Air Command
Water Rockets

Latest Update: - 5th September 2017 - Day 190 - Polaron G3 and Drone Mods

Day 188 - Skittles in Microgravity - Part 2

Date: 27th May 2017
Location: Whalan Reserve, Australia
Conditions: Mostly Sunny, calm, 23C
Members: Paul K, John K, PK, and GK

Introduction

For the second part of the experiment we wanted to see if we could improve on the micro-gravity environment inside the rocket since the last attempt. We wanted to ease the deceleration rate after burnout by using foam in the rocket which gives the rocket a more drawn out thrust tail-off. The intent here was to slow the ascent of the skittles within the observation chamber. The second modification was to speed up the agitator at the top of the chamber in order to help push the skittles back into the chamber near zero G when the skittles settle against the top of the chamber. We did this by running the modified servo at 8.4V instead of 5V like with the previous launch.

In the video below we have combined previous week's experiment with this weeks experiment for comparison.

We again flew the rocket a couple of times with this experiment and both times it was pressurised to 210psi. The parachute behaved well on both occasions with good landings. Here are some photos from the experiment.

Conclusion

As can be seen in the video the Skittles took 0.8 seconds to reach the top of the chamber after burnout with the foam and 0.7 seconds for water only. So this part of the modification didn't seem to help much.

The faster rotation of the agitator looked like it worked better and you could clearly see some of the skittles floating for a brief period of time right around apogee.

The best part of the experiment was eating it at the end.

Other Flights

This day was also NSWRA's competition day so a few more people were in attendance. For demonstration we flew a couple of flights with the Axion II rocket. The boys had entered their pyro rockets into the competition too. Paul's Black thunder rocket took off at a bit of an angle, which was probably due to rod whip and crashed nose first just before the parachute deployed. We normally use a 3 second delay with this rocket, but we only had motors with 5 second delay. The top of the rocket was crushed, but should be fairly easy to repair by replacing the top 3rd of the body tube. The other flights went well otherwise.

Here are some more photos from the day:

Flight Details

Launch Details
1
Rocket   Axion G6
Pressure   210psi
Nozzle   9mm
Water   1500mL
Flight Computer   STII - 7sec
Payload   HD Cam #16
Altitude / Time   ? feet / ? s
Notes   Good straight flight, The parachute opened late as was designed for increased free fall time.
2
Rocket   Axion G6
Pressure   210psi
Nozzle   9mm
Water   1500mL
Flight Computer   STII - 7sec
Payload   HD Cam #16
Altitude / Time   ? feet / ? s
Notes   Good straight flight, The parachute opened late as was designed for increased free fall time.
3
Rocket   Axion II
Pressure   120psi
Nozzle   9mm
Water   1500mL + foam
Flight Computer   ST II - 5 seconds
Payload   None
Altitude / Time   ? feet / ? s
Notes   Good flight parachute deployed well, but the shock cord was tied too close to the back and rocket came down nose first. No damage.
4
Rocket   Axion II
Pressure   120psi
Nozzle   9mm
Water   1500mL + foam
Flight Computer   ST II - 5 seconds
Payload   None
Altitude / Time   ? feet / ? s
Notes   Good flight parachute deployed well, but the shock cord was tied too close to the back and rocket again came down nose first. No damage.
5
Rocket   Black Thunder
Motor   C6-5
Payload   AltimeterOne
Altitude / Time   ?' / ? seconds
Notes   Angled over soon after launch, parachute did not open before the rocket hit the ground. Top 1/3 of the rocket is smashed. Body tube can be repaired. This rocket will fly again .
6
Rocket   Dust Devil
Motor   C6-5
Payload   AltimeterOne
Altitude / Time   ?' / ? seconds
Notes   Good launch, and good recovery. .
7
Rocket   FireFlight
Motor   B6-4
Payload   AltimeterOne
Altitude / Time   ?' / ? seconds
Notes   Good launch, and good recovery. .