Talk:Solid-fuel rocket
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[edit] Isp
I changed the performance numbers listed for solid / Lox-RP1 / Lox-LH2 engines. The new data reflect theoretical performance numbers, in s, for standard operating conditions (1000 psi chamber, 14.7 psi exit). These are the numbers given by Sutton in Rocket Propulsion Elements, 7th ed, pp. 188-189. The old numbers reflected a mix of sea level / vacuum Isp, which is misleading at the least. Evand 22:43, 21 Apr 2005 (UTC)
[edit] Rocket fuel
Is there any solid rocket fuels handy at home. How to determine a fuel for a rocket.
- There are a number of rocket propellants accessible to the amateur rocketeer. However, it should be remembered that engaging in rocketry safely requires care, knowledge, and a respect for the energies involved at all steps. Probably the most accessible propellant is one based on sorbitol and potassium nitrate, often referred to as rocket candy. It is related to the original candy propellant, sucrose / potassium nitrate, but easier and safer to work with. Evand 20:49, 27 August 2006 (UTC)
[edit] More accurate?
This article in the NYTimes suggests that the use of solid fuel rocket motors results in more accurate missles that when using liquid fuel motors. "Solid fuel dramatically increases the accuracy of a missile while a liquid fuel missile is not very accurate in hitting targets." How is this? --Hooperbloob 17:35, 27 August 2006 (UTC)
- NYT has it wrong. In their defense, there are a number of reasons to prefer solid propellants for missiles. The biggest is storage and operation -- solids can be stored ready to fire almost indefinitely. Storable liquid propellants, as a rule, are toxic, corrosive, degrade over time (months or years), and are less dense than solid propellants. The density means that for many military applications where volume is limited (eg space in a sub / truck / etc) the solids perform better, despite slightly lower Isp, due to the increased quantity of propellant in the same volume. Also, solid motors are frequently simpler and therefore cheaper to build in quantity, though the higher propellant cost (mainly due to labor-intensive casting procedures) may offset or reverse this. If anything, liquids would actually be more accurate, since solid propellant burn rates depend on things like storage temperature, which makes for a less precise thrust curve. I'm guessing somehow the reporter translated "solid propellants make for better missiles" into "solid propellants make for more accurate missiles." Evand 20:33, 27 August 2006 (UTC)
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- OK, that tends to make more sense, thanks for the interpretation.--Hooperbloob 22:38, 27 August 2006 (UTC)
[edit] Steel casings
"In the USA, the use of a steel casing requires a federal permit when building models[citation needed] ."
This was in the article. I believe it to be incorrect, so I marked it [citation needed] , and have now removed it. I know that steel casings are not permitted under NFPA-1127, Tripoli, or NAR rules, but I don't believe it is illegal in any way, or requiring of special permitting. If anyone has a reference, please feel free to put it back. Evand 20:14, 17 October 2006 (UTC)
