What the hell are you talking about? I didn't say you couldn't trap anti-protons, CERN proved you can (not that anyone doubted them). Just that there's no conceivable way making a "rocket" with any foreseeable technology and as such should take a back burner to other much more tangible methods, IMO. It's a fun idea but how much does one anti-proton cost?
What the hell are you talking about? I didn't say you couldn't trap anti-protons, CERN proved you can (not that anyone doubted them). Just that there's no conceivable way making a "rocket" with any foreseeable technology and as such should take a back burner to other much more tangible methods, IMO. It's a fun idea but how much does one anti-proton cost?</strong><hr></blockquote>
Scott you said you said it wasn't even worth going past the paper planning stage.I'm pointing out that research should continue because you never know when the proper breakthroughs will happen. As far imediate space travel science goes it's still in the future. Like the article in the link says. But, that's no reason to give up. Someone could stumble across something tomorrow.
I wasn't concerned about calculating these trajectories. That's easy. It's just that these are expensive trajectories in terms of energy costs -- even if you skip the energy of escaping Earth's gravitational field by presuming a starting point in Earth orbit or in the asteroid belt.
The Earth's speed going around the Sun is about 30 km/sec. In order to get an object in Earth orbit to drop into the Sun, excluding the energy needed to break Earth orbit, you essentially have to impart enough energy into the object to send that object away from the Earth at 30 km/sec tangentially to the Earth's orbit -- in other words, bring the object to a stand-still with respect to the Sun so that it can simply fall into the Sun.
So, for a one kilo object... 1/2 mv^2 = 0.5 * 1kg * (30000 m/sec) ^ 2 = 4.5*10^8 joules, or about 125000 watt hours. At $0.07/KWH, that would cost about $8.75 per kilogram. That's already expensive without counting orbital escape energy or energy possibly wasted on propelling some reaction mass in the opposite direction, and I'm using the pricing of typical terrestrial electrical power delivery for this figure. Space technology may someday yield costs that low, but it would require both new technologies and economies of scale that are a long way off. The point were energy in space is substantially cheaper than current energy costs on Earth is even further away.
By the way, using the same forgiving math out in the asteroid belt, with solar orbital velocities of about 20 km/sec, the cost would come down to about $3.90 per kilogram.
I've also excluded the costs of moving the vehicle that delivers the waste, energy used for course corrections, energy used to return the delivery vehicle *or* the cost of treating the delivery vehicle as disposable. I suppose if you were confident enough about your trajectories not requiring mid-course corrections, and not worried about creating the occasional toxic asteroid in near-Earth orbit, you could launch blobs of waste out of something like a rail gun without any enclosing vehicle. Or maybe strap on a few small rockets in lieu of a complete vehicle, with the major boost still coming from something like a rail gun.</strong><hr></blockquote>
Are these numbers based on present space flight costs? I assume they are because what else can you base it on? No one can predict what it may cost for some future technology.
That's one thing about discussing the future with people. Some people ( and I'm not talking about you Shetline ) think our understanding of physics ( or science in general ) will remain static or be based only on what we know today.
At the begining of the 1900's. It was suggested that when entering higher education one should pick an area other than physics. This is because it was felt that there was very little else to discover and we were just about to tie it all together with a grand unified field theory.
Are these numbers based on present space flight costs? I assume they are because what else can you base it on? No one can predict what it may cost for some future technology.</strong><hr></blockquote>
The price rates I came up with have nothing to do with space flight per se... they're based on typical American electrical bills. This was my way of generously low-balling the figures, to show that the costs of dropping something into the Sun are high even at very low per-energy-unit prices, simply because you need a lot of energy.
While it's true that no one can predict what future advantages technology might bring, I think it's a very safe bet that energy produced and/or delivered into space isn't going to be anywhere near as cheap as terrestrial energy production for a long, long time. Eventually we may be able to collect an enormous amount of "free" energy from the Sun, for example, but even "free" solar energy collected in space will be very expensive until the development costs and infrastructure costs have been amortized away, and until the maintenance costs have been reduced by economies of scale that can't exist before a major industrialization of space.
It might be possible to reduce the energy figures I've stated by cleverly using slingshot trajectories around other planets, or by using Lagrange points, but I was just going for ballpark figures, and lowballing in many ways, so I imagine the costs would still come out very high no matter what.
