# Space Elevator within 15 years? **URL:** \ **Category:** Great Debates\ **Created:** [March 27, 2002, 3:13pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378 "2002-03-27T15:13:44Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![Parameter\_928\_178](https://avatars.discourse-cdn.com/v4/letter/p/ed8c4c/32.png) [@Parameter\_928\_178](https://boards.straightdope.com/u/Parameter_928_178)\ **Post date:** [April 3, 2002, 3:18pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/101 "2002-04-03T15:18:44Z")
> [@](#): > > \*Originally posted by CalMeacham \* > \*\* > You can _plot_ a trajectory, certainly. But as I and othes have noted, to place your payload into that trajectory costs you. It costs you in terms of imetus, which has to come from somewhere. At some point, you have to throw away a lot of reaction mass (and spend the energy needed to get it up to speed) to force your radioactive waste out of orbit. … Momentum transfer ain’t free. As I’ve said before – launching something into the sun is an expensive and difficult proposition. > > I’m not saying you can’t put all the waste into orbit, but unless you shoved it somewhere it would all congregate at the “top” end of your space elevator. The Trojan points of the Earth-Moon system might be attractive, but that’s a quarter of a million miles away – you might as well dump it on the moon. And it’ll cost you reaction mass and energy to get it to either the Trojan points or the moon from the Elevator. \*\* This is “off the top of my head,” without any careful thinking-through. But: With the cheap-lift Space Elevator and with _radioactive material,_ you have a built-in energy source. Were you to lift some water and fit the waste container with nozzles, you could probably arrange for the radioactive-waste-generated heat to cause the water to boil and act as jet-propulsion. Perhaps you might not get a _lot_ of push but enough to get the waste container into any trajectory you might want; for example, into an orbit concentric to, but away from, Earth’s orbit or on a trajectory into the Sun. 😛 ---
**Author:** ![AndrewL](https://avatars.discourse-cdn.com/v4/letter/a/3d9bf3/32.png) [@AndrewL](https://boards.straightdope.com/u/AndrewL)\ **Post date:** [April 3, 2002, 4:04pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/102 "2002-04-03T16:04:08Z")
> [@](#): > > \*Originally posted by Parameter Π² \* > \*\*This is “off the top of my head,” without any careful thinking-through. But: > > With the cheap-lift Space Elevator and with _radioactive material,_ you have a built-in energy source. Were you to lift some water and fit the waste container with nozzles, you could probably arrange for the radioactive-waste-generated heat to cause the water to boil and act as jet-propulsion. Perhaps you might not get a _lot_ of push but enough to get the waste container into any trajectory you might want; for example, into an orbit concentric to, but away from, Earth’s orbit or on a trajectory into the Sun. 😛 \*\* To get any meaningful amount of thrust, the material would have to be highly radioactive, in which case we’d be better off holding onto it and using it as reactor fuel. Most of the radioactive waste that we’re worried about storing or getting rid of is just radioactive enough to be dangerous, without having enough energy output to be useful for anything. ---
**Author:** ![Cobalt](https://avatars.discourse-cdn.com/v4/letter/c/8491ac/32.png) [@Cobalt](https://boards.straightdope.com/u/Cobalt)\ **Post date:** [April 3, 2002, 4:23pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/103 "2002-04-03T16:23:56Z")
> [@](#): > > \*Originally posted by squeegee \* > > - **ftg** says the cable would be coming down at reentry speed (!), **cobalt** seems to confirm this. I just want to point out that I was saying it would **not** be coming down at reentry speed. That is, you would design the tether deployment system so that it wouldn’t, because coming down at reentry speed would be ruinous. ---
**Author:** ![emarkp](https://avatars.discourse-cdn.com/v4/letter/e/3be4f8/32.png) [@emarkp](https://boards.straightdope.com/u/emarkp)\ **Post date:** [April 4, 2002, 5:52am UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/104 "2002-04-04T05:52:42Z")
Now, everyone should know that a space elevator is impossible. Why? Because it would extend past the Van Allan belts. This would of course have to be a government project, and we don’t want to give them more money to use to spy on us (using that elaborate hoax as an excuse for where the money’s going of course). I’d have to put another layer on my tin-foil hat… 😃 But seriously. How can we think of making a cable into orbit if we can’t even launch the space shuttle in a stiff breeze? ---
