space tether, etc., that has an lunar orbit that follows the terminator (night/day) and harvests charged lunar dust that can rise for miles at the terminator. The dust can be processed and further refined via molten salt electrolysis. I believe that a large rotating structure can be built in low lunar orbit made from lunar dust as described w/o landing on the surface. Why go down the gravity well? The rotating habitats that can be built from lunar regolith can then be used where needed anywhere in the solar system.
@victordelmastro8264 the building of a drum like station in moon orbit is useful. You could make a non rotating outer drum from regolith. Above is quite plausible. For mining though you need to be on the surface and below it. Extract minerals and ore with robotic machines, pass them up to the station where they are processed. Only time people need to be on the surface would be maintenence. Fix machines, back to orbit and 1G environment.
This can be plausible if the charged particles are dense enough, but I think it is incredible thin. Like....thinner than the dust pollution of our atmosphere. Your idea has the benefit of spreading out a million times the coverage though. Additionally, depending on WHAT is charged, it could be a good pre-filtered stream of resources....imagine if GOLD were the dominant charged levitating particle! Your design can always be made better by having a snow-blower blast the regolith into the path of the orbiter, though. So, still a ground based miner
Since Luna has no synchronous orbit akin to that of Earth, maybe an orbital ring would be a better option. Also, because the Moon's rotation is so slow and it has an almost nonexistant atmosphere, the lunar space elevator wouldn't have to be as tall.
an OR is only useful if u have an atmosphere in the way. Othewise u just put mass drivers directly on the surface. Even if it wraps around the equator it doesn't need active support which is good cuz we still don't have that figured out
Id like to see the dedign for the crawlers/pods that travel up znd down the elevator stalk. What mechanism would they use that wouldn't be detrimental to the cable itself?
@@TheEvilmooseofdoom I was wondering about wear and tear, and how would you effect repairs to a thousands miles long cable or ribbon that's continuously in use.
being that the moon has no atmosphere that is a barrier to speed wouldent it make sense to just drill a hole in the moon and make a vertical shaft into the moon that has an actual elevator inside and use that to accelerate mass to speed? why would you even need a tower?
Digging thru would take a lot longer to do than building a tower. You then have the problem of it only connects two points on the moon. Any other point you go to would require other means of transit. Where as a Tower also allows for movement off the Moon as well as direct flights to any other point on the Moon. So unless your starting point and ending point is those two points of the tunnel, you are not likely to be saving any time or effort with a tunnel thru the Moon.
Honestly one of the top five channels on UA-cam! There's nothing better than a channel that consistently puts out a ton of great content that you don't have to wait long for. Thank you for doing what you do
This is definitely one of my "must watch all videos" channels
Not to mention the positive messaging of humanities future. If more people caught on to the idea it does not need to be terrible, we would have more people moving in the right direction.
True. Also this is one of the few channels that will be resistant to the inverse square law. Adding more people will only skew the poll results at first, but I dont see Issac straying too far from the spirit of the channel no matter how many people flood in.
Tell us your other four!
What are your other Top 4?
11:30 Small correction: we didn't put the JWST at Luna's L2 point, but at Terra's L2 point adjacent toTerra's orbit around Sol.
came here to say the same thing
Yes - I've seen the name Sun-Earth L2 en.wikipedia.org/wiki/List_of_objects_at_Lagrange_points
Sun (primary) - Earth (secondary) L2 (second of the five Legrange points as the tertiary point)
I'm a sucker for anything lunar. Thanks once again for the amazing content, Issac
No matter the elevator, and no matter the era; the music will be the same.
There will still be a few humans who will push the "up" button repeatedly, thinking that will get them there faster. 😉 Can't thank you enough for this brain-stimulating content, Isaac! Excellent as always, Sir. 🌌
You gotta hold it so we don’t stop and start, trust me my uncle was a firefighter in a different city two decades ago…
If you push the call button repeatedly, it'll sense your frustration and come faster
@@Ikbeneengeit
_And_ if you keep clicking on a loading bar, you _just _*_know_* it'll come faster!
Learned new things in this one. Never thought about taking Earth's gravity into account when contemplating a Moon Space Elevator.
Always learning on SFIA.
Great work, Isaac.
But it kind of makes sense to take Earth's gravity into account when building a lunar space elevator.
