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Flight Log Updates

#230 - Tajfun 2 L2

#229 - Mac Uni AON

#228 - Tajfun 2 Elec.

#227 - Zip Line

#226 - DIY Barometer

#225 - Air Pressure Exp.

#224 - Tajfun 2

#221 - Horizon Deploy

#215 - Deployable Boom

#205 - Tall Tripod

#204 - Horizon Deploy

#203 - Thunda 2

#202 - Horizon Launcher

#201 - Flour Rockets

#197 - Dark Shadow II

#196 - Coming Soon

#195 - 3D Printed Rocket

#194 - TP Roll Drop

#193 - Coming Soon

#192 - Stager Tests

#191 - Horizon

#190 - Polaron G3

#189 - Casual Flights

#188 - Skittles Part #2

#187 - Skittles Part #1

#186 - Level 1 HPR

#185 - Liquids in Zero-G

#184 - More Axion G6

#183 - Axion G6

#182 - Casual Flights

#181 - Acoustic Apogee 2

#180 - Light Shadow

#179 - Stratologger

#178 - Acoustic Apogee 1

#177 - Reefing Chutes

#176 - 10 Years

#175 - NSWRA Events

#174 - Mullaley Launch

#173 - Oobleck Rocket

#172 - Coming Soon

#171 - Measuring Altitude

#170 - How Much Water?

#169 - Windy

#168 - Casual Flights 2

#167 - Casual Flights

#166 - Dark Shadow II

#165 - Liquid Density 2

#164 - Liquid Density 1

#163 - Channel 7 News

#162 - Axion and Polaron

#161 - Fog and Boom

#1 to #160 (Updates)



Each flight log entry usually represents a launch or test day, and describes the events that took place.
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Day 23 - Acceleron
Coloured water ready for filling Acceleron.
Filling the dummy payload with about 600ml of water. The water empties through the same holes it is filled with.
Packing the 900mm parachute.
You can clearly see the coloured streams from each nozzle.
This launch made a nice rainbow. A small camera was attached about 3/4 way up the right segment.
Video frame showing the water columns just before the air pulse...
...and just after the first segment emptied. You can see the air vapour as well as the water column from the other nozzle.
Some launches were very close to vertical.
Slightly tangled parachute on descent.
Good lighting on the coloured columns.
Sometimes the older kids get to recover the rockets.
Descent ...
Date: 27th January 2007      7:00am - 8:45am

Location: Denzil Joyce Oval. (launch site #4)
Where exactly is that? Click the above link to see a Google Earth place mark. What is Google Earth?

Conditions: Warm, moderate breeze, partly cloudy.

Rockets: (click the name for rocket details)

Name Capacity Notes
Acceleron 12.75 L A newer cluster rocket with 3 segments and 3 nozzles.
Millennium Falcon 1.5 L A newer rocket built by our new team member.

Team Members at Launch Event: PK, GK, DK, TK, Paul K and John K.

Number of launches: 6

This day was all about test flying the Acceleron rocket again. We wanted to get more test flights under our belt to better characterise the performance of a cluster. We were quite pleased with the days results, and especially with the fact that the parachute opened on all flights.

Flight Day Events

  • Acceleron takes a lot longer to set up and launch compared to our smaller rockets. We average about 10-15 minutes now between launches. After each launch we have to reseat the o-rings in the launcher, remove the segment nosecones, remove the filler caps, fill each segment through a special filling funnel, close each segment again, re-attach the segment nosecones, pack the parachute under the top nosecone, fill the dummy payload with water, pressurise, get the team into position, roll video and launch.
  • We had Acceleron covered from a number of vantage points on video and stills so that we could see its performance. Of particular interest was the timing of the air-pulse from the individual segments as at this transition point there can be quite a difference in thrust between the segments if one is still ejecting water while another is going through the air-pulse. On slow motion replay it is very noticeable the different times that each segment goes through the air-pulse. Although they do not all happen simultaneously, we found that the rocket only rocked slightly, but kept flying straight.

    We are interested in what happens to the rocket at this point as this is the point at which the second stage will separate. We want to minimise any unnecessary loads on the separation mechanism.
  • On a couple of the flights Acceleron went fairly straight up which was encouraging as that will be needed for releasing the second stage. For the other two flights the rocket arced over a bit, but again we had fairly windy conditions, so we are looking forward to calm conditions to try again.
  • On Acceleron's last flight, we realised we had the small video camera we normally used for in-flight video for Frankovka. So we decided to just tape it to the side of one of the segments for an impromptu in-flight video. The video wasn't great but the rocket was never designed to carry a camera. It did give us another perspective though of how the rocket moves in the air with the three nozzles.

(If the video does not play, try downloading the latest Flash player from Macromedia)
Note: The video quality here is limited by what YouTube offers, we have higher definition video of all the flights, unfortunately it would take up too much space on our ISP.

  • On the slow motion replay of the flights we noticed that the water columns  tended to come together a few meters behind the rocket. We attributed this to the air coming back together after flowing around the rocket.
  • We need to improve the robustness of the fins on Acceleron. The landings are pretty hard on the fins. We have already snapped one, and the fin strut broke on this day as well. The parachute is still a little too far forward and the rocket still tends to land on the tail. The frame had bent a little, but we were able to straighten it and let it fly again.
  • When we were swapping launchers, we tugged a little too hard on the air hose and that managed to knock the SCUBA tank over. The pressure gauge was damaged and could no longer be used. The pressure regulator seemed to be okay, so we will have to swap in a new pressure gauge for the next flight day.
  • We also launched Danny's Millennium Falcon rocket a couple of times and it flew very nicely. Without a parachute it sure comes back to earth pretty fast.

Flight Record

Launch Rocket Pressure (PSI) Notes
1 Acceleron 110 1.5L of water used in each segment for a total of 4.5L. The rocket flew in a slight arc, and the nosecone fell off soon after the air pulse, but the rocket continued for another few seconds before the parachute finally started opening. One fin strut was damaged, but was easily repaired.
2 Acceleron 110 1.25L of water used per segment. The rocket went straight up with good performance from all nozzles. Parachute opned before apogee and the rocket landed well.
3 Acceleron 110 1.25L of water per segment. This was a good flight with the rocket again arcing over gently. Good parachute deploy and a good landing.
4 Acceleron 110 1.25L per segment. The rocket flew with a camera attached to the side with a piece of tape. The flight was a little short with the parachute deploying a little early.
5 Millennium Falcon 120-130? Pressure unknown as the pressure gauge was damaged. This was a very good flight and went straight up. Good bounce on landing but no real damage.
6 Millennium Falcon 120-130? The rocket arced over on this flight but flew well. Crushing of the bottle was a little more severe on this flight, but should be ok.

Design and Development

  • We have also been building a new launcher for our new regular non-cluster rockets such as J4 and Polaron. The new launcher should be adequate for the next phase of development of longer rockets. It is fully adjustable for rockets of various diameters, and uses an all-metal Gardena hose attachment release mechanism. The guide rails are now 2 meters (~7 feet) in height and a lot sturdier. The base is also much wider. The launcher can accommodate rockets with ring fins as well as conventional fins.
  • More details and photos of the new launcher with the next update.

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