I want to get a little into rocketry and i want to know what are the best chemical mixes for solid and liquid state rockets? also i wanted to know if there are such things as super chemicals. Im not sure if i made that up or not or it just a different word but, what i mean are chemicals that have been altered to have the ability to create a lot more thrust and/or specific impulse than regular chemicals.
Astronuc
Aug17-08, 07:51 AM
It's pretty hard to beat liquid hydrogen and oxygen as far as liquid propellants go, but they require cryogenic storage. The Space Shuttle Main Engines use a hydrogen-rich LH2/LOx mixture. A more energetic reaction with higher specific impulse would be H+F (hydrogen + fluorine), but that would be unsuitable in the atmosphere since HF is extremely corrosion and toxic to living things.
There are no liquid superchemicals.
As far as solids go, there is a delicate balance of energy density and explosiveness. Perchlorates are the preferred oxidizing agent, and ammonium perchlorate is commonly used.
See - http://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster#Propellant
hmm thats interesting what the specific impulse for that mixture just wondering? also im not sure if there is or not but are there any ways to make electric propulsion that you know of? or anyone else if they read this?
map19
Aug18-08, 05:46 PM
Fuels in general contain more energy the greater their mass. For ex. Diesel vs petrol.
In this case the use of kerosene and LOX is the simplest. There are other oxidisers available, for ex. hydrogen peroxide.
Goddard used gasoline and LOX. Russians and Chinese have used kero and LOX as did the Saturn V.
chemisttree
Aug19-08, 07:10 PM
hmm thats interesting what the specific impulse for that mixture just wondering? also im not sure if there is or not but are there any ways to make electric propulsion that you know of? or anyone else if they read this?
Ion propulsion (http://nmp.nasa.gov/ds1/tech/ionpropfaq.html) is the only way that I know of other than an electric powered prop or turbine.
map19
Aug19-08, 08:09 PM
Specific impulse for bi-chemical liquid fuels is around 450s.
specific impulse measured in time is 453 seconds, or, equivalently, an effective exhaust velocity of 4500 m/s, for the Space Shuttle Main Engines when operating in vacuum.