James Dean

Florida Today

MELBOURNE, Fla. — A SpaceX Dragon capsule splashed down in the Pacific Ocean just before 3 p.m. ET Wednesday to wrap up a month-long visit to the International Space Station, returning to Earth with more than 3,700 pounds of equipment and science research.

“The Dragon spacecraft has served us well,” British astronaut Tim Peake radioed to mission controllers in Houston after the Dragon floated from the outpost in darkness at 9:19 a.m., released by its robotic arm. “It’s good to see it departing full of science, and we wish it a safe recovery back to planet Earth.”

Among the 1,300 pounds of experiment on board were more than 1,000 tubes of blood, urine and saliva collected from former NASA astronaut Scott Kelly before his year-long ISS mission ended in March.

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NASA will analyze those biological samples to learn more about the long-term effects of microgravity on the human body. Another study will compare Kelly's physiology during the mission to that of his identical twin brother, former astronaut Mark Kelly, back on the ground.

"Thanks SpaceX for getting our science safely back to Earth! Very important research," Scott Kelly said on Twitter.

Also packed on the Dragon were protein crystal experiments flown by drug company Eli Lilly that could further the design of cancer treatments. And NASA engineers look forward to picking apart a spacesuit that forced a January spacewalk to be cut short when a water bubble formed in astronaut Tim Kopra's helmet.

The spacesuit glitch showed NASA hasn’t fully solved the cause of water leaks that endangered a spacewalker in 2013.

The mission that ended Wednesday was the first by a Dragon in a year, due to a failure by SpaceX's Falcon 9 rocket during a launch of cargo last June. The Dragon is critical to station operations and research in part because no other spacecraft can return large amounts of cargo to the ground.

SpaceX Dragon set to fly home from ISS

SpaceX launched the Dragon April 8 from Cape Canaveral Air Force Station on a flight that saw the company land a Falcon 9 booster on a ship in the Atlantic Ocean for the first time (a feat repeated last week on an unrelated mission).

The Dragon berthed at the station two days later with 7,000 pounds of cargo that included the Bigelow Expandable Activity Module, a prototype habitat designed by Bigelow Aerospace that is expected to be inflated later this month.

After bidding the station farewell Wednesday morning, the Dragon circled the planet three times before firing its thrusters to start its drop from orbit around 2 p.m. The spacecraft's unpressurized "trunk" split away as planned before the capsule began a fiery plunge through the atmosphere.

Drogue and main parachutes deployed to set up a gentle splashdown at 2:51 p.m., about 260 miles southwest of Long Beach, Calif. Boats were expected to return the capsule to shore within a day so time-sensitive research could be unloaded.

SpaceX and NASA are targeting a late June launch from Cape Canaveral of the company's next resupply mission, SpaceX's ninth of up to 20 planned under contract potentially worth $3.1 billion.

Follow James Dean on Twitter: @flatoday_jdean