The Sharpie is the scratch-built rocket I constructed in order to obtain my Level 2 High Power Rocketry (HPR) certification from Tripoli. I created the rocket using OpenRocket and designed it for dual-deployment recovery after reaching an apogee of 6000 feet AGL. The coupler and nose cone were created in SolidWorks and 3D printed using PLA. I designed the nose cone to be 2 parts and easily come apart so that I can affix the U-bolt for the shock cord attachment and pin the two parts together for launch. The hollow section also serves as a place to add weight in order to adjust the stability if needed. For dual-deployment, I soldered together an Eggtimer Quantum to serve as my flight computer and attached it to a 3D-printed sled in the upper section of the rocket. The Sharpie utilizes a 24″ drogue set to deploy at apogee and a 36″ main parachute set to deploy at 700 feet.

The Sharpie’s first launch was at the May 2021 Tripoli Vegas launch at the Delamar Lakebed 2 hours north of Las Vegas. Unfortunately, like the Crayon, the Sharpie also suffered a fin-break; it was severe to the point where the epoxy bond held but the cardboard shredded around where the fin attached to the body. After taking a look at the recovery site, it was clear that the Quantum activated the main black powder charge but the parachute was too snug in the lower body and could not properly deploy, leading to a high landing velocity. After giving it some thought, I decided to epoxy the fin back on and perform a composite layup on the fins similar to Joe Barnard’s Lumineer build. This was my first time performing a layup on a 3D surface and utilized 2 layers of fiberglass at 45 degrees and a final layer of carbon fiber. After all 3 sides were cured, I cut off and dremeled away the excess (which was quite a long process). I then filled in the cracks with wood filler to prevent air from entering the cracks and separating the composite layers from the wood. There was some separation of carbon fiber at the very edge of the fins where I needed to epoxy and clamp it shut, but the results were better than expected for a first attempt.

The second launch of the Sharpie was at Tripoli’s LDRS 39 event at the Bonneville Salt Flats in Utah. After a faulty igniter, the Sharpie launched beautifully. However, I was not able to find the rocket while walking out for recovery despite having a rough visual of where it landed. I found the Sharpie the next day in the event’s lost and found bin missing the nose cone…meaning I did not receive my L2 certification. I later found the nose cone broken into parts while searching for a friend’s rocket. After inspecting the data from the Quantum, everything went as planned except for the detachment of the shock cord from the nose cone. This was likely my fault for not properly tying the shock cord to the U-bolt. My next opportunity to relaunch will be in the fall after I return from Ames.