LOS ANGELES - California-based SpaceX confirmed on Monday that its reusable Dragon capsule successfully splashed down in the Pacific Ocean, marking the first time a private spacecraft has flown to and from the International Space Station more than once.

The company reported the achievement via Twitter: "Good splashdown of Dragon confirmed".

Dragon first flew in SpaceX's fourth resupply mission to the space station in 2014. This time, it's returning more than 1,860 kilograms of cargo, including items from human and animal research, biotechnology studies, physical science investigations and education activities.

One project was the first Chinese experiment brought to the space station under an agreement with Houston-based Nano-Racks, which offers services for commercial use of the orbiting laboratory.

The experiment, from the Beijing Institute of Technology, was aimed at studying the effects of space radiation on DNA and changes in mutation rates.

"Everything went according to our plan. All the data sent back look good," Deng Yulin, who led the Chinese experiment, told Xinhua News Agency by phone from Beijing.

Deng said he will soon go to Florida, where a ceremony to transfer the experiment from NanoRacks to his team is scheduled for Friday.

The Chinese research involves no technology transfers between NASA and China because these are banned by US law.

Dragon is currently the only space station resupply spacecraft capable of returning a significant amount of cargo to Earth.

The spacecraft rocketed to the space station from Florida on June 3 with supplies and Deng's experiment. It arrived there two days later. It was released by the space station's robotic arm early on Monday morning and returned to Earth.

Xinhua