klaes@wrksys.dec.com (N = R*fgfpneflfifaL 23-Oct-1989 1549) (10/24/89)
Could someone please post information concerning the exhaust
gases from the Space Shuttle's solid rocket boosters during takeoff.
Does it contain hydrogen oxide?
Thanks in advance.
Larry Klaes klaes@wrksys.dec.com
or - ...!decwrl!wrksys.dec.com!klaes
or - klaes%wrksys.dec@decwrl.dec.com
or - klaes@wrksys.enet.dec.com
N = R*fgfpneflfifaL
henry@utzoo.uucp (Henry Spencer) (10/24/89)
In article <8910231952.AA14411@decwrl.dec.com> klaes@wrksys.dec.com (N = R*fgfpneflfifaL 23-Oct-1989 1549) writes: > Could someone please post information concerning the exhaust > gases from the Space Shuttle's solid rocket boosters during takeoff. > Does it contain hydrogen oxide? I.e., water? Yes, among other things. Lots of other things. SRB fuel, if I recall correctly, is ammonium perchlorate (NH4ClO4) plus a dash of aluminum powder for extra heat, a demitasse of synthetic rubber for mechanical strength, and an assortment of minor odds and ends to control burn rate and such. So the exhaust will contain water, alumina (Al2O3) particles, carbon dioxide (from the rubber), and a witches' brew of nitrogen and chlorine compounds and partially burnt ickiness. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
stephen@milton.acs.washington.edu (Stephen Milton) (10/25/89)
In article <1989Oct24.163114.29924@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >> Does it contain hydrogen oxide? > >I.e., water? Yes, among other things. Lots of other things. SRB fuel, technically, water is not hydrogen oxide, its dihydrogen oxide. Were you referring to this, or to some extremely odd form. [][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][] []Stephen M. Milton, Operator/Consultant, UCS, University of Washington [] [] 'stephen@Milton.U.Washington.Edu' [] []Lifetime Goals: Local Autonomous Anarchy, and A Good Beef on Rye Sand.[] [][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
gwh@typhoon.Berkeley.EDU (George William Herbert) (10/25/89)
In article <1989Oct24.163114.29924@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >I.e., water? Yes, among other things. Lots of other things. SRB fuel, >if I recall correctly, is ammonium perchlorate (NH4ClO4) plus a dash of >aluminum powder for extra heat, a demitasse of synthetic rubber for >mechanical strength, and an assortment of minor odds and ends to control >burn rate and such. So the exhaust will contain water, alumina (Al2O3) >particles, carbon dioxide (from the rubber), and a witches' brew of >nitrogen and chlorine compounds and partially burnt ickiness. A _dash_ of aluminum??? The majority of the thrust is achived by the aluminum component of the fuel ! The actual materials are Ammonium Perchorate, Aluminum powder, PVC binder and extra bits to stabilize. It's about 99% those three. Yes, the exhaust if icky. suprise :) **************************************** George William Herbert UCB Naval Architecture Dpt. (my god, even on schedule!) maniac@garnet.berkeley.edu gwh@ocf.berkeley.edu ----------------------------------------
henry@utzoo.uucp (Henry Spencer) (10/25/89)
In article <1989Oct24.222743.23580@agate.berkeley.edu> gwh@typhoon.Berkeley.EDU (George William Herbert) writes: > A _dash_ of aluminum??? The majority of the thrust is achived >by the aluminum component of the fuel ! > The actual materials are Ammonium Perchorate, Aluminum powder, PVC >binder and extra bits to stabilize. It's about 99% those three. If we're being picky, the numbers (according to NASA) are 69.83% ammonium perchlorate, 16% aluminum, 12% rubber (it's not PVC, it's a polybutadiene acrylic acid acrylonitrile polymer), 2% curing agent, and more or less 0.17% iron oxide catalyst. And don't sneer at the idea of doing without the aluminum, because the rubber is also a fuel; similar combinations without aluminum have almost as high a specific impulse. (For that matter, ammonium perchlorate by itself is apparently non-trivial as a monopropellant, although it's not used that way because its physical properties aren't right.) -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
henry@utzoo.uucp (Henry Spencer) (10/25/89)
