Quote from: Kabloona on 08/14/2013 03:22 pmQuote from: robertross on 08/14/2013 03:09 pmQuote from: Kabloona on 08/14/2013 01:14 pmQuote from: Calphor on 08/14/2013 04:19 amQuote from: Kabloona on 08/13/2013 08:26 pmQuote from: robertross on 08/13/2013 08:16 pmGreat stuff Chris!For a moment there I thought ATK was using my recipe for Pistachio ice cream! Yeah, that greenish cast is strange. I suspect it's just a color balance issue with the digital camera, as fluorescent lighting will make things look green if the color balance option on a digital camera isn't set correctly. Normally solid propellants in that condition look grayish due to the aluminum powder, and I doubt it was St Patrick's day at ATK when the photo was taken. ;-)You'd be surprised then, that color is accurate. Shuttle propellant is actually red-brown. It all depends on the ingredients.What is the green ingredient? I worked with solid propellants for ten years (in the nineties) and saw colors range from black to gray to reddish (iron oxide burn rate catalyst) but never green.likely the binding agent has caused this colour cast?Conventional binders (HTPB, PBAN) are not green, and IMO it's highly unlikely ATK would use a different binder given the extensive industry experience with HTPB and PBAN. More likely an oxidizer or some sort of energetic ingredient.I don't know if it as been released in the open literature, but I can say that it is neither PBAN or HTPB.
Quote from: robertross on 08/14/2013 03:09 pmQuote from: Kabloona on 08/14/2013 01:14 pmQuote from: Calphor on 08/14/2013 04:19 amQuote from: Kabloona on 08/13/2013 08:26 pmQuote from: robertross on 08/13/2013 08:16 pmGreat stuff Chris!For a moment there I thought ATK was using my recipe for Pistachio ice cream! Yeah, that greenish cast is strange. I suspect it's just a color balance issue with the digital camera, as fluorescent lighting will make things look green if the color balance option on a digital camera isn't set correctly. Normally solid propellants in that condition look grayish due to the aluminum powder, and I doubt it was St Patrick's day at ATK when the photo was taken. ;-)You'd be surprised then, that color is accurate. Shuttle propellant is actually red-brown. It all depends on the ingredients.What is the green ingredient? I worked with solid propellants for ten years (in the nineties) and saw colors range from black to gray to reddish (iron oxide burn rate catalyst) but never green.likely the binding agent has caused this colour cast?Conventional binders (HTPB, PBAN) are not green, and IMO it's highly unlikely ATK would use a different binder given the extensive industry experience with HTPB and PBAN. More likely an oxidizer or some sort of energetic ingredient.
Quote from: Kabloona on 08/14/2013 01:14 pmQuote from: Calphor on 08/14/2013 04:19 amQuote from: Kabloona on 08/13/2013 08:26 pmQuote from: robertross on 08/13/2013 08:16 pmGreat stuff Chris!For a moment there I thought ATK was using my recipe for Pistachio ice cream! Yeah, that greenish cast is strange. I suspect it's just a color balance issue with the digital camera, as fluorescent lighting will make things look green if the color balance option on a digital camera isn't set correctly. Normally solid propellants in that condition look grayish due to the aluminum powder, and I doubt it was St Patrick's day at ATK when the photo was taken. ;-)You'd be surprised then, that color is accurate. Shuttle propellant is actually red-brown. It all depends on the ingredients.What is the green ingredient? I worked with solid propellants for ten years (in the nineties) and saw colors range from black to gray to reddish (iron oxide burn rate catalyst) but never green.likely the binding agent has caused this colour cast?
Quote from: Calphor on 08/14/2013 04:19 amQuote from: Kabloona on 08/13/2013 08:26 pmQuote from: robertross on 08/13/2013 08:16 pmGreat stuff Chris!For a moment there I thought ATK was using my recipe for Pistachio ice cream! Yeah, that greenish cast is strange. I suspect it's just a color balance issue with the digital camera, as fluorescent lighting will make things look green if the color balance option on a digital camera isn't set correctly. Normally solid propellants in that condition look grayish due to the aluminum powder, and I doubt it was St Patrick's day at ATK when the photo was taken. ;-)You'd be surprised then, that color is accurate. Shuttle propellant is actually red-brown. It all depends on the ingredients.What is the green ingredient? I worked with solid propellants for ten years (in the nineties) and saw colors range from black to gray to reddish (iron oxide burn rate catalyst) but never green.
Quote from: Kabloona on 08/13/2013 08:26 pmQuote from: robertross on 08/13/2013 08:16 pmGreat stuff Chris!For a moment there I thought ATK was using my recipe for Pistachio ice cream! Yeah, that greenish cast is strange. I suspect it's just a color balance issue with the digital camera, as fluorescent lighting will make things look green if the color balance option on a digital camera isn't set correctly. Normally solid propellants in that condition look grayish due to the aluminum powder, and I doubt it was St Patrick's day at ATK when the photo was taken. ;-)You'd be surprised then, that color is accurate. Shuttle propellant is actually red-brown. It all depends on the ingredients.
Quote from: robertross on 08/13/2013 08:16 pmGreat stuff Chris!For a moment there I thought ATK was using my recipe for Pistachio ice cream! Yeah, that greenish cast is strange. I suspect it's just a color balance issue with the digital camera, as fluorescent lighting will make things look green if the color balance option on a digital camera isn't set correctly. Normally solid propellants in that condition look grayish due to the aluminum powder, and I doubt it was St Patrick's day at ATK when the photo was taken. ;-)
Great stuff Chris!For a moment there I thought ATK was using my recipe for Pistachio ice cream!
Burn rate modifier?http://www.google.com/patents/US4411717
I worked in solid propellant R&D in the 1990's and never heard of the stuff.
Quote from: Calphor on 08/15/2013 12:03 pmQuote from: Kabloona on 08/14/2013 03:22 pmQuote from: robertross on 08/14/2013 03:09 pmQuote from: Kabloona on 08/14/2013 01:14 pmQuote from: Calphor on 08/14/2013 04:19 amQuote from: Kabloona on 08/13/2013 08:26 pmQuote from: robertross on 08/13/2013 08:16 pmGreat stuff Chris!For a moment there I thought ATK was using my recipe for Pistachio ice cream! Yeah, that greenish cast is strange. I suspect it's just a color balance issue with the digital camera, as fluorescent lighting will make things look green if the color balance option on a digital camera isn't set correctly. Normally solid propellants in that condition look grayish due to the aluminum powder, and I doubt it was St Patrick's day at ATK when the photo was taken. ;-)You'd be surprised then, that color is accurate. Shuttle propellant is actually red-brown. It all depends on the ingredients.What is the green ingredient? I worked with solid propellants for ten years (in the nineties) and saw colors range from black to gray to reddish (iron oxide burn rate catalyst) but never green.likely the binding agent has caused this colour cast?Conventional binders (HTPB, PBAN) are not green, and IMO it's highly unlikely ATK would use a different binder given the extensive industry experience with HTPB and PBAN. More likely an oxidizer or some sort of energetic ingredient.I don't know if it as been released in the open literature, but I can say that it is neither PBAN or HTPB.I know it's not HTPB or PBAN because those are not green. But can you say what the function of the green is? Binder, oxidizer, catalyst, energetic ingredient...?
It's the binder.
With lots of water under the bridge since Pegasus II was first announced, ATK merging with Orbital, proposed mini-Dream Chaser as a cargo, etc....... what more do we know on Pegasus II that we did not know in August of 2013 when this was announced?