SpaceX Dragon capsule has returned to Earth, splashing down in the Pacific Ocean off the coast of Baja California in Mexico.

The return of Dragon, which landed in the Pacific Ocean at 3:22 p.m. EDT Sunday, marks the successful completion of cargo delivery to the International Space Station (ISS) by the first private resupply flight.

NASA has signed a $1.6 billion contract with California-based SpaceX to launch 12 resupply cargo ships to the ISS through 2016, after its own spacecraft were retired last year.

"This historic mission signifies the restoration of America's ability to deliver and return critical space station cargo," Elon Musk, the billionaire founder and head of SpaceX, said in a statement.

Dragon was the first private capsule to carry cargo and equipments to the ISS. The spacecraft, which was launched in the first week of October, spent three weeks attached to the Harmony module on the ISS before splashing in the Pacific Sunday noon.

The capsule will be carried by a boat to a port near Los Angeles, where it will be prepared to make a return journey to the SpaceX's test facility in McGregor, Texas, a report from NASA said.

Before moving to the test facility, mission officials will remove some of the cargo from the capsule and send it to NASA within 48 hours. Dragon has returned with 1,673 pounds of cargo, including 866 pounds of scientific research samples.

A GLACIER freezer with samples that were collected in ISS laboratory's microgravity environment will be removed from the capsule and sent to NASA. The samples will give significant information on the impact of long-duration spaceflight on astronauts. The rest of the samples will be taken to Texas, the NASA report said.

SpaceX's next mission is likely to take place in January, 2013. NASA has signed a deal with another private company called Orbital Sciences Corporation (OSC). They hope to begin supply of cargo to the space station soon.