This blog covers the day to day progress of water rocket development by the Air Command Water Rockets team. It is also a facility for people to provide feedback and ask questions.

Sunday, December 12, 2010

Sneak Preview ...

Here is a sneak preview of the Polaron G2 rocket in the Phase 1 configuration. We decided to extend the rocket by another spliced quad for just over 21L of goodness.:) It's just on 3m long (~10 feet). When launched at 250psi, it will be the pyro equivalent of an H500.

Probably another two or three more days work is required before it's first test flight. Simulations for this rocket are looking quite good, and even more interesting for the boosted version. Though real life never quite agrees with the sims so we'll just have to fly it to see the actual performance.

Tuesday, November 30, 2010

Polaron G2 - Recovery System

I've posted more details of the G2 recovery system on our main website here:

We didn't get it quite finished for testing at last weekend's NSWRA launch, but hopefully it should be ready for testing on the next launch. So far it is working well on the table. It will need to get painted next. The update also includes a highlights video from this weekend's launch showing both pyro and water rockets.

Saturday, November 13, 2010

Simple multi-stage Parachute Release mechanism

We have been using a simple parachute deployment technique on our multi-stage rockets for the past couple of years, and although we have posted pictures of it previously we have never documented it properly. So I've added a tutorial to the main website that explains how to make it. It takes only about 15 minutes to make and doesn't really cost anything.

The tutorial can be found here:

Wednesday, November 10, 2010

Time to Backup

I thought I'd give you a friendly reminder to GO BACKUP YOUR DATA today. This week our main computer had frozen a couple of times in unusual spots. A reboot fixed it and the computer ran fine again. It had been a couple of months since I did a full backup of everything on the main drive, all of our apps, family photos and movies as well as all the rocket related data are on it. I normally tend to forget to do backups on a regular basis, so I decided to do a full drive image backup. Normally I run it overnight because it takes about 5 hours, but I had decided to do it during the day since I wasn't going to need the computer. The back up finished just fine. The very next day, the computer would not boot at all, and it turns out the hard drive had died!

Talk about dodging a bullet!! ...

I bought a new drive the next day and restored the backup to it. A couple of minor configuration tweaks and the new drive booted with everything installed on it. I sure wasn't looking forward to having to re-install all the applications, drivers, and none of the lost data.

So go do your backups now!

Tuesday, November 02, 2010

Day 97 - Flight day report

We've updated the main website with a full launch report from this weekend. The update is available here:

The update includes more photos, as well as highlights video of both flights. Both sustainer and booster videos are included in the highlights video.

"Dang ... that's the shopping list, not the launch check list"

Saturday, October 30, 2010

Acceleron V to 864' (263m)

We had a good launch day today at the NSWRA launch. We flew the Acceleron V 2-stage rocket a couple of times again. Both flights went great with the first reaching our new personal best of 864'. On the second flight we angled it a little away from the trees because of the wind direction. The rocket went up to 829 feet. Both flights were flown at 120psi again.

Just after the air pulse phase.

 View from just after apogee. Tiny cars!

I'm in the process of putting together an update for the main website with more photos and a highlights video. That should be finished towards the latter part of the week.

The update will also include more details on the Polaron G2 rocket.

Monday, October 25, 2010

Progress update

This week we continued with the nosecone plug and it's now ready to start forming nosecones. I need to get some mould release agent this week so we can start. The fiberglass is all cut up as well. The guys on  Australian rocketry's forum as well as the Yahoo water rocket forum have given me some really good tips on on preparing the mold and the upcoming moulding process.

We also pressure tested 3 more of the spliced quads to 270psi. We have 5 of these now ready for flight, with two more to be fiberglassed this week.  So far we are quite happy with the quads, but until we test them on real rockets with the kind of forces they will experience in flight and landing we won't know for sure.

To get an idea on what we are up against, we assembled the spliced quads into the Phase 3 main stage, and put a representative sustainer on top. The boosters and fins are not shown.Once on the pad it will sit at least another foot off the ground. We will definitely need a full size ladder for launch day. :)

Last night I also prepared the 3 fins to be used on Phase 1 of the rocket. All three of them weigh 83 grams, but will need to be attached to the removable fin can which will likely double that weight.

Monday, October 18, 2010

Nosecone, Testing and more fiberglassing

This weekend we pressure tested two of the spliced quads to 270psi. They both held well, and should be good to go for the 250psi launch pressure. I was a little concerned that they may stretch too much because of their length and leak, but there seems to be enough flex in the glue to cope with it.

