Re:Slightli OT question...
on
Macs In Space!
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· Score: 1
It is in fact solar flare season. We are at the peak of that solar flare cycle. We have had 12 or 13 proton flares this year already. Last year, we only 9 total all year.
While solar flares are important, they are not nearly as important as you decrease in altitude. If you are well shielded by the Earth's geomagnetic field, then the protons do not penetrate easily.
How do you know if you are well covered by the geomagnetic field...if you less than 10000 to 15000 km in altitude and are not highly inclined. 90 degree orbits (polar orbits) are not as well protected as lower inclination orbits (up to 60 degrees or so). Excepting of course the SAA's boost from solar flares (which is still relatively minor).
So most of the satellites you hear about having (big) problems during solar flares are those in the high altitude orbits. This particular satellite will not likely have a problem...it is most likely destined for an orbit similar to the Shuttles (400 to 500 km, 28 to 55 degrees, with occasionally 90 degree inclination jaunts) and therefore protected by geomagnetic shielding.
Re:Ah, I *like* this idea...
on
Macs In Space!
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· Score: 1
Check out this power point presentation. This project is to build a high temperature super conductor in a low earth orbit and return it to the ground for use. Notice the sponsors of the work.
Temperature problems in satellites are a problem, but not that big of a deal. I don't have any links on hand, but while it costs some money to deal with this problem, it has been solved easily for years.
On the GPL code issue, I would bet a little, but not much.
Why didn't someone make an edited version...and post a link to both the edited and non-edited versions, or a summary or something. There is just too much legal information thrown in to make it very readable.
How large the possible problem would be depends upon the orbit. If the orbit is below 1000 km (which is likely), the problem is not very big...it is likely a total dose problem of about 1 to 3 krad(Si) per year. Most electronics parts can survive at least 10 krad(Si) while many can survive up to 50 krad(Si), with some parts into the Mrad(Si). The Single Event Effects (bit upsets and hangs) problems will occur most likely only in the South Atlantic Anomaly (SAA). In the SAA, fluxes for energetic protons (the most common cause of SEEs) are 5 to 6 orders of magnitude higher than the rest of the orbit. The SAA covers the region around Brazil mostly.
Above 1000 km and below about 6000 km, the problem is much more extreme. Fortunately this is not a very common place for satellites.
Above 6000 km, the SEE problem (except for solar flares) dissapates some and total dose problems become more of an issue.
Above 30000 km, the total dose problems largely go away, unless you decide to go to Europa.
These are really just generalizations and if you want an answer with more fidelity, you should use software like Space Radiation (www.spacerad.com).
Power PC603 has already been in space
on
Macs In Space!
·
· Score: 2
The PC603 was used on the Iridium constellation and has been a great technical success. The G4 is the PC750, correct?...It too has been considered for space applications for some time. I know measurements on the PC750 were made as far back as 1998 to determine the suitability of it for space use. The likely reason that it hasn't been put into space already is because many people in the aerospace industry are big time skeptics of COTS (commercial off the shelf) part. They believe all things commercial are crap. Which is definitely not true. It is difficult to get the kind of yields that commercial processes get without being incredibly high quality. And the truth of the matter is that except for radiation, there is not a big difference between ground and space electronics use. The vibration characteristics and thermal characteristics of use in a car are pretty demanding. And COTS parts have been demonstrated to work successfully in space with only simple protective concepts like current monitors (for single event latch-up) and EDAC (which has been used extensively even on the ground). The PC603 is just another example of this. The IDT3081 was a good example of a commercial microprocessor put into space with great success (Clementine).
You are correct. It is not rad-hard and will experience Single Event Effects (SEE) and eventual lifetime problems (Total Ionizing Dose or TID induced). But the fact of the matter is that "Rad-hard" is not necessarily required to properly operate in space. All devices have radiation effects characteristics which are measurable. You would be surprised at how well commercial off the shelf (COTS) devices perform in space. Many devices have event rates for SEEs (bit upsets, processor hangs, etc.) on the order (average) of years per event...Not a big deal when you consider that software problems often cause bigger problems. For more information, visit www.innocon.com/rad_effects.html or http://flick.gsfc.nasa.gov/radhome.htm
My favorite was The Shadow. It was a complex beautiful game. It had that wonderful upper battlefield. It had a couple great video modes. It had a great set of easter eggs. It was a bitch to win and when you got to the Final Battle...it was worth it. Six pinballs and all you have to do is should one of every shot in the game. I got to the Final Battle and lost so many times before I won, I was on the verge of crying several times. Just the right combination of difficulty and features for me.
