The National Aeronautics and Space Administration (NASA) has selected its new class of astronauts—and for the first time, half of them are women.

Eight Americans were selected from 6,100 candidates, the second largest pool of applicants in NASA’s history. A mix of scientists and military pilots, the group of four men and four women will begin training for future space missions that may include trips to an asteroid and Mars.

The female astronauts are:

Nicole Aunapu Mann, 35, a Marine Corps major and F/A-18 pilot.

Anne McClain, 34, a major in the U.S. Army and OH-58 helicopter pilot.

Jessica Meir, 35, an assistant professor of anesthesia at Harvard Medical School.

Christina Hammock, 34, who is National Oceanographic and Atmospheric Administration station chief in American Samoa.

-Noel Brinkerhoff

To Learn More:

NASA Selects 2013 Astronaut Candidate Class (National Aeronautics and Space Administration)

NASA Unveils New Astronaut Class for Deep-Space Exploration (by Clara Moskowitz, SPACE.com)

New U.S. Astronaut Class is Half Female (Agence France-Presse)

One-Way Trip to Mars in 2023 Attracts Applicants from More Than 100 Nations (by Danny Biederman and Noel Brinkerhoff, AllGov)