This article was updated at 12:03 p.m. EDT.

NASA has picked eight Americans, a mix of scientists and military pilots, to begin training for future space missions that may one day launch them all the way to Mars. The new class includes four men and four women who will join the 49 active astronauts at the agency's astronaut corps at the Johnson Space Center in Houston.

The new U.S. space travelers, which NASA unveiled today (June 17), could be part of thefirst crews to visit an asteroidor Mars, deep-space goals that NASA aims to explore. They could also be the first people to launch to space on a U.S.-built rocket since the era of the space shuttle, which ended in 2011.

In the nearer term, the new recruits could launch on Russian rockets to serve long-duration missions on the International Space Station, which is expected to operate until at least 2020. [7 Notable Space Shuttle Astronauts]

"These new space explorers asked to join NASA because they know we're doing big, bold things here developing missions to go farther into space than ever before," NASA Administrator Charles Bolden said in a statement. "They're excited about the science we're doing on the International Space Station and our plan to launch from U.S. soil to there on spacecraft built by American companies. And they're ready to help lead the first human mission to an asteroid and then on to Mars."

NASA will discuss its new astronaut recruits during a Google+ Hangout session today (June 17) at 4 p.m. EDT (2000 GMT). You can watch the hangoutlive here on SPACE.com, or directly at:http://go.nasa.gov/126mOLK.

The new spaceflyer hopefuls were selected from more than 6,000 applications thesecond largest applicant pool NASA's ever had. With the new class being evenly split between men and women, it represents the largest percentage of female astronaut candidates in any new class. [Women in Space: A Space History Gallery]

Thelast new cohort of NASA astronautswas selected in 2009, and included nine new candidates. They officially graduated in November 2011, but none have flown to space yet. Michael Hopkins will be the first of that group to fly when he launches in September to the International Space Station.

The new candidates,NASA's 21st astronaut class, will report to the Johnson Space Center for training in August.

"This year we have selected eight highly qualified individuals who have demonstrated impressive strengths academically, operationally and physically," said Janet Kavandi, director of Flight Crew Operations at Johnson Space Center. "They have diverse backgrounds and skill sets that will contribute greatly to the existing astronaut corps. Based on their incredible experiences to date, I have every confidence that they will apply their combined expertise and talents to achieve great things for NASA and this country in the pursuit of human exploration."

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NASA Unveils New Astronaut Class for Deep-Space Exploration