Posted: 5/30/2003 1:49:31 PM EDT
[#1]
Newsgroups: sci.space.history From: Henry Spencer Subject: Re: Space Shuttle Propellants Date: Tue, 11 Nov 1997 17:14:05 GMT
In article <[email protected]>, Jeff Lewis wrote: >> With regards to the space shuttle, what are the exhausts emitted... > >Main engines, SSMEs, produce water steam, reacting LOx and LH2.
There's also a lot of unburned H2 in the exhaust. Plus traces of other things; in particular, any rocket engine running within the atmosphere will generate some oxides of nitrogen.
>The >solids produce some burnt rubber kind of stuff plus chlorides, from >burning basically tire rubber and ammonium perchlorate...
It's more complicated than that. The solids' exhaust is a real witches' brew. The ammonium perchlorate oxidizer decomposes into, mostly, nitrogen, water, oxygen, and hydrogen chloride (which becomes hydrochloric acid if dissolved in water). The rubber fuel, whose overall composition is roughly CH2, burns with some of the oxygen to give CO2 and more water. The powdered aluminum burns with more of the oxygen to give Al2O3, which quickly condenses into solid particles, which is what makes the SRB exhausts so smoky. However, this process is complicated and disorderly, and all kinds of things come out of it in smaller quantities.
>...The OMS react N2H4 and N2O4, so probably produce nitrogen, >hydrogen, oxygen, ammonia, water...
Actually the fuel is not hydrazine but MMH, CH3NHNH2, so there's also CO2 and other odds and ends in there. There won't be any significant amount of oxygen in the exhaust, it all gets used up. Assorted poorly-known weird things form in small quantities, especially during startup and shutdown when temperatures are lower. -- If NT is the answer, you didn't | Henry Spencer understand the question. -- Peter Blake | [email protected]
View Quote
|
|