Each flight log entry usually
represents a launch or test day, and describes the
events that took place.
Click on an image to view a larger image, and
browser's BACK button to return back to the
Day 146 - G2 Launcher Test Flights
31st May 2014
Location:Whalan Reserve, NSW, Australia
Conditions:Mostly sunny, light winds
Team Members at Event: PK, GK,
and John K.
Today we wanted to test the G2
launcher with a smaller rocket to see how well the release synchronization works with the boosters tied to the main stage. Although we had the synchronization done
from last time, we dialled back the timing on the main stage by
another 2ms just to make sure it would be released after all the
boosters. We figured that potentially putting a big load on the
central nozzle and having a failure there was more desirable
than one of the boosters leaving too late and releasing a rocket
with asymmetric thrust.
30 minute assembly
Ready to go
Everyone in launch position
For the first launch we decided to only pressurise the rocket
and boosters to 105psi just to reduce the loads a little. We
used 1L of water in each of the boosters, and 1.5L of water and
foam in the main stage. The main stage nozzle was fitted with a
9mm insert while the boosters used 15.9mm nozzles.
The launch went well and all the boosters remained attached
to the main stage through their boost. They separated on burnout
and parachuted safely back to Earth. The main stage flew to 506
feet (154m) and landed safely.
We repeated the launch again but this time at 120psi. Again
the boosters released correctly on burnout and landed under
parachute. This time the main stage flew to 575' (175m). This
rocket is about 80 grams heavier (632g total) than the normal Axion II
due to the booster ring brace, nozzle and thrust ring. The
thrust ring was made by gluing two sleeves of PET onto the
bottle with PL premium. The booster ring brace transfers all the
energy from the boosters into the main stage.
For the third flight we pressurised the rocket to 115psi.
Again the rocket flew well with clean booster separation. The
rocket and boosters landed safely from an altitude of 559 feet
Lights on, ready to go.
Nice shadow shot
Shortly after separation
View from 575 feet
The last launch of the day was our regular Axion II rocket
just for fun. The rocket flew well with foam to 467 feet (142m).
On the way down the shock cord wrapped itself around one of the
fins and the rocket came down slowly but nose first. The
nosecone fairing suffered a bit of damage, but the
deployment mechanism was fine, and will fly again.
The launcher seals well, and on the three launches we
could not detect any leaks. Including all the joins on the
rocket and boosters there are over 50 seals in the entire
with a potential to leak.
The launcher worked well 3 times to release the rocket
Slow motion video showed that the boosters did release
before the main stage but weren't quite as synchronized as I
think we can get them.
The PET thrust ring worked well on the main stage.
There was some condensation in the electronics box. We
should include some silica gel to help keep it dry.
Here is a highlight video from
After spending some more time looking for John's rocket, we
finally found it stuck in the grass. There was no obvious reason that we
could see why the rocket spun out of control. We suspect it may
have been the igniter plug getting caught by the motor retaining
clip. With the rocket buried in the ground the ejection charge
fired which caused it to push the motor backward and the motor
retainer clip ripped a hole in the side of the body, which was
fortunate because it let the ejection charge gasses out through
the newly created hole.
This rocket has now been retired.
You can see where the ejection
pushed the motor back tearing
with the end of the motor clip.