Experiential Learning |
Visit this page to see my international engagement at the Technische Universitat Berlin.
Personal Reflection
Despite being part of a required course in my major, the project of designing, constructing, and characterizing a small-scale Hall thruster magnetic circuit was the least typical, most demanding, and most interesting class project I've ever participated in. In contrast to my previous experiential learning experience, which was somewhat of an all-encompassing lifestyle experience, this was a beginning-to-end engineering project with significant time constraints and defined results. I'm incredibly proud of myself and my teammates for the work we've done and the results we produced. I realize the project description may not be so approachable to those uninitiated in electric propulsion for spacecraft, so allow me to recap the main stages of the project.
Like I stated in my application, a Hall thruster is a type of propulsion device that uses a magnetic field and electric field in tandem to ionize and accelerate neutral gas propellant to propel a spacecraft. This type of thruster is very efficient in comparison to traditional chemical rockets and is particularly applicable for satellite orbit corrections and long-term hauling missions such as NASA's Asteroid Initiative, which seeks to robotically capture an asteroid and bring it into orbit closer to Earth than the moon so it can be studied by manned crew. Hall thruster research is being conducted globally and is highly relevant for humanity's spacefaring future.
I would divide a Hall thruster into four essential components: a magnetic circuit, an electric circuit, the propellant system, and the channel structure. The magnetic circuit of a Hall thruster can be thought of as the 'core' of the thruster that heavily defines the way the thruster will operate (although each aspect is essential). The magnetic circuit is comprised of an iron core-piece and magnets. Our goal was to design, build, and characterize the magnetic field of a magnetic circuit while adhering to certain design parameters and logistical restrictions. The main design parameter was using permanent magnets rather than electromagnets while logistically we were restricted to a budget of $300 and the time length of the quarter.
The project began with the design phase. My partners and I used Finite Element Magnetic Modelling, a magnetic modelling software, to find a design geometry that would optimize the magnetic field of our circuit while using permanent magnets we could find and afford. After finalizing a design, we purchased iron and magnets and began planning the building and testing phases while we waited for the materials to arrive. We used computer-aided design software to make a computer model of our magnetic circuit that we used as a guide for machining.
Once the iron arrived, the construction phase began. Since I was the only one trained in the machine shop, I was tasked with doing all the machining for the project which consisted mostly of machining the iron core. Although this was a significant time commitment, I became very familiar with and more skilled on a lathe and in the machine shop in general. On top of the increasingly difficult homework and classwork I was receiving, the machining task was daunting. At times I'd be frustrated that I was spending hours and hours working in the shop while my partners were more or less standing-by and doing other things like studying, however this machining process was undoubtedly the most committed to a project I have ever been. It felt amazing being so dedicated to a process that I genuinely enjoyed and my work ethic during this time impressed and surprised me. I estimate that I spent 30 hours machining which yielded both an impressive iron core and a great confidence boost in my machining ability.
The iron and magnets were assembled, and the testing phase began. We used a gaussmeter, a device that measures magnetic fields, to characterize our circuit. We rigged together a measurement stand that held the gaussmeter probes, which was a fun engineering task in itself since we kept running into problems that had to be solved. Gathering the data was rather tedious as it tends to be, but with the data we made diagrams showing the measured magnetic field of the circuit. Finally, we compared our measurements to the magnetic model simulations and got to writing our final report. Upon completion, I felt impressed by the work we produced and shared our report with friends and loved ones to let them know the amazing science I do on campus (and why I'd fallen off the face of the Earth for a bit).
This project felt like a taste of what a career in research and development may be like after undergrad, or perhaps a microcosm of a real space technology project like those I have dreamt of being a part of. I learned many useful skills that I'll definitely be using down the line, but more importantly I learned how to wholly dedicate myself to a goal that I felt passionate about. While I've been highly committed to projects in the past none have ever felt as demanding and difficult as this one was. Also, I am excited that I finally was able to take on a class project regarding advanced space propulsion, which is precisely what I hope to do in the future.
Our research was praised by our department and I will be continuing Hall thruster research this summer. I'm especially glad for this opportunity since it will give me even more experience and connect me with people in the area of study I'm keen on entering. For the past three years I have been learning a large breadth of information that forms a basis from which there are many career paths, and I feel this project was my first step down a path that I plan on following. The part of an experimental Hall thruster we built may never propel a spacecraft, but it has propelled me on a trajectory of specialization that I've sought to pursue since I came to the university.