**Author:** ![Parameter\_928\_178](https://avatars.discourse-cdn.com/v4/letter/p/ed8c4c/32.png) [@Parameter\_928\_178](https://boards.straightdope.com/u/Parameter_928_178)\ **Post date:** [April 4, 2002, 6:01pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/105 "2002-04-04T18:01:22Z")
> [@](#): > > \*Originally posted by dalovindj \* > \*\*I like a good hijack. The “Should we or shouldn’t we ship nuclear waste into space?” issue is a minor hijack compared to the “Does the sun have feelings?” hijack which seems to come out of left field. I’d like to address them both. > > It seems to me that if we could contain the waste in some sort of super-secure container and lift it up via the space elevator and dump it into the sun, that woud be a pretty effective solution to the problem. The main concerns? On the way up the elevator what happens if a jet/terrorist bomb comes along and blows up the car high in the atmosphere? Is it possible to create a container that could contain the waste safely even in such an event? So that if it comes crashing down into the ocean it is still secure and can be recovered and there is no chance of the waste being released into the atmosphere. Once to the top of the eleveator the container could be put into an unmanned ship that travels to and from the sun using a solar-powered ion engine (relatively cheap propulsion) and releases it’s cargo when it gets close enough to the sun that it will fall in, then it returns to earth to get more waste (nuclear or any other kind). Seems like a good plan to me. Securing the elevator seems to be the biggest problem. > > How hard would it be to secure something in the middle of the Pacific? Just destroy anything that gets within a hundred or two miles without clearance. > > Now as far as the sun having feelings, I’ve never heard that theory before. I’ve heard the Gaia theory, and a couple competeing theories about Super-Organisms emerging from the interaction and memes of many people, but all of those theories were ways of describing emergent properties in systems that were filled with obvious life. The sun exists at a temperature that is far too hostile towards life as we know it. > > I suppose it could be possible that there is some system in the sun that gives it awareness, but it does seem unlikely. What would we expect to find as evidence if this were true? Even if it were to be a living entity, the amount of radioactive waste we would send into the sun would equate to not even a mosquito bite. The Sun is something like 109 times the size of the earth if I remember correctly. The total volume of waste compared to the total volume of the sun would be .000-add a shitload of zeros-01 > > I can’t imagine these minor amounts of waste would be detrimental to the sun - alive or no. > > DaLovin’ Dj \*\* Since it’s _your_ thread, **DaLovin’ Dj** , I suppose that you’re the judge of when a “hijack” is a no-no and when it’s OK. Let me try to answer your objections. As to the security of the hypothetical Space Elevator: I like proofs by counter-example. We have lots of very-isolated missile silos with nuclear warheads. **What a target to take-over!** The Soviets, now Russians, have lots of track-mounted mobile missiles with nuclear warheads. **What targets for a hijacking!** Yet to the best of my knowledge, neither we nor the Soviets/Russians have had a single incident of an attempt to grab a nuclear-weapon-tipped missile. Had there been such an attempt, I think that it _would_ have been publicized rather than covered up, for the reason of the extremely beefed-up security that publication would prompt. There would be only one Space Elevator. Based on 40 years of history with nuclear weapons, I don’t think that security of a Space Elevator will **ever** a problem: Way too many people, way too worried about the problem for anyone to _ever_ succeed at anything beyond simple sabotage. As to the Sun’s having feelings: We call ourselves thoughtfull and with feelings based on our brain activity; activity which is based on moving electrons and other, bigger, chemical things–atomic, ionic, molecular. The Sun is **nothing but** lots of moving chemical things. Standing on the outside of our space-time, I would much rather hypothesize that the Sun had thoughts and feelings than I would that animals do: There’s so much more stuff moving around and interacting–the stuff that our scientists believe produces thought and feelings. 🙂 Rebutal? ---
**Author:** ![NurseCarmen](https://avatars.discourse-cdn.com/v4/letter/n/5daacb/32.png) [@NurseCarmen](https://boards.straightdope.com/u/NurseCarmen)\ **Post date:** [April 4, 2002, 6:09pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/106 "2002-04-04T18:09:15Z")
k, this might be a stupid question, but all the talk of radioactivity set my mind aglow. Wouldn’t the cable itself become radioactive since half of it is outside the protection of our atmosphere? ---
