Once I completed my level 2 certification, I had been spending a lot of time thinking about what, exactly, I should build for my level 3 project. And more generally, how should I approach it?

Cardboard or fiberglass?

I’ve built both cardboard and fiberglass rockets, and each has advantages depending on what you’re trying to achieve. I had initially assumed any L3 project would need to be fiberglass, and I’d been looking at some very large and very heavy rockets.

Fiberglass is more durable than cardboard, and is the strongest building material aside from metal. It won’t change size based on fluctuations in temperature, and it won’t swell up or get ruined if wet. This is particularly important since the rocket parts need to slide over each other using couplers. But the primary drawback of fiberglass is that it’s really heavy.

Cardboard (especially when properly reinforced with epoxy) is still durable but more lightweight, and that is a key characteristic when you are trying to defy gravity and launch something into the air. A cardboard rocket will go a lot higher than a fiberglass rocket on the same motor.

While agonizing over this fundamental choice, a solution appeared, from out of nowhere.

Deus ex machina

I had previously met and worked with Scott Binder, the owner of Scott Binder Rocketry (“SBR”), creator of the Fusion Rocket, as well as high power rocket motors and accessories. Scott’s shop is located in Walla Walla, Washington. His flagship rocket is the Fusion, but he’s recently been developing a new, larger version of the Fusion that is specifically for L3 certification – and long story short, I agreed to do some beta testing on this rocket.

In addition to building the rocket and using it for my L3 cert, I am going to create a video tutorial with Scott for the construction of this rocket, from start to finish. I’ll link to that as soon as it’s ready.

L3 Fusion

The L3 Fusion itself is roughly 90 inches in length and a 5.5 inch diameter. With a 75mm motor mount tube, it’s capable of flying an M motor, and I plan to fly it on an Aerotech M1297 for the cert flight. The great part about cardboard is that this rocket only weighs about 22 lbs fully loaded, and it should come close to 10,000 ft. at apogee on the M1297.

The electronics bay will have two RRC3 altimeters, each powered by a 9V battery, and will use omni-directional black powder charges for separation and deployment of the parachutes during flight. The drogue chute is 24 inches and the main chute is 84 in. Descent should be less than 20 feet per second under the main chute.

There are more details forthcoming, but right now I’m excited to dive into this L3 project! I need to begin putting together a comprehensive document describing the rocket, with a lot of technical information. Later, once I begin building, I’ll include a lot of detail about the construction process and materials, with plenty of photos documenting the build step by step. And much later, once it’s complete, the most exciting part: flight!

More to come soon!

Recently, I was able to make the journey out to Brothers, OR to attend my first launch hosted by the Oregon Rocketry Club (“OROC”). From where I live in the Seattle area, this is about a 6.5 hour drive each way, so I stayed overnight in Portland. I’ve done some pretty long day trips, but trying to drive to this launch and back in a single day would just be pushing myself a bit too far.

I really only spent half a day at the launch, but it was absolutely worth the trip. I was able to launch two rockets – the cardboard HyperLOC 835 that I used for my L1 and L2 cert, and also the fiberglass Darkstar Extreme. This was the maiden flight for the latter rocket and it did not disappoint.

More importantly, this was my first chance to attend a large launch event with a lot of other people (although of course due to COVID-19, attendance was more limited than normal, and attendees were required to follow a variety of safety precautions, including wearing masks and spreading out). I got to witness lots of other flights, which was amazing, and I met some great people.

To summarize the launch site and conditions, it was hot, dry, and dusty. The winds periodically picked up, too, which made the dust more of an issue. But overall, coming from Seattle, I think this was an excellent place to launch.

I flew the HyperLOC 835 here on an I-500 motor just for fun. It was a successful flight, but the wind gusts were pretty high at times. After the parachute deployed, the winds carried the rocket far from the range. I saw where it landed (or so I thought) and began walking in that direction. Once the rocket touches the ground, though, it completely disappears behind the sage, so you have to just hope you’re still walking in the right direction. The longer you walk, the more your confidence begins to waver, and eventually it melts away as the uncertainty increases in direction proportion.

As it turns out, I apparently overshot it and went significantly further than I needed to. I walked for what felt like an eternity, eventually gave up and headed back toward the range – and then fortunately spotted the rocket hiding behind a bush.

The main event for me, however, was the chance to fly the newly completed Darkstar Extreme, my first fiberglass rocket. This one weighs about 14 lbs and is overall a much more durable rocket. I had some assistance in getting it up on the launch pad.

I have to confess: I was a bit nervous because it was the first flight for this rocket. Sure, I’d built it and done some ground testing at home in my back yard, but was that sufficient? Would everything still work? The really critical components are related to the electronics for dual deployment of the parachutes. If the rocket never separates in the air and the parachutes don’t deploy, then this thing is coming back down like a ballistic missile. Not ideal for the rocket or for all the bystanders.

I was particularly concerned about whether I’d used enough black powder in the e-bay. When it detonated, would it be with enough force to separate the rocket? I’d done some ground testing at home and it separated, but not with the level of force I would like, and I hadn’t had time to do additional testing.

As I feared, the black powder exploded but not with enough force, and it didn’t cause separation. Fortunately, the motor ejection charge detonated as planned and this did cause the rocket to separate, so at least the drogue (smaller) parachute deployed. The heavy rocket came down a bit fast under such a small parachute – roughly 55 feet per second – but this was within a tolerable range and the rocket didn’t sustain any damage whatsoever. I count myself lucky.

Incidentally, the Darkstar Extreme flew on a K-535 motor and hit about 3,500 ft in altitude.

These launch experiences are a tremendous learning opportunity for me. Each time I attend one, I learn a lot, and in particular from my mistakes. Now I realize firsthand how important it is to properly calculate, measure, and test the correct amount of black powder to use for separation charges – and to test, and test again.

In addition, this experience underscored how critical it is to have a backup plan. After this launch, I decided to go back to the workbench and completely rebuild my e-bay for the Darkstar Extreme. I would add a second (backup) flight computer, along with a second battery and power switch, additional wiring and BP charge holders, and so on. Given the difficulty of locating a rocket after it lands, I also decided to add a sonic beeper just to help reduce to chances of losing a rocket. It would be easy to walk right by your rocket just a few feet away behind some bushes, and never even realize it – but a noise making device would alleviate that problem.

Nobody said that this would be an easy journey, but it’s definitely enjoyable and rewarding. Can’t wait for the next launch!