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Cool. Nate Send a noteboard - 14/09/2011 11:04:39 PM
Petroleum is a good fuel because it stores well, burns well and simply, and is plentiful, while it is much better than ethanol in terms of energy per unit mass it isn't the peak and is somewhat false in that respect... you don't really get 3-4 miles off a pound of gasoline, you get 3-4 miles off a pound of gasoline and a pound of oxygen. Hydrogen gets about 140 Megajoueles per kilogram whereas most petroleum products do about 40-50 MJ/kg, Fat comes in around 40 MJ/kg itself, firewood, carbs, protein all come in around 20 MJ/kg, batteries tend to do about 2-10 MJ/kg... gunpowder is actually only around 3 MJ/kg but is handy because it burns very, very fast... uranium is 20,000,000 MJ/kg, fusion does a good deal better and anti-matter 180,000,000,000 MJ/kg


I had never seen those actual numbers before. Nifty.

No, a cylinder's more efficient for getting a symmetric burn on rocket fuel and there's only so many shapes that are structural sound and minimize the mass/surface area of an object. That's about the only reason rockets tend to be cylindrical.


Do they take aerodynamics into account when designing these things, or is it such a relatively small opposing force compared to gravity that they don't really care?

That's like saying knife or kettle technology has increased at a snail's pace. Rocket's are comparatively simple devices, just like guns or cars or knives they are so immediately practical that once you have them you max out the design pretty quickly because it's important. Radio hasn't improved much since it was invented either, just minor tweaks or taking advantage of computers.


I meant for space flight, not for rocket design. It would be nice to see a faster progression in space flight and space exploration and getting people into space. Even though I'm sure the list of constraining factors is enormous, it's still hard not to have the sense that we could do better if we really wanted to.
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NASA unveils new spaceflight rocket - 14/09/2011 07:50:09 PM 787 Views
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Uh huh. - 14/09/2011 10:11:09 PM 316 Views
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they did look at using nukes to launch a space ship - 15/09/2011 03:48:32 AM 472 Views
It does say in the article ... - 14/09/2011 10:20:19 PM 347 Views
We don't use petroleum in most rockets and never have used them much - 14/09/2011 10:53:14 PM 326 Views
Cool. - 14/09/2011 11:04:39 PM 307 Views
Re: Cool. - 14/09/2011 11:47:33 PM 470 Views
ah fair enough about the fuel - 14/09/2011 10:57:30 PM 346 Views
I guess it could come for oil but it doesn't have to - 15/09/2011 03:45:02 AM 274 Views
Cracking water into H2 and O2 takes a lot of energy - 15/09/2011 05:33:48 AM 351 Views
I was hoping for something Enterprise-shaped. *NM* - 14/09/2011 10:55:41 PM 134 Views
You too? *NM* - 14/09/2011 11:31:06 PM 151 Views
Hi Guys! - 15/09/2011 01:44:13 AM 568 Views
Re: Hi Guys! - 15/09/2011 02:07:11 AM 430 Views
Oh cool!! - 15/09/2011 04:07:13 AM 447 Views
Re: Oh cool!! - 15/09/2011 05:28:31 AM 446 Views
do you really believe a space elevator is doable with current materials? - 15/09/2011 05:45:01 AM 303 Views
No - 15/09/2011 12:30:51 PM 301 Views
I can't even imagine you guys out at NASA must feel - 15/09/2011 02:59:18 PM 332 Views

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