# Test 2020-4 #

3 grain 54mm Purple Pig motor with a Terry Lee dipped igniter in 3-inch test
mule flown on 17 October 2020 at the first-ever Tripoli Southern Colorado 
launch at Hudson Ranch.  In fact, this was the first-ever research flight
flown at this location!

Used 3-grain 54mm Kosdon case, Loki-style nozzle with an 0.390" throat, 
forward closure had a 1600psi pressure sensor and EasyMotor protototype 
mounted with an A23 alkaline battery, and shooter wire as a "twist and tape"
power switch.

The motor used three loose grains with 0.625" cores, thin o-rings as spacers, 
and a greased phenolic liner. 

[Burnsim](2020-test-4-burnsim.pdf) called this a 31% J-355, 838 Ns with 
about 2.36 sec burn time, and max pressure on a relatively flat burn of 
559.3s psi.

## Results ##

Perfect flight, no damage, easy recovery.

This was the first flight during which we successfully captured in-flight
chamber pressure data with an EasyMotor prototype board.  A quick look at
the data shows about 540 psi maximum, which is pretty close to the Burnsim
prediction!  Some software work remains to convert the data capture into 
actual motor performance data.  The EasyMotor data is logged in file
2020-10-17-serial-7085-flight-0007.eeprom

The airframe's launch mass was about 4420 grams.  The TeleMega on board 
reported 9.54 G max and 6.29 G average acceleration to a max speed of 
Mach 0.5 and a GPS apogee of 4669 feet.  The TeleMega data is logged in file
2020-10-17-serial-6667-flight-0003.eeprom