Opening a new era in private space flight, the U.S. company SpaceX on Tuesday became the first commercial outfit to launch its own craft toward the International Space Station.

The test flight of the Dragon space capsule, which launched atop SpaceX's Falcon 9 rocket at 3.44 a.m. (0744 GMT), aims to show that industry can restore U.S. access to the ISS after NASA retired its space shuttle fleet last year.

The mission is set to include a fly-by and berthing with the station in the next three days, before the capsule returns to Earth at the end of this month.

Shortly after liftoff, the cargo-carrying spacecraft entered orbit and live video images showed mission control staff at SpaceX headquarters in Hawthorne, California jumping from their seats, hugging and clapping.

SpaceX chief executive officer and Internet entrepreneur Elon Musk said watching the rocket rise from the launch pad was an “extremely intense moment”.

“Every bit of adrenaline in my body released at that point,” he told reporters after the flawless launch, which followed an attempt on Saturday that was scrubbed at the last second when computers detected high pressure in the central engine of the Falcon 9.

SpaceX engineers discovered the root cause was a faulty check valve and repaired it the same day.

No humans are travelling aboard the Dragon, but six astronauts are already at the $100-billion space lab to help the capsule latch on, to unload supplies and then restock the capsule with cargo to take back to Earth.

On May 24, the spacecraft's sensors and flight systems are to undergo a series of tests to see if it is ready to berth, including a complicated fly-under at a distance of about 2.5 km.

If NASA gives the green light, the Dragon will then approach the ISS on May 25 in an attempt to berth with the station.