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 73 - Polaron VIb and other
Filling each of the boosters with 1.25L of
The main stage uses 2.4L of water and foam.
Launched at 120psi.
You can just see the main stage powering its
way up near the top of the image.
Landing just in the clearing between the
Onboard view of the launch site.
Apogee image of parachute being deployed.
Altimeter plot from the flight.
A collection of some of the pyro rockets
flown by NSWRA members on the day.
Packing the main parachute for Polaron VIb's
Also launched at 120psi.
A different view of the same launch.
The arrow points out the main stage still
A composite panorama made by combining
frames from onboard video while descending under
Recovery personnel are quickly on the scene.
Big rockets are easy to locate in the tall
Simultaneous booster separation.
View from around 170m above the launch pad.
Looking back towards Doonside road.
Although the video shows the parachute out
of the payload bay at apogee, the altimeter
shows that it didn't fully open until a couple
of seconds past apogee.
Photon II pressurised to 180psi.
Severe bending on launch caused the
nosecone to rip off deploying the parachute, and
promptly ripping it off as well.
One of V1.6 boards bites the dust, but most
components can be reused.
Altimeter data clearly shows the nosecone
failure on launch.
More pyro rockets on the pad.
Getting ready to play rocket Origami...
...First you get it going fast at 130psi...
... and before you know it you have a swan
made of folded plastic.
Despite this view all electronics and camera
survived without damage.
February 2009(8:00am to 1:30pm)
Location:Doonside, NSW, Australia
Conditions:Calm ~5km/h, 26 degrees C,
light sprinkle, overcast clearing in
Team Members at Event:
GK, PK, AK, PaulK, JohnK and
After almost 3 months of not flying at
Doonside, it was good to get back out on the
range. We rebuilt the Polaron VI rocket in
the weeks leading up to launch day. We
wanted to have a backup rocket (Polaron VII)
for the day as well, in case there was a
problem with the main rocket.
We made enough 2L spliced pairs for both
rockets, but the Wednesday before when
pressure testing 4 new spliced pairs,
3 of them developed leaks around the
110-130 psi mark. They did not explode but
air started leaking through the splice.
While it was disappointing that so much work
went into them, we still had enough bottles
with a couple of spare ones for at least one
rocket. The splices that didn't leak, used
the Sikaflex at the joint where the bottles
meet and PL was used to hold them together.
We are currently attempting to fix the leaks
in the bottles to see if they can be
salvaged. Dad spent quite a bit of time with
a long brush, applying the Sikaflex to the
inside of the bottles.
We did have a spare nosecone deployment
mechanism and a spare set of fins with us
but it turned out
we did not need them on the day.
Launch Day Events
We arrived at the launch site around
8am. The weather was mild, with overcast
conditions, virtually no wind, and there
was even a brief shower, but not enough
to cause anyone much concern, especially
the pyro guys.
Because Polaron takes so long to setup,
we set it up first before the weather
worsened. We pressurised the rocket to
120psi and launched. There was a minor
leak at the nozzle which really wasn't
The rocket went straight up and was very
stable. It powered all the way to apogee
with a good simultaneous booster
separation and good parachute
deployment. On review of the inflight
video we noticed that the rocket did not
spin at all which we were really happy
about. We had spent quite a bit of time
making sure the fins were aligned
properly, that the rocket was straight,
and that the nozzle was also pointing
down the centerline of the rocket.
Something the previous version of the
rocket did not do so well. The larger
nozzle and larger fins also played a key
part in its stability.
Altitude was 568' (173 m) which was
about what we expected because of the
slightly higher weight, more drag on the
thicker and bigger fins, and more
importantly the lower pressure.
We prepped Polaron VIb for a second
flight and launched it at the same
pressure. The flight was almost
identical to the first with a nice
straight non-spinning flight. We ended
up with good onboard video and good
altimeter data again. The rocket landed
well without damage.
