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After our recent article featuring the concept of a lunar elevator, many of you posted questions about both lunar elevators and space elevators in general. Liftport’s Michael Laine has graciously agreed to provide answers for these questions, and if anyone has additional questions, leave them in the comment section here. We’ll post Michael’s answers in a subsequent post.
For those of you who have really big questions, you may want to attend the first lunar elevator workshop in Seattle, Washington this coming weekend, July 29-August 1 in Seattle Washington. See this link for more information.
And there’s also a space elevator conference August 13-15 at the Microsoft Conference Center in Redmond, Washington. Find more details at this link.
Security: How can the tether be protected from suicide or other attack by rogue aircraft?
One question each about each type of elevator.
1) with the Lunar elevator, what is the probability of a disabling micrometeor strike?
2) With an Earth elevator, won’t atmospheric effects such as high winds or storms disrupt the position of the elevator and destabalize it?
1) what would be its speed, how long would it take to get there?
2) how much material resources would it take?
I frequently hear that it would take days or weeks to climb a terrestrial space elevator. I assume it would take at least as long for a lunar one. Obviously this is a far cry from the 6 hour trip described in some science fiction novels, such as Arthur C. Clarke`s “The Fountains of Paradise.” Is such a speed impossible or would it merely require a much more massive cable, as Clarke describes in his book?
What’s the status of liftport group? Stasis? Deep coma?
Is there any hope for intermediary income on the way to a lunar elevator using the technologies as they are developed or is it an all-or-nothing investment?
I have a more philosophical question. Though before writing the lead up to it and asking it, I will say that I question whether these types of schemes can ever really work.
My question is more of a why question. We humans have through history extended our exploitive grasp of this world, populated enormously, and largely have converted much of the natural biological reality of this planet into polluted trash heaps. The problem I see is that if humanity does start to colonize space, or say the solar system, we most likely will exponentially expand our power and ability to convert the whole thing into this galaxy’s first stellar trash system. I doubt these things will happen honestly, but the desire to push humanity into becoming some sort of space faring species-civilization almost by axiomatic reasoning means we will use up the solar system as much as possible. We would then presumably move on to the other stars to exponentially expand our energy appetites and onwards we would go. If you assume our current exponential rate of growth in energy and resource use and ignore sticky issues of light speed within 5 million years we will consume the entire observable universe.
Gordon Lightfoot wrote a nice little song, “Too Many Clues in This Room,” which opened up with
The space shuttle ends where the subway begins,
There’s a tear on the face of the moon.
From dusk until dawn we have searched all day long,
But there’s too many clues in this room.
Sort of sums it up in a way. Is our species condemned to be some sort of two legged locust swarm that now having reached certain limits on this planet chomps at the bit to exploit and trash out the solar system?
LC
Yeah, I agree with LBC. It would be neat to have, but what are the environmental costs? How would such a system be constructed maintained, and powered? Would tidal effects weaken it? What if it collapses – who would be in danger, and what kind of damage would it do?
Would it really be worth it?
BTW, I like the new look of UT!
This whole idea of a space elevator to the moon sure is neat, however is it realistic? How many decades would we suppose it would take to build this? Then how much maintenance is going to be required for the relatively short life a device like this will have?
In the end, I think this is a fantastic idea, and a complete waste of resources. We should be focusing on other drive types.
Of course as long as we continue our idol worship of the dollar, nothing will really change.
With some of the recent large earthquakes, several scientists have pointed out that when these happen and the earth settles, the actual spin rate can be altered. I believe for a recent one, the change was in the order of a few milliseconds / day.
How large would an earthquake have to be to change the spin enough to be an issue for a space elevator?
For a Lunar elevator, not only would you have lunar quakes to worry about, but also meteor impacts sending shock waves around the surface. Do we have any idea what sized impact or lunar quake would be required to affect a lunar elevator?
Many here seem very skeptical. Although, I am wondering how much would the CNT elevator ribbon would weigh?
How massive does the counterweight need to be at Clarke orbit?
Even when long Carbon-nano-tube ribbons can be manufactured, will we need to adrress our orbital debris problem before construction?
Big challenges. Geez.
