The propulsion team made a significant amount of progress this semester. We constructed our own test stand for a 42mm single grain motor, built the motor, and tested it multiple times with different propellant compositions. All but one of these tests were successful. We then upgraded the main beam of the test stand to solid aluminum in preparation for larger motors. After successful tests of the 42mm motor, a 4.5 in (114.3 mm) single grain motor with 3.4 pounds of propellant was tested.
Post-fire data analysis showed that the 4.5 in diameter motor achieved a peak thrust of 170 pounds, peak chamber pressure of 620 psi, total impulse of 3258 Ns, and a specific impulse of 212 seconds. The test fire was a complete success, and the data obtained agreed with our theoretical predictions.
We are currently in the process of manufacturing a three grain 4.5 x 27-inch rocket motor. The total propellant mass is approximately 12 pounds. This motor is estimated to produce a peak thrust close to 400 lbf, a peak chamber pressure of 534.2 psi, and a specific impulse of 197 seconds. Manufacturing of the motor has been completed as of the week of Nov 26, 2018, and we anticipate launching it on December 1.