Scott you said you said it wasn't even worth going past the paper planning stage.I'm pointing out that research should continue because you never know when the proper breakthroughs will happen. As far imediate space travel science goes it's still in the future. Like the article in the link says. But, that's no reason to give up. Someone could stumble across something tomorrow.</strong><hr></blockquote>
Yea so self this idea until it's even possible to concive how this might work out. Until then don't waste a lot of money on this because it aint going to get us to Mars anytime in the next 100 years.
BTW, at present methods, it costs $100 billion to produce one milligram. The way they do it now is by smashing high energy (very fast) protons against a metal target. Anti-protons are eve then not readily produced; this method is only .5% efficient! We have a long way to go for it to be practical.
Anyway, anyone ever hear of project Orion strated in the late 50s? It was a nuclear pulse space ship, but it wasn't an internal combustion rocket engine, but an external combustion engine. Basically a crew module up in front, mini nuclear bomb pellet dispenser in the center, and huge shock absorbers with a push plate behind it. Basically the mini bombs would be ejected rearward and explode behind the ship and it would push against the pushplate making the ship go foward. They had a small prototype made using chemical explosions instead of nuclear and it worked rather well. The design was further refined with 'shaped' nuclear charges, directing as much force towards the pusher plate. Befor ethe project ended they made estimated that an optimised ship could do a round trip to Mars in only 250 days! Basically what killed the project was the 1963 nuke test ban treaty, but also alot of infighting with in all the departments involved with the project. The Orion group estimated specific impulse in the range of 2000-6000 seconds with possible future versions all the way up to 10,000-20,000 seconds. In comparison the space shuttle uses hydrogen/oxygen fuel that gives you a specific impulse of 460 seconds. Obviously you cant do planetary lift offs with nuclear pulse ships....
So, for a one kilo object... 1/2 mv^2 = 0.5 * 1kg * (30000 m/sec) ^ 2 = 4.5*10^8 joules, or about 125000 watt hours. At $0.07/KWH, that would cost about $8.75 per kilogram. That's already expensive without counting orbital escape energy or energy possibly wasted on propelling some reaction mass in the opposite direction, and I'm using the pricing of typical terrestrial electrical power delivery for this figure.
By the way, using the same forgiving math out in the asteroid belt, with solar orbital velocities of about 20 km/sec, the cost would come down to about $3.90 per kilogram.</strong>
Hehe... this is an interesting problem with a lot of trades and risks.
Lets consider nuclear waste disposal. LEO "delta V" will be about 15 km/s, so I'll add your two numbers, 20 and 30 km/s, for $12.65/kg to get a kg of nuclear waste from Earth to LEO to the Sun. I'll take that number and multiply it by 50, for a total of $632.5/kg.
I'll take that number. Seriously. That's cheap for nuclear waste disposal. Why? Just look at the total budget numbers for the Yucca Mountain nuclear waste repository: $58 billion to dispose of 77000 tons of nuclear waste. This translates to $753.25/kg!
For regular trash disposal, it'll be ridiculous to send it off the planet; however, nuclear waste is a different ball game. The trades and risks can be discussed, but I don't think space disposal of nuclear waste is a ridiculous idea And remember, continuous launches (monthly) of an expendable like the Atlas V will reduce the costs down to $1000/kg, if not less.
<strong>I suppose if you were confident enough about your trajectories not requiring mid-course corrections, and not worried about creating the occasional toxic asteroid in near-Earth orbit, you could launch blobs of waste out of something like a rail gun without any enclosing vehicle. Or maybe strap on a few small rockets in lieu of a complete vehicle, with the major boost still coming from something like a rail gun.</strong>
The thing is, it doesn't have to be sent into the Sun. It can be sent to crash on Mercury, on Venus, or Jupiter. Those will be less demanding orbital transfers. More efficient engines can also be used and nuclear waste is interestingly synergistic in this application. Ion engines are also hugely efficient, able to deliver a delta V of 5 km/s using 100 kg of xenon for a 500 kg vehicle. If it's possible to use the nuclear waste as an RTG energy source, it'll be a little bit better performance. The rail gun is also seems to be the perfect launch method for sending nuclear waste payloads into orbit.
