|Date:||23rd April 2016|
|Location:||Mullaley, NSW, Australia|
|Conditions:||Strong Wind 30km/h+, mostly clear, 23C|
|Members:||PK, GK, Paul K and John K|
This week we travelled to our high power launch site near Mullaley to try to launch the full size Polaron G2 that we last launched at Thunda. Because there were four of us going this time we needed more space in the car for all the equipment and rockets. So we built a rocket transportation box out of plywood for the roof-rack. As we always need a table at the launch site we used a trestle table as the lid of the box.
When we arrived at the launch site there was a very strong wind blowing easily 20-30km/h with even higher gusts. It looked like we were going to need to scrub the launch, but we set up the launch pads and got everything ready in case the winds would die down. They did not. Because of the large range we figured we'd still launch something smaller even if it meant we had to go a long way to retrieve it.
For the first launch we set up the fiberglass reinforced Axion G5. The expected time to apogee was around 8 seconds and so we set the delay to 9 seconds to open the chute later to reduce drift. Choosing the right parachute was also an issue. The bigger parachute we normally use with this rocket was going to mean a long drift, and so we opted for the smaller chute with a hole we use on similar size and half weight rockets. This was going to be marginal but with the added drag of the horizontal rocket this was considered reasonable. We connected the break wire to the normal string, but with the wind blowing so hard and the string thrashing around it ripped it from the break-wire and deployed the parachute. Luckily this happened before we pressurised the rocket so we had to simply repack it.
As we came up to pressure of around 220psi the top coupling had let go and launched the entire top spliced quad from the rest of the rocket. The parachute remained attached to the rest of the rocket. No damage was done to the nosecone section, but the fairing near the coupling was shredded. This fairing also had the camera attached. When the top section let go it sent the camera spinning at a high rate of speed about 15 meters from the pad. It survived without problems and recorded the entire event. These things are pretty resilient.
We replaced the 22mm tornado tube with a spare one hoping to avoid a repeat and set the rocket up again. This time we managed to get it up to 210psi and launch it. The rocket flew well if a little squirly near the end of the ascent, but deployed the parachute well and started drifting a long way down range. We didn't include an altimeter or camera this time in case we lost them. When John brought the rocket back we saw that it was in two pieces. The rocket had broken on landing and snapped the entire throat of the bottle near the lower coupling. The chute may have just been a little too small for this rocket. We got all the pieces back and replacing the reinforced spliced quad is simple so good overall flight considering the conditions.
We built a 2-stage pyro rocket with the boys during the week especially for this trip, so we decided to only launch the sustainer on its own, It was still expected to reach around 1000 feet on a D12-5. The rocket flew well and opened the parachute right at apogee and the very light rocket proceeded to drift a loooong way down range. We just barely saw it drop into the field so we set up the LaRF and pointed it in the direction of the rocket. We then proceeded to walk the laser for almost 1km ~3000 feet (as measured on Google Earth) and walked right up to the rocket which was perhaps 5m off the laser line. We then marched back another 1 km back
Although it was disappointing that we couldn't launch the Polaron G2, we were still happy to have gone out and launch some rockets and spend time with fellow rocketeers from the club. Congratulations also to those who certified to their next level under such difficult conditions.