Trying again using KNSO with our new casting bases. We also have a real
eye-dropper now for measuring the surfactant. 4 38mm grains of
-1.875" length, using formula of
+1.875" length, 250 gram batch using formula of
-* 65% KNO3
-* 35% Sorbitol
-* 1% red iron oxide
-* 3 drops Polystep-B1
+* 65% KNO3, 162.5g
+* 35% Sorbitol, 87.5g
+* 1% red iron oxide, 2.5g, added after melt
+* 3 drops Polystep-B1, added before pour
## Process ##
## Observations ##
-Pour went really smoothly. One grain looked "perfect" with the propellant
+Pour went really smoothly. Easier than previous batches, perhaps due to
+a bit more surfactant, perhaps just getting better, perhaps due to putting
+the mandrels in post-pour. One grain looked "perfect" with the propellant
settled evenly and a couple mm of open gap at the top of the casting
tube. We think this one may have been slightly under-filled compared to
the others, all of which had some evidence of propellant sticking to the
exagerated in the flight accel data, which seems completely explainable by
the nozzle throat erosion causing pressure to faill during that period.
-Pretty cool for our first real flight test!
+The airframe saw an average of 12 G acceleration on the way to Mach 0.6 and
+2838 feet above the laucnh site which is at 8800 feet MSL. Perfect
+recovery! Pretty cool for our first real flight test!