Air Command
Water Rockets

Day 180 - Light Shadow and Polaron G2 flights

Date: 10th September 2016
Location: Mullaley, Australia
Conditions: Partly cloudy, light breeze, 18C
Members: PK and GK

Mullaley

It was time for an HPR trip again to Mullaley this weekend. Since these trips only happen a few times a year we wanted to get our L1 rocket "L1ght Shadow' ready in time. We spent about 6 weeks putting it together. Here is a build log of the rocket.

The trip up was fine but when we got to Gunnedah it rained fairly heavily at night but cleared up again the next morning in time for launch. The only problem was the sticky mud in the field.

L1ght Shadow

We wanted to fly Light Shadow first on one of the H motors but unfortunately the certifying officer had to cancel the night before launch due to a family emergency and as he also had our motors we couldn't fly it as a pyro rocket. So we set it up as a water rocket and flew it to test the deployment mechanism.

We pressurised the rocket to 242psi and launched it. The rocket took off nice and fast and flew straight up to 631' according to the StratoLogger although the AltimeterOne in the nosecone read 673'. The nosecone ejected right at apogee, but it took a little time for the parachute canopy to fully inflate. We knew this rocket wasn't going to fly very high at this pressure due to its weight. But we were very happy with the flight. The rocket landed a couple of hundred meters away in the soft mud without damage.

We decided to not launch it again, as we would like to fly it as a pyro rocket next at the next HPR launch.

Video Highlights

Polaron G2

We finally took the Polaron G2 for a spin again after the last visit was just too windy. Setup was quite straight forward and we filled each of the boosters with 4 liters of water and the main stage with 4 liters and foam. The only main modification was that the main's nozzle was a little larger to try to improve stability by dumping more water sooner.

We pressurised it to 190psi and again there was a leak at one of the nozzles. We then attempted to launch it. The boosters released but the main stage stuck on the pad. So we released it manually. The rocket flew fairly well with the boosters separating on cue. Although the rocket wobbled a bit on the way up it still reached 764 feet. The parachutes opened well and the rocket landed nicely in the field. The reason the main didn't release was because the wire between the servo and the secondary lever broke.

We replaced the wire and set the rocket up again. This time we pressurised it to 200psi and launched it without a problem. The rocket took off but a couple of seconds into the boost the main stage had bent a little at the middle coupling resulting in a spiral flight. Although both parachutes deployed, the on-board video showed that the main canopy was caught up in the shroud lines of the backup for most of the descent, and only in the last 10m or so actually slipped out and fully opened.

The rocket landed in the armpit-high canola field. This was the first time I've had the privilege of walking through canola. After 5 minutes I was ready to give up, as it's almost impossible to make your way through it. The swarm of bees from the nearby hives added little to the experience. With the rain the night before soaking the plants in 5 minutes I was completely soaked and boots were full of water. After a short search I finally saw the parachutes pop up a little above the flowers, I was no where near where I thought the rocket was. I was maybe 30m away and it still took a few minutes to get to it and out of the field again. Due to the bent rocket, it had only reached an altitude of 619 feet.

It was fun to fly it again, but I think this rocket is now retired in this configuration. We will use the reinforced spliced-quads in other rockets.

Video Highlights

Flight Details

Launch Details
1
Rocket   Light Shadow
Pressure   242psi
Nozzle   15.5mm + launch tube
Water   2800mL
Flight Computer   StratoLogger CF & ST II - 0 seconds
Payload   HD Cam 16 V3, AltimeterOne
Altitude / Time   ? feet / ? s
Notes   Good straight flight. Parachute deployed at apogee. Good landing.
2
Rocket   Polaron G2
3 x Gluon G2 Boosters
Pressure   190psi
Nozzle   9mm (G2)
15.5mm (boosters)
Water   4000mL + foam (G2)
3 x 4000mL (boosters)
Flight Computer   ST II - 9 seconds
Payload   AltimeterOne, HD cam #16 V3, uMAD, 2 x STII timers
Altitude / Time   764 feet ( 233 m ) / ? seconds
Notes    
3
Rocket   Polaron G2
3 x Gluon G2 Boosters
Pressure   190psi
Nozzle   9mm (G2)
15.5mm (boosters)
Water   4000mL + foam (G2)
3 x 4000mL (boosters)
Flight Computer   ST II - 9 seconds
Payload   AltimeterOne, HD cam #16 V3, uMAD, 2 x STII timers
Altitude / Time   619 feet ( 188 m ) / ? seconds
Notes