Another Look at Destroyerator's Parachute

 

This dimension is about 9 feet across

This dimension is about 10 feet

Destroyerator's Parachute and Deployment Bag

I received the TAC-9C parachute and deployment bag from Giant Leap Rocketry today. This will be the main parachute for the sustainer (the upper stage) of Destroyerator. I can't really tell how big it will be fully inflated but it's rated for 70 pounds descent weight and appears that it will be 15-18 feet across. The other parachute and bag in the pictures is from Positive Ascent, which is 7-8 feet across when inflated. This will likely be used as Destroyerator's booster parachute.

My Next Big Project - Any Name Ideas for this One?

After not really doing much with rocketry since it isn't the season for flying, I finally took some time and designed my next rocket. It will be a 2 stage rocket, but much much larger than the 4 inch diameter one I designed a while back and never built.

This rocket will be very large, even dwarfing Positive Ascent (my 30 pound level 3 rocket). The specifications of the rocket are in the screen shots below from Rocksim V9.0 but here is a summary:

Sustainer:
Length: 155 inches (12.9 feet)
Diameter: 7.5 inches
Motor Mount: (98mm, L to N motors)
Unloaded Weight (approximate): 56.5 pounds

Booster:
Length (exposed): 71.5 inches (5.96 feet)
Diameter: 7.5 inches
Motor Mount: (98mm, M and N motors) 
Unloaded Weight (approximate):  32.9 pounds

2 Stage Configuration Specifications (Sustainer + Booster):
Length: 226.5 inches (18.875 feet)
Diameter: 7.5 inches
Unloaded Weight (approximate): 89.4 pounds
Ready to Fly Weight: 110 to 150 pounds

It is obvious that this is a very large and complex project, especially since I have never staged composite rocket motors. Part of my plan of attack is to use redundant electronics and separation charges everywhere. This means 2 timers and 2 altimeters in the booster, and 2 timers and 2 altimeters in the sustainer. The sustainer's motor will also have redundant igniters to make sure it lights.

It is also very important for me to make sure everything is worked out in my head and on paper and Rocksim before I build anything to make sure the design will work. It is particularly important for the inter-stage section of the rocket, as this is where I am most unfamiliar.

Another important aspect of this project for me is to not get overwhelmed and take it one step at a time. I expect this project to take anywhere from 3 to 5 times as long to complete as Positive Ascent. That means 300 to 500 hours or so. But the build is very much part of the fun of this project.

So far, the parachute and deployment bag are on order from Giant Leap Rocketry. Other than that, I will be ordering parts to start building the 2 motor mount/fincan assemblies and inter-stage section.

Here's what the rocket looks like so far in Rocksim:

 Single Stage

 Single Stage Specifications

2 Stage

2 Stage Specifications

MARS Rocket Launch - 10-2-10

I attended the October sport launch of the MARS rocket club in Geneseo NY and launched Positive Ascent for its 5th flight. This time the motor was a Cesaroni L1030 Red Lightning motor, with a total impulse of 2788 Newton-seconds. It was a nice flight to 3955 feet, and landed only a few hundred feet away. Thanks to Nick F.P. for taking the excellent pictures of the launch and recovery.

 Mach diamonds

Mach diamonds close-up

Drogue recovery, about 1500 feet up still

Main recovery gear perfectly deployed

Just before booster touchdown

Rocket Update

So I decided not to start the 2 stage project now, and instead bought another motor system to fly in Positive Ascent. I bought the Aerotech 54/2560 hardware from Ken Allen of Performance Hobbies in Geneseo right after I flew Positive Ascent on a K590-Classic-DualThrust motor to 2532 feet. It was a good flight. It was a very sluggish flight due to the low average thrust of the motor, and it landed very close, which was nice.

In addition to the new hardware from Aerotech, I bought a K700 reload for it, which is a 2400 Newton-Second White Lightning motor.

Ready for assembly

This is the "business end" of the assembled motor.

This past weekend I launched Positive Ascent on the K700W with PYRO in Potter, NY. It was very windy, gusting to about 25mph. The rocket still performed perfectly in the strong winds and flew to 2726 feet. However, the 8 foot parachute stayed inflated when it touched down and dragged the rocket about 200 feet through the muck fields, packing the booster section with dirt. Fortunately, there was no damage.

54mm 2 Stage Rocket Project

Now that my level 3 is over and the "high" from it is wearing off, I'm eager to plan my next rocketry project. I've decided to try a 2 stage high power rocket, which I've never done before. It will be a complex and expensive project (though not nearly as expensive as my L3 rocket).  The rocket's 2 stage configuration will be nearly 10 feet tall. It is a 4 inch diameter and my estimate for its weight without motors is about 12 pounds, even though Rocksim's prediction is 10.6 pounds. The models typically come out heavier than estimated from Rocksim.

Here is the Rocksim drawing of the model:

 Here is what the sustainer alone will look like:

 Here are the Rocksim performance predictions:

The rocket will require the use of 3 timers, in addition to the usual 2 altimeters for recovery device deployment. The timers I'm planning on using are the Perfectflite MT3G timers. These are switched on using a G switch on liftoff. Then after the programmed time has elapsed, the single output of the timer is initiated.

In the case of the booster, there will be 2 timers. The first will be used to trigger the black powder charge to separate the booster from the sustainer. Then the second timer in the booster will wait a few seconds after the separation charge to fire its output, which will be the boosters parachute charge.