Can’t agree w/LBC, no offense but the “Cosmic Litterbug” thing sounds like self-important hand-wringing to me. And a bit of a straw man to boot. It fails to acknowledge the wondrous possibilities and envisions an unrealistic bleakness for the future human endeavor.
The Sun doesn’t seem to fret over the fact that it is destined to squander it’s H and He and balloon halfway to Pluto spoiling the party for all the planets in the process.
Events and Things (people for instance) happen because they are possible and therefore inevitable regardless of the probability. That seems a central (philosophical) lesson of the Heisenberg uncertainty principle – things that would seem impossible happen anyway. And the UNIVERSE is indifferent to it all!
Does the Gulf of Mexico care about all that oil? Not that I can tell – oil is just the newest reality for the flora and fauna to adapt to.
The people are the ones worried about adapting – our biggest challenge is adapting to a world where we don’t use oil for everything – that troubles us the most.
If a Space Elevator is possible it ultimately will happen – our challenge – as always – will be practicing good stewardship of our environment and the technologies we invent to explore and manipulate it.
We have made a some messes in space over the last half century but we do have the ability to learn from our mistakes. That learning actually forms one of the sounder rationales for building an elevator – it’s a clean way to get payloads to space.
If it does work it will certainly have the capacity to reduce the zooming space junk we find so alarming – that alone would make it much better than rockets.
I see HAL beat me to it, the issue with all the present orbital debris.
Another point is, how would a Space elevator change the way satellites are launched and maneuvered? Wouldn’t that elevator intersect other LEOs at some point in time? How do you protect it from dead/zombie satellites?
I can see a Space Elevator for the Moon since it is easier to build there is no orbital debris and the counterweight is near Earth-Moon L1, all big pluses.
O.k. guys, Thanks for all your interesting questions, thoughts and concerns. Between the two posts, I’ve got a ton of writing in front of me!
I will work to respond in a considered, thoughtful way. Some of these are straightforward questions with reasonably straightforward answers. A few, anyway. Most are compound, complex and convoluted! It’s gonna take me a couple days to work my way through this. So your choice is 1) I can slop through this in 45 minutes and no one will really be satisfied, or 2) I can craft sincere responses that are backed up with as much care and knowledge (and outside resources) as I can muster. I choose option 2. But that means it will take a lot more time.
Thanks for your interest and enthusiasm (and your skepticism – at this stage in the game, that is a healthy response)!
Take care.
MJL
Michael Laine
President, LiftPort – The Elevator to Space Companies
twitter.com/mlaine
That is of course a question for Laine, but meanwhile it is also discussed in the Wikipedia articles on space elevators.
@ LBC:
One man’s trash heap is another man’s raw material. No, really, trash heaps are much more recycled today (for methane, plant soil and other raw material), and of course eventually it is all recycled in the geo-/biosphere.
The line of discussion seems off topic, but as we are on it: I’m not aware that we are “using up” energy or other resources. For example Earth is an open and recycled system, so we can import what we are using up locally (mainly fission fuels) or replace use of what we use at an unsustainable rate (mainly fossil fuels and minerals, which are recycled over geological time).
As for the rest, if and when we colonize we will as here have only the local resources to live on, with local trade over an economical region. Light speed economics will eventually put stop for anything expanding “exponentially” but precisely colonization itself. And we can’t ignore that.
I too have a question: how is coriolis effect going to be compensated in space elevator plans? I’m not so much interested in stabilizing the elevator itself, it can be done once and that’s it. But lifting a cargo should destabilize the elevator if not compensated (rocket pushing in the direction of earth spin, ?), or is this not a problem and why?
I would like to know, what is the weight limit? Just how heavy can we make a space elevator before gravity and mass push the structure into the Earth? Seems like a lot of weight in a very small area.
I am curious about what our intrepid austonaut might experince as they are hoisted aloft. Assuming that this is a slow and gentle process, at what point will the elevatee begin to experience ‘weightlessness’, [and I aknowledge that this is term is layman’s language for the complexity of free fall]. Will this be a sudden event during the trip heavenwards, or a gradual shedding of the kilogrammes? Many thanks, Peter.
@ LBC:
[continuing with the earlier comment, which I had to cut short.]