Consider the trades between having a limited storage repository at Yucca mountain, which already is too small for the projected amount of nuclear waste and has safety concerns unique to itself, compared to a sending nuclear waste out into space through a rail gun and then sent to another place through an ion engine. Which accident will be better? A containment accident somewhere on the ground or a floating blob in LEO? Or worst case, a dispersed payload in the atmosphere or nuclear waste contaminating ground water?
<strong>Space technology may someday yield costs that low, but it would require both new technologies and economies of scale that are a long way off. The point were energy in space is substantially cheaper than current energy costs on Earth is even further away.</strong>
Energy in space is a long ways away, but suffice it to say, it'll be nice to have a healthy space program to try get us there in both launch costs and energy production. We can't imagine the consequences of such investment, but I don't think it'll worthless if nothing came of it except to make space development better known.
<strong>Lets consider nuclear waste disposal. LEO "delta V" will be about 15 km/s, so I'll add your two numbers, 20 and 30 km/s, for $12.65/kg to get a kg of nuclear waste from Earth to LEO to the Sun. I'll take that number and multiply it by 50, for a total of $632.5/kg.
I'll take that number. Seriously. That's cheap for nuclear waste disposal.</strong><hr></blockquote>
I'll grant you the potential appealing price/value ratio for disposing of nuclear waste. But like I'd said before, the downside risks are very high. A rocket blows up and contaminates a huge area around the launch site, a rail gun misfires and instead of reaching escape velocity you drop a few kilos of plutonium on Cleveland, or burn it up in the atmosphere and get yourself a lovely world-wide dispersal of fine particulate plutonium oxide... lots of unpleasant scenarios possible here.
Dumping on other planets rather than the Sun... hmmm. Definitely could bring down costs. Venus would probably be the cheapest planet to dump on. I'd save Mars for potential terraforming. Of course, I think we'd want to do a lot of scientific exploration and analysis first before we went ahead and contaminated any of the planets with nuclear, chemical, or biological waste.
[quote]<strong>Energy in space is a long ways away, but suffice it to say, it'll be nice to have a healthy space program to try get us there in both launch costs and energy production. We can't imagine the consequences of such investment, but I don't think it'll worthless if nothing came of it except to make space development better known.</strong><hr></blockquote>
Don't get me wrong that I was saying anything against having a vigorous space program -- I'm all for it, including the adventure of human space travel along side unmanned robotic exploration.
I merely wanted to address the specific issue of dumping things into the Sun, because this is a popular idea whose drawbacks are unknown to many people. For years, I thought shooting garbage into the Sun was a great idea myself, until I learned more about the risks and costs, not to mention the basic physics of the problem.
<strong>BTW, at present methods, it costs $100 billion to produce one milligram. The way they do it now is by smashing high energy (very fast) protons against a metal target. Anti-protons are eve then not readily produced; this method is only .5% efficient! We have a long way to go for it to be practical.
Anyway, anyone ever hear of project Orion strated in the late 50s? It was a nuclear pulse space ship, but it wasn't an internal combustion rocket engine, but an external combustion engine. Basically a crew module up in front, mini nuclear bomb pellet dispenser in the center, and huge shock absorbers with a push plate behind it. Basically the mini bombs would be ejected rearward and explode behind the ship and it would push against the pushplate making the ship go foward. They had a small prototype made using chemical explosions instead of nuclear and it worked rather well. The design was further refined with 'shaped' nuclear charges, directing as much force towards the pusher plate. Befor ethe project ended they made estimated that an optimised ship could do a round trip to Mars in only 250 days! Basically what killed the project was the 1963 nuke test ban treaty, but also alot of infighting with in all the departments involved with the project. The Orion group estimated specific impulse in the range of 2000-6000 seconds with possible future versions all the way up to 10,000-20,000 seconds. In comparison the space shuttle uses hydrogen/oxygen fuel that gives you a specific impulse of 460 seconds. Obviously you cant do planetary lift offs with nuclear pulse ships....</strong><hr></blockquote>
Actually I have heard of this. There was also a program called NERVA which one of the proposals was to use a by product of nuclear waste to power this engine. I don't have any info on this part of the project but I do remember reading about it at the time and thinking what a neat idea. Here's a link about the NERVA program.
