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 click the browser's BACK button to return back to the page.

Date:  28th February 2009 (8:00am to 1:30pm)
Location: Doonside, NSW, Australia
Conditions: Calm ~5km/h, 26 degrees C, light sprinkle, overcast clearing in afternoon
Team Members at Event: GK, PK, AK, PaulK, JohnK and JordanK

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 an issue.
  
  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' (178 m).
• 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 launches.
  
  The release lever extension we added to the launcher worked well at the high pressure with no issues releasing the rocket.
  
  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 ~ $8.
• 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 well.
• 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 affect the launch.
  
  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 Details