SpaceX's Dragon cargo spacecraft splashed down at 3:05 p.m. EDT Sunday, in the Pacific Ocean, approximately 300 miles west of Baja California, returning more than 3,500 pounds of NASA cargo and science samples from the International Space Station.

A boat will carry the Dragon spacecraft to a port near Los Angeles, where it will be prepared for a return journey to SpaceX's test facility in McGregor, Texas, for processing. Some cargo, including a freezer packed with research samples collected aboard the space station, will be removed at the port in California and returned to NASA within 48 hours.

"The space station is our springboard to deep space and the science samples returned to Earth are critical to improving our knowledge of how space affects humans who live and work there for long durations," said William Gerstenmaier, associate administrator for human exploration and operations.

"Now that Dragon has returned, scientists can complete their analyses, so we can see how results may impact future human space exploration or provide direct benefits to people on Earth."

Investigations included among the returned cargo could aid in better understanding the decreased effectiveness of antibiotics during spaceflight while also improving antibiotic development on Earth. Others could lead to the development of plants better suited for space and improvements in sustainable agriculture.

The T-Cell Activation in Aging experiment, which also launched to space aboard Dragon, seeks the cause of a depression in the human immune system while in microgravity. The research could help researchers develop better protective measures to prevent disease in astronauts.

Dragon is the only space station resupply spacecraft capable of returning large amounts of cargo to Earth. The spacecraft lifted off from Cape Canaveral Air Force Station in Florida April 18, carrying approximately 5,000 pounds of supplies and science investigations to the space station. The mission was the third of at least 12 cargo resupply trips SpaceX plans to make to the space station through 2016 under NASA's Commercial Resupply Services contract.