NASA has dished out generous helpings of seed money to four companies for work on commercial crew vehicles in the second round of its Commercial Crew Development (CCDev-2), advancing a total of $269.3 million to mature concepts for private spacecraft to carry astronauts to the International Space Station and other low-Earth-orbit destinations.

Boeing was the big winner in CCDev-2, getting $92.3 million on top of the $18 million it won last year. Sierra Nevada Corp., last year’s top winner, will get $80 million to go with the $20 billion it received in 2010.

Space Exploration Technologies Inc. (SpaceX), which already has flown its Dragon cargo capsule to orbit and back, has been granted $75 million to develop a launch abort system and other hardware so the Dragon can carry crew. Blue Origin, the secretive startup organized by Amazon.com founder Jeff Bezos, was allotted $22 million to continue work on its vertical takeoff and landing craft.

“We’re committed to safely transporting U.S. astronauts on American-made spacecraft and ending the outsourcing of this work to foreign governments,” stated NASA Administrator Charles Bolden in the April 18 press release announcing the awards. “These agreements are significant milestones in NASA’s plans to take advantage of American ingenuity to get to low Earth orbit, so we can concentrate our resources on deep space exploration.”

Boeing has produced its first test article for the CST-100 capsule it is building with CCDev-1 and -2 funds, matched with corporate money. Similarly, Sierra Nevada is building composite structures for its Dream Chaser lifting body vehicle. Both can be launched on a variety of launch vehicles.

SpaceX is using its own Falcon 9 rocket to launch the Dragon, while the Blue Origin’s New Shepherd vehicle uses internal engines after the fashion of the old DC-XA testbed.

Losing out in the selection were Orbital Sciences, which like SpaceX is under contract to build a commercial cargo vehicle — Cygnus — to supply the ISS, and has started a separate lifting-body effort for commercial crew. ATK, which had teamed with Europe’s EADS Astrium to propose a vehicle dubbed Liberty that would use the five-segment solid-fuel first stage developed for the defunct Ares I rocket and an Ariane 5 main stage conversion as its upper stage, also lost out.

“The next American-flagged vehicle to carry our astronauts into space is going to be a U.S. commercial provider,” stated Ed Mango, NASA’s Commercial Crew Program manager. “The partnerships NASA is forming with industry will support the development of multiple American systems capable of providing future access to low Earth orbit.”