Basic Information
Name	Xi-34
Launch date:	25 March 2023
Rocket description	- 3”/ 76.2 aluminum airframe (0.035”/0.89mm) - 4 fins, 2024 aluminum (0.065”/1.65mm) - 3D printed tangent-ogive PLA nosecone - 3D printed PLA boattail fairing/motor retainer - 42 inch ellipsoidal "Fruity Chutes" parachute - 16 inch hexagon drogue parachute
Payload	- Raven3 altimeter (primary role) - BREO-N flight computer for backup apogee separation and backup main deploy - BREO-N flight computer (2^nd backup, apogee only) - BRB900 GPS transmitter - Liftoff-activated and apogee-activated smoke trackers with Legendary formulation. - SJ100 on-board video camera, aft-facing
Liftoff mass	3.273 kg.
Stability Margin (minimum)	2.36
Flight objectives	- Third flight test of APM-E.14 motor with AXP-AP4.7 propellant. - Trial of improved drogue chute deployed at apogee to stabilize rocket during descent to improve on-board camera footage.

Motor details
Motor name	APM-E.14 (38mm)
Propellant	AXP-AP4.7 (Ammonium Perchlorate 65.8% /Epoxy (New Classic) 24%/Aluminum 10% /Lampblack 0.2%)
Grain mass	369 grams
Estimated Impulse	721 N-sec. (est.)
Class	J

Additional information

- A larger hexagon drogue chute fabricated of light gage ripstop nylon was packed and stowed in the mid-fuselage, released as rocket separates at apogee. Drogue canopy hem and line attachment was made more robust (improved stitching) compared to previous flight.

- A heating system was developed and installed in the avionics rack to prevent the cold-temperature sensitive BREO flight computers from getting overly-cold. The system consists of a 40W heater cartridge (from 3D printer) connected in series with a thermostatic switch. Power supplied by an external 12V wet cell. A copper sheet heat sink/radiator was installed in contact with the heater cartridge. This sink/radiator fitted over the two BREO units. Improved over Xi-33 by changing thermostat to 50° C. unit (was 45° ). Also, heater remained plugged in until just prior to launch.

Weather conditions
Temperature	-4°C (25°F)
Wind	N 20-30 km/hr (ground level)
Sky	Crystal clear, bright sun
Other	-11°C. wind chill
Ceiling	unlimited

Launch Event Description

Prior to beginning our trek to the launch site, the avionics heater was connected to the 12V wet cell battery, which was carried in a camera bag with a strap slung over my shoulder.

Once we arrived at the site (a 10 minute walk), we followed our checklist to set up the launch system and prep the rocket. Once the launcher was set up, the BRB transmitter and receiver were activated and verified that a good GPS signal was obtained. The lift-off activated smoke charge was powered-up then armed. The on-board camera was powered-up and set to record mode. The BREO units and Raven unit were activated and verified to be functioning nominally. The access hatch was then closed. The electrical plug for the heater was kept in place until we were ready to launch.

For filming the flight, I used my Sony HDR-CX240 Handycam fitted with scope tube, as usual. The camera had been housed inside an insulated box heated with a pair of chemical hand warmers. It was taken out of the box just prior to filming the flight.

We headed to where the Launch Controller was located. After verifying the sky was clear, the countdown proceeded. At the zero mark, the ignition button was pressed. The igniter fired and less than a second later, the rocket roared skyward, climbing straight vertical, then veering about 10 degrees to the left. The motor burned with a bright flame for approximately two seconds. I was able to visually follow the entire ascent thanks to the lift-off activated smoke charge which left a thin but distinct trail. At apogee, two smoke clouds appeared as the pyro charges fired to separate the rocket into two sections. The bright red drogue chute was seen to deploy. The rocket then descended, drifting with the wind, leaving a smoke trail in its wake. After approximately half a minute, the smoke trail ceased, as the charge burned out. It was still easy to follow the descent owing to the red drogue chute and the sun glinting off the rocket. After an additional half minute, two smoke clouds appeared from the main pyro charges, followed shortly after by a clearly heard ‘pop’ sound. The main chute was seen to fully deploy and the rocket drifted slowly earthward. Touchdown occurred about a half minute later at a distance estimated at 1500 feet to the south west of the launch site.

