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#31
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nuclear space engine - would it work ??
In article ,
Robert Kolker wrote: ...Recycling buys some time but the moment of truth comes. Either the population stops growing or we mine metal from the oceans... Even a relatively cautious prediction concludes that Earth's population will peak and then start falling late in this century, as the poorer countries industrialize and go through the "demographic transition" of falling birth rates. The trends are already visible -- half the planet's population already lives in countries with fertility below replacement level, whereas virtually nobody did fifty years ago. This has been coming for a long time -- the idea that the population would just keep growing and growing and growing was always based on a very simplistic analysis. The tough part will be getting through the next century. The population at peak will be a lot higher than it is today. As will energy demand -- China is already about to pass the US as the planet's #1 CO2 producer. Earth is really quite well supplied with most resources. (For example, there is no way we are ever going to run out of aluminum -- a significant fraction of the total mass of Earth's crust is aluminum -- although it may get somewhat more expensive to produce.) The handful of elements that we really are a bit short of are likely to be hard to find in space. The one resource that's a really good candidate for import from space is energy. -- spsystems.net is temporarily off the air; | Henry Spencer mail to henry at zoo.utoronto.ca instead. | |
#32
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nuclear space engine - would it work ??
Scott Hedrick wrote:
"Robert Kolker" wrote in message . .. I think the soundest approach is population limitation. You first. Right there is the problem. Heavy taxes will have to be levied on having more than two children. Bob Kolker |
#33
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nuclear space engine - would it work ??
bombardmentforce wrote:
The dinosaurs had no asteroid survival plans, our only plan is to plan to plan on warning. And neither do we. If a big asteroid or comet hits 99.999 percent of the human race will perish whether we have space wessels or not. There is no way of getting more than a few off the planet regardless of how much we spend on space wessels. And if a few do get off, where shall they live? The Solar System is a very bad neighborhood. The only place that is fit for humans is planet earth hidden in a magnetosphere envelope. Bob Kolker |
#34
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nuclear space engine - would it work ??
David Spain wrote: I image only a fraction of the energy released by the bomb is actually providing propulsion. IIRC you need some kind of super shock absorber that resonates with the explosive pulses connecting the plate to the spacecraft if you want to provide a comfortable experience for the occupants. Also IIRC the bomb detonates at a goodly distance (many, many, many miles) from the spacecraft. There is lot of downloadable Orion material here, including the now declassified official reports on Project Orion: http://www.lepp.cornell.edu/~seb/cel...ion/index.html Pat |
#35
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nuclear space engine - would it work ??
I haven't read all the responses so this may have been said.
The point of using nukes was the high specific impulse. That allows a high final velocity like ion engines. Unlike ion engines they would not be calibrated in milimouse-farts so the acceleration time is not an issue. As a design concept it was of interest and maybe still is. But the first practical test of an ion engine was only a two years ago after decades of easy, safe ground based lab research. That sent a European package to the moon. Consider the engineering time required to solve the nuke propulsion details given the ground based tests of the shock absorbing system and the like in the New Mexico desert. -- Bush has announced himself as a Christian Zionist. That means he is a traitor to America. -- The Iron Webmaster, 3693 nizkor http://www.giwersworld.org/nizkook/nizkook.phtml flying saucers http://www.giwersworld.org/flyingsa.html a2 |
#36
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nuclear space engine - would it work ??
Henry Spencer wrote:
Earth is really quite well supplied with most resources. (For example, there is no way we are ever going to run out of aluminum -- a significant fraction of the total mass of Earth's crust is aluminum -- although it may get somewhat more expensive to produce.) The handful of elements that we really are a bit short of are likely to be hard to find in space. The one resource that's a really good candidate for import from space is energy. There is the Sun. We should use it. Bob Kolker |
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nuclear space engine - would it work ??
On Thu, 05 Oct 2006 10:12:16 GMT, Matt Giwer
wrote: snip But the first practical test of an ion engine was only a two years ago after decades of easy, safe ground based lab research. That sent a European package to the moon. NASA's Deep Space 1 launched in 1998, with an ion engine. It was pretty successful. Dale |
#38
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nuclear space engine - would it work ??
"Henry Spencer" wrote in message ... China is already about to pass the US as the planet's #1 CO2 producer. Gee, didn't they sign the Kyoto treaty? |
#39
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nuclear space engine - would it work ??
Matt Giwer wrote: But the first practical test of an ion engine was only a two years ago after decades of easy, safe ground based lab research. No, there was Deep Space 1, and decades before that SERT II (although the NASA PAO seems to have oddly forgotten that mission when it was talking about Deep Space 1): http://www.grc.nasa.gov/WWW/ion/past/70s/sert2.htm Pat |
#40
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nuclear space engine - would it work ??
Pat Flannery writes:
Matt Giwer wrote: But the first practical test of an ion engine was only a two years ago after decades of easy, safe ground based lab research. No, there was Deep Space 1, and decades before that SERT II (although the NASA PAO seems to have oddly forgotten that mission when it was talking about Deep Space 1): http://www.grc.nasa.gov/WWW/ion/past/70s/sert2.htm And I even dimly remember some russian, err, soviet mission with an (experimental?) ion engine much earlier... can't find it right now. It was some interplanetary probe, I think. Jochem -- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery |
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