@jackesioto Yes but it simply does not occur to most. Including me.
Anybody who says the sentence “but let’s discuss the basic lunar elevator” officially out of my league. I still bite my tongue when I’m eating food I like.
I just want to say that i truly appreciate your channel a lot. It's one of the best channels out there and very educational and touches on one of my favorite subjects space and the technology coming with it thank you
Thanks 😊
just an idea: several lunar elevators (at least 4). make 2 towers (>10km)on the poles of the moon, one on each pole. and from each tower 2 elevators. one to L1, the other one to L2. the towers should be able to move a slight bit because they have to hold the elevators steady.
these towers could then also be the anchor points of a lunar orbital ring that goes vertically from north to south. hopefully, there is an orbit similar to the sun synchronous orbit on earth. from there, they can send tethers down to many points on the surface, and it would make surface to surface transport very easy.
I’ve just discovered this channel and it’s already one of my very favourites Isaac A is amazing.
The mass driver would be first, because a killer ap for the Moon industrial park is volatiles for propellant and life support and construction materials for cislunar infrastructure, and you can build gobs of them for the price of a skyhook or space elevator, especially if you're trying to build the orbital stuff out of pre-mass-driver priced material.
The mass driver makes elevators and skyhooks cheaper, so that's how you would bootstrap things:
1. ISRU extraction (volatiles for propellant, life support; agregate for mooncrete/moonmortar, moonbrick; metals, etc.
2. Start churning out mass drivers.
3. Use mostly Moon materials to build a rotating skyhook for Earth in the Lunar orbital plane.
4. Close the inner loop with an Earth-Moon L1 space elevator, mostly for traffic down to the Moon's surface.
5. Close the outer loop with an Earth-Moon L2 space elevator, mostly for traffic to the cislunar system from the rest of the Solar System. (You launch outbound traffic from mass drivers.)
Of course, You'd be doing other things with the Lunar mining, manufacturing, fabrication, and construction in the meantime, but we're discussing transportation infrastructure on the Moon. The Moon becomes the rail and industrial hub.
Yesss!
As always, great choice in topic Isaac! Looking forward to listening to it a few times over!
I'm not a fan of lunar space elevators (rotovators make more sense, IMO), however you missed one of the lunar space elevator's party tricks: If you extend beyond L1 much more than is required for counter-weight, you can extend all the way into low Earth orbit. The "orbital" velocity, given the 29 day period, is tiny, allowing it to work in much the same way as the lower tip of a static orbital tether. Rockets from Earth require an order-of-magnitude less energy to dock with the tether-tip, compared to going into a proper orbit.
There's a limit to how close you can get, since the moon's orbit is not circular, so the lower tip will drift closer and further from Earth each month. But theoretically, you could even use that to dip into the Earth's atmosphere once a month.
Love the content Isaac 👍
Thanks!
@@isaacarthurSFIAhi, are you interested in the new game Armored Core 6?
@@kuiper6948 Not enough hours in the day I'm afraid :)
Wow, I had no idea it was so much more complicated for a lunar space elevator than I thought. Fascinating video.
We will have mass drivers long before space elevators. I dimly remember an article in Analog probably 40 years ago that actually talked about the possibilty of a reverse mass driver for landing space craft on the lunar surface.
Yeah, it seems no worse than landing on an aircraft carrier. Higher speeds, but no crosswinds or waves to deal with.
I feel like you came back to earth for this convo, you been in the stars in deep thought for months now, glad to have you back.
Just a little detail. We did not put the JWST at the L2 point of the Earth-Moon system. We put it at the L2 point of the Sun-Earth system.
Darn, Did I accidentally say lunar L2?
@@isaacarthurSFIA You did, or you strongly implied it. I am heating up my kettle of tar and cutting open a feather pillow to deal with that now. ;)
Great job again Isaac and team!
Thanks Isaac, another great show who needs T.V , love to your family. PEACE and LOVE to EVERYONE ❤❤.
Thank you, Isaac. Tethers and sky-hooks have been concepts that fascinated me for a long time.