Like I stated in my application, a Hall thruster is a type of propulsion device that uses a magnetic field and electric field in tandem to ionize and accelerate neutral gas propellant to propel a spacecraft. This type of thruster is very efficient in comparison to traditional chemical rockets and is particularly applicable for satellite orbit corrections and long-term hauling missions such as NASA's Asteroid Initiative, which seeks to robotically capture an asteroid and bring it into orbit closer to Earth than the moon so it can be studied by manned crew. Hall thruster research is being conducted globally and is highly relevant for humanity's spacefaring future.
I would divide a Hall thruster into four essential components: a magnetic circuit, an electric circuit, the propellant system, and the channel structure. The magnetic circuit of a Hall thruster can be thought of as the 'core' of the thruster that heavily defines the way the thruster will operate (although each aspect is essential). The magnetic circuit is comprised of an iron core-piece and magnets. Our goal was to design, build, and characterize the magnetic field of a magnetic circuit while adhering to certain design parameters and logistical restrictions. The main design parameter was using permanent magnets rather than electromagnets while logistically we were restricted to a budget of $300 and the time length of the quarter.
The project began with the design phase. My partners and I used Finite Element Magnetic Modelling, a magnetic modelling software, to find a design geometry that would optimize the magnetic field of our circuit while using permanent magnets we could find and afford. After finalizing a design, we purchased iron and magnets and began planning the building and testing phases while we waited for the materials to arrive. We used computer-aided design software to make a computer model of our magnetic circuit that we used as a guide for machining.
Once the iron arrived, the construction phase began. Since I was the only one trained in the machine shop, I was tasked with doing all the machining for the project which consisted mostly of machining the iron core. Although this was a significant time commitment, I became very familiar with and more skilled on a lathe and in the machine shop in general. On top of the increasingly difficult homework and classwork I was receiving, the machining task was daunting. At times I'd be frustrated that I was spending hours and hours working in the shop while my partners were more or less standing-by and doing other things like studying, however this machining process was undoubtedly the most committed to a project I have ever been. It felt amazing being so dedicated to a process that I genuinely enjoyed and my work ethic during this time impressed and surprised me. I estimate that I spent 30 hours machining which yielded both an impressive iron core and a great confidence boost in my machining ability.
The iron and magnets were assembled, and the testing phase began. We used a gaussmeter, a device that measures magnetic fields, to characterize our circuit. We rigged together a measurement stand that held the gaussmeter probes, which was a fun engineering task in itself since we kept running into problems that had to be solved. Gathering the data was rather tedious as it tends to be, but with the data we made diagrams showing the measured magnetic field of the circuit. Finally, we compared our measurements to the magnetic model simulations and got to writing our final report. Upon completion, I felt impressed by the work we produced and shared our report with friends and loved ones to let them know the amazing science I do on campus (and why I'd fallen off the face of the Earth for a bit).
This project felt like a taste of what a career in research and development may be like after undergrad, or perhaps a microcosm of a real space technology project like those I have dreamt of being a part of. I learned many useful skills that I'll definitely be using down the line, but more importantly I learned how to wholly dedicate myself to a goal that I felt passionate about. While I've been highly committed to projects in the past none have ever felt as demanding and difficult as this one was. Also, I am excited that I finally was able to take on a class project regarding advanced space propulsion, which is precisely what I hope to do in the future.
Our research was praised by our department and I will be continuing Hall thruster research this summer. I'm especially glad for this opportunity since it will give me even more experience and connect me with people in the area of study I'm keen on entering. For the past three years I have been learning a large breadth of information that forms a basis from which there are many career paths, and I feel this project was my first step down a path that I plan on following. The part of an experimental Hall thruster we built may never propel a spacecraft, but it has propelled me on a trajectory of specialization that I've sought to pursue since I came to the university.
Evaluation from Justin Little, S.P.A.C.E. Lab PI
Daniel played a key role in the successful completion of this junior project. His team was given the ambitious task of designing and testing a magnetically-shielded Hall thruster magnetic circuit. With only the help of a few journal articles, he helped his team design a Hall thruster magnetic circuit using finite element methods, machine a prototype, take measurements using a Gaussmeter, and analyze the data. The sum of this work was very impressive and taught us much about the design process for permanent magnet Hall thrusters. I am happy to say that he will be continuing this work in my lab, with the ultimate goal of improving and adapting the magnetic field design and test methods into a working Hall thruster.