— NASA has narrowed the field of private space companies vying for the $175 million in public funds the U.S. space agency expects to award in early February for demonstration flights to the international space station, according to industry sources closely following the competition.

At least eight firms – and perhaps as many as 14 – submitted proposals in late November under the Commercial Orbital Transportation Services (COTS) program, sources said.

Established in 2006, the COTS program was created

to spur the development of privately operated space transportation systems capable of delivering cargo and eventually astronauts to the space station.

In mid-2006 NASA selected two companies, Space Exploration Technologies Corp. and RocketplaneKistler (RpK),

to share about $500 million. But NASA subsequently

pulled the plug on RpK’s award, concluding the company had not lived up to the terms of the agreement the company signed with the agency. That freed

up the $175 million NASA intends to give to some other company next month.

According to multiple industry sources, NASA has notified four companies that they are finalists for the $175 million. The four have been told to be

prepared to meet soon with COTS selection officials in Houston

to defend their proposals.

was one of the companies notified the week of Jan. 14 that it had made the cut, Eva DeCardenas, a spokeswoman for the Houston-based company, confirmed Jan. 17.

The other companies, according to sources are: Andrews Space of Seattle, Orbital Sciences of Dulles, Va.

, and PlanetSpace of Chicago.

NASA spokewoman Beth Dickey would not confirm that a downselect had taken place, noting that

the COTS competition

still is

under way.

Industry sources said NASA intends to announce its final selection Feb. 7, the date by which the U.S. Government Accountability Office is required to rule on RpK’s challenge of NASA’s use of Space Act Agreements for the COTS program. RpK maintains that a traditional federal contract would be a better fit for COTS.