In article <572@milton.acs.washington.edu> stephen@milton.acs.washington.edu (Stephen Milton) writes: >>> Does it contain hydrogen oxide? >>I.e., water? Yes... > >technically, water is not hydrogen oxide, its dihydrogen oxide... No, technically water is hydrogen oxide (ref: Hdbk of Chemistry & Physics, table of inorganic compounds). It is normal to omit numeric prefixes when no ambiguity is present (e.g. N2O4 is nitrogen tetroxide, not dinitrogen tetroxide), and also common to refer to the most common or "normal" oxide of XXX as "XXX oxide" (e.g. Fe2O3 is iron oxide even though FeO also exists; if one is being fussy one uses "ferric" and "ferrous" or "iron (III)" and "iron (II)" to distinguish). Chemical nomenclature in practice is nowhere near as formalized and pedantic as it could be in theory. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
gwh@typhoon.Berkeley.EDU (George William Herbert) (10/26/89)
In article <1989Oct25.022019.14407@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <1989Oct24.222743.23580@agate.berkeley.edu> gwh@typhoon.Berkeley.EDU (George William Herbert) writes: >> A _dash_ of aluminum??? The majority of the thrust is achived >>by the aluminum component of the fuel ! >> The actual materials are Ammonium Perchorate, Aluminum powder, PVC >>binder and extra bits to stabilize. It's about 99% those three. > >If we're being picky, the numbers (according to NASA) are 69.83% ammonium >perchlorate, 16% aluminum, 12% rubber (it's not PVC, it's a polybutadiene >acrylic acid acrylonitrile polymer), 2% curing agent, and more or less >0.17% iron oxide catalyst. > >And don't sneer at the idea of doing without the aluminum, because the >rubber is also a fuel; similar combinations without aluminum have almost >as high a specific impulse. (For that matter, ammonium perchlorate by >itself is apparently non-trivial as a monopropellant, although it's not >used that way because its physical properties aren't right.) Okay, Henry, you got me :) I had a tech paper from some time back that had PVC listed as the propellant, but i checked again and Heny appears to be right. Maybe it got changed sometime. As for the 'no aluminum' bit, it really was described as making most of the difference. There's a whole lot more energy in Al than rubber... **************************************** George William Herbert UCB Naval Architecture Dpt. (my god, even on schedule!) maniac@garnet.berkeley.edu gwh@ocf.berkeley.edu ----------------------------------------
henry@utzoo.uucp (Henry Spencer) (10/26/89)
In article <1989Oct26.025442.17842@agate.berkeley.edu> gwh@typhoon.Berkeley.EDU (George William Herbert) writes: >>And don't sneer at the idea of doing without the aluminum, because the >>rubber is also a fuel; similar combinations without aluminum have almost >>as high a specific impulse... > >... As for the 'no aluminum' bit, it really was described as making >most of the difference. There's a whole lot more energy in Al than rubber... I confess I was a bit surprised myself, but Sutton lists a PVC/AP combination as having only about 10% less exhaust velocity than PVC/AP/Al. Aluminum is a lot more energetic, but it also exacts a price: aluminum oxide has a very high molecular weight, and it tends to condense out to complicate things further. I'm not up enough on the fine points of solids to really assess the tradeoffs. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
jones@bach (Clark Jones) (10/28/89)
Given all of the nasties that come out of the tail end of a working SRB, it is kind of suprising that the Luddites haven't tried to shut down the STS program on the basis of the airpollution generated. After thinking about some of that stuff, I think I'll skip watching a launch in person for fear of being downwind. :-) Actually, it might not be such a bad idea if the Luddites could get NASA to abandon the SRBs. Only a critter as stupid as Congress would go for that unreliable a system in the first place. ;-) BTW, anyone besides me remember the saga of the Little Joe II? It was a solid fuel rocket designed to be used in testing the Apollo escape tower. One high- up NASA official said it was "the most reliable rocket we've built". The third (and final) launch produced a shattered charge about 7 sec. before scheduled escape tower ignition, generating a much more realistic test of the escape system than NASA had planned. (They counted it a "successful test"!) IMHO, the ONLY place that manned solid rockets belong are in ejection seats, and then you put in a dozen or so, and as long as 75% or so fire when you "pull", and NONE fire when you _DON'T_ "pull", you're OK. You can even tollerate a couple of them shattering while in use. Clark Disclaimer: The opinions expressed above are mine and not those of Schlumberger because they are NOT covered by the patent agreement!