This time the rocket went up to 584'
We setup the medium launcher next with
the long launch tube and placed the
Photon II rocket on it. Photon II has
smaller fins and V1.6 of the flight
computer compared to the previous
version. It also had the altimeter on
board. It was still fitted with the older
split nosecone, as we ran out of time in
finishing the new payload section.
We filled it to 180psi and launched. The
take off was very fast, but the
parachute deployed way too early and
ripped off despite the strong 80lb kevlar
line we have on it.
The rocket still went
over 200 feet before tipping over and
crashing nose first. On video frame by
frame replay, it was very evident what
happened. (see photo on left) The rocket
just bent too much under the high
G-loads during launch and the wind sheer
force ripped the nosecone off, deploying
the parachute. I had half expected this
to happen after seeing what happened
during the last time we launched this
rocket. We will now reconsider what we
want to do with this rocket, as it is unflyable in its current condition. The
length and thin walls just don't make it
practical for high acceleration
The release lever extension we added to
the launcher worked well at the high
pressure with no issues releasing the
Damage Report:- Servo motor horn
broken - but servo motor survived.
Altimeter survived with no damage,
Flight computer V1.6 board snapped in
half, but we have spare boards, and we
can reuse a lot of the components, so
minimal financial damage there.
The nosecone survived, payload section
of FTC completely buckled. Main body
tube crumpled near the top. Repair bill
Last flight for the day was Axion II. We
always bring backup rockets should some
get damaged. Axion has been a good
performing rocket and so we set it up on
the launch tube that Photon uses.
The rocket went up well on 130psi, but
the parachute failed to open. The
onboard camera clearly recorded the
servo activation sound at apogee, but
the parachute never came out. There may
have been two reasons for this. One of
the rubber bands was broken when
inspecting the damage. If it was broken
prior to liftoff, the parachute may have
had a problem being ejected out.
However, the likely cause may have been
that there is an overhang of plastic
over the parachute bay near the top of
the payload. This rocket uses a larger
than normal parachute bay because it
uses a larger parachute, but still used
a smaller door. The parachute was likely
to have caught itself on that.
The rocket came down nice and straight
and ended sticking up out of the ground.
It made a very good impression of a
crankshaft when it was recovered.
The onboard video turned out really
well, but because the rocket was facing
downward, on the way down it only
recorded the sky. The interesting thing
in the video showed that the rocket spun
in one direction, then reversed its spin
direction twice. I am not sure what
aerodynamic forces cause that to happen.
Damage Report:- Oddly enough, all
the electronics survived well without
any damage and were still operational
and powered even though the nosecone was
completely crumpled. The only
casualty was a broken servo motor horn
which we have lots of spares of. The
servo was fine. The top three 1.25L spliced
pairs were buckled but we have plenty of
spares as well as spare nosecones. Total
repair bill is ~10c - servo horn.
We have started using vimeo for our
videos as they offer a much better
quality over YouTube. We will continue
to post the same videos on YouTube as
We had a couple of smaller issues with
our launchers on the day. After the
second flight of Polaron we noticed that
the central release mechanism had
separated again from the mounting
bracket. The brass mechanism is soldered
to the metal bracket and the solder
joint broke. This is the second time we
have seen this, so the next step will be
to attach that a little better. It did not
The other issue was one of the foot
supports on the medium launcher came
loose again where its joined by epoxy.
We will also improve that joint to
prevent it happening again.
We will now seriously look at making
another launcher that is much faster and
easier to set up/pack up on the day.
We also flew one of Paul's little pyro
rockets. Thanks Andrew for helping Paul
get it prepared. The rocket went well
and recovered well under streamer. It almost landed back on the
guide rail it launched from.
My wife expressed interested in building
a pyro rocket just for fun, and both
Paul and John want to build a new one as well,
so it looks like I'll know what to get for
the next birthday presents (shhhh but
don't tell them).
flight with a fast take off. Went
fairly high. Launched with a 1200mm
launch tube. Servo activated but
parachute failed to come out. Bad
crash nosecone destroyed as well
first three bottles. Camera and all