Basic Information

Name

Z-4

Launch date:

25 October, 2014

Rocket description

63.5mm airframe (plastic)

4 fins, birch plywood

aluminum conical nosecone

2 ft. circular parachute

Payload

Raven altimeter

Flashing LED light

Liftoff mass

TBA

Flight objectives

- Flight with 25% greater total impulse than Z-2.

- Test flashing LED light for visibility during free-fall

Motor details

Motor name

Impulser

Propellant

KNSB

Grain mass

286 grams

Nominal impulse

336 N-sec

Class

H

Weather conditions

Temperature

10°C

Wind

W 15 km/hr

Sky

Clear

Other

Sun just below horizon

Launch Event Description

Shortly after ignition, rocket rose quite rapidly and straight vertical. Disappeared from view after burnout. After about 15 seconds, a ‘pop’ heard from apogee charge. Nothing visual, and no flashing light observed. After an additional 30 seconds or so, a second ‘pop’ heard and rocket descending by chute was spotted about ½ kilometer downwind. After approximately 15 seconds, rocket was seen to touchdown.

Flight Analysis

Event:

Time (sec)

feet

metres

Apogee

14.2

3330

1015

Separation

15.1

-

-

Main deployment

52.6

525

160

Touchdown

68.2

Range

1637

499

Descent rates:

ft/sec.

m/sec.

Free-fall

77.0

23.5

Main parachute

28.5

8.7

Post-flight analysis and comments:

Flight and recovery was nominal. Flashing LED did not prove to be a visual aid at any time during descent. Impulser motor casing suffered a slight bulge near nozzle from overheating. Thermal liner was a single ply poster board for this flight (normally two plies used).