* NASA to award $50 million for demonstration projects
* Proposals were due Tuesday, awards in November
* Money comes from federal stimulus funds
By Irene Klotz
CAPE CANAVERAL, Fla., Sept 23 (Reuters) - A NASA proposal to spur the development of private space taxis to ferry astronauts to the International Space Station once the space shuttle is retired has drawn a bid from U.S. aerospace giant Boeing Corp (BA.N).
Boeing is willing to invest "a substantial amount" of its own resources in the project, company officials said on Wednesday, but declined to give more financial details.
"We made sure that our investment was at a level that was serious," based on what NASA said it wanted to see in the proposals, said Pat Schondel, vice president for business development for Boeing's Space Exploration division.
The U.S. space agency is retiring its fleet of space shuttles after six more missions and plans to buy rides for astronauts, at a cost of $50 million a seat, from Russia.
The new NASA program, known as Commercial Crew Development, has $50 million in stimulus money from the American Recovery and Reinvestment Act of 2009 to help the effort.
NASA hopes to stimulate interest in the commercial sector for passenger space flights, including taking astronauts to the space station in orbit about 225 miles (360 km) above Earth.
Boeing paired with Bigelow Aerospace, a Las Vegas-based commercial space technology start-up, for its proposal, which is based on several previous capsule designs and an interchangeable launch vehicle.
"We see launchers and companies that provide launchers as merchant suppliers. We want to be able to launch on any launcher that's available," Schondel said.
Partnering with Bigelow will help Boeing develop space taxis that can serve both government and commercial customers, he added.
Among the companies competing with Boeing are Orbital Sciences Corp ORB.N and Space Exploration Technologies (SpaceX), both of which hold NASA contracts to deliver cargo to the space station; Sierra Nevada Corp, and Paragon Space Development Corp.
NASA would not reveal how many proposals it received, saying it could impact the competition. Tuesday was the deadline.
A NASA website shows more than 60 companies have expressed interest in the program, although many were identified as subcontractors.
The funds may be divided among two or more bidders. Awards are expected to be announced in November.
The U.S., Russian and Chinese governments are the only entities currently capable of human orbital space flight, although several U.S. companies are developing vehicles and support services to do so. (Editing by Jim Loney and Andre Grenon)