SEAS students take to the skies

Altitude is a critical consideration when designing tools to measure human-related effects on climate change. A ground-based device might not be able to measure a wide enough area to derive useful data, but a device too high – suh as a satellite – might not be able to track changes in the air and transmit the information in real time. Low-altitude drones are an ideal solution, but they are expensive to build.

For their senior capstone project, seven engineering students from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) collaborated with NASA’s Jet Propulsion Laboratory (JPL) to design a low-cost blimp capable of measuring emissions from factories, traffic or wildfires. They divided into four sub-groups, each of which spent the year designing a critical component for the drone, then launched their prototype from Crow Island Airpark in central Massachusetts.

“We wanted to build something that could stay in the air and measure these very important parameters over longer time periods than you can with any existing methodologies,” said Blake Woodford. “We were trying to create a platform that others could use, and be very diligent in the documentation so even people without engineering backgrounds could still use it.”

The four subgroups for the project were: Woodford, who built the payload; Joey Liu and John Deneen, who built the power plant and propulsion system; Denzel Ekes and Cole Kuster, who designed the guidance, navigation and control (GNC) system; and Ruben Fonseca and Nate DeLucca, who designed the structure of the blimp.

“Everyone on the team were mechanical engineering concentrators, so it was a situation where a lot of us had to step up and become pseudo-electrical engineers or computer scientists to get the project done,” said Ekes. “Within the path I took in mechanical engineering at Harvard, control systems never really came up. But my part of the project was to work on GNC, so it was essentially a sixth class teaching me how controls work. It was a lot of teaching myself the level of material necessary to make sure the project was a success.”

Once all the subsystems were done, the students had a 25-foot-long blimp that, once filled with helium, could hover in the lower atmosphere and maintain long-distance wireless communication for long periods of time. When launch day arrived, the team packed everything up and headed to Crow Island.

“We got to the Science and Engineering Complex the morning before we left for the launch, then stayed until 6 a.m. the following day doing a full-scale integration,” Deneen said. “We filled up the balloon, attached everything except for the fins, then broke it all down, packed it up and put it into a truck. Most of us only got a couple hours of sleep before we drove out to the site. We were expecting to be fully inflated and have everything on the aircraft by 3 or 4 p.m. We expected the vehicle to be able to operate in 15 mile-per-hour winds, but on launch day it was gusting far beyond what we’d designed it for. We were doing our best to park cars to block the wind, but it was a nightmare trying to get it inflated.”

High winds led to a failed first launch, as the blimp failed to gain altitude. As it returned to the ground, a fin detached and ruptured the blimp’s envelope. Undaunted, the team was able to repair the blimp and launch a second time, this time with more success.

“One thing we learned from this project is that integration in the field tends to take much longer than you expect,” Ekes said. “The second flight test was significantly smoother. Everyone knew what to do, and we were able to get everything situated. It did fly and was able to collect data.”

Liu added, “Even if the final integration and flight wasn’t a 100-percent success, we were still able to check all the individual subsystems and say they worked independently.”

“ES100: Engineering Design Projects” is a required course for fourth-year engineering students pursuing S.B. degrees. Students often take on projects that force them to learn skills or topics not covered by their previous coursework, and the JPL project was no different.

“Inflatable structures aren’t something I’d ever touched in my core disciplinary courses,” Fonseca said. “It forced us to dig deep into the literature and figure out how inflatables, envelopes and airships work. I think we have a significantly greater understanding of airships now, and definitely more than the average mechanical engineering student. It was definitely something that took us out of our comfort zone, but in the end, we learned a lot from it.”

This was the third year JPL sponsored group capstone projects at SEAS. The first two years were projects related to the upcoming Europa Clipper launch.

“This was one of the most complex group projects I was part of at SEAS,” Woodford said. “It was really cool at the end of the year to be able to present it to JPL. One of the engineers came up to us afterwards and said he was glad we got to experience all the stages of the engineering process, all the highs and lows. At the end of the day, it was such a fun project to work on. When someone asks me what my thesis is, I can say, ‘Oh, it’s a blimp.’ It made me very glad I studied what I did.”