"There's no such thing as a free lunch." ~ You haven't looked into tethers yet, have you? If you have the right mix of loads, you can actually generate energy with tethers, sell that off as electricity.... It would take a lot of energy to get them up there and working, but as long as you are mining on the moon, and shipping material back to Earth, that will provide energy to maintain the tether. Then you can use it to launch smaller loads from the middle to an upper atmosphere to a stable low earth orbit. The tricky part is it's like a plate-spinning act in a magic show, you've got to watch and manage a number of complicated dynamics at the same time. But as long as you can orchestrate the movements, it really is a free lunch.
Yep, they have amazing options, but I don't think you can do electrodynamuc tethering around the moon, not a good enough magnetosphere iirc
@@isaacarthurSFIA ~ It has been a while, I'm rusty, but I think you can do a pure kinetic rotivator right down to the moon surface and off it, as long as you balance the loads. You need as much going down as you have coming up, or you need some external thrust for your tether. You can't drive it by electro-magnetism either, as you say. If it gets a bit out of whack, you have to apply thrust to correct and you have to do it pretty fast. Like I said, it's like spinning plates. But unlike on Earth, you can operate the thing right down to stationary pick-up / drop-off right on the surface.
On the down-side, if you get the sums wrong, imagine 5,ooo miles of the cables that hold up the Golden Gate, falling down across that city, first parts going fairly slowly, but the later parts moving at 34,ooo km/h or so .... Exactly how far along the surface that could spread out and wreck stuff, I don't know, but I think it would rival SFO's big Earthquake that's coming. You could do a mind-boggling amount of damage with that.
Have you read DiskWorld, and the shade squares come down and so do their cables?
@@Kneedragon1962cool blog bro
It would be very cool if someday humans build a pluto-charon surface attached structure and name it Acheron River in respect to Isaac Arthur
Could you catch an aluminium spacecraft on lunar elevator with a magnet? Similar to the trick where you try swing an aluminium sheet through a horse show magnet which makes it stop.
You can, but it isn't optimal. Using aluminum limits decel speed by how much eddy current waste heat you can radiate away & the MP of aluminum. Also using a magnet, especially the superconducting variety, let's u do regenerative braking to recover almost all of the kknetic energy of the payload.
Fine for a first go, but probably not what u stick with for any length of time
The more i think about it, it seems Mars should be very secondary to a lunar base in many ways. It seems like we have a much better chance of getting a lunar base up and running thrn moving out to mars and the Jovian moons.
mars is so dumb as a first step. Grav wells are for suckers &, other than a small base, most people who live in the mars system will probably live on/in/near it's moons for the near to medium future(next several hundred years at least)
Oh Isaac, a space elevator for my birthday! You take me to the moon!
Happy birthday my friend :)
Happy birthday 🎂
I got Ringworld episode for my wedding...
Happy. Birth day
What about hanging a stationary elevator on an orbiting ring? Like the elevator stations of lofstrom loops
Yes you can do that too
If you thought a regular space elevator's dynamics were hard to manage... That would be doable, but would be a pretty absurd megaproject. If you plan on moving vast quantities of material it is a great idea, and doesn't need any exotic materials. The issue is that it doesn't scale down particularly well. It really wants to be as close to symmetric around the planet as possible. Any failure to distribute the loads will result in flexing, and that would be bad. It really wants to have base stations distributed around the planet, and thousands of them. It is probably how you would go about dismantling an entire planet, but up to that point I don't see it having upsides that make up for the complications it brings. On the plus side, you might actually be able to build it without putting anything into space. Imagine you have a hyperloop setup that has a continuous ribbon of magnetic tape running through it, suspended by superconductors. You could accelerate this to ~20km/s, and then gradually raise the whole thing on tethers. If you can build a near enough frictionless pipe this could be extremely useful, because you stop caring about material properties at all. That makes it a viable structure even in the atmosphere of Jupiter (though then you are talking more like 200km/s, and having that much mass going at speeds where the speed of light becomes relevant means it could go very badly wrong, but it could work in theory with materials we have now!).
While a space elevator is a megaproject because it requires a complete covering of a 1 dimensional line between the surface and geostationary, such a project does not really function without a complete covering of a 2 dimensional plane. It is vastly larger than project than a single elevator, though in theory much simpler. It would also fail even worse than an elevator; if it does the entire structure fails! That would be bad.
I like the lunar pole to L1 choice best of all. The anchor station at L1 never moves... doesn't need to!
L1 isn't the anchor. It's better to think of it as the mid-point: you need a whole other tether beyond L1 to counter the weight of the mass of the tether between L1 and the moon. Same as you need the same weight of tether/anchor beyond GEO for a space elevator to Earth.
well clearly L1 moves as the lunar orbit isn't circular. I'm aware of the mass needed earthside of L1. I am surprised that there will be significant slack at periapsis that must be taken in at the base!
Recently LTT started hosting a 24/7 stream on their channel that loopsntheir content. Would love something like that for this channel!
I dont know if this is appropriate or not to say but i've become so used to Isaacs speech impediment that i see it almost like just another accent. Just like a british accent i now associate it with intelligence. Keep up the great work.
Same! I NEVER struggle to understand him anymore. Probably his friends and family do not either. I wonder if he has become clearer, or we have become more attuned?
@@donperegrine922you could tell quite easily by simply going back to an older video
I love his 'style' of talking; it's a banger, for sure!
Near the end of this universe, if there's no barrier or one that "we" can pass through, can we go start over in another younger universe carrying the knowledge and skills that we would have before the exit? Head start?
Extremely fresh and original content
I firmly believe that a Lunar Space Elevator is more practical than an Earth version. The Earth-bound version is a huge risk if it goes wrong, whereas a Lunar version is safer.
another fantastic episode. finished just as a walked into work
have you though about intelligent dwarf civilizations like the size of bugs and how they would interact with larger intelligent species
Moon stuff! Moon stuff! Moon stuff! 🌙
Oh yea!
Could get pretty high in one of those.
Since the Lagrange points are for the Earth Moon system, which other uses might the Earth want for Lagrange 1? You need development on multiple faces of the moon, and the lunar speed rails need to carry both people and materials or finished goods to the equator. I'd still focus on idustrializing the moon first and once the moon has operations throughout, it probably gains the support to build. It's actually my same strategy for trying to justify building one in Equador. Once the trade throughout Latin America is all lawfull and there are secure property rights and you have other trains and activities occuring throughout the land funneling resource to Quito, you can have one for Earth as well if they are possible.
Couldn't a space tether also be a power generator in Earth Orbit, power is obtained via electromagnetic induction of the elevator crossing the Earth's magnetic field.
Remember an unsuccessful Italian experiment, facilitated by NASA space shuttle mission researching such an option.
Yeeyee Arthursday
Every time people talk about time travel I cannot avoid thinking- earth rotates on it's own axis at around 1000 miles per hour (at the equator), also oscilates a bit and it's also affected by the movements of the moon. It rotates around the sun, in what we know as a solar year at around 67000 miles per hour. The sun does a galactic rotation every 225-250 years around the galaxy at around 490000 miles per hour. We also know that the solar system is moving towards the Leo constellation at around 242 miles per second and the whole galaxy is moving towards the Great Attractor at about 621 miles per second. Obviously those are only the most noticeable movements, but the position of earth, the solar system, the galaxy, local group, etc. are affected by any strong enough gravities, giving them additional movements to take in to consideration. So, my point is, (and by all means, I understand the fun part of futurism might be the "science fiction" part) before we talk about time travel, we need to talk about the mastery of space, not only as in "space travel", but pretty much as a part of reality we can trivialize. Pretty much instant teleportation if we think about it.
another great episode
This is my personal favorite of his music themes.
What about a space station that constantly orbits earth AND the Moon? Then low earth (or moon) orbit can connect for the transfer.
I would think that since the space between Earth and the Moon is essentially "weightless," having a continuous bridge between them seems massively pointless, even if you have the means to do it easily. It seems much more practical to just have a system where an Earth elevator moves a craft to an ideal distance into space, and then "flings" it toward the moon at a particular speed, and then a complementary elevator from the moon will "catch" that pod, with all the relative speeds being balanced so that from the perspective of the pod, it would feel no change in acceleration at any point in the journey, and would be internally identical to if it had been a continuous elevator, and require zero fuel (aside from some back-up fuel for emergencies). It would be similar to those devices that launch a ball bearing off a roller-coast style rig, and then the bearing flies through the air and lands on a similar roller coaster style rig, with no significant impact when it lands, because the angles are calculated out.
