Dartmouth Engineer - The Magazine of Thayer School of EngineeringDartmouth Engineer - The Magazine of Thayer School of Engineering

On a Mission to Mars

How did students, with no background in rocket science or aerospace design, end up winning NASA’s BIG Idea Challenge? By leaning on a Dartmouth engineer’s greatest assets: design-thinking and collaboration.

By Eun Lee Koh
Photography by Lars Blackmore

Mars Greenhouse
Illustration courtesy of Dartmouth's DEMETER Greenhouse Team.

IT ALL STARTED with an email she would typically ignore.

In the summer of 2018, Professor of Engineering Laura Ray received an announcement from NASA seeking proposals for its annual BIG Idea Challenge. The challenge? Design a greenhouse for Mars that can grow food and sustain a colony of astronauts on a 600-day surface mission to the red planet.

She had received solicitations like this before, but something about this made her look twice.

“Now, we normally wouldn’t take this on, but I thought, ‘This could be perfect for our capstone design class,’” said Ray, who was then serving as interim dean and as a faculty advisor for ENGS 89/90, Thayer School’s engineering design capstone course that pair student teams with real-world industry-sponsored projects. “This wasn’t just about engineering, but also food science and nutrition, the conditions on Mars, and bringing together environmental engineering, energy, mechanical and electrical engineering, and complex systems. This was the kind of challenge made for our students.”

Dartmouth's DEMETER Team

FAST FORWARD A YEAR LATER, the Dartmouth team’s Mars greenhouse DEMETER, which (spoiler alert) went on to win the BIG Idea Challenge in April, now serves as the basis for NASA’s advanced concept of operations for a greenhouse that could be tested in lunar and cislunar operations for further development. 

Finalized in October through the Game Changing Development program at NASA, the newly developed greenhouse concept, dubbed CYBELE, largely draws from the Dartmouth team’s winning proposal and is now part of NASA’s early efforts to establish a long-term human presence on Mars.

BACK IN THE FALL OF 2018, as ENGS 89 began, Ray collaborated with her fellow faculty advisors Professors John Collier, Benoit Cushman-Roisin, and Lee Lynd to pull together a team of students with diverse training and skillsets. Led by Alexa Escalona ’18 Th’19 and Zoe Rivas ’18 Th’19, the team comprised of David Dick Th’19, Grace Genszler Th’19, Thomas Hodsden ’18 Th’19, Peter Mahoney ’19 Th’19, Morgan McGonagle ’18 Th’19, and Christopher Yu ’19 Th’19.

Despite the students’ initial enthusiasm for the project, the team members knew their work was cut out for them. 

The team began the project knowing nothing about farming and agriculture on Earth, much less an extraterrestrial environment. As children, some had aspired to become astronauts, but none had taken actual courses in aerospace engineering. (Dartmouth does not have an aerospace engineering program.)

Even the most basic questions—what crops to grow or how to grow plants in a greenhouse—introduced a unique set of challenges on Mars. The Martian soil, they learned, was filled with perchlorates deadly to the human thyroid. The atmosphere was bombarded by radiation. 

In addition, the team need to figure out how to package the greenhouse, transport it through space, then deploy it—all without human intervention.

“Anything you do on Mars has to be done in a very tightly controlled environment—you can’t just let in fresh air, you can’t waste water, energy is very precious,” said Molly Anderson, Game Changing Development principal technologist for next-generation life support at NASA’s Johnson Space Center in Houston. “You have to do it in ways that are mass-efficient, energy-efficient, cost-efficient, and integrated tightly with the habitat that the crew is living in.”

With these hurdles to overcome, the team leaned on their greatest skills as Dartmouth engineers: design-thinking and collaboration. 

“Design-thinking is what truly helped us,” Escalona said. “We’re so used to using that type of thinking at Dartmouth. We always tackled every problem from a needs-based approach and iterated and iterated until we got it right.”

“We took a ground-up approach,” Hodsden said. “We began with the calories and nutrients the human astronauts would need to be happy and healthy so far from home. Then, we considered a number of different growing systems that would be the best fit for the greenhouse. Once we decided on a hydroponic approach for the greenhouse, we designed a structure to contain it, then figured out how it could be packaged to meet the size constraints and shipped from Earth.”

The team grew strawberries using a hydrophonic system and set-up that closely mimicks conditions on Mars.

The students were also unafraid to ask for help, and quickly adapted to working outside of their specific engineering disciplines. They conducted independent research, visited the Dartmouth Organic Farm to learn more about farming, and solicited guidance from life sciences faculty on crop cultivation and nutrition. Max Fagin Th’11, Thayer alumnus and senior aerospace engineer, who served as an additional advisor to the project, guided them on aerospace engineering and design.

AT THE START, the team started with 90 different varieties of crop species. Through research, they winnowed it down to eight—kale, soy, sweet potato, potato, broccoli, strawberry, wheat, and chufa—hardy crops that also provide the necessary nutrition for human survival. 

Mars Greenhouse folding membranes
A close-up of the greenhouse's folding membranes.

They prototyped multiple structures and layouts, before deciding on the torus-shaped dome, and iterated on a number of different ways to package the greenhouse, before deciding on folding, collapsible membranes. 

“We teach students to be good problem solvers and encourage them to be unintimidated by the fact that that their background doesn’t match the problem,” Collier said.

“As students here, we’re used to not being boxed into one specific type of engineering,” Rivas said. “My background and training is as an environmental engineer, but to work on a project of this magnitude, I had to step outside of that. We might not have had the opportunity to work on and contribute to all the different parts of this project, if we were only trying to stay in our corners.”

“The project was very interdisciplinary,” said Hodsden, a mechanical engineer. “I was able to channel some of my background in CAD design for this project, but it involved a lot of systems engineering and a lot of biology. It helped to have a team with such diverse backgrounds. We could all kind of occupy a different role in the project, but also have the opportunity to step into new roles as we identified new challenges.”

In April, the team traveled to NASA’s Langley Research Center in Virginia to present their greenhouse concept to a panel of NASA scientists. Named Demeter after the Greek goddess of harvest, the greenhouse had the potential to grow the food crops in a rotating, nutrient-filled, hydroponic system that provides enough nourishment for a four-person crew on a 20-month mission to Mars. In addition, to support the health and well-being of astronauts, their design included a running track around the perimeter of the greenhouse and a relaxation area.

The team edged out four other university team finalists from MIT, University of California, Davis; University of Colorado, Boulder, with Harvard, Cornell, and University of Hawaii, Manoa; and the University of Michigan with Pennsylvania State University, Purdue University, and the University of Wisconsin, Platteville.

Escalona, who earned a summer internship at NASA upon the team’s win in April, had the opportunity to further the Dartmouth team’s work through the Game Changing Development program. Escalona was part of the team that drafted the advance concept of operations document for CYBELE, in collaboration with other interns and under the mentorship of NASA scientists.

“It is incredibly humbling to know that all the work we put into this project could someday become part of something so monumental as a future human mission to Mars,” Escalona said. “This was literally a dream, to be part of something so much bigger than myself.”

Eun Lee Koh is the editor of Dartmouth Engineer.

Categories: Features

Tags: award, complex systems, engineering capstone, innovation, NASA, projects, students

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