**Author:** ![Cobalt](https://avatars.discourse-cdn.com/v4/letter/c/8491ac/32.png) [@Cobalt](https://boards.straightdope.com/u/Cobalt)\ **Post date:** [April 4, 2002, 7:38pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/107 "2002-04-04T19:38:49Z")
> [@](#): > > \*Originally posted by NurseCarmen \* > \*\*Wouldn’t the cable itself become radioactive since half of it is outside the protection of our atmosphere? \*\* The upper cable would be exposed to more cosmic radiation and, perhaps worse, the Van Allen belt radiation. But that doesn’t mean it would become significantly _radioactive_. It might, eventually, cause mechanical failure problems (eg. you have to be careful of the concrete in your nuclear generators here on Earth because prolonged radiation exposure can eventually weaken the material). ---
**Author:** ![AndrewL](https://avatars.discourse-cdn.com/v4/letter/a/3d9bf3/32.png) [@AndrewL](https://boards.straightdope.com/u/AndrewL)\ **Post date:** [April 4, 2002, 9:51pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/108 "2002-04-04T21:51:40Z")
> [@](#): > > \*Originally posted by NurseCarmen \* > \*\*Wouldn’t the cable itself become radioactive since half of it is outside the protection of our atmosphere? \*\* There are different kinds of radiation. Things only become radioactive when exposed to neutron radiation, which is typically only found as a result of fission reactions. Aboce the earth’s atmosphere, the cable will be exposed to proton radiation and high-evergy electromagnetic waves. These will not cause it to become radioactive, although they may degrade the tether material over time. ---
**Author:** ![squeegee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/squeegee/32/14537_2.png) [@squeegee](https://boards.straightdope.com/u/squeegee)\ **Post date:** [April 5, 2002, 6:19am UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/109 "2002-04-05T06:19:17Z")
> [@](#): > > \*Originally posted by Cobalt \* > I just want to point out that I was saying it would **not** be coming down at reentry speed. That is, you would design the tether deployment system so that it wouldn’t, because coming down at reentry speed would be ruinous. Ah, gotcha. You’d said something to the effect of “that’s why you need Massive Brakes”, which I thought meant you’d need massive brakes _because_ it’s moving at reentry speed, not to _prevent_ it from moving that fast. Agreed, there’s no reason why it should move that fast, and it would be ruinous. ---
**Author:** ![Parameter\_928\_178](https://avatars.discourse-cdn.com/v4/letter/p/ed8c4c/32.png) [@Parameter\_928\_178](https://boards.straightdope.com/u/Parameter_928_178)\ **Post date:** [April 5, 2002, 9:08pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/110 "2002-04-05T21:08:16Z")
> [@](#): > > \*Originally posted by AndrewL \* > \*\* > To get any meaningful amount of thrust, the material would have to be highly radioactive, in which case we’d be better off holding onto it and using it as reactor fuel. Most of the radioactive waste that we’re worried about storing or getting rid of is just radioactive enough to be dangerous, without having enough energy output to be useful for anything. \*\* I thought that the whole idea of the Elevator was to get stuff up to where only a tiny bit of energy would be needed to escape Earth’s gravity well. If this is true then any thrust needed to get a new trajectory could be very small–as are the thrusts provided by solar sails. Either way, it was just an “off the top of my head” notion to say that the cost of getting rid of the radioactive waste would be almost the same cost of raising it up the Space Elevator; that the cost of moving into a new trajectory–into, say, a permanent orbit– **could** be made to be nearly trivial. 🙂 ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [April 6, 2002, 2:09am UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/111 "2002-04-06T02:09:27Z")
From geostationary orbit, you still need about half of the change in velocity to get out of the solar system as you need to get out of the Earth’s gravity well in the first place. In other words, from orbit you are pretty much halfway to anywhere in the universe, if you’ve got the time. But being in an airless, weightless environment, you have the option to accelerate very slowly, like with a solar sail. ---