Whenever I get the space and money I will be buying one.
It is sad to see pinball dying...I wish I had more time to play. Those people that thing that pinball is no fun cause it is mechanical are IMHO crazy. That is the best part. Moving the machine in just the right way. Being able to feel the balls on the flippers. Death Saves (if you don't know, just check out rec.games.pinball) and bang backs. Milking a single ball for hours...if you do it right, pinball playing is an art that combines tactile experience with plot of a novel.
Hell I even watch "The Shadow" the movie just cause I like the pin...i wouldn't suggest it as a classic.
"Once commercialism comes into the picture, it'll lose focus on the scientific efforts that are it's passion."
At least as far as the ISS is concerned, they already have. There are a large number of limitations to ISS that will make it not nearly as useful as it could be...for instance, the current design for the antenna to communicate with has it in such a position that it will only communicate with Earth on a limited basis because it will be blocked by ISS itself. This is already a bandwidth limited antenna. The current situation is not conducive at all to performing science...at least no science on a budget. So to make any real time measurements, you have to have a setup that is either manually controlled or you have to give up precise timing because you will be uncertain as to when you will have access to your experiment.
Plus the other commentor talking about how the shuttle already fulfills most of the needs of people in LEO. If ISS were to go higher, it would be more useful (i.e. the gravity would be less).
Check out this site. It has several presentation about re-entry plans. It is not trivial and the US is probably the best in the world at it, but it has to be controlled. These objects you return are essentially meteorites in the way they enter the Earth without control. Very dangerous.
I hope to see the day when launch costs get cheap enough ($1/pound vs 10K$/pound) to send humans into space; but before humans spend too much time in space, it is necessary to develop a good way to eliminate the dangers of radiation. This will be the most expensive and difficult challenge (IMO) for future space exploration.
He said: "Yes it is. One of the design issues of the space suites is to protect against radiation from the sun. IMO that is part of the environment."
I say: "Technically it is a transient part of the environment. And a space suit does not provide much protection. For instance most satellites have up to 1000 mil (1 inch) Al shielding and this does not have a significant impact upon Galactic Cosmic Rays. GCRs also are the most dangerous to human beings because they deposit the most energy per unit material. This is the reason most manned space missions are at 400 to 500 km; it is much safer because of the impact of geomagnetic shielding."
He said:"These goods would fall into orbit around the earth and be used for whatever... A space station or brought back to earth for sale.
That is brought back to earth for sale. Most likely by a space craft similar to the space shuttle! "
I say:"The cost of a vehicle like the space shuttle is enormous. I don't have the figure at hand, but it is on the order of a million dollars (taxpayer money) each flight. Just getting up and going down. Tough to make a profit with those sort of costs."
As to the comment about water being on the moon, I believe another reader answered it. At this point, no one knows.
"How can you pollute an already lethally radioactive environment?"
The environment is not radioactive. Radiation passes through the environment...but it also does that here. Our atmosphere provides an excellent shield but we still experience galactic cosmic rays on earth...IBM has been looking at upset rates on large commercial memories in servers for about the last 50 years.
"They wouldn't have any governmnet regulations"
There are space treaties to the effect that no one nation or company could own the moon or other parts of space.
As to all your other assertions, most of them are without merit. Water was not found on the moon...they tried and still don't know. And many of the other "advantages" are also false. For instance, goods falling into earth's atmosphere would need to be assured of a safe reentry. High Gs and high temperatures would eliminate most inexpensive methods.
You are correct about NASA being behind the rest of the world in a lot of areas.
The real reason for this gap is because of a lack of good people and because we adopted the mindset of the Apollo and Voyager missions. We overspecify everything that goes into space and because of that use old technology and old ideas. Did you know that Voyager is still going and has mostly escaped the bounds of our solar system? That is one hell of a lot of overspecing.
Now that we have years of experience from space the Europeans learn from it instead of us.
Since I currently work in the aerospace industry and have experience with both governmnet and industry types, I must say that you are right where your father was concerned, but you are not right today. NASA is not the place it once was. It no longer contains the best and the brightest. Right now, the government is about as far behind technology as they possibly could be. And better faster cheaper has produced remarkable success stories except for the last couple screw-ups that are largely due to part of NASA. No private company has gone into space extensively because there are not enough rewards to going into space. I personally think this current venture is a boondoggle and a horrible thing for anyone (government or private) to do. But the fact of the matter is that NASA has fewer and fewer good people. And they have been playing games with taxpayer money. Programs have been funded with other programs monies. Check out www.spacer.com or NasaWatch to get a feel for the problems with NASA and the space industry as a whole. Don't get me wrong, private industry can be pretty stupid too (i.e. Roton) but NASA has had much more success with unmanned missions that manned ones.
