Basic Information

Name

Z-30

Launch date:

10 May, 2017

Rocket description

- 63.5mm aluminum airframe

- 4 fins, birch plywood, reduced span

- birch elliptical nosecone

- 3 ft. ellipsoidal parachute

- ultra-low-power pyros

Payload

- Raven altimeter

- BRB900 GPS transmitter

- Smoke charge (activated by Raven at 2500 ft. level)

- Apogee Backup Timer

- SJ1000-SC Video camera

Liftoff mass

2.350 kg.

Flight objectives

1^st flight of Helios-X rocket motor

Motor details

Motor name

Helios-X

Propellant

A24 ANCP

Grain mass

180 grams

Nominal impulse

362 N-sec

Class

I

Additional information

Raven unit#2 used for this flight (previously flown solely on DS rocket)

Weather conditions

Temperature

9°C

Wind

WNW 20 km/hr

Sky

Clear

Other

-

Ceiling

unlimited

Launch Event Description

Setup of the rocket proceeded smoothly with no glitches. Raven checkout beeped 9V and gave 4 positive indications for the 4 pyros. Backup timer was then tested and confirmed to be operating nominally. For videotaping the flight, I used the hand-held camcorder (with scope tube).

After verifying the sky was clear, the countdown proceeded. At the zero count, no indication of ignition was observed. After waiting a safe period of time, the rocket was approached and igniter inspected. The igniter had fired but had failed to initiate the pyrogen slug. The igniter was changed and a second attempt at launch proceeded.

On this attempt, immediately after ignition switch was closed, a bright flash was seen at the base of the rocket. The rocket then accelerated rapidly off the pad. The motor burned for approximately two seconds. The bright flame of the exhaust was clearly visible during the burn. Around 15 seconds after burnout we heard the ‘pop’ of the apogee separation charge. A smoke cloud was spotted from the pyro charge, followed by two additional smoke clouds from the backup pyro charges. The rocket was immediately sighted as it began its tumbling descent. Owing to the sun glinting off the rocket’s chrome bands as it tumbled, the descent was easy to follow. No smoke from the smoke charge was sighted. At the expected altitude, the parachute charge was seen to fire. However, the parachute did not deploy and the rocket landed about a thousand feet downrange in a ploughed field.

Although we could clearly see where the rocket had landed, we nevertheless programmed the BRB GPS coordinates of the landing site into the Garmin hand-held GPS unit. The distance was indicated as 0.22 miles (0.35km). When we arrived at the landing site, the rocket appeared to be in good condition. The parachute was seen to be about half-extracted from the rocket body. It was noted that all four deployment pyros had fired. Raven beeped out an apogee of 2760 feet (841 m.), which closely matched the simulation prediction. No damage was apparent to the rocket.

Flight Analysis

Event:

Time (sec)

feet

metres

Apogee

13.2

2759

841

Separation

14.3

2747

837

Main deployment

-

-

-

Touchdown

53.0*

-

-

Range

-

1217

371

Descent rates:

ft./sec.

m/sec.

Free-fall

72.3

22.0

Main parachute

-

-

Post-flight analysis and comments:

A good video of the entire flight was taken with the hand-held camera. A tripod mounted camera situated a short distance from the pad nicely captured lift-off. The on-board video camera, however, failed to generate a file. Post-flight testing of the camera reproduced the anomalous behavior. The problem was resolved by “resetting” the camera software.

Post-flight examination confirmed that the rocket suffered no damage. The Helios-X motor had performed exactly to expectation and was in nominal post-firing condition.

The reason for the chute failing to fully extract was unclear. For the next flight, a slightly larger pyro charge will be used in conjunction was modified nosecone retention.

The smoke charge had not fired.  Examination of the igniter and Raven data indicated that the igniter bridgewire drew nominal current, fully heated, melted and broke apart as expected, but had failed to initiate the pyrolant that had coated the bridgewire. It was noticed that the coating did not fully covered the bridgewire, which led to the failure of the pyrolant to initiate. In the future, the pyrolant coating will be carefully applied such that the bridgewire is completely covered.