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.
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.
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?
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.
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).
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.
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.
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.
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.
AndrewL, I don’t know if routine radioactive waste contains any U-235 but, if so, I just found on **Derleth**'s Homepage that if you throw in an “n-”, you get 165 Joules/Kilogram!
**That **should make plenty of steam for gentle thrusters.
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.
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:
Famous science fiction writers from 30 years ago thought it would be a good idea.
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.
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.
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.
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.
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.
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!
