Sometime in the next six years, astronauts bound for the International Space Station may find themselves strapped inside a private commercial spacecraft known as Dragon.

They would take off from a refurbished launch pad at Cape Canaveral Air Force Station built by privately held Space Exploration Technologies (SpaceX), the same firm that owns the Dragon capsule, its Falcon launch vehicle and the helicopters that would pluck the capsule from the sea on its return.

Hiring others to fly crews to the space station is a necessity for the United States, which has shut down manufacturing lines for the 28-year-old space shuttle program.

After two deadly accidents and operating costs 20 times more expensive than originally planned, the shuttles are due to be retired in late 2010 following six more missions to complete construction of the space station, a $100 billion project involving 16 nations.

Beginning this year, station-bound astronauts will be transported solely by Russia, which sells rides to the U.S. government at a cost of about $50 million a seat.

The U.S. space agency NASA plans to develop a new space transportation system which, in addition to reaching the space station 225 miles above Earth, can travel to the moon and other destinations even farther away.

But an independent panel of 10 aerospace executives, tapped by President Barack Obama, assessed NASA's plan and found it not viable, with the proposed new transport launcher's debut coming a year or so after NASA is scheduled to take the space station out of orbit in 2016.

The program is fatally flawed, panel head Norm Augustine, testified to Congress this week.

With a $3 billion hike to NASA's $18 billion annual budget, the panel estimates the country can restore beyond-Earth exploration programs. It suggests, however, the United States turn to commercial providers to ferry crews to orbit, as an alternative to paying Russia.

SpaceX, which already holds NASA contracts to deliver cargo to the station outpost, figures it will cost the government about $20 million a seat for round-trip travel aboard Dragon.

We're trying to free NASA's money and talent to tackle the tough problems of going beyond Earth orbit rather than running a trucking service to Earth orbit, Augustine said.

We think we're at a situation a little like the airlines were when the government stepped in and awarded contracts to carry the mail. That was the thing that made the airlines viable, he added.

RISKS AND OPPORTUNITY

Nevertheless, critics say commercial firms are not ready to take on the business of flying astronauts to space.

To confuse the expectation that one day commercial transport of crew will be there with the assumption of its existence in the near term, I think is risky in the extreme, former NASA administrator Mike Griffin said at a Congressional hearing this week.

There will be a day when the U.S. government, as one option, can turn to commercial providers, but that day is not yet and it is not soon.

While the government weighs its options, commercial space advocates are moving ahead. On September 3, SpaceX signed a contract worth $50 million to deliver 18 communications satellites for telecoms company Orbcomm. That is in addition to its $1.6 billion contract with NASA and a backlog of other business.

Earlier this year, Aabar Investments of Abu Dhabi bought a 32 percent stake in aspiring suborbital space operator Virgin Galactic, a unit of Virgin Group, in a deal valued at $280 million.

Though Virgin Galactic is mostly known for courting well-heeled tourists for $200,000 rides, it is developing a complementary business to launch satellites from its spaceship's carrier aircraft, a vehicle named White Knight.

The systems that have been developed are not only going to be good for the government, but good for the private sector and that lowers the cost substantially for everyone, said Mike Gold, who oversees Washington D.C. operations for Bigelow Aerospace, which plans to launch three-person habitats in space for research and commercial customers.

NASA should no longer have the luxury of building systems that can only be utilized by the government, Gold said. The entrepreneurial space industry has never been in this strong of a position, but it's a window of opportunity and if they don't do the right thing it could be 10 years before we see true commercial and space utilization develop.

(Editing by Pascal Fletcher and Alison Williams)