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Basic
Information |
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|
Name |
Z-26 |
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Launch date: |
29 October, 2016 |
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Rocket description |
- 63.5mm aluminum airframe - 4 fins, birch plywood, reduced span - birch elliptical nosecone - 3 ft. ellipsoidal parachute - SM = 1.05 (initial) |
|
Payload |
- Raven altimeter - BRB900 GPS transmitter - Smoke charge (activated by Raven at 2500 ft. level) - Apogee Backup Timer - SJ1000-SC Video camera |
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Liftoff mass |
2.578 kg. |
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Flight objectives |
Compare performance to Z-25 (same configuration) |
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Motor
details |
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Motor name |
Impulser-X |
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Propellant |
KNDX |
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Grain mass |
371 grams |
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Nominal impulse |
437 N-sec |
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Class |
I |
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Additional
information |
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-Smoke charge modified to 60/40/1 KN/Sorbitol/RIO. -Chute deploy altitude set at 470 ft (143m.) -Stability Margin (initial) = 1.03 |
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Weather
conditions |
|
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Temperature |
4°C |
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Wind |
NW 15 km/hr |
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Sky |
Light overcast |
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Other |
RH 75% |
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Ceiling |
4300 ft. |
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Launch
Event Description |
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Once again, the trek to the launch site was somewhat hindered by muddy conditions due to recent rains. It was necessary to stop every now and then to scrape mud off the launch wagon wheels. Once we arrived, setup proceeded smoothly with no glitches. The BRB transmitter was switched on, then on-board camera was activated. Raven flight computer confirmed all four pyro channels functionality. Backup timer was tested and confirmed to be operating nominally. For videotaping the flight, I used the hand-held camcorder (with scope tube). A second camera was set up on a tripod near the launch controller station. After verifying the sky was clear, the countdown proceeded. Immediately after ignition switch was closed, smoke was seen issuing from the nozzle and one second later, the rocket soared off the pad, with nice vertical climb. The motor burned for less than two seconds. The rocket quickly disappeared from sight after burnout. After about 20 seconds we heard the ‘pop’ of the apogee separation charge. The rocket was not sighted nor was a smoke trail seen (as expected due to the grey cloudy sky). About a half minute later a ‘pop’ was heard and the rocket, under a fully blossomed parachute, was spotted about a thousand feet downwind. The rocket gently drifted earthward, carried downrange by the wind. Touchdown occurred about half a minute later. We then programmed the BRB GPS coordinates into the Garmin hand-held GPS unit, which indicated the landing site was in the middle of a cornfield, 0.28 miles (450m.) away. When we arrived at the touchdown site, the rocket appeared to be in perfect condition. Raven beeped out an apogee of 3511 ft (1070m.). Before packing up, we used the anemometer to measure and record the wind speed and weather vane to record wind direction. It was noticed that the wind speed had dropped significantly by this time. Based on this observation, it is advisable in the future to record the wind speed just prior to launch. |
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Flight
Analysis |
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Event: |
Time (sec) |
feet |
metres |
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Apogee |
14.7 |
3511 |
1070 |
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Separation |
15.5 |
3501 |
1067 |
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Main deployment |
58.3 |
466 |
142 |
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Touchdown |
77 |
- |
- |
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Range |
- |
1496 |
456 |
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Descent rates: |
ft./sec. |
m/sec. |
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Free-fall |
73.8 |
22.5 |
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Main parachute |
19.9 |
6.1 |
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Post-flight analysis and comments: |
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Post-flight examination confirmed that the rocket was in great shape. Excellent on-board HD video was obtained. The peak altitude of 3511 ft. correlates exactly to the peak altitude of 3606 ft. for Flight Z-25, taking into account the greater air density due to lower launch temperature (4°C. versus 26°C.). The smoke charge did not ignite, although the igniter did fire. Post-flight examination of the charge revealed that the igniter, which was different than usual, had a design flaw that directed heat of the burning pyrolant away from the charge surface. This will be rectified for the next flight. |
Raven baro and accelerometer graph:
Barometric and axial acceleration data Z-26\Z-26_Raven_basic.jpg
Acceleration data during burn Z-26\Z-26_accel.jpg
BRB:
GPS path of flight trajectory Z-26\Z-26_BRB_mapped.jpg
Photos:
Z-26 Rocket on pad awaiting launch Z-26\DSCN0402a.JPG
Liftoff Z-26\liftoff_capture1.jpg
Liftoff (view from tripod camera) Z-26\liftoff_capture2.jpg
Initial ascent Z-26\ascent_capture.jpg
Liftoff, on-board camera view Z-26\Z-26 onboard-ascent.jpg
Parachute deployment, on-board camera view Z-26\onboard_capture1.jpg
Gentle descent Z-26\landing_capture1.jpg
On-board view, approaching touchdown Z-26\onboard_capture2.jpg
Touchdown in a corn field Z-26\landing_capture2.jpg
Rocket at touchdown site Z-26\DSCN0406a.JPG
Author marking GPS coordinates at landing site Z-26\DSCN0407a.JPG
Videos:
Final descent into corn field, on-board camera Z-26\Z-26_onboard-final-descent.MP4