Finally, your description of our species in the end is applicable on _all_ species: “some sort of […] locust swarm that now having reached certain limits on this planet chomps at the bit to exploit and trash out […]”. This is the natural state for species, so nothing new there.
In fact, we are the descendants of the oxygen releasing “locust swarm” that once turned this planet from a free oxygen poor to a free oxygen rich trash heap. This swarm killed off the main amount of species and replaced it, polluting the atmosphere with a lethally poisonous, corrosive and explosive gas on a scale we have yet to dream of.
The strain to adapt to this pollutant lead to fundamental change in all cellular life all the way from hereditary machinery over metabolism to immune (cancer, oxidation) defense.
The upshot then was that after the mass extinction the productivity and habitability of the planet skyrocketed, as well as the biosphere increased energy potentials inaugurated the diversity that lead to multicellulars among other new developments.
If we colonize, something similar will happen with biomass and diversity but on a massively larger scale. Even if we chose to confine our biosphere to Earth, our ability to scrounge and use resources should eventually lead to a similar albeit not so dramatic change.
Now that looks like I’m arguing morality, but I’m only mentioning the positive consequences of competition for resources as in evolution and, say, market economy. It leads to increased efficiency to the benefit of those who adapt. [Note: globally, not as in the individualistic libertarian ideology, as the analogy mostly breaks down there for obvious reasons. Beware of ideologies! :-D]
But indeed it has no “recognition” of what waste it is producing or what resources it modifies and at what rates. It makes do.
So, is there morality that will concern us here? I think so, but not the “green” ideology of our species being benign against others, that hasn’t happened yet. (Nor is it likely outside our pets which we have started to have empathy for and get empathy from in many case. But that is AFAIU unique and a slow process. Again, beware of ideologies.)
But the usual dominant morality of empathy and altruism among own species, which all morally capable species have. Humans and our descendants will benefit from colonization. So it’s the moral thing to do.
LBC, to answer your “why” do it question, it’s basically a matter of survival. If we don’t leave our planet (at least some of us), we stand a good chance of going extinct the next time we’re hit by an asteroid. And even if we do survive such an event, the surviving won’t be good for those who remain. Plus dwindling resources will add to the misery.
We must get off this planet because our very survival likely depends upon it.
I find a certain amusement in such statements as these. In line with the cosmology blog page from last week on the aging universe and with the aging sun and the rest it is funny to listen to people go on about how depressing these things are. Yet here we are in a world that bristles with nuclear weapons, we are tearing up the planet (20,000 species lost per year, a Belgium’s worth of arable land on the planet lost per year, more natural ecosystems destroyed by urban sprawl and the increased demand for petro-corn, global heating and …), and we humans have an unfortunate history of putting mentally ill people in charge of our affairs. In effect our species is really little more than a somewhat brainy form of ground ape on an out of control exponential rampage. The future time frames by which our species could face utter annihilation could easily be a few centuries, and for that matter maybe a few years. And we want to colonize space with ideas of surviving mega-eons into the future by escaping this planet and a long term future of a dying sun? This a serious disconnect with regards to time scales and the impending issues which really impact us.
LC
Can the space elevator connect to the moon, Venus and Mars, to help build a carbon nanotube or space shield that shelters protects defends earth against supernova gamma ray bursts, intense solar flares, asteroids? Carbon nanotubes can withstand incredible heat and have incredibly high tensile strength to sling shot a ship towards another star in zero gravity it might reach half light speed? Earth is doomed if everybody must keep electing politicians. They want to save the country they say
Oops, too late, we were already hit with asteroids as you typed that. (Well, interplanetary dust particles, but you didn’t specify the size.)
While the individual risk of dying from an asteroid is up there with the ones that you see yearly (say, from lightning), the only known extinctions from an asteroid is from the Chixculub impact.
The non-avian dinosaurs killed represented maybe a few hundred species of the estimated ~ 4000 that ever existed. As a comparison, avian dinosaurs estimates to ~ 9000 species. Sea species was hit severely, ~ 30 % extinct.
So out of the millions of species that exist at any given time and billions over the whole biosphere life time, the risk that a land species dies from impact is on the order of 10^-6 – 10^-7 or so.
You call that “a good chance”? Ridiculous.