We also made another couple of spliced quads which are now curing. This now gives us 5 of the spliced-quads which (if they all pass the pressure tests) will be used for the Phase 1 of the Polaron G2 rocket. 3 of the segments will be coupled together with tornado tubes and a couple as spares.

We have also started making a plug for the fiberglass nosecone. The plug is made from 10 layers of 19mm MDF. Each layer was individually machined to shape and then glued together. We have opted for the efficient ellipltical nosecone, as our rockets travel well below the speed of sound.The nosecone is 110mm wide.


Here is the nosecone plug before final sanding

Sunday, October 10, 2010

Fins and Fiberglassing

As a part of the work we are doing with Polaron G2, we are looking at different fin materials.

This week we are comparing 3 different ones. The first one is a regular 4mm 3-ply plywood fin. This fin is very tough, but the main drawback is its weight. At 74 grams it is the heaviest. Thickness is 4.2mm.

The second one we tried making out of two 1.5mm sheets of balsa wood glued together at 90 degrees to each other with PVA glue. We then put one layer of 200gsm fiberglass on either side. Epoxy resin was used for this. The fin is quite tough and weighed in at 43 grams. The thickness is 3.9mm but the main drawback is the amount of work involved to do this and the higher cost.

 The 3 fins tested. Left to right: corriflute, balsa/glass sandwich, plywood.

The last fin is made from corriflute, the material we have been using until now. It weighed in at 25 grams, but has a thickness of 5mm. It is quite tough, and has a good finish, but the main drawback is that it is made from polypropylene and hence harder to glue and paint. The leading and trailing edges are also harder to create nice and smooth.

So far the balsa sandwich is probably a good compromise, unless we can find some nice lightweight plywood.

We have also spent some time this week getting Acceleron V rebuilt and serviced so it can be launched again. We also did a 50psi leak check. We'll try to launch it again soon just for fun.

We were supposed to go out to the NSWRA launch today, but after driving half way there in pouring rain, we decided to turn back. As we got back, the weather cleared up but the wind had picked up. So we went back to the workshop and fiberglassed 3 of the spliced-quads. We are going to give them at least 5 days to fully cure before pressure testing. We are going to try to push them to 270psi for the 250psi launch pressure. We'll see how much they'll actually hold.

 3 x 5.3L spliced quads wrapped in fiberglass.

Wednesday, September 29, 2010

Polaron G2 - Development continues

I've updated our main site with some of the progress that has been made on getting G2 assembled. It's good to be able to see it in actual size rather than just on paper. It made me realize that we are going to need to rethink some of our logistics in terms of getting the rocket setup on the pad and configured. We are going to need to bring a full size ladder. The update is here:

I had to take photos of the rocket lying down, as the ceilings are too low in the house to stand it up. We are going to need an extra long guide rail for this rocket too. Most likely 2.5 - 3m long.

The update also includes a highlights video from the last weekend's NSWRA launch where we tested the Mk3 stager with a more powerful booster. The flights went really well, and the stager performed as expected.

Here is a size comparison diagram for the Polaron G2 rocket. 

 Here it is starting to take shape lying next to Polaron G1.

Friday, September 17, 2010

Joe Genius - Rocket Science

A bit of fun this week. One of our video clips made it onto this week's episode of Joe Genius:

The clip (shown about half way through the episode) is around 3 years old now - here is the original that it came from:

What else would you do on a hot day? :)

Saturday, September 11, 2010

Splicing production line

We have spent the last few days cleaning, cutting, shrinking, curling, sanding and splicing quite a few 2 liter bottles. These will form the pressure chamber for the Polaron G2 rocket as well as the boosters. We are making a number of “spliced-quads” that are just a couple of spliced-pairs of bottles, spliced together. This gives us a longer section of rocket body that is more efficient since we get more volume per length of rocket while still retaining the modular aspect of the design.

When all the splicing is finished, we will reinforce all of the bottles with fiberglass.  Each spliced quad has a 5.3 L capacity. Phase 1 of the G2 will combine 3 of the spliced quads giving a total capacity of 15.9 L. Our current thinking for phase 2 is that we are likely to add a spliced pair to the bottom as the foam mixing chamber. This will increase the capacity of the main stage to 19 L.

Some 2L spliced-pairs, 1.25L spliced-pairs as well as a spliced-quad.