These kind of engines would be good for say interplanetary travel but far too dangerous for earth to orbit. Just ask the Russians they had one blow up while testing. Don't know much about that as they hushed it up pretty quick.
But like I'd said before, the downside risks are very high.</strong>
The risks are debatable and can be mitigated. It must also be considered that the rewards are very high. Nuclear waste is disposed of forever, and opens up nuclear power as a more viable energy source, especially with mature reprocessing and transmutation reactor technology.
Yucca mountain does nothing for nuclear power, except serve as a denouement for nuclear energy.
<strong>A rocket blows up and contaminates a huge area around the launch site, a rail gun misfires and instead of reaching escape velocity you drop a few kilos of plutonium on Cleveland, or burn it up in the atmosphere and get yourself a lovely world-wide dispersal of fine particulate plutonium oxide... lots of unpleasant scenarios possible here.</strong>
Things can be made less unpleasant with the proper containment tech. Keep in mind that leak proof, burst proof, rust proof, etc., containers must be developed for Yucca mountain. The same can be done for a semi-dumb waste payload. A lot of things can mitigate breaches of containment. A 2000 kg payload requires a much smaller rocket, so a smaller explosion will occur. Payloads can be designed that survives entry back to Earth. There are recovered pieces of Columbia equipment in pristine condition because they were in zipped up packs. Any rail system developed will be developed so that failed payloads land in the ocean or in a deserted area.
<strong>Dumping on other planets rather than the Sun... hmmm. Definitely could bring down costs. Venus would probably be the cheapest planet to dump on. I'd save Mars for potential terraforming. Of course, I think we'd want to do a lot of scientific exploration and analysis first before we went ahead and contaminated any of the planets with nuclear, chemical, or biological waste.</strong>
How about crashing it on the Moon and later burying deep. I've always wanted a lunar colony
<strong>Don't get me wrong that I was saying anything against having a vigorous space program -- I'm all for it, including the adventure of human space travel along side unmanned robotic exploration.</strong>
You and me both!
Here's a question for everyone to ponder directly related to the space program and the space shuttle. What would be the state of hydrogen fuel cell technology without its technological development for NASA programs? This is a technology that's slated to power our cars in the next 20 or 30 years or so.
Here's a question for everyone to ponder directly related to the space program and the space shuttle. What would be the state of hydrogen fuel cell technology without its technological development for NASA programs? This is a technology that's slated to power our cars in the next 20 or 30 years or so.
Yeah and at the 1962 Worlds' Fair, automakers promised we would have flying cars before the year 2000. <img src="graemlins/lol.gif" border="0" alt="[Laughing]" />
Maybe if the Japanese develop it, I doubt the US will have hydrogen fuel cell technology for cars in the next 50 years.
As for factual input, to date there have been at least 24 plutonium-powered electrical generators
Maybe if the Japanese develop it, I doubt the US will have hydrogen fuel cell technology for cars in the next 50 years.</strong>
I can buy 50 years. Now what was the question again? What would be the prospect be for hydrogen fuel cell cars without the technological development done for NASA's space programs? The thought wouldn't cross people's minds? It would be developed sooner? It would be developed much later, if at all?
I'll be back next Monday, so I hope to see some actual discussion and thought on this.
Comments
<strong>
Scott,
Obviously no one knows how to do this yet. We can't even make a good enough magnetic bottle for hydrogen fusion.
But do you really believe that our technology will remain where it's at?
<a href="http://science.nasa.gov/newhome/headlines/prop12apr99_1.htm"; target="_blank">http://science.nasa.gov/newhome/headlines/prop12apr99_1.htm</a>;
</strong><hr></blockquote>
What the hell are you talking about? I didn't say you couldn't trap anti-protons, CERN proved you can (not that anyone doubted them). Just that there's no conceivable way making a "rocket" with any foreseeable technology and as such should take a back burner to other much more tangible methods, IMO. It's a fun idea but how much does one anti-proton cost?
