Washington: Carrying over 3,700 pounds of NASA cargo, science and technology demonstration samples from the International Space Station (ISS), a SpaceX Dragon cargo spacecraft splashed down in the Pacific Ocean on Thursday morning (India time). The Dragon spacecraft was taken by ship to Long Beach where some cargo will be removed and returned to NASA and then prepared for shipment to SpaceX's test facility in McGregor, Texas, for processing, the US space agency said in a statement. A number of technology and biology studies conducted in the unique microgravity environment of the space station returned aboard the spacecraft, 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. In this one-of-a-kind laboratory, researchers were able to observe nanoscale behaviours at slightly larger scales - knowledge which may have implications for advancements in particle filtration, space exploration and drug delivery technologies. "CASIS Protein Crystal Growth 4" experiment also has applications in medicine - specifically, drug design and development. Growing protein crystals in microgravity can avoid some of the obstacles inherent to protein crystallisation on Earth such as sedimentation. This will enable scientists to use "designer" compounds to chemically target and inhibit an important human biological pathway thought to be responsible for several types of cancer. The spacecraft also returned to Earth the final batch of human research samples from former NASA astronaut Scott Kelly's historic one-year mission. Additional samples taken on the ground, as Kelly continues to support these studies, 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. Dragon is the only station re-supply spacecraft able to return a significant amount of cargo to Earth. The spacecraft lifted off from Cape Canaveral Air Force Station in Florida on April 8 and arrived at the space station on April 10. The spacecraft carried an experimental inflatable space habitat that might be crucial for future deep space explorations. The Bigelow Expandable Activity Module (BEAM), a $17.8 million project, will test the use of an inflatable space habitat in micro-gravity. During its two-year test mission, astronauts will enter the module for a few hours several times a year to retrieve sensor data and assess conditions. Inflatable habitats are designed to take up less room on a rocket, but provide greater volume for living and working in space once expanded. This test allows investigators to gauge how well the expandable habitat protects itself against solar radiation, space debris and contamination.