As it was getting late at this point, we jotted down the GPS coordinates of the touchdown site on our checklist, but we chose not to program the coordinates into the Garmin, as we could clearly see the rocket, or rather, the main parachute billowing in the wind. We headed to the touchdown site. As we approached, I could see that the main parachute was repeatedly lifting the rocket forward section and AvBay into the air and dropping them forcefully against the ground. The ‘ground’ was a hard sheet of ice and it was clear that some damage was being done by this dynamic action. Arriving at the touchdown site, I noticed the nosecone was broken away and the BRB unit (which had been housed in the nosecone) was lying forlornly on the ice. Otherwise the rocket appeared to be in great shape. Raven beeped out an apogee of 4201 feet (1280m.).

Flight Analysis
Event:	Time (sec)	feet	metres
Apogee*	15.7	3926	1197
Separation*	16.2	3917	1194
Chute deployment ^▪	80.5	678	207
Touchdown	118	-	-
Range	-	1781	543
Max. velocity	742 ft/sec.	226 m/sec.	mach 0.71
Descent rates:	ft./sec.	m/sec.
Drogue	55.3	16.9
Parachute	18.0	5.5

* Corrected for non-standard base temperature.

Post-flight analysis and comments:

Post-flight examination of the flight data indicated that the operation of the Raven was fully nominal, with a reported apogee of 4201 feet (3926 feet, corrected for base temperature of -6°C.). The BREO-1 unit recorded data for the entire flight. The BREO-2 unit stopped recording after 82 seconds of flight, shortly after main deployment. The reported apogee for the two units was within 1% of the Raven value. Both BREO units fired their apogee pyros. The BREO-2 unit did fire its main (chute) pyro just prior to shutting down. The improved heating system for the BREOs clearly helped maintain longer operation of the BREOs. Nevertheless, BREO-2 did shut down prematurely as it cooled. Prior to next winter, the BREOs will likely be replaced with a more cold-temperature tolerant unit such as Raven

Operation of the BRB (GPS) unit was fully nominal. There was no data drop-out over the entire flight duration. GPS-based apogee reported by the BRB was 3626 ft. (1105 m.) which is 7% lower than the barometric apogee, corrected for base temperature. A comparison of the BRB GPS reported altitude versus barometric altitude (Raven) shows a clear lag in reported altitude for the BRB unit during ascent. After apogee, as the rocket descended, the GPS altitude correlated exactly with the corrected barometric altitude.

Examination of the Raven flight computer acceleration data indicated that, once again, the APM-E.14 motor had a nominal burn that matched the design data.

Both the lift-off activated and apogee activated smoke grains burned nominally and were of exceptional aid in visual sighting the rocket throughout its entire flight.

Once again, the SJ100 on-board video camera worked very well, providing good quality footage of the entire flight.

The improved drogue chute, which was intended to stabilize the rocket during descent following apogee, deployed and blossomed. It worked as intended, stabilizing the rocket to some extent, providing for improved on-board camera footage. The drogue chute also slowed the descent somewhat (55 fps versus typically 75 fps for tumble descent) which, of course, has advantages and disadvantages.

Pyros:

Xi-34\DSCF7091.JPG

Making drogue chute:

Xi-34\DSCF7056.JPG

Xi-34\DSCF7055.JPG

Xi-34\DSCF7097.JPG

Raven data:

Barometric and axial acceleration curves Xi-34\Xi-34_Raven_basic.jpg

Axial acceleration curve Xi-34\Xi-34-Raven-accel.jpg

BREO data:

Altitude versus flight time for both BREO units Xi-34\Xi-34_BREOs.jpg

Launch photos: