If I were a betting man my money would be on a grain problem. When solids go
immediately on ignition usually a problem with the grain is the cause, i.e.
liner or insulation failure, grain fracture, etc. I'm not too familiar with
KNSB/sugar propellants but they are not far from the old black powder variety.
A rock hard propellant with poor mechanical properties. Easy to get flame in a
location where it's unwanted. I wonder: What kind of insulation/liner was
used? What are the bond properties of KNSB/sugar to this material? Can't
imagine the propellant was a single pour, what kind of bond was there at the
pour interface? Was the motor heat cycled by climate after propellant loading
was finished? Did propellant suffer from transportation damage--grain cracks,
etc. Poor mechanical properties were one of the reasons composite propellants
were invented.
I feel badly for the fellows that built this motor as no one wants to see their
work literally go up in smoke. Maybe one of the reasons for the "Sugar Shot to
Space" is because of the high probability that it is not going to happen.
Anyway, it is easy to be a critic when one is not involved. Glad no one was
injured.
Barry C Jolly
On Sunday, February 19, 2023 at 05:18:04 AM EST, roxanna Mason
<rocketmaster.ken@xxxxxxxxx> wrote:
One of two things:1 - Nozzle attachment system under engineered, or2 - Grain
defect caused an over-pressure.Did you have instrumentation, i.e. Pc trace?
That will discern between 1 or 2.
Ken
On Sun, Feb 19, 2023 at 12:54 AM neutronium95 <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
The 12 inch S motor blew out the nozzle on ignition. I wasn't there, but a few
different videos have been shared around.
This is the best one I've seen:
https://media.discordapp.net/attachments/355526822760415243/1076745130389815346/2023-02-18_sugar_failure_corrected.mp4
-Daniel F.
Feb 18, 2023, 8:13 PM by zeinin@xxxxxxxxx:
What happened at FAR? Facebook doesn't have anything on it
On Sat, Feb 18, 2023, 8:04 PM Matthew JL <prmattjl@xxxxxxxxx> wrote:
Heard about the CATO at FAR today - hope everyone’s OK and that the setback
proves minuscule.
Best,
-Matt L.
On Fri, Dec 16, 2022 at 8:32 PM Rick Maschek <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
We are static firing our 12" S-26,500 KNSB motor tomorrow...total impulse
355,000 Nsec.
If all goes well, it will be mated with our 10" for a 2-stage to finally finish
Sugar Shot to Space.
Rick