<strong>
What the hell are you talking about? I didn't say you couldn't trap anti-protons, CERN proved you can (not that anyone doubted them). Just that there's no conceivable way making a "rocket" with any foreseeable technology and as such should take a back burner to other much more tangible methods, IMO. It's a fun idea but how much does one anti-proton cost?</strong><hr></blockquote>
Scott you said you said it wasn't even worth going past the paper planning stage.I'm pointing out that research should continue because you never know when the proper breakthroughs will happen. As far imediate space travel science goes it's still in the future. Like the article in the link says. But, that's no reason to give up. Someone could stumble across something tomorrow.
<strong>
I wasn't concerned about calculating these trajectories. That's easy. It's just that these are expensive trajectories in terms of energy costs -- even if you skip the energy of escaping Earth's gravitational field by presuming a starting point in Earth orbit or in the asteroid belt.
The Earth's speed going around the Sun is about 30 km/sec. In order to get an object in Earth orbit to drop into the Sun, excluding the energy needed to break Earth orbit, you essentially have to impart enough energy into the object to send that object away from the Earth at 30 km/sec tangentially to the Earth's orbit -- in other words, bring the object to a stand-still with respect to the Sun so that it can simply fall into the Sun.
So, for a one kilo object... 1/2 mv^2 = 0.5 * 1kg * (30000 m/sec) ^ 2 = 4.5*10^8 joules, or about 125000 watt hours. At $0.07/KWH, that would cost about $8.75 per kilogram. That's already expensive without counting orbital escape energy or energy possibly wasted on propelling some reaction mass in the opposite direction, and I'm using the pricing of typical terrestrial electrical power delivery for this figure. Space technology may someday yield costs that low, but it would require both new technologies and economies of scale that are a long way off. The point were energy in space is substantially cheaper than current energy costs on Earth is even further away.
By the way, using the same forgiving math out in the asteroid belt, with solar orbital velocities of about 20 km/sec, the cost would come down to about $3.90 per kilogram.
I've also excluded the costs of moving the vehicle that delivers the waste, energy used for course corrections, energy used to return the delivery vehicle *or* the cost of treating the delivery vehicle as disposable. I suppose if you were confident enough about your trajectories not requiring mid-course corrections, and not worried about creating the occasional toxic asteroid in near-Earth orbit, you could launch blobs of waste out of something like a rail gun without any enclosing vehicle. Or maybe strap on a few small rockets in lieu of a complete vehicle, with the major boost still coming from something like a rail gun.</strong><hr></blockquote>
Are these numbers based on present space flight costs? I assume they are because what else can you base it on? No one can predict what it may cost for some future technology.
That's one thing about discussing the future with people. Some people ( and I'm not talking about you Shetline ) think our understanding of physics ( or science in general ) will remain static or be based only on what we know today.
At the begining of the 1900's. It was suggested that when entering higher education one should pick an area other than physics. This is because it was felt that there was very little else to discover and we were just about to tie it all together with a grand unified field theory.
[ 02-11-2003: Message edited by: jimmac ]</p>
<strong>
Are these numbers based on present space flight costs? I assume they are because what else can you base it on? No one can predict what it may cost for some future technology.</strong><hr></blockquote>
The price rates I came up with have nothing to do with space flight per se... they're based on typical American electrical bills. This was my way of generously low-balling the figures, to show that the costs of dropping something into the Sun are high even at very low per-energy-unit prices, simply because you need a lot of energy.
While it's true that no one can predict what future advantages technology might bring, I think it's a very safe bet that energy produced and/or delivered into space isn't going to be anywhere near as cheap as terrestrial energy production for a long, long time. Eventually we may be able to collect an enormous amount of "free" energy from the Sun, for example, but even "free" solar energy collected in space will be very expensive until the development costs and infrastructure costs have been amortized away, and until the maintenance costs have been reduced by economies of scale that can't exist before a major industrialization of space.
It might be possible to reduce the energy figures I've stated by cleverly using slingshot trajectories around other planets, or by using Lagrange points, but I was just going for ballpark figures, and lowballing in many ways, so I imagine the costs would still come out very high no matter what.