I like those space catapults that use a cylindrical swing arm that ratchet up and then baseball pitches junk into space.
Thank you!
Good news everyone! Isaac Arthur explained why there were whalers on the moon. They were operating the harpoons.
One fun thought is the way you could launch large space ships is using a space fountain to lift them off the surface of the moon in either earths orbit or from the backside of the moon to set the ship into solar orbit and then accelerate to a faster speed
sorry to call you out, but at 11:45 you said the JWST was at the Earth-Moon L2 point, ~200,000 miles beyond the moon. Isnt it actually at the Earth-Sun L2 point, about 1.5 million miles beyond Earth's orbit?
nice
I think that the best option for a rocketless launch assist system on the moon is actually a launch loop.
A system that doesn't support launching and landing on the moon is far less useful than one that does. Also if the payload has to be a certain shape makes it even less useful. My option would be to use starship to establish industrial capacity on the moon and constructing a launch loop, on the equator, raising up to 20km from the surface where it would avoid any craters (saving you the pain of building multiple Km long supporting towers),launching you straight to orbit with no orbit raising required and ships could dip their periapsis and match speed with the platform and be caught by tethers. They would then apply regenerative breaking to slow down. The reverse for launching. At one G accel,it would need to be about 285km long (including safety margins). At 3 G's,you could get away with 120km. And i would prefer to be capable to have about 150 tons of payload capacity,the mass of a starship or its payload.
If you got that then you go for an orbital ring,which straight up beats any space elevetor in every scenario i can think of.
Orbital rings get far too little attention,and more episodes about them would be very welcomed.
Hopefully these deliver mass from space to the terrestrial surface slowly.
All this makes me wonder. What will industrialization look like in space? Transformation and refining of in-situ materials. Metal forging, machining, 3D printing? Solar powered forges? Laser ray casting? Construction from raw materials in space is an interesting topic in itself as well.
And also the collection and transformation of useful materials for space agriculture and generation of living organic matter. Nitrogen, oxygen, carbon dioxide, phosphorus, calcium...
Watch. Sci fi movies
Good stuff
Holy fuck!!!! Isaac!! My brain is gone. I hear you talking in reverse!!!!
Am I losing my mind??
I Will restart my phone!!
It won't be long before this channel has one million subscribers!
I subscribed when there was less than half a million subscribers.
Hi Mr Arthur, could you cover exotic weaponry some day? Like the monopole cannons and cosmic strings from the xeelee sequence, or other similar spacetime-messing weapons. Cheers, and keep up the quality content!
A lot has been done already.
Because the moon is tidally locked with Earth, space elevators will only function on the side of the moon which faces away from Earth. any point, from limb to limb, as long as there's clean access to the elevator's intended altitude, the elevator should be able to have enough centrifugally induced tension for the tether to work. Any attempts to fly the tether toward Earth will result in the tether not being able to achieve centrifugal tension, resulting the tether's collapse. All tethers must extend parallel to the line of centrifugal force, along the Earth/moon tidally locked line.
No, an L-1 elevator has the same requirement as an L-2 elevator. You need enough of a net counterweight Earthward of L-1 to tension an L-1 elevator, just as you need enough of a net counterweight outward of L-2 to tension an L-2 elevator. The engineering case of the L-1 elevator is tensioned by an overbalance of Earth gravity, whereas the L-2 case is tensioned by an overbalance of centrifugal force. The libration points are DEFINED as the balance points where the vector sums of both gravity fields and inertia allows a trajectory motionless with respect to the Moon. Inward (Earthward) from L-1 at the same radial velocity (Moon's "RPM" around the Earth) an object will immediately tend to bend it's trajectory toward the Earth more sharply than L-1s path, because inward from L-1 (the balance point between Earth gravity on the one hand and the sum of Moon gravity and centrifugal force on the other hand), the balance is tilted in favor of Earth gravity. It's not orbiting fast enough in that place to maintain a concentric trajectory with the Moon unless pulled Moonward by the rest of the structure anchored on the Moon, which it is in turn tensioning Earthward.
An L-1 elevator is slightly EASIER, in fact, than an L-2 one because L-1 is close to the Moon than L-2, making a shorter construct for a given capacity.
13:39 Imagine building that in Space Engineers.
