170607-O-N0101-002 HOUSTON (June 7, 2017) Navy Lt. Kayla Barron, a submarine warfare officer, smiles as she is introduced as one of 12 new astronaut candidates during an event at NASA's Johnson Space Center in Houston, Texas. After completing two years of training, the candidates could be assigned to missions performing research on the International Space Station, launching from American soil on spacecraft built by commercial companies, and launching on deep space missions on NASA's new Orion spacecraft and Space Launch System rocket. (U.S. Navy photo courtesy of NASA by Bill Ingalls/Released)