The 178-foot (54-meter) tall Falcon 9 rocket lifted off at 3:44 a.m. (0744 GMT) from a refurbished launch pad just south of where NASA launched its now-retired space shuttles.

The U.S. space agency is counting on companies like Space Exploration Technologies, or SpaceX, to take over flying cargo – and eventually astronauts – to the $100 billion space station, which orbits about 240 miles (390 km) above Earth.

Currently, NASA is dependent on Russia to fly crew to the station, at a cost of more than $60 million per person. Russia, Europe and Japan also cargo to the station.

If its test flight is successful, SpaceX would become the first private company to reach the space station, a microgravity research complex for biological, materials, fluid physics and other science experiments and technology demonstrations.

SpaceX, founded and operated by internet entrepreneur Elon Musk, and Orbital Sciences Corp already hold contracts worth a combined $3.5 billion to fly cargo to the station. SpaceX also is among four firms vying to build space taxis to fly astronauts, tourists and non-NASA researchers.

Separately, NASA contributed nearly $400 million to SpaceX’s $1.2 billion commercial space program, which includes development and up to three test flights of Falcon 9 rockets and Dragon capsules.

An analysis by the U.S. Government Accountability Office shows that a similar program under a traditional NASA procurement would have cost four to 10 times as much, said NASA’s Alan Lindenmoyer, who manages the agency’s commercial spaceflight initiatives.

If Dragon can be successfully maneuvered and operated in orbit, it is expected to be cleared for a berthing at the space station on Friday. DM

Photo: The SpaceX Falcon 9 test rocket is being prepared for launch from Complex 40 at the Cape Canaveral Air Force Station in Florida May 18, 2012. REUTERS/ Michael Brown