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Robots may be the only thing capable of getting into space via space elevator if humans don't find way around radiation belts

Although technology designated for the creation and implementation of space elevators has been increasing in popularity (even at NASA), a recent article in New Scientist claims that space elevators may inadvertently kill travelers due to a high levels of ionising radiation. 

The Van Allen radiation belts, two rings of charged particles trapped in the Earth's magnetic field, would ultimately kill any humans on the space elevator.  Astronauts who traveled through the belt in a spacecraft went relatively unharmed because they do so at a fast pace -- people on the elevator, however, may spend a half week in the belts.  Even at short intervals, the Van Allen radiation belts have been responsible for damaging shuttle and satellite integrated circuits and sensors.

Researchers are looking into several different ways they would be able to protect space travelers from the high level of radiation.  The first way is to move the elevator away from the equator so that the more intense parts of the belts can be avoided.  Some scientists have been quick to point out that even a relocation to the north or south might not be enough to reduce the amount of radiation exposure.  Another idea being discussed is to create some sort of radiation shield to help block radiation when the travelers enter the Van Allen belts.  But the shield would ultimately weigh down the elevator line enough to disrupt the motion of the cable and/or add unwanted stress on the line.

The idea of creating a 62,000-mile elevator to carry supplies and humans into space has been met with a bit of interest and optimism from researchers.  Even though there was no winner in the recent Space Elevator Games competition held in a New Mexico desert, contest organizers believe someone has the ability to win next year.  The University of Saskatchewan Space Design Team, however, was close but ended up being disqualified after going over the time limit by two seconds.

Needless to say, humans might still be using the good old rocket ship for some time to come even when, or if, a space elevator is built.

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Moon travel... heh
By bobsmith1492 on 11/16/06, Rating: 0
RE: Moon travel... heh
By oTAL on 11/16/2006 7:20:07 AM , Rating: 3
*lol*
I was thinking the exact same thing...
If anybody wants to know more about the space elevator read the wikipedia page on it. It's pretty good (it was when I read it anyway...)
This is stuff that is being discusse for ages now.


RE: Moon travel... heh
By PrinceGaz on 11/16/2006 8:24:44 AM , Rating: 1
Well it is one of the reasons why we never had a manned landing on the moon, and why all manned space missions have never gone above a low Earth orbit. Other reasons include the direct solar radiation that would be received during the trip there and back, as well as whilst on the Moon's surface as the Moon has no Van Allen radiation belts to protect it from that solar radiation.

Man might one day travel to the Moon and beyond, but not with present day technology. Well, not with present day technology if he wants to come back alive, that is.


RE: Moon travel... heh
By rtrski on 11/16/2006 9:05:59 AM , Rating: 3
"...why we never had a manned landing on the moon..."
"...manned space missions have never gone above a low Earth orbit..."

PLEASE tell me you're joking? Do flat-earthers still really exist like this?

Even if you don't believe we never landed on the moon, orbiting the moon certainly qualifies for outside of low earth orbit. And shielding isn't nearly as much an issue for a rocket ascent; they're totally different technologies. Sure, there's still a thrust-to-weight ratio and fuel allowances involved, but the elevator needs to deal with differential stresses related to a point-load in different positions along its length; for a rocket ascent the issue is solely the tradeoff of fuel vs. weight and thrust.



RE: Moon travel... heh
By PrinceGaz on 11/16/2006 7:31:16 PM , Rating: 2
I was not being entirely serious in my post where I doubted whether man had ever gone to the moon, but there are some very pertinent facts about manned space travel that are worth considering.

With the exception of the Apollo 11-17 missions, no other manned space missions have ever entered into an orbit more than a few hundred miles above the Earth. There is a good reason why no manned missions have ever gone up to 22,000 miles for the very useful geostationery orbit, and that is because of radiation. If it really wasn't a problem, why are the Apollo "moon landing" missions the only manned flights ever to go abover a few hundred miles?

Unfortunately a space-elevator can only be used to transfer material to and from a geostationery orbit at 22,000 miles up, it cannot be used for low orbit transfers due to the orbit velocity difference.

I'm sure by the time we have a space-elevator however, that we will also have devised suitable means of shielding occupants from the deadly radiation. Certainly something more effective than a few millimetres of aluminium at any rate.


RE: Moon travel... heh
By Meaker10 on 11/16/2006 9:17:48 AM , Rating: 2
Yes because in the 60s we had robots that could align a mirror towards to the earth so that when you shine a laser it reflects back :/


How pessimistic
By Lord Evermore on 11/16/2006 4:54:45 AM , Rating: 4
Why bother to say this at this point? This is like the people who said we'd never be able to create heavier than air flying machines (although these guys at least give it some benefit of doubt).

Shielding, obviously, is one way and you can't say we won't invent better stuff eventually. It doesn't even have to be solid or liquid shielding - electromagnetic shielding of some kind could be used.

And half a week on the elevator? They obviously aren't thinking big. We want elevators that get us to the top in a matter of days at most; only hours might be a long way off, until we can find a way to handle the acceleration. If it's half a week just in the radiation belts, how long must the entire trip be? Why would we bother putting up an elevator that takes 2 weeks to make a one-way trip?

