Wednesday, May 1 marked the midpoint of finals week for most Penn State students — a time to shed study guides and pack up the room in anticipation of hitting the road and driving off into the almost-summertime sunset.

But as campus residents were tying up loose ends in State College, a robotic arm laid a grey substance in two concentric circles deep within the confines of the Caterpillar Demonstration & Learning Center in Edwards, Illinois.

The device was 3D printing a one-third scale model of a structure, designed by a team of Penn State faculty members and students, that could shelter humans living on Mars.

The structure was Penn State’s entry in NASA’s 3D Printed Habitat Challenge, which asked participants to print “subscale shelters out of recyclables and materials that could be found on deep-space destinations, like the Moon and Mars.” Designed by a team of twenty Penn State faculty members and students, the final shelter, named PennStateDen@Mars, took home second place in the competition and a prize of $200,000.

“We’re at the forefront of developing 3D printing of concrete technology, and looking at multiple areas that all inform one another,” said Shadi Nazarian, an associate professor in Penn State’s Department of Architecture.

Nazarian and Stuckeman Chair in Design Innovation José Duarte, alongside colleagues Sven Bilén and Ali Memari, led the 3D printing team through several stages of the NASA competition, which began in 2015. Although their team wasn’t involved in the initial installment of the contest, May’s placement marked its completion of the fifth level of the third stage of the extensive program.

Their final scaled design was 13.5 feet tall and built out of recyclable materials and indigenous substances that could be found and used on Mars, such as igneous rock and even water in a unique cement mix.

Due to facility restrictions, the team had to print their structure in 10-hour increments in front of a panel of judges. Their fully-printed shelter was then subjected to a series of tests that examined its structural integrity and the quality of its material mix. Competitors were responsible for every detail of their structure, from the materials used in its cement mix to the digital programming of the robotic arm that conducted the printing.

“Autonomous construction is one major goal of this project and a major goal of NASA,” Nazarian said of the robotic aspect of the process. “That’s one of our major tasks: to develop automated construction technologies.”

The Penn State team faced off against eventual winners AI SpaceFactory in the final round of the competition, a New York firm that describes itself as a “multi-planetary architectural and design agency.”

Eighty teams signed on to compete in phase three according to Nazarian, but many dropped out along the way due to budgetary and time restrictions. By the final stage, Penn State was the only university team remaining.

Their opponent’s less restrictive time and resource limitations make the Penn State team’s accomplishment more impressive. Coordinating an hour-long meeting between 20 busy students and professors each week was difficult. But Duarte said that the team’s professional diversity gave it a key competitive edge.

“It’s hard because we have a lot of other things to do,” he said. “But at the end, we compensate for that because we are a very diverse group, we complement each other.”

Duarte also noted that Penn State’s status as a “leader” in the growing world of 3D-Printing and an active group of students contributed to the team’s success.

The team will put its prize money towards the continuation of its research, with a special focus on studying “different types of materials that are immediately useful on Earth” according to Nazarian. Despite the competition’s focus on interplanetary construction, the team’s work already features many important earthly applications. Nazarian described working with a specific type of geopolymer concrete that could drastically reduce carbon emissions. Autonomous construction advancements could make building in dangerous or inaccessible sites possible and safer.

These qualities represent the project’s interdisciplinary foundation — a combination of several different fields that merge to accomplish a single scientific goal.

“All of these areas inform one another, and the result is a transformed language of architecture,” Nazarian said. “It opens up very interesting new possibilities.”