What is the feasibility of lunar balloons like zeppelins going from the Venusian surface up to a balloon that would go up higher to where it could be winched up to high balloon height, relatively close to orbit? Could that allow a Venusian mining operation?
Assuming you had a hypothetical supermaterial that could support a space elevator to geostationary orbit, at what point would you stop feeling gravity? In orbit you don't feel gravity because you're in freefall (you just have enough tangential momentum to keep you from hitting the earth so your ballistic arc "misses"). Just because there's a whole elevator connecting the top at geo-stationary to the surface of the earth doesn't mean it's not experiencing those same forces but obviously you would feel gravity on the surface. So at what point would you start to feel weightless? Or over what range would you gradually feel lighter? Would it be from the surface where you'd weigh 100% of your normal weight at 1g, to 0 at geostationary since the speed at every point closer to the earth than geostationary would be moving slower than the necessary orbital velocity at its given altitude?
Its like they said "How are we getting into space?" And the answer was 'trucks'. Cause we used trucks, uh rockets. Those things for fireworks? Yes that's exactly what we used! So, now elevators.
If using the lunar mass driver to land incoming spaceships is so dangerous, wouldn't that imply that using orbital ring mass driver to slow and land arriving to earth will be equally or greater danger?
This time not just to the ship and mass driver but also earth itself?
Depending on the setup, it doesn't seem any worse conceptually than landing on an aircraft carrier. That used to be dangerous, but is highly automated these days.
A relatively grounded topic for Isaac
Ironically..
Interesting topic.🤔🙂
I thought the JWST was at the Sun/Earth L2, but you said it was at the Earth/Moon L2. Which is it? 23:00
What’s orth?
If the Earth only spun more quickly!
Never been so early on an Issac Arthur video!
Me either!
Same!
Me too
Well I guess same. 😂
Have you looked at the chain system at the end of Seven Eves?
13:43 is the most incredible thing I've ever seen. Does anyone know where I can find the original? Thank you!
Dont worry about the cost, auctioning off the Advertisement space on the moons surface will pay for it.
A skyhook probably won't work on the moon due to gravitational anomalies on its surface preventing a stable orbit.
Perhaps an Earth-Space-Tower might best be built from Space down instead of building from Earth up ?!!
It depends on whether you're building a compression/active support tower or a equator through GSO "beanstalk" in tension. The latter type of structure has to be built space down to maintain tension. A compression or active support structure has to be built bottom up to maintain support. You can't lay a course of brick top down because as soon as the mason releases the bricks they fall to the ground faster than he can lay the lower courses to connect it to the ground. Since a space tower is supposed to extend beyond the atmosphere, you could build the top in orbit, but it would be going sideways at orbital speed, so how do you connect it to the ground?
Definitely put it on the farside of the Moon, so as not to ruin the view.
I’m pretty high, but I don’t think I’m moving in circles….
Could you make a bridge connecting the surface of the Moon to an orbital ring around the Earth?
2:24 - I wish people would use relative numbers, rather than exact like this ... This gives me no no idea, and only overwhelms my brain ... something like X is 3.4 times the lunar speed, and 8 times the length .... etc. (made up numbers) - That would be much more insightful!
- I wish everyone well.
and it will be unit independent -> half the number of numbers to process
4:44 - same here, although less overwhelming. - To say "3x Earth diameter and 1/11th the distance to the moon" would make it easy to grasp the sizes.
Has anybody ever suggested that smaller planets are more likely to create space faring civilizations, due to space elevators?
Surely a planet with low enough gravity would make space elevators a possibility, pretty much immediately upon reaching the space age, because they wouldn't need to invent crazy strong materials?
Should we expect to find most space faring species are smaller and weaker than us, because lower gravity makes space more accessible by definition?
If there is something to this idea, then does that imply that humans actually are space orcs?
Maybe most space travelling species only ever used rockets in the void of space.
The idea of strong, large, borderline indestructible monkeys firing themselves out of a massive gravity well on rockets.... Terrifying.
Higher gravity would likely decrease species size depending on food sources and overall calorie intake. If the calorie sources and oxidizers are similar to Earth they would have to be smaller or starve to death if they don't dedicate much more time to food.
We can do space travel because we have 3% of our population concerned with food sourcing in our most developed countries.
