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ENG File: ow1524g2.eng

Discussion

The test produced less impulse than we had hoped. The nozzle throat that had been mistakenly manufactured too large for the first test had been fixed, so we expected higher pressures and a higher delivered ISP. Though higher pressure was achieved, it only lasted for half of the burn. After about 3 seconds, the pressure and thrust decreased in a very odd linear fashion. The first half of the burn produced slightly more thrust than we expected, while the second half under-performed by enough to counteract the extra impulse from the first ~3s.

This static fire was the first time we tried splicing a liner. Though it wasn't required for a motor of this length, we decided it would be a good idea to get experience with the technique before moving onto motors long enough to need splicing. As shown in the following pictures, the splice point survived the burn, even as other sections of the liner were nearly destroyed during the test and disassembly.

(The cut o-ring on the forward closure in the fourth picture was damaged during disassembly)