Nittany Lion Paw Prints on Martian soil? Maybe someday.

As human exploration of Mars becomes more of a possibility, planning for the basic needs of the explorers begins with conceptualizing a shelter. A team of Penn Staters is making a strong case that they should be the ones to join with NASA in developing the technology to create a habitat on Mars.

PennStateDen@Mars is an interdisciplinary team, led by Stuckeman School of Architecture and Landscape Architecture faculty members Shadi Nazarian and José Duarte, competing in NASA's 3D-Printed Habitat Challenge, a Centennial Challenges competition that asks inventors to design a human shelter that can be 3D-printed on site using indigenous or recycled materials.

The goal of the four-phased competition is to create an autonomous machine that will someday be deployed to the moon, Mars, or beyond to construct shelters for human habitation, according to a NASA release.

"The ideas and technologies this competition has already produced are encouraging, and we are excited to see what this next phase will bring," Monsi Roman, program manager of NASA's Centennial Challenges, said in a statement. "The solutions we seek from our competitions are revolutionary, which by nature makes them extremely difficult. But this only fuels our teams to work harder to innovate and solve."

PennStateDen@Mars is answering the call. The team, comprising faculty and students in the colleges of Arts and Architecture, Engineering, and Agricultural Sciences, earned a second-place finish and $150,000 in August 2017 for its entry in phase 2 of the challenge, which required competitors to develop the fundamental 3D-printing technology necessary to produce a structurally sound habitat, including the printer itself and construction materials.

"The design of our shelter is rooted in our understanding of the strengths and limitations of the printing system, but it also draws inspiration from vernacular architecture," Duarte said. "So far, 3D-printing technology is based on horizontal layering, but we are taking a different approach. We are looking at traditional dome construction based on brick layering."

Building on the success of their design, the team is competing in phase 3 of the challenge, which focuses on continuing to develop and apply the technology to print the habitat at a 1/3 scale. The third phase ends with an on-site competition in Peoria, Illinois, from April 29 through May 4, 2019. The winner of phase 3 will receive a $500,000 prize, second will receive $200,000, and third will receive $100,000. All prize money is to be used for development of the technology in preparation for the fourth and final phase of the challenge, which requires a full-scale printed habitat.

While the second-place prize money was welcomed, Duarte said the team is actively raising funds to help compete in all levels of phase 3 and phase 4.

The team's goal in the challenge is to win and vault Penn State's 3D technological advances into the international spotlight, but Duarte said the team has other uses for the technology as well.

"It's important to note that the technology can also be applied to build and repair other structures such as roads and bridges," Duarte said. "We have been talking to different companies who might be interested in developing and applying this technology to the building sector."

For more information on Penn State's 3D research, visit additiveconstruction.psu.edu.