It began with two members and one big dream: create a club that allows students to apply their engineering knowledge from class by building drones, planes, and rockets from scratch. Meet Northeastern’s Aerospace Club, or AeroNU. With 200 members nearly a decade later, the Redshift team at AeroNU is quite literally reaching for the sky as they strive to complete the “Dollar Per Foot” challenge. Hosted by the nonprofit Friends of Amateur Rocketry, this is a challenge where students from different universities across the United States measure how high their rocket travels, with each foot earning one dollar. With the aim of reaching 20,000 feet within a couple of years, many AeroNU members are working diligently to complete the components of their rocket. As with any endeavor, there are plenty of challenges to overcome. One of the biggest challenges happened last spring when the engine fractured during manufacturing.
Down in the Mechanical and Industrial Engineering Capstone Lab, the AeroNU Propulsion team works tirelessly to design a liquid rocket engine full of small channels and features, grooves, overhangs, and screw holes. Because of the complex shape, according to Propulsion Lead Mark Galle, “this [engine is] pushing the boundaries in complexities.” The engine’s geometries are more complex than usual 3D printing allows. In addition, the engine is too large to print in one piece, so the team decides to print two halves and later join them. This was risky, but the resources were already available and the team decided it was worth a shot.
One of the best parts of AeroNU, according to its members, is the opportunity to step up and learn. Even those with experience, such as Propulsion Lead Sam Wohlever, are always curious to learn more.
Unfortunately, during the first print, the filament broke, causing the printer to stop and the bed to cool down. After the bed heated back up, microcracks appeared due to the thermal cycling. During the second print, the filament broke even more and the engine inevitably fell apart due to the internal microfractures.
Hope was not lost for the team — they had prepared for issues like this. The team called for an emergency meeting to go over technical issues, redesigns, and next steps. They decided that even though it would be more expensive and require outside resources, the best course of action to create the engine would be direct metal laser sintering, a laser-based 3D printing method that fuses powder into layers. This method is more reliable because of its precision and accuracy.
With the new plan in mind, the team got back into the lab and made a few adjustments, including creating and reorienting the entire engine into a single piece. In the end, the engine came out wonderfully. Although the first engine may have cracked under stress, AeroNU most certainly did not. They too emerged stronger and wiser, as they learned quite a bit from this rough patch. One of the biggest lessons learned was the idea of cost.
“The [first] method that we were using was a great way to save a whole lot of money,” Redshift Project Lead Isaac Kramer said. “However, it was far more complex and riskier than the way that we ended up doing it.” When working on a liquid rocket engine — something that involves dangerous chemicals, explosive items, and hot gases — there comes a point where saving money is not as important as quality.
“In all of our work, there is always a goal,” Wohlever said. “Really, what we’re striving for in this club is learning and improvement, both on an individual and club scale.
One of the best parts of AeroNU, according to its members, is the opportunity to step up and learn. Even those with experience, such as Propulsion Lead Sam Wohlever, are always curious to learn more.
“In all of our work, there is always a goal,” Wohlever said. “Really, what we’re striving for in this club is learning and improvement, both on an individual and club scale. We’re able to take so many applicable skills away from this.” It is this mindset, this passion, and this drive that allows a club like AeroNU to bounce back from setbacks. Members learn from their mistakes and understand that the path to success is not at all straight and perfect, but full of turns.
