A SpaceX Dragon cargo ship returned to Earth today (Sept. 17) after a one-month stay at the International Space Station. At 10:16 a.m. EDT (1416 GMT), the Dragon splashed down in the Pacific Ocean loaded with more than 3,800 lbs. (1,700 kilograms) of cargo.

NASA astronaut Randy Bresnik and the European Space Agency's Paolo Nespoli released the Dragon from the Harmony module early this morning, at 4:47 a.m. EDT (0847 GMT), using the Canadarm2 robotic arm. The Dragon then fired its thrusters to separate from the space station.

Once the Dragon spacecraft was a safe distance from the orbiting laboratory, SpaceX flight controllers in Hawthorne, California, sent the command for the Dragon to begin its deorbit burn. Roughly 5.5 hours later, the Dragon splashed down off the coast of Baja, California, where SpaceX personnel aboard a recovery vessel picked up the spacecraft to bring it back to a shipping port near Los Angeles. [Gallery: Dragon, SpaceX's Private Spacecraft]

The Dragon arrived at the space station on Aug. 16 packed with more than 6,400 lbs. (2,900 kg) of food, supplies and science experiments for the Expedition 52 crew. Science equipment on board included a protein-crystal growth experiment to research a new treatment for Parkinson's disease, another experiment for growing lung tissue from stem cells and 20 mice that would demonstrate the physiological effects of spaceflight. NASA also sent up some ice cream for the astronauts.

For the vessel's return trip, the crew loaded the Dragon with "science samples from human and animal research, biology and biotechnology studies, physical science investigations, and education activities," NASA officials said in a statement.

SpaceX's first Dragon capsule to visit the International Space Station bobs in the Pacific Ocean after a successful splashdown that capped its successful test flight on May 31, 2012. The capsule landed off the coast of Baja California. (Image credit: SpaceX/Michael Altenhofen)

"NASA and the Center for the Advancement of Science in Space (CASIS), the nonprofit organization that manages research aboard the U.S. national laboratory portion of the space station, will receive time-sensitive samples and begin working with researchers to process and distribute them within 48 hours of splashdown," the statement said.

This was the 12th contracted cargo resupply mission (CRS-12) for SpaceX. While this was a brand-new Dragon capsule at the time of launch, SpaceX officials said they plan to launch only used cargo spacecraft to the space station from now on. This was the last new Dragon to deliver cargo to the space station.

Email Hanneke Weitering at hweitering@space.com or follow her @hannekescience. Follow us @Spacedotcom, Facebookand Google+. Original article on Space.com.