The Red and Black Sky Attack

Rocketry sure has changed since I was a kid! I remember the days of doing the small Estes kits with my dad, and wanted to do the same with my boys - We did a few of those, but when looking for the latest rocketry info online, I found that there were many new innovations in the field since I was a kid! We quickly graduated from the small kits to custom / advanced rockets as you see here in the photo. This is documentation on how we built the biggest one - The Red and Black Sky Attack - I hope you enjoy it as much as my boys and I did!

The "Small" tube (Bigger diameter than any entire rocket that I had ever built before) is the motor tube and the plywood doughnuts will be epoxied to that tube to keep it centered inside of the rocket body. The fins are cut from thick thick G-10 fiberglass. They fit through slots cut into the rocket body and stop at the motor tube. They are then epoxied in 3 places - Outside of the rocket body, inside of the rocket body, and onto the motor tube - More pics of that in a minute.

Here you can see the nosecone and the 2 sections of the outer rocket tube. The one part that is still raw cardboard (Not white / wrapped in fiberglass) has an outer diameter that is the same as the inner diameter of the white tubes, and will be used as a connector tube to join the sections together.

The parachute retention straps are seatbelt material - EXTREMLY strong! They are epoxied to the motor tube and the wrapped in fiberglass to ensure they will not separate. Once that all dried, we put in the middle centering ring and epoxied that in as well.

For this step, we drew a line centered between 2 fins and bolted the launch rail guides on and then epoxied / fiberglassed the lower fins to the inner rocket body and outer motor tube. We made the custom stands to hold it up at working level, and cut out a slot in the rear stand to help center that fin. We then made the fin jig to keep the other fins at exactly 120 degrees apart while drying so the weight of the fins would not make them sag while drying. The bottom plywood doughnut is not epoxied in here, it's just press fit to keep everything centered and will be removed to for the next steps.

Once the fins epoxy was dry, we filled the 3 cavities with 2 part expanding foam to give it more rigidity and adhesion. After that dried, we shaved it down so that the rear centering ring would hit flush to the bottom of the fins.

We centered the motor retention ring on the plywood centering ring and marked / drilled out all the bolt holes. The motor we used for the first flight was a 54mm "K-12 75 Redline" - If you are not familiar with the specs for motors, each letter basically doubles the previous letter, so a "B" motor is like 2 "A" motors, and a "C" motor is like 2 "B" motors or 4 "A" motors. To put that into a rough perspective, the "K" motor we used was like having 1024+ "A" engines going off at once! That's why everything at this end is so solid :)

Here you can see where we attached the upper fins (We did this in the same way we did the lower fins, but on the other side of the middle centering ring). The short section that goes between the main body and the nosecone will house the electronics and the 2 parachutes for the upper section. The lower section will have 2 parachutes as well.

We drilled out a hole in the side of the body and made a 45 degree mirror holder out of paint stirrer sticks so the camera would see down instead of out. We then made a aerodynamic shroud by cutting a much smaller nosecone in half. We made it contour to the larger body by taping a piece of sandpaper to the body and running it up and down until it had the perfect fit. This camera transmits in the Amateur Radio bands (I am licensed) to a ground station, but if I were to do it over again, I would just have it save locally to an SD card.

This is the ground station that was used to receive the onboard camera video - It fed into a capture card on a laptop

There are 4 parachutes in this rocket in two identical sets of 2. One set deploys at apogee (Highest point the rocket reaches before starting to come down), and the other set at a predetermined height. The smaller red and white chutes are called drogue chutes and pull the much larger (8 foot) red and black chutes out of the fireproof bags.

We already covered the camera, but in addition to that there is a primary and backup altimeter / flight data recorder as well as a tracking beacon that is not shown here that is housed inside the nosecone. We drilled a small hole in the side of the main tube and aligned a brass rod through that hole and a piece of thin plywood inside the electronics section. Once that was aligned we epoxied small tubes that were used as guides for the rod to the plywood. I found some cool "Remove Before Flight" keychains online and attached one to the end of the brass rod. When you pull the rod out of the rocket, it turns on the camera, and then powers up the 2 altimeters / flight data recorders.

Here it is all primed and sanded and ready for the paint job.

Small, Medium, and Large :)

We launched with a rocketry club that uses a sod farm as the launch field so there are huge areas with no trees. They even have a standing waiver with the FAA where air traffic is diverted away from the area on the launch days!