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Test #
Date
Site
Result
Characterization Static Fire #1November 25, 2017Crow IslandNozzle Failure
Characterization Static Fire #2November 25, 2017Crow IslandNozzle Failure
Characterization Static Fire #3November 25, 2017Crow IslandMotor success, pressure transducer failure
Characterization Static Fire #4November 25, 2017Crow IslandMotor success
Characterization Static Fire #5December 2, 2017Crow IslandMotor Success! Highest pressure to date: 695 psi
Characterization Static Fire #6December 2, 2017Crow IslandSuccess, excellent BATES curve
OW-152-4G #1Janurary 14, 2018Crow IslandFull Duration. First Try.
OW-152-4G #1Janurary 27, 2018Crow IslandSuccess
OW-98-FIN1 #1Janurary 27, 2018Crow IslandSuccess of a very angry motor
OW-152-8G #1Feburary 24, 2018Crow IslandFull Impulse. Thrust and Pressure higher than expected. Nozzle cracked.
OW-152-8G #2April 7, 2018Crow Island

Liner Burnthrough at T+3

OW-152-4G #3July 21, 2018FARPending

 

Discussion

Expand this: Much better, but not as good as we had hoped. Solids loading is lower than originally designed due to difficulty with vacuum casting. Now that we aren't vacuum casting, solids loading should go back up to regain performance. Though more testing is needed to prove it, a theory behind the increased burn rate seen in OW-152-8G #1 is that the high pressure cracked the 400u AP leading to increased surface area. This failure mode, in addition to the relative high cost and limited availability of 400u AP, suggests that we should ditch it altogether. To slow down the burn rate of the resulting bimodal propellant, we should replace the burn rate catalyst with a burn rate supressor such as oxamide. Without the burn rate catalyst we may need to add an opacifier, but it is also possible that the Al fills this role (link literature). The only other issue is that bimodal propellants may be more difficult to cast, but this isn't much of an issue because there would still be three different particle sizes, two of AP and one of Al.