LOS ANGELES, March 3 (Xinhua) -- American spacecraft Crew Dragon docked with the International Space Station (ISS) on Sunday for its unmanned debut flight.

After making 18 orbits of Earth since its launch, the spacecraft of U.S. private spaceflight company SpaceX successfully attached to the ISS via "soft capture" at 5:51 a.m. Eastern Time (1051 GMT).

Flight computers guided the craft directly into a docking port, unlike previous cargo Dragon spacecrafts that have been attached to the space station after capture by a robotic arm.

Hours later, crew members are expected to open the capsule's hatch and hold a welcome ceremony for the craft.

The spacecraft will remain docked to the ISS for five days before departing on March 8. After undocking from the space station, Crew Dragon will begin its descent to Earth.

Rocketed into orbit early Saturday, the capsule carried a test dummy named Ripley -- after the heroine from the "Alien" movies -- and 400 pounds (about 181 kg) of supplies and experiments to the ISS.

The demonstration mission, called Demo-1, is the first flight test of a space system designed for humans built and operated by a U.S. commercial company through a public-private partnership.

The mission also marks a significant step toward to the return of human launches to the space station on a U.S.-built spacecraft from U.S. soil since 2011.