Astronauts aboard the International Space Station released Space Exploration Technologies' unmanned Dragon cargo capsule on Thursday, the last milestone for a pioneering commercial test flight.

Dragon was the first privately owned spaceship to reach the space station, a project of 15 nations. It is scheduled to splash down in the Pacific Ocean southwest of Los Angeles at 11:44 a.m. EDT (1544 GMT).

Space Exploration Technologies, or SpaceX, is one of two firms hired by NASA to fly cargo to the station following the retirement of the space shuttles last year.

Using the station's robot arm, astronauts detached the capsule from its berthing port at 4:07 a.m. EDT (0807 GMT) and released it at 5:49 EDT (0949 GMT) as the spacecraft sailed 250 miles above Earth.