Project Karman

September 2015 - December 2016

Goal:

The final goal of this project is to build a rocket that will reach a height above the Karman line (100 km above sea level). This is being approached in multiple smaller-scale rockets designed to test specific aspects of the final rocket. While Project Karman is still going on at AIAA, I only contributed to it for about a year and a half before moving on to other projects within the club.

My main contribution to Project Karman was as a member of the Parachute Test Rocket (PTR) sub-group. It was focused on testing the rocket's recovery method using a special dual-deploy technology called a 'Tender Descender', and CO2 canisters for separation (rather than a lot of black powder).

My Role:

I participated in discussions focused on the rocket's design including its air frame and how the sections would be laid out within the body. I constructed many sections of the rocket with a few other members, and gained a lot of practical experience in hobby-rocket building. The rocket was designed to be test launched multiple times, and as such I attended many launches and became well-versed in rocket assembly and launch procedures.

The Technology:

The recovery system utilized two parachutes: a preliminary drogue parachute and the main parachute. A normal dual-deploy parachute would simply have two sections for these parachutes to deploy from. Our rocket used the same space for both parachutes, and thus had to employ a different technique to keep the main parachute from opening at apogee (which could lead to a much greater drift distance). The Tender Descender was used to keep the main parachute within the rocket until a lower, more desirable altitude for it to deploy. It is essentially a clip with a small blast charge that keeps the parachute inside the rocket until the desired altitude. At that altitude, the flight electronics electrically ignite the blast charge, forcing the clip open and allowing the main parachute to exit the rocket and unfurl.

The other novel technology this rocket used was CO2 canisters to separate the rocket sections rather than traditional black powder charges. Black powder requires oxygen to fuel the controlled separation explosion, and the final rocket design will be deploying a parachute at such an altitude with significantly less oxygen than our normal rocket flights. To solve this low-oxygen problem, we used CO2 canisters (think of the canisters used in paintball guns) to separate the rocket. Small black-powder charges that do not require as much oxygen were used to blast a puncture needle onto two CO2 canisters. Once punctured, these canisters provided enough pressurization to separate the rocket sections and deploy the parachutes as planned.

Results:

The test rocket had many launch iterations. Initial designs failed due to flawed workmanship and finicky technology. At the end of the PTR project, it was determined that the Tender Descender is not reliable enough to use in such a high-value final rocket design. The solution that is being employed currently by the team is to design their own custom method of controlling parachute deployment. They Karman team is in the process of building larger 2-scale rocket comprising of a booster rocket and top section rocket. The project has grown considerably since my joining in its early state, and I am interested to see how it fares in the future as they progress further.

Skills Learned:

  • Refined design skills with SolidWorks

  • Learned how to use a laser cutter and 3D printer

  • Became familiar the fundamentals of rocket-building

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©2018 by David Siegel