Boeing and SpaceX will build the next generation of spacecraft that will carry US astronauts to the International Space Station (ISS), NASA has said, hailing a new chapter in space flight.
The $US6.8 billion ($A7.4 billion) contract announced by NASA administrator Charles Bolden at the Kennedy Space Center in Florida will enable the United States to develop its own crew transport vehicles that could carry astronauts to the ISS within the next three years, US officials said on Tuesday.
"Today, with the selection of Boeing and SpaceX to be the first American companies to launch our astronauts to the International Space Station, NASA has set the stage for what promises to be the most ambitious and exciting chapter in the history of human space flight," Bolden said.
The announcement ends an arrangement in which the US space program was compelled to hitch a ride on the Russian Soyuz to transport US rocket scientists - at a cost of $US70 million per seat.
"From day one, the (Barack) Obama administration has made it clear that the greatest nation on Earth should not be dependent on other nations to get into space," Bolden said.
"Thanks to the leadership of President Obama and the hard work of our NASA and industry teams, today we are one step closer to launching our astronauts from US soil on American spacecraft and ending the nation's sole reliance on Russia by 2017.
"It was not an easy choice, but it is the best choice for NASA and the nation."
Boeing's acorn-shaped space capsule is called the Crew Space Transportation-100, or CST-100 for short, and is designed to carry up to seven passengers or a mix of crew and cargo to the space station, which circles the planet in low-Earth orbit.
The vehicle designed by SpaceX - the company headed by Internet entrepreneur Elon Musk, who made his fortune as co-founder of PayPal and also serves as CEO of Tesla Motors - is the Dragon Version Two, or V2.
