Under a new deal, NASA will be paying a trio of companies over the next 21 months to develop spacecraft capable of flying US astronauts to the International Space Station.
The lion's share of the $1.1 billion allotted for the next phase of NASA's so-called “"Commercial Crew" program will be split between Boeing and Space Exploration Technologies, a privately held firm run by Internet entrepreneur Elon Musk.
Boeing will receive $460 million to continue developing its CST-100 capsule, which is intended to fly aboard a United Launch Alliance Atlas 5 rocket. ULA is a partnership of Boeing and Lockheed Martin.
Space Exploration Technologies, or SpaceX, was awarded $440 million to upgrade its Dragon cargo capsule, which flies on the firm's Falcon 9 rocket, to carry people.
In May, a Dragon capsule became the first privately owned spacecraft to reach the station, a $100 billionoutpost that flies 240 miles (386 kilometres) above Earth. The test flight was part of a related NASAprogram to hire commercial companies to fly cargo to the station.
Privately held Sierra Nevada Corp received a partial award of $212.5 million for work on its Dream Chaser, a winged vehicle that resembles a miniature space shuttle which also launches on an Atlas 5 rocket.
All three firms are prior recipients of NASA space taxi development work. The new awards will more than triple NASA's investments in commercial crew programs, which so far total $365 million.