**Author:** ![Parameter\_928\_178](https://avatars.discourse-cdn.com/v4/letter/p/ed8c4c/32.png) [@Parameter\_928\_178](https://boards.straightdope.com/u/Parameter_928_178)\ **Post date:** [April 6, 2002, 8:33pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/112 "2002-04-06T20:33:51Z")
**AndrewL** , I don’t know if routine radioactive waste contains any U-235 but, if so, I just found on \*\*[Derleth\*\*'s Homepage](http://odin.prohosting.com/derleth/index.html) that if you throw in an “n-”, you get 165 Joules/Kilogram! \*\*That \*\*should make plenty of steam for gentle thrusters. 🙂 ---
**Author:** ![squeegee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/squeegee/32/14537_2.png) [@squeegee](https://boards.straightdope.com/u/squeegee)\ **Post date:** [August 21, 2002, 3:30pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/113 "2002-08-21T15:30:59Z")
Just to keep things current: [Private group begins work on space elevator](http://news.yahoo.com/news?tmpl=story2&cid=96&ncid=753&e=10&u=/space/20020819/sc_space/going_up__private_group_begins_work_on_space_elevator) ---
**Author:** ![dalovindj](https://avatars.discourse-cdn.com/v4/letter/d/65b543/32.png) [@dalovindj](https://boards.straightdope.com/u/dalovindj)\ **Post date:** [August 21, 2002, 8:16pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/114 "2002-08-21T20:16:24Z")
> [@](#): > > “The space elevator will be built about 50 years after everyone stops laughing.” That’s a great line. Thanks for the update, **squeegee**. I recently read an article in “pop sci” or maybe it was “pop mechanics” along similar lines. It sounds like this stuff may be working itself towards becoming a reality. Space is our only hope in the long run. We need cheap access. DaLovin’ Dj ---
**Author:** ![partly\_warmer](https://avatars.discourse-cdn.com/v4/letter/p/bc8723/32.png) [@partly\_warmer](https://boards.straightdope.com/u/partly_warmer)\ **Post date:** [August 21, 2002, 9:11pm UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/115 "2002-08-21T21:11:19Z")
Try the company’s summary or FAQ at: [http://www.highliftsystems.com/](http://www.highliftsystems.com/) They make it sound like the technology’s all in place, but, for many of the reasons stated above, I smell a rat. Having worked as a manager on one of NASA’s multi-million dollar scam projects, I see lots of the same sort of argumentation: 1. Famous science fiction writers from 30 years ago thought it would be a good idea. 2. Evading the main difficulties. Quote “The ribbon, being the only componant of the space elevator not commercially available…” Then they proceed to define the exact dimensions of this “unavailable” componant. Scam, scam, scam. 3. Phony “bottom line” estimates of the problem “The bottom line is that the NIAC Phase I and current Phase II studies examined the entire system in detail and found a space elevator design that will work with current or near-future technology, a method to deploy the ribbon, and specific scenario for safe operation.” Either it’s current technology, or it isn’t, guys. If it is, where is it? If it’s not available, what makes you think it ever will be? No evidence provided. Note the “cover our asses” provisions: a) There must be a way to deploy the ribbon (which they haven’t figured out), and b) they have no concrete idea of what “a scenairo for safe operation” is. I’m not saying the investigation isn’t worthwhile. And if they succeeded it would change the future of mankind. So I’m all for it. It’s just that scientists are very adept at telling people what they want to hear so they can get money. Been there. ---
**Author:** ![Satyagrahi](https://avatars.discourse-cdn.com/v4/letter/s/f475e1/32.png) [@Satyagrahi](https://boards.straightdope.com/u/Satyagrahi)\ **Post date:** [August 22, 2002, 5:31am UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/116 "2002-08-22T05:31:37Z")
Hey, a _ **great** _ thread, guys. Thank you for resurrecting it from last year. I, too, read Clarke’s _The Fountains Of Paradise_ many. many years ago and was thrilled by the concept. Like Daniel Burnham said, “Make no little plans; they have no magic to stir men’s blood.” Now, to add my 8 drachmas: Most of the difficulties mentioned in the thread seem to involve the bottom 100 kilometers of the tether; the part in the atmosphere; a small percentage of whole length. This section of the tether is the one where you worry about wind forces during and after construction, terrorism, angular momentum forces requiring a massive anchor, etc. etc. And more etc. So why not eliminate that small, troublesome part and have the counter-weighted downward half of the tether extend just to the edge of the atmosphere? A high-performance airplane–maybe a scramjet, maybe something else–flies up to the bottom end of the tether, makes a rendezvous, unloads its cargo, and flies down to Earth for another load. Simple. 🙂 Of course…the tether is rotating like two spokes around the hub of a bicycle tire…but so what? That just makes it fun. 🙂 Before your mind boggles entirely, [here’s a great diagram with a link to a solid scientific paper on the subject.](http://www.tethers.com/HASTOL.html) So where do I send my $10 for a tourist excursion ticket? ---