I believe that the law is at fault here. Look at the following excerpt from the RIAA.
-Start- What You Can Copy
First, for your personal use, you can make analog copies of music. For instance, you can make analog cassette tape recordings of music from another analog cassette, or from a CD or from the radio, or basically from any source. Essentially, all copying onto analog media is generally allowed.
Second, again for your personal use, you can make some digital copies of music, depending on the type of digital recorder used. For example, digitally copying music is generally allowed with mini-disc recorders, digital audio tape (DAT) recorders, digital cassette tape recorders and some (but not all) compact disc recorders (or CD-R recorders). As a general rule for CD-Rs, if the CD-R recorder is a stand-alone machine designed to copy primarily audio, rather than data or video, then the copying is allowed. If the CD-R recorder is a computer component, or a computer peripheral device designed to be a multi-purpose recorder (in other words, if it will record data and video as well as audio), then copying is not allowed.
Admittedly, the rules for digital copying are a little more complicated, but they exist for a reason. Under the Audio Home Recording Act, the manufacturers of some types of digital recorders pay a modest royalty to partially compensate the artists, record companies and music publishers hurt through unauthorized copying. These devices also incorporate technology to prevent what is known as serial copying, that is, second and higher generation copies. Thus, while you are allowed to make a copy from an original, you are not permitted to make (and compliant recorders will not permit)copies from copies. The royalty provisions and the serial copying provisions are an important part of the compromise that allowed these digital recording technologies into the market.
-Stop-
The rules are unneccessarily complicated. If one instance of digital copying is allowed, they all should be allowed ***For Personal Use***. And mp3.com has no way to control whether copyrights are being violated. They should pursue the consumers of mp3.com who they believe are violating the copyright.
This law seems to stink like it was paid for heavily by the recording industry with no real thought paid to the long term consequences.
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It is in fact solar flare season. We are at the peak of that solar flare cycle. We have had 12 or 13 proton flares this year already. Last year, we only 9 total all year.
While solar flares are important, they are not nearly as important as you decrease in altitude. If you are well shielded by the Earth's geomagnetic field, then the protons do not penetrate easily.
How do you know if you are well covered by the geomagnetic field...if you less than 10000 to 15000 km in altitude and are not highly inclined. 90 degree orbits (polar orbits) are not as well protected as lower inclination orbits (up to 60 degrees or so). Excepting of course the SAA's boost from solar flares (which is still relatively minor).
So most of the satellites you hear about having (big) problems during solar flares are those in the high altitude orbits. This particular satellite will not likely have a problem...it is most likely destined for an orbit similar to the Shuttles (400 to 500 km, 28 to 55 degrees, with occasionally 90 degree inclination jaunts) and therefore protected by geomagnetic shielding.
Check out this power point presentation. This project is to build a high temperature super conductor in a low earth orbit and return it to the ground for use. Notice the sponsors of the work.
Temperature problems in satellites are a problem, but not that big of a deal. I don't have any links on hand, but while it costs some money to deal with this problem, it has been solved easily for years.
On the GPL code issue, I would bet a little, but not much.
Why didn't someone make an edited version...and post a link to both the edited and non-edited versions, or a summary or something. There is just too much legal information thrown in to make it very readable.
How large the possible problem would be depends upon the orbit. If the orbit is below 1000 km (which is likely), the problem is not very big...it is likely a total dose problem of about 1 to 3 krad(Si) per year. Most electronics parts can survive at least 10 krad(Si) while many can survive up to 50 krad(Si), with some parts into the Mrad(Si). The Single Event Effects (bit upsets and hangs) problems will occur most likely only in the South Atlantic Anomaly (SAA). In the SAA, fluxes for energetic protons (the most common cause of SEEs) are 5 to 6 orders of magnitude higher than the rest of the orbit. The SAA covers the region around Brazil mostly.
Above 1000 km and below about 6000 km, the problem is much more extreme. Fortunately this is not a very common place for satellites.
Above 6000 km, the SEE problem (except for solar flares) dissapates some and total dose problems become more of an issue.
