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.
Warder to starry_nite
Chapterfish — Nate's Writing Blog
http://chapterfish.wordpress.com
Chapterfish — Nate's Writing Blog
http://chapterfish.wordpress.com
NASA unveils new spaceflight rocket
14/09/2011 07:50:09 PM
- 700 Views
I wanted to be happy but I have to say I am a little sad.
14/09/2011 08:48:53 PM
- 253 Views
I have to agree
14/09/2011 10:05:08 PM
- 245 Views
It does say in the article ...
14/09/2011 10:20:19 PM
- 273 Views
We don't use petroleum in most rockets and never have used them much
14/09/2011 10:53:14 PM
- 252 Views
Hi Guys!
15/09/2011 01:44:13 AM
- 497 Views
do you really believe a space elevator is doable with current materials?
15/09/2011 05:45:01 AM
- 233 Views