We are making a few spare spliced quads with the idea that some of them will likely fail pressure tests, others will be used for burst tests and some will get damaged on landing. We want to have at least two complete G2 rockets ready for a launch day in case something goes wrong or the other can be used for spare parts. 

Tuesday, September 07, 2010

Polaron G2

Okay time to get a little more serious with these water rockets. We haven't really been optimizing a lot of our rockets as we carried out various experiments. But it's time to start pushing the envelope a little more with the next set of rockets. These will focus on optimizing the rocket as a whole for better performance using the lessons we have learned.

Polaron G2 is a new rocket now in the planning stages, and we are starting to gather materials for it.

Here are a few 2L bottles ready for processing into rocket components. We will also be trying out some new construction techniques. Polaron G2 will follow the Polaron series of rockets in overall design, and will be developed in 3 phases. The first phase will be a full size single stage rocket, with drop away boosters in phase two, and with phase 3 a small sustainer will be added to the main stage.

Time allowing I will try to keep this blog updated with more regular progress, with major milestones covered on our main website. We are revisiting each aspect of the rocket and seeing how things can be improved. The rocket will also need an upgraded launcher with a longer guide rail.

Currently the target launch pressure is at 250psi, but things may change depending on how various tests go with the design.


Saturday, September 04, 2010

MAD Deployment

I've updated our main website with the road trip report to Parraweena. We test flew PK's Magnetic Apogee Detector on a couple of the flights and it worked very well. We also did a couple of 2-stage flights testing a sustainer support brace for the Mk 3. stager.

The update is here: and includes photos, as well as a highlights video.

PK's Magnetic Apogee Detector.

2 Stage rocket testing the Mk 3 stager sustainer support brace.


Tuesday, August 31, 2010

Road trip to Parraweena

We had a great weekend this week attending the launch at Parraweena. The weather couldn't be more perfect with sunny conditions and almost no wind. There were a couple of minor dramas getting there, but definitely well worthwhile. We saw some great rockets go up and had a chance to test fly some of our rockets as well. I am in the process of writing up a trip report and will post it with pictures and video in the next few days.

Here is a photo of a larger 2-stage rocket testing the Mk3. Stager.

Photo: Darren from Suburban Rocketry.

I also flew my larger pyro rocket on a G64 which was a very nice flight. I mounted a camera inside to get a view of the area from the predicted 3000 or so feet. The flight was very good and managed to get reasonable video from it.

Friday, August 06, 2010

Mk3. Staging Mechanism Details

We’ve uploaded the full details of how the Mk3. staging mechanism works to here:
And a full tutorial on how to build it is here:
The tutorial has step-by-step instructions with photos as well as a 2 part video that shows the procedure.

We’ve also uploaded a launch report of all the test flights we have had with the stager over the last 2.5 months. The launch report contains a highlights video from these launches:


Sunday, August 01, 2010

More Mk3. Stager test flights

This morning we had good weather and so we took the Mk3 stager test rockets to the local park. It was a little bit breezy but we decided to launch anyway. The stager had 3 out of 3 successful flights again which was good. We did get one of the sustainers stuck in a tree, and had to come back later in the day to retrieve it.

I am currently putting together 3 videos about the stager. One is a highlights video of the test flights from the last two months, and the other two are a 2-part tutorial on how to build it. We're also writing up a construction tutorial for the website with photos. It's a lot of writing/editing to do, so I expect it will take at least a week to get it all put together. We also need to use some spare time to prepare more rockets for next week's Doonside launch.


Saturday, July 31, 2010

Slow progress and weather

It's been a while since the last update. In the last month we've had family visiting from overseas and spent about a week up in Cairns snorkeling at the barrier reef with the kids. It was nice to have a break from cold Sydney. We have also temporarily swapped houses with my parents so that the visiting family could all stay in the same house with us. Our house just couldn't handle 7 people comfortably for a month. As a result I haven't had easy access to my workshop.

But excuses aside, some rocket development has been continuing. In the last couple of weeks we built a couple of bigger test rockets to test the Mk3. Stager. We were supposed to do the final trial flights today, however, the Doonside launch has been canceled due to rain and muddy conditions making the launch site inaccessible.

We are hoping that the weather will improve tomorrow morning, so we could try the rockets at the local park at a lower pressure.

Here are the two rockets fitted with the Mk3. stagers ready for test flights. We built two just in case there is a problem with one or if it crashes and gets damaged.


