I imagine the real rational for this is...What about all those people who don't have access to the internet. If the USPS has email service, they can be sent emails just like regular mail, and the USPS will print them out and deliver them....Suddenly the whole world is connected to the internet...isn't that what all the politicians (sp?) want to give their taxpayers?
I believe that this was the same book quoted in a special issue of Scientific American in May 99 or so. I believe he is quite wrong. If you look at the recent solar flare (july 14th through the 18th), at http://crlgin.crl.go.jp/s edoss/solact3/do?d=2000%2C7%2C19 you'll see that the spectrum is much harder than that mentioned in that article (he talks about 1 MeV protons)...this flare had many many protons above 100 MeV. note: I noticed the graph here doesn't explain the data much...go down to proton flux and look at the red white and blue lines...the white line is protons with energy greater than 100 MeV, the blue is greater than 50 MeV, and teh red is greater than 10 MeV. This is a real danger. If you look in another one of my posts, I cut and pasted the spectrum for particles (just protons) expected on one of the upcoming Mars missions...this spectra too is much more penetrating than what Robert Zubrin's book describes (assuming it matches the SciAm article, I don't have the book, but will check it out).
Space suits don't really perform that job. When astronauts are on EVA, they accumulate more dose than normal of course. They provide modest shielding, but most of the shielding is coming from the Earth's geomagnetic shielding, not the space suit or even the Shuttle/ISS itself.
AFAIK, this is the proton energy spectra to be used in upcoming Mars missions. This spectra is much worse than what you are currently experiencing on Earth and would most likely kill you. Notice the high energy particles. A 2000 MeV particle can penetrate some 3 to 4 meters through Aluminum...a small shielded area won't cut it, IMHO.
http://www.radiation-effects.com/Com posite.pdf has information about the first proton transport measurements on composite materials. If you have any questions about it, email me at boing_boing23@nospam.hotmail.com
Didn't mean to overwhelm you with calcs...just pointing out that the cost is going to be huge most likely and it will be difficult to get into space.
Lightweight materials in general stop radiation in proportion to their density...i.e. you still need ~ the same total weight. In the case of composite materials, it has been observed that the transport of radiation has been higher than predicted, especially with the lower energy particles (the ones that deposit more charge and are more dangerous to human beings).
"It depends on how long the journey takes really. Even today we've had men in space for a year and no more protection than our Mars ship would have. But still, a manned craft would have more shielding, they're not going to want to have people die from radiation sickness half way there are they?:) "
By those men in space for more than a year, you mean Mir, right?
Mir's orbit because of geomagnetic shielding provides more shielding than we could provide through shielding of material directly. On the way to Mars and at Mars, there will be little to no Geomagnetic shielding...the problem of radiation will be much worse.
....Random calculating below...... I believe to have a manned spacecraft with enough shielding would be too heavy.
So with some quick calculations... 100 Mev Proton has a range of 1.44 ft in Aluminum, so lets assume that we our ship to be a 10 ft radius sphere (simplified to make math easier) with a 1 ft Al wall to shield from radiation...that gives us a mass for just the shell (no contents) of...calculating... ~55742 lbs. If we make that 20 ft radius, we get ~2.5 million lbs.
My guess is for a mission to Mars we would need the 20 foot radius size...so we are talking about really big launch costs here and possibly having to assemble the ship in orbit.
..........End of calculating........
I just don't see it happening anytime soon. I think it would be very interesting and exciting, but I think we have a long way to go.
Besides, I would rather NASA get funded for this than some of the other stuff they are doing.
Now that is just a quick guesstimate, but I think it will tough for us to carry everything we want there and back with protection for the mission at
I personally don't believe the technology is there.
There are two major problems in my mind. The first in technological and the second is sociological.
1) We have no means to protect our astronauts effectively from space radiation. The space radiation environment in terms of energetic protons is worse on Mars than it was for the recent solar flare. That solar flare would likely have killed any astronauts had we put them in as little shielding as Mars missions will have. There is no effective way to shield against energetic protons without adding a large amount of weight. This weight of course drives up cost and causes manuverability problems.