Sure current materials and science may say that those are the best we can do, but we don't expect to be throwing up a cable tomorrow, so we look ahead to what we'll be capable of later, when we can use better capabilities to build on the basic ideas we work out now. The Wrights didn't expect people to be crossing the Atlantic in open-frame paper planes.




RE: How pessimistic
By Lord Evermore on 11/16/2006 4:58:58 AM , Rating: 2
Heh. And now I read the article and they mention some of what I said. And I didn't remember that the belts extend so far. Still, kind of a sensational headline for the article, given that they're just saying "here are some things that the space elevator will need to deal with". It's like calling cars death traps because you need to wear your seatbelt and not ram it into a wall.


RE: How pessimistic
By peternelson on 11/16/2006 6:02:21 AM , Rating: 2
Not really news, this has been known for a long time, with regards to travelling through belts in spaceships too (of course exposure time varies).

Rather than weigh down the elevator with radiation shielding, it has been proposed instead that the cargo payload on the elevator would provide the radiation screening necessary. Actually solid lead isn't very good against this form of radiation, but some other substances block it quite well.

So there are two options: pack the cargo on the elevator so it shields humans from radiation. OR use the elevator for cargo and robots, and send humans up in the shuttle or similar rocket.

Such has been long discussed so New Scientist is not offering any new information here other than recap the recent competition.


RE: How pessimistic
By drank12quartsstrohsbeer on 11/16/2006 9:27:02 AM , Rating: 2
quote:
OR use the elevator for cargo and robots, and send humans up in the shuttle or similar rocket.

I think this is the plan.
The elevator's only practical purpose is to do the heavy lifting, imho



The solution is obvious
By EODetroit on 11/16/2006 9:26:39 AM , Rating: 2
Obviously you just tell all passengers to duck and cover during that part of the journey.




RE: The solution is obvious
By marvdmartian on 11/16/2006 9:45:07 AM , Rating: 3
Won't matter what you do. The musak playing over the elevator speakers will kill all passengers by the time they reach outer space!!


Get the facts...
By Shadowself on 11/16/2006 10:16:37 AM , Rating: 1
I always love people talking about space when they don't have any experience dealing with the requirements of it and don't bother doing the actual calculations (which are not THAT complex). You hear such crap.

quote:
The Van Allen radiation belts, two rings of charged particles


There are actually three "belts" (toroids actually): two primary ones and a smaller hotter one situated between the other two. If your references claim there are only two then you need to update your references!

quote:
Astronauts who traveled through the belt in a space shuttle went relatively unharmed because they do so at a fast pace...


No astronaut has ever traveled through the belts in the shuttle. The maximum orbit of the shuttle is less than 500 miles. The belts start WAY above that! The astronauts on the way to the moon went through the belts both coming and going, but they only spent a few hours (maximum) going through them. Other than the astronauts going to the moon (either circling it or landing on it) have gone through the belts. No others have.

quote:
The first way is to move the elevator away from the equator so that the more intense parts of the belts can be avoided.


This is completely unworkable.

First: Currently there are no materials strong enough from which to make such an elevator. Just the tension forces are enough to tear apart anything we have today. Maybe someday, but not today. There are no "carbon nano tube matrix" materials in bulk which will do the job. Plus the matrix used to keep these in bulk material are radiation sensitive. They'll fall apart being constantly in the belts.

Second: The stresses on the elevator will be GREATLY increased if the base is moved off the equator and the top end is moved away from the geostationary position. The system is then subject to not only off angle stresses like the article correctly claims, but since it is both at a northern attach point and runs through the Clarke Belt it is subject to tremendous coriolis forces. This makes a working material even more decades off -- if ever.




RE: Get the facts...
By KristopherKubicki (blog) on 11/16/2006 11:30:09 AM , Rating: 3
Hello,

While I don't doubt you have some knowledge of this, let me through a few facts out:

quote:
There are actually three "belts" (toroids actually): two primary ones and a smaller hotter one situated between the other two. If your references claim there are only two then you need to update your references!


There are only two distinct radiation-generating toroids, an inner proton toroid and an outer electron toroid -- though the intensity of the outer toroid varies greatly. There might be more research on this that I am not aware of, but it seems that describing it as two toroids is very acceptable.

quote:
No astronaut has ever traveled through the belts in the shuttle.

Correct, we used the wrong term here and have corrected it. Needless to say, the astronauts that went to the moon through the Van Allen belts were sent during times when the radiation was known to be the weakest. It's not to say we couldn't do the same with a space elevator -- we would just need periods of time that are longer than the windows used for the moon landers.


By copiedright on 11/16/2006 6:06:58 AM , Rating: 2
The radiation from the Van Allen belts is actually not that strong. There are actually 2 belts of radiation and the lower belt, the one which we pass, does not extend the entire length of the trip.

I would worry more about the lower frequency radiation problems such as heat and maybe Ultra-violet.




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