Also, too low a gravity and things like atmosphere start to disappear without either a Venus level magnetosphere or a very small and dense planet which would increase gravity.
It's a sensitive balancing act when talking about planet size and life sustaining.
@@aronlinde1723Hmm I hadn't thought about gravity impacting size in that way. Very interesting, so low gravity guys would be big, yet weak for their size.
Yet low gravity specis would be small and compact but powerful?
Thanks
A space elevator on a low gravity planet is feasible with the right materials on that said planet. Scientists even proposed on building a Space elevator on Mars using Kevlar, which is a known strong material. A alien civilization living on a low gravity planet would have an easier time to reach space faring capability due to less emphasis on using ... They could also use rockets as well since it would take it would less fuel to get to orbit. Spacecraft concepts like space planes are feasible in a low gravity world.
Aliens living on a low gravity would infact be taller than on a normal 1g planet or a super earth. Gravity would put less stress on their bones and cardiovascular system. The brain wouldn't need to work hard to pump blood into the system. There are hypothetical depiction of what Martian humans will look like over the generations living there and one thing they point out is how tall they could be due to low g and environmental factors.
@GiordanoBruno42 there are other factors as well. Everyone likes to think about large planets like ours, but we seem to be a bit of an anomaly in that area. I personally think moons are a better option, such as the ones around Saturn and Jupiter. They are also protected by the magnetosphere of the giant they orbit, the main problem with them tends to be radiation from said planets as well though. If the right conditions are met though, it could be viable.
I am now slightly disappointed we arent tidally locked to the moon, otherwise we could build a literal bridge there. Theres always Pluto and Charon though
Arg. Ultra cheap freight of the moon? From a space elevator costing what compared to the ships it would replace? Would cost how much to maintain per year/ton? Would last how long before radiation etc trashes it?
You would need a strong motive, it's not something that would be done otherwise.
@@TheEvilmooseofdoom
What motive for higher cost, more limited transport? It’s like Space elevators from earth, even ignoring that no material can do it, it would be wildly more expensive and more limited. These are not result folks pay huge bucks to get.
@@KellyStarks The only way to generate a ROI is through a lot of use. There is little on the moon that needs to get off the moon in any quantity that would make it worth doing until we're building really large space based structure... like in a few hundred years from now.. If..
@@TheEvilmooseofdoom
Even then skyhooks or space elevators can’t compete, since their carrying capacity is pretty load, over high fixed and operating costs. One group wanting to start a space elevator groups own numbers, assuming you could make pure (full cable length) carbon nanotube cables for the price per ton of Kevlar composites. Figured you’ld need billions of tons of cable (about $400 billion back than), to lift a thousand tons a year from earth. Assuming the cable would last 40 years in space (iffy), that’s $10 million a ton, ot $5,000 a pound assuming the cables maxed out for load, and is only including the cost of the cable. Compared with RLV’s like the DC-x with full costs with high launch markets a fifth that, and dev and up frount costs maybe 100 times less then the cable material costs….. new craft could be much cheaper to operate, especially in a big fleet to support a big lift/landing market. And if you consider the cost to build, and rebuild the space elevators (like shipping that much cable material to the assembly orbit point with other transports, construct its geosync launch port, cable crawlers, space tug fleet, etc….
There’s simply no scenario where things like space elevators and orbital rings could Handel a big market, or be capable of of competing with conventional launchers or RLV’s.
@@KellyStarks Where are you getting these high operating costs from? Using a cable system to move cars on a space elevator is ridiculous nonsense. That group is worthless.
Did anyone ever design winch for non-uniform tapered cable like those described in the video?
How that even work?
As Neil DeGrasse Tyson pointed out, if one reduced everything to the size of a schoolroom Earth globe, the current space station would be about 3/8ths of an inch off the surface of the earth. Every picture I see of a space elevator shows a tower, or tether, much higher than that. In fact, the tether would have to be much taller than geostationary orbit because one has to account for the weight of the tether. The space station can get away with it's orbit because it is supporting only it's own weight. Add a few million tons of tether and the equation becomes a lot different.
I'd love to see an examination of O'Neil's book, The High Frontier
What about building a lunar orbital ring?
Is the moon or some of the other planets / asteroids solid enough to secure a space elevator to it?