<strong>
Scott you said you said it wasn't even worth going past the paper planning stage.I'm pointing out that research should continue because you never know when the proper breakthroughs will happen. As far imediate space travel science goes it's still in the future. Like the article in the link says. But, that's no reason to give up. Someone could stumble across something tomorrow.</strong><hr></blockquote>
Yea so self this idea until it's even possible to concive how this might work out. Until then don't waste a lot of money on this because it aint going to get us to Mars anytime in the next 100 years.
Anyway, anyone ever hear of project Orion strated in the late 50s? It was a nuclear pulse space ship, but it wasn't an internal combustion rocket engine, but an external combustion engine. Basically a crew module up in front, mini nuclear bomb pellet dispenser in the center, and huge shock absorbers with a push plate behind it. Basically the mini bombs would be ejected rearward and explode behind the ship and it would push against the pushplate making the ship go foward. They had a small prototype made using chemical explosions instead of nuclear and it worked rather well. The design was further refined with 'shaped' nuclear charges, directing as much force towards the pusher plate. Befor ethe project ended they made estimated that an optimised ship could do a round trip to Mars in only 250 days! Basically what killed the project was the 1963 nuke test ban treaty, but also alot of infighting with in all the departments involved with the project. The Orion group estimated specific impulse in the range of 2000-6000 seconds with possible future versions all the way up to 10,000-20,000 seconds. In comparison the space shuttle uses hydrogen/oxygen fuel that gives you a specific impulse of 460 seconds. Obviously you cant do planetary lift offs with nuclear pulse ships....
So, for a one kilo object... 1/2 mv^2 = 0.5 * 1kg * (30000 m/sec) ^ 2 = 4.5*10^8 joules, or about 125000 watt hours. At $0.07/KWH, that would cost about $8.75 per kilogram. That's already expensive without counting orbital escape energy or energy possibly wasted on propelling some reaction mass in the opposite direction, and I'm using the pricing of typical terrestrial electrical power delivery for this figure.
By the way, using the same forgiving math out in the asteroid belt, with solar orbital velocities of about 20 km/sec, the cost would come down to about $3.90 per kilogram.</strong>
Hehe... this is an interesting problem with a lot of trades and risks.
Lets consider nuclear waste disposal. LEO "delta V" will be about 15 km/s, so I'll add your two numbers, 20 and 30 km/s, for $12.65/kg to get a kg of nuclear waste from Earth to LEO to the Sun. I'll take that number and multiply it by 50, for a total of $632.5/kg.
I'll take that number. Seriously. That's cheap for nuclear waste disposal. Why? Just look at the total budget numbers for the Yucca Mountain nuclear waste repository: $58 billion to dispose of 77000 tons of nuclear waste. This translates to $753.25/kg!
For regular trash disposal, it'll be ridiculous to send it off the planet; however, nuclear waste is a different ball game. The trades and risks can be discussed, but I don't think space disposal of nuclear waste is a ridiculous idea
<strong>I suppose if you were confident enough about your trajectories not requiring mid-course corrections, and not worried about creating the occasional toxic asteroid in near-Earth orbit, you could launch blobs of waste out of something like a rail gun without any enclosing vehicle. Or maybe strap on a few small rockets in lieu of a complete vehicle, with the major boost still coming from something like a rail gun.</strong>
The thing is, it doesn't have to be sent into the Sun. It can be sent to crash on Mercury, on Venus, or Jupiter. Those will be less demanding orbital transfers. More efficient engines can also be used and nuclear waste is interestingly synergistic in this application. Ion engines are also hugely efficient, able to deliver a delta V of 5 km/s using 100 kg of xenon for a 500 kg vehicle. If it's possible to use the nuclear waste as an RTG energy source, it'll be a little bit better performance. The rail gun is also seems to be the perfect launch method for sending nuclear waste payloads into orbit.
Consider the trades between having a limited storage repository at Yucca mountain, which already is too small for the projected amount of nuclear waste and has safety concerns unique to itself, compared to a sending nuclear waste out into space through a rail gun and then sent to another place through an ion engine. Which accident will be better? A containment accident somewhere on the ground or a floating blob in LEO? Or worst case, a dispersed payload in the atmosphere or nuclear waste contaminating ground water?