**Author:** ![Satyagrahi](https://avatars.discourse-cdn.com/v4/letter/s/f475e1/32.png) [@Satyagrahi](https://boards.straightdope.com/u/Satyagrahi)\ **Post date:** [August 22, 2002, 5:39am UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/117 "2002-08-22T05:39:31Z")
Hey, a _ **great** _ thread, guys. Thank you for resurrecting it from last year. I, too, read Clarke’s _The Fountains Of Paradise_ many. many years ago and was thrilled by the concept. Like Daniel Burnham said, “Make no little plans; they have no magic to stir men’s blood.” Now, to add my 8 drachmas: Most of the difficulties mentioned in the thread seem to involve the bottom 100 kilometers of the tether; the part in the atmosphere; a small percentage of whole length. This section of the tether is the one where you worry about wind forces during and after construction, terrorism, angular momentum forces requiring a massive anchor, etc. etc. And more etc. So why not eliminate that small, troublesome part and have the counter-weighted downward half of the tether extend just to the edge of the atmosphere? A high-performance airplane–maybe a scramjet, maybe something else–flies up to the bottom end of the tether, makes a rendezvous, unloads its cargo, and flies down to Earth for another load. Simple. 🙂 Of course…the tether is rotating like two spokes around the hub of a bicycle tire…but so what? That just makes it fun. 🙂 Before your mind boggles entirely, [here’s a great diagram with a link to a solid scientific paper on the subject.](http://www.tethers.com/HASTOL.html) So where do I send my $10 for a tourist excursion ticket? ---
**Author:** ![Satyagrahi](https://avatars.discourse-cdn.com/v4/letter/s/f475e1/32.png) [@Satyagrahi](https://boards.straightdope.com/u/Satyagrahi)\ **Post date:** [August 22, 2002, 5:44am UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/118 "2002-08-22T05:44:50Z")
Hey, a _ **great** _ thread, guys. Thank you for resurrecting it from last year. I, too, read Clarke’s _The Fountains Of Paradise_ many. many years ago and was thrilled by the concept. Like Daniel Burnham said, “Make no little plans; they have no magic to stir men’s blood.” Now, to add my 8 drachmas: Most of the difficulties mentioned in the thread seem to involve the bottom 100 kilometers of the tether; the part in the atmosphere; a small percentage of whole length. This section of the tether is the one where you worry about wind forces during and after construction, terrorism, angular momentum forces requiring a massive anchor, etc. etc. And more etc. So why not eliminate that small, troublesome part and have the counter-weighted downward half of the tether extend just to the edge of the atmosphere? A high-performance airplane–maybe a scramjet, maybe something else–flies up to the bottom end of the tether, makes a rendezvous, unloads its cargo, and flies down to Earth for another load. Simple. 🙂 Of course…the tether is rotating like two spokes around the hub of a bicycle tire…but so what? That just makes it fun. 🙂 Before your mind boggles entirely, [here’s a great diagram with a link to a solid scientific paper on the subject.](http://www.tethers.com/HASTOL.html) So where do I send my $10 for a tourist excursion ticket? ---
**Author:** ![Satyagrahi](https://avatars.discourse-cdn.com/v4/letter/s/f475e1/32.png) [@Satyagrahi](https://boards.straightdope.com/u/Satyagrahi)\ **Post date:** [August 22, 2002, 5:47am UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/119 "2002-08-22T05:47:57Z")
That’s interesting: I hit the Submit button _ **once** _. The hamsters must be drunk. ---
**Author:** ![lokij](https://avatars.discourse-cdn.com/v4/letter/l/5e9695/32.png) [@lokij](https://boards.straightdope.com/u/lokij)\ **Post date:** [August 23, 2002, 5:38am UTC](https://boards.straightdope.com/t/space-elevator-within-15-years/100378/120 "2002-08-23T05:38:11Z")
I’m curious as to why so many people seem to want to eject nuclear waste into the sun or outside of our solar system. From a purely scientific standpoint heavy elements (such as nuclear waste) are extremely scarce items in the solar soup we live in. Scarcity suggests it might be prudent to store them some place safely tucked away but also someplace where we can also get at them should we need them for some future reason. I recall that gasoline was discarded at early refineries as a waste product with no use, and natural gas was burned off as a waste product at one time too. Throwing heavy metals into the sun strikes me as terrifically wastefull, look at how long it took the sun to make and eject the stuff in the first place! [Previous page](https://boards.straightdope.com/t/space-elevator-within-15-years/100378.md?page=5) [Next page](https://boards.straightdope.com/t/space-elevator-within-15-years/100378.md?page=7)