The Moon is in al likelihood solid enough for space elevator construction.
The moon, mercury, venus, & mars do. Airless rocky moons get a layer of powdery inpact regolith, but they have a solid rocky surface underneath. For asteroids depends on the type but probably not. Then again putting an elevator on an asteroid is a waste of time, effort, & resources anyways. A beer can has enough delta-v to escape most of em.
At a certain depth, which the rather shallow Apollo core samples detected, the regolith begins to "vacuum cement" together, enough that the astronauts had a hard time pulling out the core sample. That should secure things if bedrock is not accessible at the site. Under Lunar gravity, ENOUGH of even loose material should secure a scoop anchor. (It works for ships anchoring on muddy sea bottoms.)
Nice to hear your voice again
mogadishu for earth capitol 2424!
Weirdly enough i was just wondering about where a geostationary orbit of Venus would be before i watched this.
A metor will hit it
Thanks Isaac. I think orbital facilities at L1 through L5 should come first. However, I have a novel approach to 'mining' lunar regolith that doesn't require landing on the moon. I propose a space tether, etc., that has an lunar orbit that follows the terminator (night/day) and harvests charged lunar dust that can rise for miles at the terminator. The dust can be processed and further refined via molten salt electrolysis. I believe that a large rotating structure can be built in low lunar orbit made from lunar dust as described w/o landing on the surface. Why go down the gravity well? The rotating habitats that can be built from lunar regolith can then be used where needed anywhere in the solar system.
Isaac, Arthur is his surname.
@@seriousmaran9414 The error has been corrected.
Now what do you think of the concept?
@victordelmastro8264 the building of a drum like station in moon orbit is useful. You could make a non rotating outer drum from regolith. Above is quite plausible.
For mining though you need to be on the surface and below it. Extract minerals and ore with robotic machines, pass them up to the station where they are processed.
Only time people need to be on the surface would be maintenence. Fix machines, back to orbit and 1G environment.
That just limits you to what's available as charged lunar dust. Which limits what you can harvest which makes it hard to justify the system.
This can be plausible if the charged particles are dense enough, but I think it is incredible thin. Like....thinner than the dust pollution of our atmosphere. Your idea has the benefit of spreading out a million times the coverage though.
Additionally, depending on WHAT is charged, it could be a good pre-filtered stream of resources....imagine if GOLD were the dominant charged levitating particle!
Your design can always be made better by having a snow-blower blast the regolith into the path of the orbiter, though. So, still a ground based miner
Since Luna has no synchronous orbit akin to that of Earth, maybe an orbital ring would be a better option. Also, because the Moon's rotation is so slow and it has an almost nonexistant atmosphere, the lunar space elevator wouldn't have to be as tall.
an OR is only useful if u have an atmosphere in the way. Othewise u just put mass drivers directly on the surface. Even if it wraps around the equator it doesn't need active support which is good cuz we still don't have that figured out
Summoning raptors
Yds
Id like to see the dedign for the crawlers/pods that travel up znd down the elevator stalk. What mechanism would they use that wouldn't be detrimental to the cable itself?
I wouldn't think they'd use a cable at all and have something move up a track instead.
@@TheEvilmooseofdoom I was wondering about wear and tear, and how would you effect repairs to a thousands miles long cable or ribbon that's continuously in use.
@@Cmdtheartist That's why I doubt they'd use a cable or ribbon and instead use a track system.
Nice, as long as it doesn't get stuck between floors.
being that the moon has no atmosphere that is a barrier to speed wouldent it make sense to just drill a hole in the moon and make a vertical shaft into the moon that has an actual elevator inside and use that to accelerate mass to speed? why would you even need a tower?
We discussed that option in moon mega city :)
Digging thru would take a lot longer to do than building a tower. You then have the problem of it only connects two points on the moon. Any other point you go to would require other means of transit. Where as a Tower also allows for movement off the Moon as well as direct flights to any other point on the Moon. So unless your starting point and ending point is those two points of the tunnel, you are not likely to be saving any time or effort with a tunnel thru the Moon.
oh i thought this was about an elevator *to* the moon lol still good tho
I think IA is due for a new skyhook episode if we're talking space elevators
I'm all for covering the moon into towers in Phase 2. Phase 3 is transform it into the Death Star 😎