High Power Rocketry
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During my senior year of college, I helped a friend found the JHU Rocketry Club, now known as the AstroJays. The goal of the club was to allow students to participate in High Power Rocket (HPR) activities, i.e. launching rockets for fun, or in collaboration with other research efforts on campus.
HPR Certification Levels
Early on in the club, members were provided kits for level 1 class rockets, so that they could start working their certification levels. To give a brief overview, hobby rockets with motors ranging from class H to class O are regulated, and require levels of certification to legally operate. Class partitions per motor size are as follows:
- Level 1: Class H - I
- Level 2: Class J - L
- Level 3: Class M - O
Anything beyond class O is no longer considered hobby level, and requires specific approval from various regulatory bodies like the FAA. To earn a level certification, an individual must demonstrate a working rocket with that level of motor (known as a certification flight). Certification flights are the only time when someone with a lower level certification may use a higher class level of motor. Ultimately the goal was for the club to design and build a custom level 3 rocket for the Spaceport America Cup, but that meant that someone in the club needed to be at least level 2 certified, in order to handle the level 3 motor.
Rebel Scum
For my certification attempts, I started with the High-Tech rocket kit sold at Apogee Rockets. The level 1 certification simply required me to build the kit, and successfully launch and recover the rocket via the normal parachute system. My certification flight went perfectly, and I recovered my rocket completely intact.
Following my level 1 certification, I began to retrofit my rocket for a level 2 certification flight. The requirements for a level 2 flight include using a motor from the J-L range, as well as demonstrating an electronic avionics system—because level 2 rockets fly so much higher, they require a drogue parachute to deploy at apogee, and then rely on an electronics system to deploy the main chute closer to the ground. You also have to pass a written test, in addition to the flight, in order to complete the level 2 certification process.
To upgrade my rocket, performed the following modifications:
- replaced engine mount with custom structure designed for a larger class J motor
- added an arduino based avionics system for detecting altitude and activating the main chute
- replaced the old fins with twice as many to ensure stability
- added a new coat of paint and decals
The it was with the addition of the Star Wars decals that the rocket earned the name Rebel Scum.
Unfortunately the rocket did not separate at apogee, causing it to ballistically arc downward and crash into the ground.
Upon inspecting the wreckage, I did note that the parachute mechanism had activated, so it likely would have been a successful flight had separation occurred. I suspect the lack of separation was due to the increased mass of the new components, which provided too much inertial resistance for the separation charge to overcome.
Spaceport America Cup
In the summer of 2018, I traveled with two other club members to New Mexico to participate in the Spaceport America Cup. During the year, members of the club had all collaborated to construct a level 3 rocket for the competition, which would carry a fluidics experiment developed by one of the research labs at JHU.
Ultimately, we couldn't launch at the competition due to a few structural inadequacies discovered at the launch site, but the team earned good marks for the design of the rocket and its novel experiment payload. After I graduated, the club repurposed the level 3 motor for a new rocket being developed in conjunction with a custom hybrid rocket engine.
