Three aerospace firms were awarded a combined $US1.1 billion ($A1.06 billion) from NASA on Friday to develop commercial spaceships to carry astronauts into space within the next five years, the US space agency said.
Sierra Nevada Corporation, SpaceX and Boeing were given the green-light from NASA for development of the craft in the next phase of a program aimed to revive the commercial space industry and allow NASA to focus on other priorities.
Boeing received $US460 million, SpaceX $US440 million and Sierra Nevada $US212.5 million. Boeing and SpaceX are developing crew capsules, while Sierra Nevada's design is for a winged plane-style craft.
"Today, we are announcing another critical step toward launching our astronauts from US soil on space systems built by American companies," NASA Administrator Charles Bolden said. "We have selected three companies that will help keep us on track to end the outsourcing of human spaceflight and create high-paying jobs in Florida and elsewhere across the country."
NASA has provided funds several times in recent years to encourage commercial space development with the goal of turning over the shuttling of astronauts and cargo to the International Space Station to outside companies.
Since retiring its space shuttle fleet last year, it has continued to develop the next-generation Orion spacecraft designed for longer distances with an eye on a possible trip to an asteroid and later Mars.
In May, SpaceX's Dragon capsule became the first non-governmental spacecraft to dock to the ISS and deliver cargo to the orbiting laboratory. It has said its capsule is designed to be easily modified to carry astronauts.
Russia's Soyuz is the only spacecraft capable of ferrying astronauts to the ISS.