AerospaceNU Club and Co-op Create a Path for Innovation and Change
Kelso Fiedler, E’24, mechanical engineering with a minor in aerospace engineering, and MS’25, mechanical engineering, exploited the range of experiential learning opportunities and PlusOne master’s program to advance his knowledge, ultimately leading to a full-time job at his co-op employer.
Kelso Fiedler, E’24, mechanical engineering with a minor in aerospace engineering, and MS’25, mechanical engineering with a concentration in thermofluids, exploited experiential learning and the PlusOne master’s program to advance his knowledge. He utilized student groups, volunteer work, and co-ops to establish himself as an innovator in aerospace engineering, with a focus on making an impact on society.
“Aerospace engineering is an innovative field where breakthroughs are always happening; most problems have no direct formula or exact solution—only experimentation. Many of history’s major paradigm shifts came from innovations in transportation and the movement of goods, from wheels and aqueducts to steam engines, cars, and planes. That’s why I want to work at the forefront of mechanical and aerospace engineering,” says Fiedler.
He believes understanding the needs of people and society is the first major step to driving positive change through innovation. For Fiedler, that means volunteer work, particularly teaching and mentoring young people. “The majority of my success has been from the mentorship and help of others,” he says. “I want to pass on the knowledge I have gained and give back to the world in the way I have been supported.”
During his first and second years at Northeastern, he volunteered with Roxbury Robotics, a College of Engineering community outreach program aimed at exposing engineering and robotics to local youth. Currently, he works at Master Genius Academy, teaching second and third graders basic engineering with hands-on activities.
Gaining hands-on and leadership experience with AerospaceNU
He gained hands-on experience and the opportunity to grow as a mentor and leader when he joined Aerospace NU during his first year in 2021. The club was also Fiedler’s way of exposing himself to the aerospace field. He became the propulsion project lead in the fall of his second year. In this position, he led a team of 22 undergraduates. They wanted a real engineering challenge, so they tasked themselves with designing, manufacturing, and testing a regeneratively cooled bi-propellant liquid rocket engine. This type of engine is lighter and more efficient, but it’s significantly more difficult to design and test.
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Fiedler gained valuable leadership and aerospace engineering skills with the club AerospaceNU. They tested their regeneratively cooled bi-propellant liquid rocket engine.
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The challenge was to figure out how to cool the engine without exploding it. They used cryogenic oxygen—oxygen so cold it becomes a liquid—and kerosene to fuel their engine. Regenerative cooling works in reducing the temperature of the chamber walls by running fuel up the sides of the engine before pumping it back into the combustion chamber. It’s similar to running water over a hot pan; the fuel acts like the water. This process doubles as a way to absorb the heat the engine releases and inject it back into the combustion chamber, resulting in lower engine weight, higher thrust, and increased efficiency.
The hands-on experience Fiedler gained at AerospaceNU was the launch pad for his success during his two co-ops and eventually his undergraduate capstone project.
Electric vehicle co-op at Bosch
When he began applying to companies for a co-op, it wasn’t just about gaining experience, but also about being a part of a project that is beneficial to society and the environment.
His first co-op was with Bosch in 2022 as an electric vehicle thermal systems co-op optimizing energy usage of electric vehicle heating, ventilation, and air conditioning (HVAC) systems. He performed and analyzed thermal chambers and drive cycle tests on the fully electric Tesla Model Y.
When driving any electric vehicle, the battery, motor, and power electronic systems get progressively hotter. Cooling technologies ensure they stay within their operating temperature, keeping passengers safe and the car at top performance. Fiedler was tasked with characterizing the functionality of the car’s thermal system to optimize energy consumption; he analyzed coolant and refrigerant temperatures, pressures, and flow rates.
The branch he worked with was also designing and building a degassing bottle, a cooling circuit technology. For coolant running through a system to be efficient, there must be no gas bubbles. Removing the bubbles by draining all the coolant and refilling it takes time, and the designs that remove the bubbles without draining it are largely inefficient. So, Fiedler came up with a design for a degassing bottle that improved degassing capability. He built a prototype of his design, ran experiments, and presented it to Bosch.
For his capstone, Fiedler challenged himself to follow the entire engineering design process with his unique Tesla valve for a valved pulsejet engine.
“It was challenging to develop a product from the very beginning, but I learned so much. It was very rewarding to develop my idea through the entire engineering process,” Fiedler says. “And in industry, I think there are more opportunities for rapid innovation that academia can’t necessarily support.”
Co-op at Relativity Space leads to full-time job
For his second co-op in 2023, he worked at Relativity Space as a propulsion test engineering intern at their test site in NASA’s Stennis Space Center in Mississippi.
“I chose Relativity Space because of the company’s mission and culture. They are redefining the boundaries of aerospace technology with the goal to improve life on Earth.”
Fielder was on the ground support equipment team, which was building a vertical dual-bay liquid rocket engine test stand capable of withstanding about 260,000 pounds of thrust. After months of work, Relativity tested the Aeon R engine on the stand.
“There is nothing like witnessing a rocket engine firing. You experience the full range of frequencies the human ear can register. You can feel the power; that amount of momentum disturbs the air. It’s humbling, but it’s also inspirational. When people come together with a common goal, they can make anything possible,” Fiedler says.
Fiedler designed and built the valved pulsejet engine he used for experiments with his Tesla valve.
After his co-op at Relativity Space, Fielder began working on his capstone project. His co-ops helped sharpen his thermofluids skills as well as his ability to collaborate effectively within a team, which came in handy when working on his capstone. He and his team designed a valved pulsejet engine, which is the simplest jet engine, but it’s not the most reliable. Traditional valved pulsejets use one-way check valves or reed valves to allow air into the chamber and prevent air from escaping the chamber. The valves do this by opening and closing at about 200 to 400 times per second, which causes the jet to be prone to failure.
Fiedler wanted to improve the reliability of a valved pulsejet engine. His idea was to replace the reed valves with a specially designed Tesla valve, a uniquely shaped valve pattern with no moving parts. He designed, simulated, and experimented with a Tesla valve design tailored to the experimental pulsejet. He and his team built the pulsejet engine and experimented with reed valves and a Tesla valve. Their experiments proved the viability of the Tesla valve as a replacement for reed valves in valved pulsejet engines.
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Throughout his year as a PlusOne master’s student, Fiedler continued to work on his pulsejet engine in Boston’s MIE Capstone Lab.
The hands-on and experiential learning Fiedler took part in—AerospaceNU, co-op, and his capstone—gave him the chance to cultivate technical skills in aerospace engineering.
“I learn best with hands-on activities; my skill set is more tailored to designing and building a project, rather than solving equations. Northeastern’s opportunities for experiential learning, which for me were AerospaceNU and co-op, helped me build the technical skills I need to be successful,” Fiedler says.
Fiedler was offered a full-time position at Relativity Space, which he will begin after graduating from the mechanical engineering and thermofluids Plus One Master’s program in May 2025. He will be rejoining the ground support equipment team at the Stennis Space Center as a full-time propulsion test engineer.