2) We are afraid to have anyone die while visiting Mars. See the aftermath of the Challenger accident if you don't believe that. This fear will keep us off Mars for a long time, because it is likely that if, on average for the first dozen or so attempts, we send 100 men to Mars, I think only 30 or 40 would be likely to come back at best.
For these 2 reasons, I don't think that we will make it to Mars within the next 20 or 30 years. 50 or 100? Maybe.
Why the hell is this article labelled security through Obscurity is a Good Thing (tm)? Nothing I read in that article talked about security through obscurity.
What I read is that he thinks it is a bad plan for people who find vulnerabilities in software to release no-brains tools to exploit them and to do it because it is profitable to them.
He didn't say, "Don't tell everyone about the security problem"; He said tell the appropriate people first, don't do it for your own gain, and finally don't put up a website with a set of tools to exploit the vunerability that script kiddies can use.
Why didn't slashdot label this right is the bigger question? Is slashdot being run by script kiddies?;-)
"And don't forget the ziilions of zero-g experiments in..."
I attended a conference discussing microgravity (note: not Zero-G; ISS experiences gravity ~10^-6 compared to Earth) and the scientists there had a very difficult time justifying the cost of ISS for microgravity experiments. It turns out that the gravity is not much better than they can get elsewhere. Elsewhere would be cheaper too if NASA wasn't subsidizing the hell out of ISS projects (For any people who want to put something into space, they should look into it...I believe the cheapest mission was on the order of $8000 for about a foot by foot by half foot box). Anyway, apparently ISS will have to manuever enough because of its orbit being so filled with crap and so close to other satellites that the gravity will not be very consistent. So I don't believe the zero-G experiments are worth the price on ISS.
"The infrastructure of the US and the entire world..."
I debate this point also. The shuttle is quite limited in its range and capacity. Launch vehicles of other sorts would likely have been much cheaper in most instances, if it had not been for NASA looking for other uses for the shuttle. They have subsidized many satellite launches; If they had not, any number of other launch vehicles probably would have offered cheaper access to space.
You know you do...but perhaps the best way to deal with the legal issues is to for the people working on MAME to directly contact the copyright holders. Most would probably be willing to sign a legal agreement that MAME is fair use. They won't mind people playing for free, but if someone starts selling, then they will want part of the profit, is my guess.
I know most of this forum is real big into OCing, but for the majority of users it is definitely the wrong thing to do.
A couple weekends ago, I spent four or five hours looking at someone's computer to solve the frequent crashing problem he had. After all that time looking, I was getting nowhere...so I checked the BIOS settings and low and behold, his computer was overclocked...he had been told that it was normal & natural...no big deal. Except that this machine was crashing about every 20 minutes, and he had no need for the extra speed.
So before you get excited about this, I just wanted to point out that sometimes the better solution is to not try and get that extra 20% or get that extra 20% through distributed computing (e.g. Seti@home).
Or perhaps we should be more careful in our votes...we all vote for corporations on a daily basis. By buying products (which everyone thinks of automatically), but also where we invest our money. How many of you slashdotters dislike Microsoft (insert any company whose practices you personally dislike here), but own Microsoft through your 401K, etc.?
I agree with your sentiments...but what about the limitations already on speech (yelling "fire" in a theater)? Does that single limitation mean we do not have free speech?
I don't think so. Most satellites are one of kind. There are a few companies that have put out spacecraft "buses" that are the same, but the payloads are different. The cost of putting someone/something up in the orbit to collect all the piece and build something new with them would be _much_ greater than the cost to just build something new. Satellites and space vehicles are non-trivial to build...that's why they cost so much on the ground. Recycling parts is a pipe dream at this point.
Very few satellites are as low as 150 nmi and LEO environments can be up to 1000 nmi...so you are talking about a larger section of space.
