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Lunar testing would be a problem because down-mass to the surface will have to be kept pretty low for the forseeable future until a Moon Megalander is built and signifigant fuel supplies are exploited from Lunar ice. The GCNR engine chaimber and fuel pump/capsule will be pretty heavy. And the engine would probobly have to be brought back to Earth for study, which would be alot of trouble.
There are alot of caves in places where people don't live. If the engine were tested in a cave in the middle of nowhere, the ground itself would act as a sufficent "filter" to protect groundwater, since nobody lives nearby. Seepage takes a while, long enough for the worst of the daughter chemicals to decay probobly. Even if this scheme were abandoned and the engine tested above-ground, the fallout would be pretty mild and localized in the long run. And frankly, a pro-nuclear US administration could tell the eco-nuts to go to he||, the only BIG political hurdle is the rediculus court order system.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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As i've mentioned previously, groundwater doesn't move all that fast. If it were fired into a cave in the middle of nowhere, I bet the water would take so long to reach anywhere inhabited or be diluted so fully that the fallout would not be a problem.
The trouble with digging a tunnel big enough to test a decent sized rocket engine which will be expelling alot more gas volume than others (hydrogen has very low density) is that you would need a really really big tunnel. A cave is already dug for you, just cap it when we're done.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Groundwater moved slowly in certain kinds of rock, yes; shales, arkoses, for example. But caves occur usually in limestone, especially the big caves you want to use; and those caves are associated with underground RIVERS. In limestone areas, groundwater can flow through small caves and cracks in the limestone at the rate of several miles a day.
Possibly there are lava tubes somewhere in a desert climate that could be used. Even anti-environmental governments will encounter stiff resistance to such an effort though.
We will need advanced nuclear-ion/VASMR or GCN for trips to the outer solar system. If we wait for them to be available for Mars, it'll be some time before we reach the red planet; after 2050. That's why I'm placing my bet on lunar derived chemical propulsion, probably with solar-ion to raise cargo to lagrange.
-- RobS
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Hmmmm but it still isn't a large amount of radioactive material in the first place, so we find a cave with an underground river far away from people then. Plus I think that above-ground testing would be tollerable with safety precautions, like firing the engine down a long tube lined with water sprayers to condense and trap the worst of the fuel vapors perhaps. *shrug*
If we are going to take a "side trip" to the Moon, then its quite possible that a Mars trip would have to wait a while anyway. The deciding factor in how long GCNR takes is when we start really, if Nasa sent a few million its way tomorrow and resolved to use it, I think it would be done when we are ready to move beyond the Moon.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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The last few posts seem to have strayed a little off the "Need for a new Booster" topic. We don't need GCNRs to get to Mars within ten to fifteen years. So long as we have a powerful enough booster (Energia derived Vulkan), it can easily be done with off-the-shelf rocket engines. New propulsion system development cost: zero. Environmental problems: none.
Once manned flights to Mars become reality, it will be easier to introduce low risk, environmentally sound technologies like simple solid core NTRs and/or nuclear electric ion drives. These will require only moderate development funding, but in order to get the programme "off the ground", development costs at the front end must be kept to a minimum, and any possible environmental objections avoided. Any near term funding for GCNR research or similarly problematic technologies will reduce funding available to build Mars ships now. We should focus on the near term if we actually want to see Humans on Mars in the near future, or at all.
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Environmental problems: none.
It's funny you should mention that. In Dennis Jenkins's awesome Space Shuttle book, he summarizes an environmental impact study done on the Shuttle & Titan solid rocket boosters. This study revealed that it would take thirty Titan launches and 44 shuttle launches per year to cause any detectable environmental impact. The most dangerous thing about the SRBs (aside from the single Shuttle SRB failure) is the toxicity of the propellant when it is being poured into the propellant segments.
Who needs Michael Griffin when you can have Peter Griffin? Catch "Family Guy" Sunday nights on FOX.
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SRB exhaust is slightly polluting; aluminum oxide and CFC's I think? The liquid fuel used for Titan and Proton is ultra toxic. The sooner Proton is gone, the better.
I don't object to SRB's for environmental reasons, but the STS SRBs cost almost twice what Yhuznoyhe charges for Zenit main stage. Also, Zenit has vastly superior ISP and a much better dry mass ratio. RD-170 can be throttled, gimbaled, has multiple stop-restart capacity, etc. SRB vs. Zenit? No contest.
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Space.com article on cargo shuttles
NASA hasn't gone totally deaf to the idea of an SDV (or, as the article says, anything that falls under the generic title "Shuttle-C.") However, it looks like they're more interested in automating the orbiter (something they talked about one year before Columbia.) Both the SDV and autonomous orbiter have their uses (and hopefully they automate the orbiter soon so ISS can get finished.)
Who needs Michael Griffin when you can have Peter Griffin? Catch "Family Guy" Sunday nights on FOX.
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