The cargo ship Dragon, owned by California-based company Space Exploration Technologies, ended its 28-day stay at the International Space Station today and headed for a splashdown in the Pacific Ocean.

Station commander Steven Swanson used a robotic crane to release the capsule, built and operated by SpaceX, as the company is known, at 9:26 a.m. EDT/1326 GMT as the two vehicles soared in orbit 266 miles (428 km) above Earth.

The capsule will return with more than 3,500 pounds (1,586 kg) of science samples for analysis on Earth, along with equipment no longer needed aboard the space station and spacesuit components in need of refurbishment.

"Thanks to everybody who worked this Dragon mission. It went very well," Swanson radioed to flight directors at NASA's Mission Control Center in Houston after Dragon left the station's orbit.

Dragon arrived at the space station on April 20, Easter Sunday, with a delivery of supplies and science experiments for the crew, and a pair of legs for the experimental humanoid robot aboard that one day may be used in a spacewalk.

The capsule was due to make a parachute descent into the Pacific shortly after noon EDT, splashing down about 300 miles west of Mexico's Baja California peninsula.

The mission marked the third of 12 under SpaceX's $1.6 billion contract with NASA for space station cargo runs.

The company also is vying against Boeing and privately owned Sierra Nevada Corp., for a related NASA project to develop space taxis to ferry astronauts to and from the space station.