SpaceX’s Dragon spacecraft has returned to Earth after spending 30 days in space bringing back with it tonnes of experiment, science samples, among other things.

The Dragon also brought back the first Chinese experiment ever to visit the International Space Station (ISS). The Dragon splashed into the Pacific Ocean at 8:12 am EDT – about five hours after its departure from the space station. The return of the spacecraft marks the completion of SpaceX’s 11th contracted cargo re-supply mission for the US space agency NASA.

Dragon brought back with it 1,860 kg of cargo, including science samples from human and animal research, biotechnology studies, physical science investigations and education activities.

One of the science samples was the first-ever Chinese experiment brought to the space station, which is fully commercial, under an agreement with Houston-based NanoRacks, which offers services for the commercial utilisation of the orbiting laboratory.

Aimed at studying the effects of the space radiation environment on DNA and the changes in mutation rate, the experiment was being carried out by the Beijing Institute of Technology.

“Everything went according to our plan. All the data sent back looks good,” Professor Deng Yulin, who led the Chinese experiment, was quoted as saying. Deng said he will soon fly to Florida, where a ceremony of transfer of the experiment between NanoRacks and his team is scheduled for Friday.