Also, that 65,000 pieces of space junk is not just limited to LEOs, but goes all the way up to GEO which is ~22,000 nmi...much more space than you are suggesting.
furthermore, typical orbiting times for a revolution of a LEO are approximately 1 to 2 hours.
The junk is well monitored and while I am not happy it is up there, it is not much of a concern in all reality to orbiting satellites and the space station.
I know this will probably get super modded down, but...
Is it me or is NASA spending an inordinate amount of time promoting itself. I watch the news in the morning and it is amazing how often NASA comes up. Not to mention slashdot.
Now I find space exploration interesting, but NASA is putting out more PR than big corporations. Ever seen a copy of NASA Tech Briefs...pure fluff almost.
For instance, this article really didn't contain much information. This probably has been sitting on the NASA website for months and no one picked it up there.
One more instance of this type of thing, I have seen NASA divisons at conferences renting booths beside Corporations in the industrial exhibits. How is this legal? I don't want NASA to be spending my taxpayer money on PR.
Dan Goldin is an interesting figure. Check out www.nasawatch.com to find out all kinds of interesting stuff about him...and nasa too.
Re:Macs in space: been there, done that
on
Macs In Space!
·
· Score: 1
$10000/lb
Re:Ah, I *like* this idea...
on
Macs In Space!
·
· Score: 1
Propellent and engines on the spacecraft or a separate small vehicle to accomplish that. Many satellites are launched by the shuttle etc...they do not stay in that orbit.
Slashdot Mirror
surface mount technology
I imagine the real rational for this is...What about all those people who don't have access to the internet. If the USPS has email service, they can be sent emails just like regular mail, and the USPS will print them out and deliver them....Suddenly the whole world is connected to the internet...isn't that what all the politicians (sp?) want to give their taxpayers?
I believe that this was the same book quoted in a special issue of Scientific American in May 99 or so. I believe he is quite wrong. If you look at the recent solar flare (july 14th through the 18th), at http://crlgin.crl.go.jp/s edoss/solact3/do?d=2000%2C7%2C19 you'll see that the spectrum is much harder than that mentioned in that article (he talks about 1 MeV protons)...this flare had many many protons above 100 MeV. note: I noticed the graph here doesn't explain the data much...go down to proton flux and look at the red white and blue lines...the white line is protons with energy greater than 100 MeV, the blue is greater than 50 MeV, and teh red is greater than 10 MeV. This is a real danger. If you look in another one of my posts, I cut and pasted the spectrum for particles (just protons) expected on one of the upcoming Mars missions...this spectra too is much more penetrating than what Robert Zubrin's book describes (assuming it matches the SciAm article, I don't have the book, but will check it out).
Space suits don't really perform that job. When astronauts are on EVA, they accumulate more dose than normal of course. They provide modest shielding, but most of the shielding is coming from the Earth's geomagnetic shielding, not the space suit or even the Shuttle/ISS itself.
AFAIK, this is the proton energy spectra to be used in upcoming Mars missions. This spectra is much worse than what you are currently experiencing on Earth and would most likely kill you. Notice the high energy particles. A 2000 MeV particle can penetrate some 3 to 4 meters through Aluminum...a small shielded area won't cut it, IMHO.
Energy (MeV) Particles/cm2
0.100000001 9.99999996e+011
0.200000003 9.99999996e+011
0.300000012 9.99999996e+011
0.400000006 4.99999998e+011
0.5 4.99999998e+011
0.600000024 4.99999998e+011
0.699999988 4.99999998e+011
0.800000012 2.99999986e+011
0.899999976 2.99999986e+011
1 2e+010
2 2e+010
3 2e+010
4 2e+010
5 1e+010
6 1e+010
7 1e+010
8 1e+010
9 1e+010
10 1e+010
20 5e+009
30 5e+009
40 5e+009
50 5e+009
60 5e+009
70 5e+009
80 5e+009
90 5e+009
100 1e+009
200 1e+009
300 1e+009
400 1e+009
500 500000000
600 500000000
700 500000000
800 500000000
900 300000000
1000 200000000
2000 100000000
3000 4.5
http://www.radiation-effects.com/Com posite.pdf has information about the first proton transport measurements on composite materials. If you have any questions about it, email me at boing_boing23@nospam.hotmail.com
Didn't mean to overwhelm you with calcs...just pointing out that the cost is going to be huge most likely and it will be difficult to get into space.
