NASA unveiled the four astronauts who will eventually participate in the first U.S. commercial flight to the International Space Station (ISS).

According to the Washington Post, Sunita Williams, Robert Behnken, Eric Boe and Douglas Hurley are a group of military veterans, pilots and now are now experienced NASA astronauts.

NASA awarded contracts last year to Boeing and SpaceX to build spacecraft and rockets capable of ferrying NASA's astronauts to the ISS in order to end reliance on the Russian space agency. NASA currently sends its astronauts to Kazakhstan, which results in the U.S. paying Russia about $76 million per trip.

Boeing and SpaceX have already been flying unmanned spacecraft to the ISS on resupply runs. NASA hopes to launch its first commercial flight with astronauts aboard by the end of 2017.

"I am pleased to announce four American space pioneers have been selected to be the first astronauts to train to fly to space on commercial crew vehicles, all part of our ambitious plan to return space launches to U.S. soil, create good-paying American jobs and advance our goal of sending humans farther into the solar system than ever before," NASA Administrator Charles Bolden said in a press release. "These distinguished, veteran astronauts are blazing a new trail - a trail that will one day land them in the history books and Americans on the surface of Mars."

The astronauts will now meet with Boeing and SpaceX, the companies that will ultimately build the spacecraft used to ferry them.

"Congratulations to Bob, Doug, Eric and Suni on being the first group of astronauts selected for flight training as part of NASA's Commercial Crew Program," Gwynne Shotwell, president and COO of SpaceX, said in the release. "We look forward to working with them even more closely as we prepare for the first human missions to the space station on Crew Dragon. Human spaceflight is why SpaceX was founded, and we look forward to supporting our nation's exploration efforts by launching astronauts from America again."