UNIVERSITY PARK, Pa. — Zena Cardman’s career has taken her to some of the most extreme and remote places on Earth. Her new job could send her even farther.

Cardman, a doctoral student in Penn State’s College of Earth and Mineral Sciences, was named a member of NASA’s 2017 class of astronauts on Wednesday, June 7. Vice President Mike Pence joined NASA officials in introducing the 12 men and women during a ceremony at the Johnson Space Center in Houston.

“I am beyond humbled and proud to be a part of our space program, and in the company of this new class of astronauts,” said Cardman. “It’s such a diverse group, and I’m thrilled to join my experience in microbiology and field research with the test pilots, medical doctors, engineers and everyone else. I am so grateful for the mentors and colleagues who helped me along the way.”

More than 18,300 people applied to the astronaut program, more than doubling the previous record of 8,000 set just before the dawn of the space shuttle era in 1978, according to NASA.

“We look forward to the energy and talent of these astronauts fueling our exciting future of discovery,” acting NASA Administrator Robert Lightfoot said. “Between expanding the crew on board the space station to conduct more research than ever before, and making preparations to send humans farther into space than we’ve ever been, we are going to keep them busy. These candidates are an important addition to the NASA family and the nation’s human spaceflight team.”

Cardman and the others are now considered astronaut candidates and will start a two-year training program in August before they can become full astronauts and qualify for spaceflight missions.

They are joining at an exciting time for the space agency. Private companies are developing rockets that could someday take passengers to space, and NASA has plans to send future manned missions to Mars.

“We’re very excited that (Zena) is bringing Penn State’s long tradition of excellence in astrobiology into the U.S. space program,” said Jennifer Macalady, associate professor in Penn State’s Department of Geosciences and Cardman’s adviser at Penn State.

Cardman is pursuing her doctorate in geosciences at Penn State, where she studies microbe-rock interactions and what they can tell us about life on early Earth and beyond.

“I’m especially interested in life that lives in oddball environments on Earth, the extremophiles,” Cardman said after learning she was an astronaut finalist. “For me, that’s a good analogy for environments that might be habitable on another planet.”

Cardman said profound questions about the possibility of life on other planets has driven her research, including her current work studying the almost-alien lifeforms that grow on the walls of damp, remote caves that never see the light of day.

“Right now I’m studying cave slime,” she said. “That’s a really interesting environment. It’s totally dark all the time. Life there is not fueled by normal things we look outside our windows and see.”

Cardman, who hails from Williamsburg, Virginia, previously studied tiny organisms that thrive around hydrothermal vents deep in the ocean while pursuing her master’s degree at the University of North Carolina at Chapel Hill. She also received her bachelor’s degree in biology from North Carolina with minors in creative writing, chemistry and marine sciences.

Beyond her degrees, Cardman brings a diverse set of experiences to the space program, from spending time in the engine room of a sailboat with the Sea Education Association to a field season in the stark isolation of the Palmer Long-Term Ecological Research station in Antarctica.

“From a NASA perspective, you want to be as versatile as possible,” she said. “You want to be a payload who’s worth your weight. You want to be able to be that scientific Swiss Army knife in the field.”

Cardman and the other astronaut candidates will report to the Johnson Space Center in August to begin training in spacecraft systems, spacewalking skills, teamwork and other skills, according to NASA.

They could then be assigned to missions ranging from working on the International Space Station to participating in deep space missions on NASA’s new Orion spacecraft, the space agency said.

“It’s a really exciting time,” Cardman said. “Maybe more so than any in my lifetime. There is a lot of change happening, so we are not sure where this current class is going to end up going. That’s almost more exciting than knowing.”

Penn State has strong connections to NASA. Four Penn Staters have flown in space: alumni Paul Weitz, Robert Cenker and Guion S. Bluford Jr. — the first African-American astronaut, who flew on the space shuttle Challenger in 1983 — and alumnus and Associate Professor of Kinesiology James Pawelczyk. In May, NASA awarded Penn State $1.7 million as part of the NASA Aeronautics’ University Leadership Initiative.

Christopher House, professor of geosciences at Penn State, last year was chosen to join the Curiosity Mars rover science team. House is also director of Penn State’s Astrobiology Research Center and the NASA Pennsylvania Space Grant Consortium, which seeks to provide opportunities for Pennsylvanians to learn about and participate in NASA’s aeronautics and space programs by supporting and enhancing STEM education, research and outreach programs.