Lightweight materials in general stop radiation in proportion to their density...i.e. you still need ~ the same total weight. In the case of composite materials, it has been observed that the transport of radiation has been higher than predicted, especially with the lower energy particles (the ones that deposit more charge and are more dangerous to human beings).
"It depends on how long the journey takes really. Even today we've had men in space for a year and no more protection than our Mars ship would have. But still, a manned craft would have more shielding, they're not going to want to have people die from radiation sickness half way there are they? :) "
By those men in space for more than a year, you mean Mir, right?
Mir's orbit because of geomagnetic shielding provides more shielding than we could provide through shielding of material directly. On the way to Mars and at Mars, there will be little to no Geomagnetic shielding...the problem of radiation will be much worse.
....Random calculating below......
I believe to have a manned spacecraft with enough shielding would be too heavy.
So with some quick calculations...
100 Mev Proton has a range of 1.44 ft in Aluminum, so lets assume that we our ship to be a 10 ft radius sphere (simplified to make math easier) with a 1 ft Al wall to shield from radiation...that gives us a mass for just the shell (no contents) of...calculating... ~55742 lbs. If we make that 20 ft radius, we get ~2.5 million lbs.
My guess is for a mission to Mars we would need the 20 foot radius size...so we are talking about really big launch costs here and possibly having to assemble the ship in orbit.
..........End of calculating........
I just don't see it happening anytime soon. I think it would be very interesting and exciting, but I think we have a long way to go.
Besides, I would rather NASA get funded for this than some of the other stuff they are doing.
Now that is just a quick guesstimate, but I think it will tough for us to carry everything we want there and back with protection for the mission at
I personally don't believe the technology is there.
There are two major problems in my mind. The first in technological and the second is sociological.
1) We have no means to protect our astronauts effectively from space radiation. The space radiation environment in terms of energetic protons is worse on Mars than it was for the recent solar flare. That solar flare would likely have killed any astronauts had we put them in as little shielding as Mars missions will have. There is no effective way to shield against energetic protons without adding a large amount of weight. This weight of course drives up cost and causes manuverability problems.
2) We are afraid to have anyone die while visiting Mars. See the aftermath of the Challenger accident if you don't believe that. This fear will keep us off Mars for a long time, because it is likely that if, on average for the first dozen or so attempts, we send 100 men to Mars, I think only 30 or 40 would be likely to come back at best.
For these 2 reasons, I don't think that we will make it to Mars within the next 20 or 30 years. 50 or 100? Maybe.
IMHO
Why the hell is this article labelled security through Obscurity is a Good Thing (tm)? Nothing I read in that article talked about security through obscurity.
;-)
What I read is that he thinks it is a bad plan for people who find vulnerabilities in software to release no-brains tools to exploit them and to do it because it is profitable to them.
He didn't say, "Don't tell everyone about the security problem"; He said tell the appropriate people first, don't do it for your own gain, and finally don't put up a website with a set of tools to exploit the vunerability that script kiddies can use.
Why didn't slashdot label this right is the bigger question? Is slashdot being run by script kiddies?
"And don't forget the ziilions of zero-g experiments in..."
I attended a conference discussing microgravity (note: not Zero-G; ISS experiences gravity ~10^-6 compared to Earth) and the scientists there had a very difficult time justifying the cost of ISS for microgravity experiments. It turns out that the gravity is not much better than they can get elsewhere. Elsewhere would be cheaper too if NASA wasn't subsidizing the hell out of ISS projects (For any people who want to put something into space, they should look into it...I believe the cheapest mission was on the order of $8000 for about a foot by foot by half foot box). Anyway, apparently ISS will have to manuever enough because of its orbit being so filled with crap and so close to other satellites that the gravity will not be very consistent. So I don't believe the zero-G experiments are worth the price on ISS.