<strong>Space technology may someday yield costs that low, but it would require both new technologies and economies of scale that are a long way off. The point were energy in space is substantially cheaper than current energy costs on Earth is even further away.</strong>
Energy in space is a long ways away, but suffice it to say, it'll be nice to have a healthy space program to try get us there in both launch costs and energy production. We can't imagine the consequences of such investment, but I don't think it'll worthless if nothing came of it except to make space development better known.
[ 02-11-2003: Message edited by: THT ]</p>
<strong>Lets consider nuclear waste disposal. LEO "delta V" will be about 15 km/s, so I'll add your two numbers, 20 and 30 km/s, for $12.65/kg to get a kg of nuclear waste from Earth to LEO to the Sun. I'll take that number and multiply it by 50, for a total of $632.5/kg.
I'll take that number. Seriously. That's cheap for nuclear waste disposal.</strong><hr></blockquote>
I'll grant you the potential appealing price/value ratio for disposing of nuclear waste. But like I'd said before, the downside risks are very high. A rocket blows up and contaminates a huge area around the launch site, a rail gun misfires and instead of reaching escape velocity you drop a few kilos of plutonium on Cleveland, or burn it up in the atmosphere and get yourself a lovely world-wide dispersal of fine particulate plutonium oxide... lots of unpleasant scenarios possible here.
Dumping on other planets rather than the Sun... hmmm. Definitely could bring down costs. Venus would probably be the cheapest planet to dump on. I'd save Mars for potential terraforming. Of course, I think we'd want to do a lot of scientific exploration and analysis first before we went ahead and contaminated any of the planets with nuclear, chemical, or biological waste.
[quote]<strong>Energy in space is a long ways away, but suffice it to say, it'll be nice to have a healthy space program to try get us there in both launch costs and energy production. We can't imagine the consequences of such investment, but I don't think it'll worthless if nothing came of it except to make space development better known.</strong><hr></blockquote>
Don't get me wrong that I was saying anything against having a vigorous space program -- I'm all for it, including the adventure of human space travel along side unmanned robotic exploration.
I merely wanted to address the specific issue of dumping things into the Sun, because this is a popular idea whose drawbacks are unknown to many people. For years, I thought shooting garbage into the Sun was a great idea myself, until I learned more about the risks and costs, not to mention the basic physics of the problem.
[ 02-11-2003: Message edited by: shetline ]</p>
<strong>BTW, at present methods, it costs $100 billion to produce one milligram. The way they do it now is by smashing high energy (very fast) protons against a metal target. Anti-protons are eve then not readily produced; this method is only .5% efficient! We have a long way to go for it to be practical.
Anyway, anyone ever hear of project Orion strated in the late 50s? It was a nuclear pulse space ship, but it wasn't an internal combustion rocket engine, but an external combustion engine. Basically a crew module up in front, mini nuclear bomb pellet dispenser in the center, and huge shock absorbers with a push plate behind it. Basically the mini bombs would be ejected rearward and explode behind the ship and it would push against the pushplate making the ship go foward. They had a small prototype made using chemical explosions instead of nuclear and it worked rather well. The design was further refined with 'shaped' nuclear charges, directing as much force towards the pusher plate. Befor ethe project ended they made estimated that an optimised ship could do a round trip to Mars in only 250 days! Basically what killed the project was the 1963 nuke test ban treaty, but also alot of infighting with in all the departments involved with the project. The Orion group estimated specific impulse in the range of 2000-6000 seconds with possible future versions all the way up to 10,000-20,000 seconds. In comparison the space shuttle uses hydrogen/oxygen fuel that gives you a specific impulse of 460 seconds. Obviously you cant do planetary lift offs with nuclear pulse ships....</strong><hr></blockquote>
Actually I have heard of this. There was also a program called NERVA which one of the proposals was to use a by product of nuclear waste to power this engine. I don't have any info on this part of the project but I do remember reading about it at the time and thinking what a neat idea. Here's a link about the NERVA program.
<a href="http://www.ans.neep.wisc.edu/~ans/point_source/AEI/sep95/rocket_programs.html"; target="_blank">http://www.ans.neep.wisc.edu/~ans/point_source/AEI/sep95/rocket_programs.html</a>;
Nixon cancelled the program in the early 70's.
These kind of engines would be good for say interplanetary travel but far too dangerous for earth to orbit. Just ask the Russians they had one blow up while testing. Don't know much about that as they hushed it up pretty quick.