Sunday, July 04, 2010

Mk3. Staging Mechanism test flights

This morning dad and I went down to the local park to continue with the staging mechanism test flights. This was the third separate set of test flights, with minor failures on the first two sets. We finally got the stager working properly today on 5 out of 5 launches so we were happy. We only flew the stager on a small booster (2.1L spliced pair) and a 1.25L second stage. The flights were done at 110psi and 120psi.

Next we'll need to test it on a larger rocket a few times, but will need to take it to Doonside for testing as the local park would be too small for it.

Here you can see the small sustainer shortly after staging. The parachute is already being deployed on the booster.

If the next set of tests proves successful, then we'll post a full tutorial on how to make it.

Sunday, June 27, 2010

Doonside Launch - certification

It was a good flight weekend this week. As we are mid way through preparing the next water rocket for flight, and the launch weather looked iffy for Doonside, I decided to only bring the new pyro rocket "Waterless" (a LOC/Precision Weasel) with me as well as Paul's "Pod 2" rocket.

I had been wanting to fly the new rocket for a couple of months but didn't have a motor for it. I finally flew it on an E15-4W and it was a good flight. The delay seemed on the long side and the parachute opened a little late, but it was a good recovery and the rocket landed without damage. The flight was my mid-power certification flight so I was happy. I can buy up to G motors now. :)

We have had a couple of small water rocket launches at our local park since the last main website update as we are testing a staging mechanism, but have had a couple of failures, so after a couple of modifications we are ready to try it again. If the design proves successful, I'll post full construction details.

Saturday, June 19, 2010

Williams Westernationals 2010 Highights video

I've finally finished editing the video of the trip to Perth from a couple of weeks ago. I've also used a number of clips shot by Shane Miles as he had some great detailed shots of the high power launches.

Here are the highlights from the two HPR launch days:

(It's best to view the video at 480p or HD in YouTube)


Tuesday, June 15, 2010

Parachute Cam and Polaron G1

This weekend we a had a really good launch day. The weather was perfect and the rockets behaved themselves. During some unrelated test flights we took the opportunity to mount one of the tiny MD-80 cameras in the center of the parachute looking down.

Although quite a bit shaky, the video did give us a different perspective on the rocket in flight. The full launch report including photos and a highlights video is available here:

The update also includes the test flights of the fiberglass Polaron G1 rocket. On the second flight we flew it at 230psi to 751' (229m) which was our highest (by 5 meters) single stage flight.


Tuesday, June 08, 2010

Williams "Wildfire" Westernationals 2010

This weekend I took a break from water rocket development and headed over to Perth to attend the Williams "Wildfire" Westernationals 2010.

What an awesome experience it was to see a lot of high power rockets go up. It was great to finally meet a lot of the people in person from the Australian Rocketry forum as well. They are great bunch of guys too. A big thank you goes to Scoop and Mel and all those who helped organise and cater the event.

Congratulations to all those who did their L1, L2 and L3 certifications.

Here are some pictures from the event:

Very strong the dark side is ......


Thursday, May 27, 2010

Water Rocket Labs

Well finally after many delays and procrastinations, I've uploaded the website extension. Originally it was going to be a separate entity, but I have decided to just make it a sub-section of the new site. This also makes it logistically easier to administer.

"Water Rocket Labs" was developed to help water rocketeers make better decisions about building their rockets. The site provides data and analysis about various aspects of water rocketry including materials and their performance.

The focus is not only on the data itself but also on the procedures and test equipment used to obtain the data. This allows others to follow the same procedures and compare their results against the data presented at the labs. The data is cross linked to the experiments, test procedures and test equipment used to obtain them.

Some of the experiments included in the site have been published before on our main site, however, there is a range of experiments we had not published before. With the previously published results I have trimmed them down only to the relevant information.

We will continue to update our regular site with launch reports, articles, construction details etc, but all new science or engineering results will go into the Labs section.

There are around 80 pages of information in the extension. Some sections are still sparsely populated, but we now have the framework to add more data as we obtain it.

Here it is:

We invite people to submit their data to the Labs that will hopefully help others make better decisions about building water rockets.


Sunday, May 23, 2010

Water Rocket Launcher Article

Over the last month I've slowly been putting together an article to help explain the range of different launcher design options rocketeers have when building their own.

The article is available here:

Along similar lines as the recovery guide I've tried to include lots of links to examples showing how the different components have been implemented by the water rocket community.

Monday, May 17, 2010

Moving Main Website

I've been putting it off for long enough, so this weekend I have started relocating our main website. Up until now we have been hosting it on a free 50Mb partition we get with our ISP. The problem was that we were running out of room, well for quite a while now actually, so a lot of the actual images had to be hosted elsewhere.

