The SpaceX Dragon capsule is connected with the International Space Station with the robotic arm, on May 25. 2012. U.S. companySpaceX's unmanned Dragon capsule, the first commercial spacecraft to visit the International Space Station, was released from the orbital outpost.(Xinhua/file photo NASA)
SpaceX's Dragon cargo ship returned to Earth on Wednesday after a one-month journey to the International Space Station, U.S. space agency NASA said.
The unmanned spacecraft was released from the orbiting lab at 9:19 a.m. EDT (1319 GMT) and splashed down in the Pacific Ocean at 2:51 p.m. EDT (1851 GMT) about 261 miles (420 kilometers) southwest of Long Beach, California, where a recovery team will retrieve it.
More than 3,700 pounds (1,700 kilograms) of cargo, science and technology demonstration samples were brought back from the space station, including research in the burgeoning field of nanotechnology.
The Microchannel Diffusion study, for example, examined how microparticles interact with each other and their delivery channel in the absence of gravitational forces, said NASA.
The spacecraft also returned to Earth the final batch of human research samples from former NASA astronaut Scott Kelly's one-year mission, which ended in March.
The samples will "provide insights relevant for NASA's Journey to Mars as the agency learns more about how the human body adjusts to weightlessness, isolation, radiation and the stress of long-duration spaceflight," it said.
Dragon, the only resupply spacecraft able to return to Earth intact, lifted off from Cape Canaveral in Florida on April 8, and arrived at the space station on April 10, carrying almost 7,000 pounds (3,200 kilograms) of supplies and scientific cargo on the company's eighth NASA-contracted commercial resupply mission.