[ 02-11-2003: Message edited by: jimmac ]</p>
But like I'd said before, the downside risks are very high.</strong>
The risks are debatable and can be mitigated. It must also be considered that the rewards are very high. Nuclear waste is disposed of forever, and opens up nuclear power as a more viable energy source, especially with mature reprocessing and transmutation reactor technology.
Yucca mountain does nothing for nuclear power, except serve as a denouement for nuclear energy.
<strong>A rocket blows up and contaminates a huge area around the launch site, a rail gun misfires and instead of reaching escape velocity you drop a few kilos of plutonium on Cleveland, or burn it up in the atmosphere and get yourself a lovely world-wide dispersal of fine particulate plutonium oxide... lots of unpleasant scenarios possible here.</strong>
Things can be made less unpleasant with the proper containment tech. Keep in mind that leak proof, burst proof, rust proof, etc., containers must be developed for Yucca mountain. The same can be done for a semi-dumb waste payload. A lot of things can mitigate breaches of containment. A 2000 kg payload requires a much smaller rocket, so a smaller explosion will occur. Payloads can be designed that survives entry back to Earth. There are recovered pieces of Columbia equipment in pristine condition because they were in zipped up packs. Any rail system developed will be developed so that failed payloads land in the ocean or in a deserted area.
<strong>Dumping on other planets rather than the Sun... hmmm. Definitely could bring down costs. Venus would probably be the cheapest planet to dump on. I'd save Mars for potential terraforming. Of course, I think we'd want to do a lot of scientific exploration and analysis first before we went ahead and contaminated any of the planets with nuclear, chemical, or biological waste.</strong>
How about crashing it on the Moon and later burying deep. I've always wanted a lunar colony
<strong>Don't get me wrong that I was saying anything against having a vigorous space program -- I'm all for it, including the adventure of human space travel along side unmanned robotic exploration.</strong>
You and me both!
Here's a question for everyone to ponder directly related to the space program and the space shuttle. What would be the state of hydrogen fuel cell technology without its technological development for NASA programs? This is a technology that's slated to power our cars in the next 20 or 30 years or so.
[ 02-11-2003: Message edited by: THT ]</p>
<strong>
Here's a question for everyone to ponder directly related to the space program and the space shuttle. What would be the state of hydrogen fuel cell technology without its technological development for NASA programs? This is a technology that's slated to power our cars in the next 20 or 30 years or so.
[ 02-11-2003: Message edited by: THT ]</strong><hr></blockquote>
Yeah and at the 1962 Worlds' Fair, automakers promised we would have flying cars before the year 2000. <img src="graemlins/lol.gif" border="0" alt="[Laughing]" />
Maybe if the Japanese develop it, I doubt the US will have hydrogen fuel cell technology for cars in the next 50 years.
As for factual input, to date there have been at least 24 plutonium-powered electrical generators
( not technically reactors ) launched by NASA.
[ 02-12-2003: Message edited by: MrBillData ]</p>
<strong>...
You really are locked into a certain mind set aren't you?
[ 02-12-2003: Message edited by: jimmac ]</strong><hr></blockquote>
Thank you... Just as reality is locked into a certain factual set.
Maybe if the Japanese develop it, I doubt the US will have hydrogen fuel cell technology for cars in the next 50 years.</strong>
I can buy 50 years. Now what was the question again? What would be the prospect be for hydrogen fuel cell cars without the technological development done for NASA's space programs? The thought wouldn't cross people's minds? It would be developed sooner? It would be developed much later, if at all?
I'll be back next Monday, so I hope to see some actual discussion and thought on this.
<strong>
Thank you... Just as reality is locked into a certain factual set.
Narrow mindedness is often perceived as reality.
<strong>
Narrow mindedness is often perceived as reality.
Arrogance is ill-perceived reality.
<strong>
Arrogance is ill-perceived reality.
Hey, you don't have to be arrogant to be right.
Besides, isn't that a little like the pot calling the kettle black here?
<img src="graemlins/lol.gif" border="0" alt="[Laughing]" />
[ 02-12-2003: Message edited by: jimmac ]</p>
make with the pictures of experimental spacecraft and stuff !