Above 30000 km, the total dose problems largely go away, unless you decide to go to Europa.
These are really just generalizations and if you want an answer with more fidelity, you should use software like Space Radiation (www.spacerad.com).
The PC603 was used on the Iridium constellation and has been a great technical success. The G4 is the PC750, correct?...It too has been considered for space applications for some time. I know measurements on the PC750 were made as far back as 1998 to determine the suitability of it for space use. The likely reason that it hasn't been put into space already is because many people in the aerospace industry are big time skeptics of COTS (commercial off the shelf) part. They believe all things commercial are crap. Which is definitely not true. It is difficult to get the kind of yields that commercial processes get without being incredibly high quality. And the truth of the matter is that except for radiation, there is not a big difference between ground and space electronics use. The vibration characteristics and thermal characteristics of use in a car are pretty demanding. And COTS parts have been demonstrated to work successfully in space with only simple protective concepts like current monitors (for single event latch-up) and EDAC (which has been used extensively even on the ground). The PC603 is just another example of this. The IDT3081 was a good example of a commercial microprocessor put into space with great success (Clementine).
You are correct. It is not rad-hard and will experience Single Event Effects (SEE) and eventual lifetime problems (Total Ionizing Dose or TID induced). But the fact of the matter is that "Rad-hard" is not necessarily required to properly operate in space. All devices have radiation effects characteristics which are measurable. You would be surprised at how well commercial off the shelf (COTS) devices perform in space. Many devices have event rates for SEEs (bit upsets, processor hangs, etc.) on the order (average) of years per event...Not a big deal when you consider that software problems often cause bigger problems. For more information, visit www.innocon.com/rad_effects.html or http://flick.gsfc.nasa.gov/radhome.htm
My favorite was The Shadow. It was a complex beautiful game. It had that wonderful upper battlefield. It had a couple great video modes. It had a great set of easter eggs. It was a bitch to win and when you got to the Final Battle...it was worth it. Six pinballs and all you have to do is should one of every shot in the game. I got to the Final Battle and lost so many times before I won, I was on the verge of crying several times. Just the right combination of difficulty and features for me.
Whenever I get the space and money I will be buying one.
It is sad to see pinball dying...I wish I had more time to play. Those people that thing that pinball is no fun cause it is mechanical are IMHO crazy. That is the best part. Moving the machine in just the right way. Being able to feel the balls on the flippers. Death Saves (if you don't know, just check out rec.games.pinball) and bang backs. Milking a single ball for hours...if you do it right, pinball playing is an art that combines tactile experience with plot of a novel.
Hell I even watch "The Shadow" the movie just cause I like the pin...i wouldn't suggest it as a classic.
as I do, you might enjoy this site. It gives a better format in my opinion that NOAA, but it is essentially the same data.
"Once commercialism comes into the picture, it'll lose focus on the scientific efforts that are it's passion."
At least as far as the ISS is concerned, they already have. There are a large number of limitations to ISS that will make it not nearly as useful as it could be...for instance, the current design for the antenna to communicate with has it in such a position that it will only communicate with Earth on a limited basis because it will be blocked by ISS itself. This is already a bandwidth limited antenna. The current situation is not conducive at all to performing science...at least no science on a budget. So to make any real time measurements, you have to have a setup that is either manually controlled or you have to give up precise timing because you will be uncertain as to when you will have access to your experiment.
Plus the other commentor talking about how the shuttle already fulfills most of the needs of people in LEO. If ISS were to go higher, it would be more useful (i.e. the gravity would be less).
Check out this site. It has several presentation about re-entry plans. It is not trivial and the US is probably the best in the world at it, but it has to be controlled. These objects you return are essentially meteorites in the way they enter the Earth without control. Very dangerous.
I hope to see the day when launch costs get cheap enough ($1/pound vs 10K$/pound) to send humans into space; but before humans spend too much time in space, it is necessary to develop a good way to eliminate the dangers of radiation. This will be the most expensive and difficult challenge (IMO) for future space exploration.
I thought the troll part was funny.
He said: "Yes it is. One of the design issues of the space suites is to protect against radiation from the sun. IMO that is part of the environment."
I say: "Technically it is a transient part of the environment. And a space suit does not provide much protection. For instance most satellites have up to 1000 mil (1 inch) Al shielding and this does not have a significant impact upon Galactic Cosmic Rays. GCRs also are the most dangerous to human beings because they deposit the most energy per unit material. This is the reason most manned space missions are at 400 to 500 km; it is much safer because of the impact of geomagnetic shielding."
