Basic Information

Name

Z-26

Launch date:

29 October, 2016

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

Liftoff mass

2.578 kg.

Flight objectives

Compare performance to Z-25 (same configuration)

 

Motor details

Motor name

Impulser-X

Propellant

KNDX

Grain mass

371 grams

Nominal impulse

437 N-sec

Class

I

 

Additional information

-Smoke charge modified to 60/40/1 KN/Sorbitol/RIO.

-Chute deploy altitude set at 470 ft (143m.)

-Stability Margin (initial) = 1.03

 

Weather conditions

Temperature

4°C

Wind

NW 15 km/hr

Sky

Light overcast

Other

RH 75%

Ceiling

4300 ft.

 

Launch Event Description

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.

 

Flight Analysis

Event:

Time (sec)

feet

metres

Apogee

14.7

3511

1070

Separation

15.5

3501

1067

Main deployment

58.3

466

142

Touchdown

77

-

-

Range

-

1496

456

Descent rates:

ft./sec.

m/sec.

 

Free-fall

73.8

22.5

 

Main parachute

19.9

6.1

 

 

Post-flight analysis and comments:

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