|Date:||3rd October 2020|
|Location:||Whalan Reserve, Australia|
|Members:||PaulK, JK, PK, GK|
Today we tested the new Nova rocket that we spent the previous two weeks building and getting ready for launch. The weather conditions were perfect on the day, and so we took full advantage of the calm conditions and flew the rocket first. We were going to do a deployment mechanism test first on our Axion rocket but we knew the good conditions wouldn't last and so we set up to launch the rocket first.
The night before I ran a number of simulations and also checked the rocket's stability in OpenRocket, and found that the rocket was going to be fairly unstable in the first part of its flight due to the amount of water in it. 900mL was going to be optimal amount. I reduced this down to 700mL which was going to cost us a little bit of altitude, but it meant that the center of gravity would move forward sooner. This normally wouldn't have been an issue but with the small nozzle the water wasn't going to be draining very fast.
On the day, setup was quite straightforward, and we opted for the smaller parachute just so that we could reduce any potential drift.
For the first flight we were going to go for 300psi (~20.5 bar), but reached just shy of that before we decided to launch. The launch was very straight and it was quite noticeable how smooth and quiet it was. Parachute deployed right around apogee. So we were glad the deployment mechanism worked well. We were expecting an altitude of around 700 feet, but with the foam it went all the way to 940 feet (286m). Again foam has shown itself to give a significant boost in performance.
We did not fly an video camera on these flights as we didn't make room for it in the deploy mechanism, and didn't want to strap it to the side especially if we didn't know how the rocket was going to go.
On landing a part of the nosecone had cracked because PLA is quite brittle and the deployment mechanism had quite thin walls. The mechanism broke around where it was held down by the screws. We taped it up and were ready to fly again.
Because the conditions were still good, we decided to fly it again. This time we pressurised it to 340psi (23.5 bar) set the timer to 7 seconds and launched it. The rocket again flew very nicely and parachute deployed right around apogee. It reached an altitude of 1057 feet (322m). The rocket came down safely and cracked the nosecone a little more but fine otherwise.
Both of the flights went significantly higher than what the simulator predicted. We again attribute this to the foam that was used.
With the two flights out of the way we went back and wanted to do some deployment mechanism testing on our regular Axion rocket. We made an adaptor that screws to the top of the bottle and attaches the deployment mechanism. As we were coming up to pressure, the top of the bottle burst and destroyed the payload bay and nosecone. All the electronics survived fine without damage.
We had only printed the two mechanisms and so testing was over for the day.
Because we already had the rest of the rocket on the pad, we just replaced the top bottle with our normal deployment mechanism and launched it at 110psi to reduce the overall altitude because the wind had started to pick up. The flight went fine without incident.
Paul also managed to fly his pyro rocket Fireflight a couple of times on B6-4 motors. Those flights went very well and the rocket recovered safely both times.
We will probably save the Nova rocket for a high power launch for its
next flight simply because at higher pressures the rocket is likely to drift
further at Whalan and could end up in someone's back yard. Pehaps 380psi
will be the next launch pressure. We will also re-print the deployment
mechanism in a tougher material and perhaps re-design it somewhat to resist
cracking in a number of places.