The number of applications for the 2013 class of astronauts was the second-largest ever received, the space agency reported Monday.
The group of four men and four women will receive a wide array of technical training at space centers around the globe to prepare for missions to low-Earth orbit, an asteroid and Mars, it said.
"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 announcing the selections.
"They're excited about the science we're doing on the International Space Station and our plan to launch from United States soil to there on spacecraft built by American companies," he said. "And they're ready to help lead the first human mission to an asteroid and then on to Mars."
Five of the candidates are serving military officers, while three are civilian scientists.
"They have diverse backgrounds and skill sets that will contribute greatly to the existing astronaut corps," Janet Kavandi, director of Flight Crew Operations at Johnson Space Center, said. "They have diverse backgrounds and skill sets that will contribute greatly to the existing astronaut corps."