To expand the 50Mb partition just wasn't possible with this ISP without signing up for actual 'hosting' where they wanted another $50 setup fee and then an extra $110/year for 100Mb of space. That was just ridiculous. So we have gone with an alternative hosting company where we only pay $70/year for 10Gb of space.

The usual domain: will be replaced with . We've had the domain registered for quite a while but it was getting forwarded to the people telecom site.

I will be replacing the people telecom pages soon with forwarding pages to the new site, and eventually remove them completely. If you have links with they can simply be replaced with as all the underlying website structure remains the same.

The site is now live but there may be a number of disruptions over the next week or so.

The extra space will allow us to upload the website extension we have been working on and have had to put on hold until we had more space. We'll also now be able to add extra features to the site, that weren't possible before.


Thursday, May 06, 2010

Testing beyond 300psi and old videos

This week dad set up new test equipment for us to use so that we can test beyond 300psi. Which is what our high pressure test panel went up to. We now have test capability up to around 800psi, though we would need to replace the air hose with a high pressure one for the upper range. We mostly wanted to see at what pressure the fiberglass bottles will fail so that we know what the safe launch pressure is.
We now have a nice giant pressure gauge which makes it easy to see.... even by those at the back of the classroom. :)

As we look to upgrade Acceleron V to higher pressures we have to check the individual components to see if they will be up to the job. Here dad was testing the thin plastic tubing we are using for the sustainer air supply line. It goes between the baseplate release mechanism and the staging mechanism with a non-return valve along the way. It says on the side it is rated to 50psi operational pressure. We have been pressurising it to 130psi (having previously tested it to 180psi) With our rocket pressures now nearing 250psi, this was always likely to be a weak point ......

Here it is still holding around 630psi! ....If you notice in the background, the whole experiment is now covered with a pile of concrete pavers.

Old Videos

About a week ago we noticed that some of the older videos on our website weren't playing. I'm not sure how long it's been like that. These mostly covered flight days 1 to 55. It turns out MySpace changed how videos are embedded and that broke all the existing embeded URLs. *sheesh*

So tonight I've gone back and fixed up all the embedding code to reflect how MySpace wants to do it .... until next time. We've stopped using MySpace around day 55 for our videos and now almost exclusively upload to YouTube.

I must go back and check over other broken links on the website as some things have disappeared. I try to fix them as I come across them, but there are always new ones. If people come across broken links please let me know and I'll try to fix them if possible.

Wednesday, April 28, 2010

Fiberglass rocket launch report

I've updated our main website with the latest launch report on the flights of one of the fiberglass rockets. The update is available here:

It includes photos and a highlights video from the day. The small rocket that was launched at 245psi managed to get up to 744' (226m). We thought that was pretty reasonable considering it was slightly bent, used a small 9mm nozzle, and no launch tube. .... right... can't sit around here typing .... must get back to the workshop :) ....


Tuesday, April 27, 2010

Great Photos from Acceleron V flights

Andrew Eltobaji from NSWRA took some great photos of our 2 stage rocket from a month ago. He definitely has great skill in catching fast moving rockets in action.

See some of his other pyro rocket photos here: and click on the NSWRA folders on the left side.

Here are some of his photos from the day. I have included them here in their almost full resolution. (Blogger will not let me upload the full resolution.)  Be sure to click on the photos so you can zoom in and get a good look at the detail. I wish I could take good photos like that!

Flight #2

I'm actually not that close to the rocket ... telephoto lenses are great!

It looks like the red booster is a little late in starting its air pulse.

Blue food colouring in the water is a great way to contrast against the white clouds

Secondary (backup) parachute is being deployed.

Coming in for a gentle landing

Flight #1

Good laminar flow from all of the nozzles during the booster's water phase.

Without the blue colouring, things are less messy on the ground.

Rocket is suspended sideways to cause extra drag and land more gently.


Saturday, April 24, 2010

Fiberglass rocket flights

This week has been a very busy week in trying to get a couple of fiberglass rockets ready for today's Doonside launch. We ended up flying the smaller one four times, with some failures as well as some very good and promising results. There was a very strong wind at the launch site and so we decided not to launch the bigger rocket. We ended up launching the last rocket at 245psi - our highest launch pressure to date.

I'm in the process of putting together a launch day report again, which should hopefully be available in the next couple of days.