While this is all happening in the booster, the sustainer will be coasting upwards. The 3rd timer is in the sustainer and will be used to ignite the sustainer's motor a second or so after the separation charge. At this point, the sustainer will be functioning as a standard single stage rocket, and the altimeters will handle dual deployment as usual.

At this point, I need to some up with some money to start buying supplies for the components.

Muck Fest 2010 (My Level 3 Cert Flight)

PYRO/TWNY hosted their first annual Muck Fest over the 4th of July weekend. I finally was able to fly my level 3 certification flight on an M1230 Imax motor. The altitude achieved was 8097.5 feet (averaged between both altimeter readings). Maximum velocity was about .75 mach, or 570 miles per hour. The flight was perfect, and it landed roughly half a mile away. I didn't realize until watching the video that the rocket actually fell into the pilot chute when it opened. It's very lucky that it didn't tangle or the main never would have opened. When it's approaching apogee, it appears that it starts to head straight back down before the drogue comes out. I'm fairly certain this is an illusion caused by a shear layer of wind that caused the smoke trail to change direction suddenly. Here's a video of the flight, thanks to Tom Binford:

Video: My Level 3 Certification Flight

I did also fly my Super Weasel for its first flight. I chose a G126 White Thunder motor. It was a perfect flight to approximately 1500 feet. Sorry there are no videos or pictures of that launch.

I also flew my Eclipse on the new J340 Metal Storm from Aerotech to 2528 feet for a nice launch. I had a video of that launch but it accidentally was deleted from the camera before an upload was possible.

I also did 2 flights with my Ariel. The first was an H112J to about 2000 feet. That flight landed just 50 feet from the pad it launched from. The second was on a Pro29 H123 Skidmark motor to about 1300 feet. That one landed in a large unclimbable (I tried and got nowhere) tree about 50 feet up. A video of that launch is here:

Video: My Ariel Lands in a Tree

I took a few pictures and videos of other people's launches. Here is Mike Dutch's I-Roc Extreme on a K motor:

Video: Dutch's I-Roc Extreme

Bill Clune launched a traffic cone on Monday. Here's a sideways video of how that flight went:

Video: Bill'sTraffic Cone Launch

The other level 3 certification flight went well also. It was Dan's flight to 9800 feet on a Pro75 Skidmark M1770 motor. The video was taken by Tom Binford:

Video: Dan's Level 3 Certification Flight

Here's Tom Binford's research full L motor in his upscale Goblin.

The Goblin on its way back from a nice flight to 5400 feet.

Debra Kolom's N research motor. Perfect flight to 12003 feet.
Debra's N3800: Video

Matt and Kevin's AMRAAM on an Aerotech J350W made a nice flight.

That's all I have from the launch right now. I'm awaiting stills of the L3 liftoff. There were many more flights than what I have listed, including several L motors and other high power launches. The weather was perfect all weekend and brought a bigger crowd than usual.

Finishing the Super Weasel

The Super Weasel is now ready for flight. The last coat of clear coat is drying on the booster section now.
Below is a look at one of the fin sections with primer and wood filler in need of sanding. This is the most time consuming part of rocketry for me because I always attempt to get the best finish possible, except in the case of this rocket. Since I plan on launching in 3 days, one of which I am working, and the other I plan on focusing on my L3, I allowed some minor imperfections to pass "inspection."

The following are what the booster section looked like with one coat of primer and wood filler, all sanded and ready for the next coat of primer:

The color scheme I went with deviates from the Rocksim preview due to me changing my mind about a dozon times in the last 2 days. What I came up with is at the very least, bright. It's very simple and not the most attractive but I don't think it looks bad for completing all finishing on the rocket in 2 days.

No, the lights on the lawn mower are not on, it's from the camera flash.

Super Weasel Nearly Ready for Finishing

At this point, all of the fillets are done. They are really oversize, and I honestly think the wood of the fins would break before the root of the fin/ body tube joints (this is a good thing).

This is my attempt at motor retention, which is a unique challenge on a minimum diameter rocket. I ran a 100lb Kevlar cord around the drogue recovery harness inside the airframe. The idea is that these cords are small enough that they don't interfere too much with installation of the motor. Once the motor is installed, the cords can be tied around the aft end of the motor, preventing it from sliding out. I've never seen this setup but I think it will work well.

This is the completed aft assembly, including the installed rail buttons. The next step is priming and filling.

Super Weasel

Here's a quick shot that shows what a small supersonic rocket flight looks like:

http://www.youtube.com/watch?v=cCBdECjAM9E

Anyway, I am now calling the rocket the "Super Weasel" due to my intention to fly it supersonic some day.

All of the fiberglass pieces are now applied, and two sections are sanded. The sanding is making them come out what seems to be very nice. Only the first coat of primer will really show the texture.

Also, one set of fillets is done. I used 5 minute epoxy, and dragged a plastic spoon across the epoxy to create the fillet shapes. Frequently dipping the spoon in rubbing alcohol prevents the epoxy from sticking to it uncontrollably and allows a very smooth finish on the fillet.

I also made the drogue recovery harness anchor. It consists of the unused 29mm centering rings from the motor mount kit and a piece of 3/8" tubular Kevlar cord. This assembly will be epoxied in place in the body tube.

On a different note, the weather forecast is looking agonizingly perfect for my level 3 certification flight this Saturday. Take a look - 3 different weather sources can't all get it wrong can they? We will see...