He said:"These goods would fall into orbit around the earth and be used for whatever... A space station or brought back to earth for sale.
That is brought back to earth for sale. Most likely by a space craft similar to the space shuttle! "
I say:"The cost of a vehicle like the space shuttle is enormous. I don't have the figure at hand, but it is on the order of a million dollars (taxpayer money) each flight. Just getting up and going down. Tough to make a profit with those sort of costs."
As to the comment about water being on the moon, I believe another reader answered it. At this point, no one knows.
I personally *know* the person who conceived the mission and it was not a NASA person.
"How can you pollute an already lethally radioactive environment?"
The environment is not radioactive. Radiation passes through the environment...but it also does that here. Our atmosphere provides an excellent shield but we still experience galactic cosmic rays on earth...IBM has been looking at upset rates on large commercial memories in servers for about the last 50 years.
"They wouldn't have any governmnet regulations"
There are space treaties to the effect that no one nation or company could own the moon or other parts of space.
As to all your other assertions, most of them are without merit. Water was not found on the moon...they tried and still don't know. And many of the other "advantages" are also false. For instance, goods falling into earth's atmosphere would need to be assured of a safe reentry. High Gs and high temperatures would eliminate most inexpensive methods.
Maybe I am just responding to a troll?
You are correct about NASA being behind the rest of the world in a lot of areas.
The real reason for this gap is because of a lack of good people and because we adopted the mindset of the Apollo and Voyager missions. We overspecify everything that goes into space and because of that use old technology and old ideas. Did you know that Voyager is still going and has mostly escaped the bounds of our solar system? That is one hell of a lot of overspecing.
Now that we have years of experience from space the Europeans learn from it instead of us.
Clementine was not NASA's idea and was not designed mostly by NASA.
Since I currently work in the aerospace industry and have experience with both governmnet and industry types, I must say that you are right where your father was concerned, but you are not right today. NASA is not the place it once was. It no longer contains the best and the brightest. Right now, the government is about as far behind technology as they possibly could be. And better faster cheaper has produced remarkable success stories except for the last couple screw-ups that are largely due to part of NASA. No private company has gone into space extensively because there are not enough rewards to going into space. I personally think this current venture is a boondoggle and a horrible thing for anyone (government or private) to do. But the fact of the matter is that NASA has fewer and fewer good people. And they have been playing games with taxpayer money. Programs have been funded with other programs monies. Check out www.spacer.com or NasaWatch to get a feel for the problems with NASA and the space industry as a whole. Don't get me wrong, private industry can be pretty stupid too (i.e. Roton) but NASA has had much more success with unmanned missions that manned ones.
I believe that the law is at fault here. Look at the following excerpt from the RIAA.
-Start-
What You Can Copy
First, for your personal use, you can make analog copies of music. For instance, you can make analog cassette tape recordings of music from another analog cassette, or from a CD or from the radio, or basically from any source. Essentially, all copying onto analog media is generally allowed.
Second, again for your personal use, you can make some digital copies of music, depending on the type of digital recorder used. For example, digitally copying music is generally allowed with mini-disc recorders, digital audio tape (DAT) recorders, digital cassette tape recorders and some (but not all) compact disc recorders (or CD-R recorders). As a general rule for CD-Rs, if the CD-R recorder is a stand-alone machine designed to copy primarily audio, rather than data or video, then the copying is allowed. If the CD-R recorder is a computer component, or a computer peripheral device designed to be a multi-purpose recorder (in other words, if it will record data and video as well as audio), then copying is not allowed.
Admittedly, the rules for digital copying are a little more complicated, but they exist for a reason. Under the Audio Home Recording Act, the manufacturers of some types of digital recorders pay a modest royalty to partially compensate the artists, record companies and music publishers hurt through unauthorized copying. These devices also incorporate technology to prevent what is known as serial copying, that is, second and higher generation copies. Thus, while you are allowed to make a copy from an original, you are not permitted to make (and compliant recorders will not permit)copies from copies. The royalty provisions and the serial copying provisions are an important part of the compromise that allowed these digital recording technologies into the market.
-Stop-
The rules are unneccessarily complicated. If one instance of digital copying is allowed, they all should be allowed ***For Personal Use***. And mp3.com has no way to control whether copyrights are being violated. They should pursue the consumers of mp3.com who they believe are violating the copyright.
This law seems to stink like it was paid for heavily by the recording industry with no real thought paid to the long term consequences.