"The infrastructure of the US and the entire world..."
I debate this point also. The shuttle is quite limited in its range and capacity. Launch vehicles of other sorts would likely have been much cheaper in most instances, if it had not been for NASA looking for other uses for the shuttle. They have subsidized many satellite launches; If they had not, any number of other launch vehicles probably would have offered cheaper access to space.
Trivia Question: Anyone remember the town in which the Blob was filmed?
http://www.fourmilab.ch/documents/rocketaday.html
Don't look like a fake link to me
Here is an article about the same sort of concept except with a solution from 1993.
You know you do...but perhaps the best way to deal with the legal issues is to for the people working on MAME to directly contact the copyright holders. Most would probably be willing to sign a legal agreement that MAME is fair use. They won't mind people playing for free, but if someone starts selling, then they will want part of the profit, is my guess.
I know most of this forum is real big into OCing, but for the majority of users it is definitely the wrong thing to do.
A couple weekends ago, I spent four or five hours looking at someone's computer to solve the frequent crashing problem he had. After all that time looking, I was getting nowhere...so I checked the BIOS settings and low and behold, his computer was overclocked...he had been told that it was normal & natural...no big deal. Except that this machine was crashing about every 20 minutes, and he had no need for the extra speed.
So before you get excited about this, I just wanted to point out that sometimes the better solution is to not try and get that extra 20% or get that extra 20% through distributed computing (e.g. Seti@home).
Or perhaps we should be more careful in our votes...we all vote for corporations on a daily basis. By buying products (which everyone thinks of automatically), but also where we invest our money. How many of you slashdotters dislike Microsoft (insert any company whose practices you personally dislike here), but own Microsoft through your 401K, etc.?
The whole idea is extremely absurd.
How is software going to determine what is pornography if the courts can't come up with a good definition of it?
I agree with your sentiments...but what about the limitations already on speech (yelling "fire" in a theater)? Does that single limitation mean we do not have free speech?
I don't think so. Most satellites are one of kind. There are a few companies that have put out spacecraft "buses" that are the same, but the payloads are different. The cost of putting someone/something up in the orbit to collect all the piece and build something new with them would be _much_ greater than the cost to just build something new. Satellites and space vehicles are non-trivial to build...that's why they cost so much on the ground. Recycling parts is a pipe dream at this point.
Very few satellites are as low as 150 nmi and LEO environments can be up to 1000 nmi...so you are talking about a larger section of space.
Also, that 65,000 pieces of space junk is not just limited to LEOs, but goes all the way up to GEO which is ~22,000 nmi...much more space than you are suggesting.
furthermore, typical orbiting times for a revolution of a LEO are approximately 1 to 2 hours.
The junk is well monitored and while I am not happy it is up there, it is not much of a concern in all reality to orbiting satellites and the space station.
I know this will probably get super modded down, but...
Is it me or is NASA spending an inordinate amount of time promoting itself. I watch the news in the morning and it is amazing how often NASA comes up. Not to mention slashdot.
Now I find space exploration interesting, but NASA is putting out more PR than big corporations. Ever seen a copy of NASA Tech Briefs...pure fluff almost.
For instance, this article really didn't contain much information. This probably has been sitting on the NASA website for months and no one picked it up there.
One more instance of this type of thing, I have seen NASA divisons at conferences renting booths beside Corporations in the industrial exhibits. How is this legal? I don't want NASA to be spending my taxpayer money on PR.
Dan Goldin is an interesting figure. Check out www.nasawatch.com to find out all kinds of interesting stuff about him...and nasa too.
$10000/lb
Propellent and engines on the spacecraft or a separate small vehicle to accomplish that. Many satellites are launched by the shuttle etc...they do not stay in that orbit.