Friday, April 16, 2010

Fiberglass pressure test results

We have now tested a number of glass reinforced spliced-pairs of bottles. The results so far look quite promising in improving the performance of our rockets. The extra weight of the reinforcing requires an extra 30psi to compensate, but the much higher launch pressure should raise the altitude considerably.

Next we need to assemble these into a proper rocket and pressure test it for leaks.

The full update including performance simulations is available here:

The update also includes a progress build on our first MPR pyro rocket.

Saturday, April 03, 2010

Fiberglassing pressure vessels

Yesterday we had our first go at fiber-glassing some bottles in order to be able to safely increase the launch pressure. We wrapped one spliced pair with a single layer of glass and the other with a double wrap.

The bottle on the left has a single layer and the one on the right is double layer. The bottles are only spliced with Sikaflex 11FC glue for an air tight seal. We are going to give the splices a week to fully cure before hydro testing them to destruction. I'll post the results of these tests when they are available.


Tuesday, March 30, 2010

Acceleron V flights Update and Video

I have finished doing the launch report for this weekend's 2 stage flights. The update is available here:

The update includes photos, altimeter plots, flight event time lines as well as a highlights video.

Here is a view of the Doonside launch field.


Saturday, March 27, 2010

New personal records

We had a great launch day today at Doonside. We finally got the Acceleron V rocket with Axion IVb sustainer flying properly. upwards and also not into pieces. We launched the pair twice on the day at 120 psi.

 Acceleron V taking off on its second flight.

The sustainer reached 787' (239m) on the first flight and 810' (246m) on the second flight. Our previous highest altitude was 637' (194m). We also set our longest water rocket flight time at 1:00 min.We were hoping to break the 200m mark with this flight, and got the 800' mark as well. We are going to have a good look at the data from these flights and see where we can make further improvements.

I will be putting together a main website update over the next few days with more details, video and photos from day.


Sunday, March 21, 2010

Comparing real world data to simulator data

We've uploaded the flight day 89 launch report to our main website here:

The update includes pictures and video from the launch day as well as a comparison of acceleration data from a couple of flights and 3 water rocket simulators.


Thursday, March 18, 2010

Doonside launch

Over the past couple of weeks we have been continuing to build rockets, although a little slower due to other non-rocket related commitments.

This weekend we flew a couple of different experiments at Doonside. We wanted to flight qualify the Acceleron V sustainer testing the jet foaming tornado coupling insert in the process.

We also flew three test flights with Craig's pyro rocket flight computer. It didn't control deployment but was along for the ride to gather flight data. The data from these flights and simulation results for comparison will be published in the next main site update.

I'm still in the process of writing up the full launch report which will take at least a couple more days.


Wednesday, March 03, 2010

Dual Deployment

On Saturday we had a good launch day at Doonside. We tested a dual deploy mechanism on a couple of smaller rockets, and even managed to explode one on the pad. We also test flew the MD-80 clone camera on 3 of the flights.

The full update is available here:

The update includes, videos of both water and pyro action from the day. There are also a couple of updates on some of the other things we have been working on.

Photo: Andrew E.


Sunday, February 21, 2010

Acceleron V rebuild

We've made good progress this week in getting Acceleron V back on the launch pad. Early in the week we tested the new narrow nozzle seals to make sure they will hold up to the pressure. This was also a pressure test of the booster side of the launcher. During assembly we noticed that one of the nozzle seals was distorting too much when the bottle was tightened. So dad machined up a new nozzle seal cutter that was a little wider and we made 3 new nozzle seals out of harder rubber. These worked well during assembly and in the pressure test.

Pressure testing the new nozzle seals. You can see the fog in the upper bottles as we let the pressure out.

On Friday we pressure tested the sustainer release mechanism and air supply. During the test we noticed that there was a very minor leak (1 or 2 drops per second) in the release head. On closer inspection it looked like there were a couple of small vertical grooves in the o-ring seat. So we spent today replacing the Gardena release mechanism with a new one. We are letting the epoxy fully cure before doing another test.

We spent the rest of today re-assembling Acceleron back to its normal configuration,.

Attaching the fins with the use of a fin alignment jig.

There are still lots of little jobs to do on the rocket, but it's good to see it back together again. We will do an integration pressure check to around 60psi to make sure there are no leaks in the Tornado couplings without putting too much stress on the entire rocket.

Next major milestones include a re-assembly of the sustainer. Depending on our progress schedule we may fly it at this weeks NSWRA launch day to flight qualify it before it gets used with the Acceleron booster.