SpaceX's Dragon splashed into the Pacific, just five hours after leaving the orbiting lab.
"Welcome home, Dragon!" the California-based company said via Twitter.
After a one-month visit, the SpaceX cargo ship was set loose Sunday morning. Astronaut Steven Swanson, the station commander, released it using the big robot arm as the craft zoomed more than 260 miles above the South Pacific.
"Very nice to have a vehicle that can take your science, equipment and maybe someday even humans back to Earth," Swanson told Mission Control.
The SpaceX Dragon is the only supply ship capable of returning items to Earth. The others burn up on re-entry. This was the fourth Dragon to bring back space station goods, with 3,500 pounds aboard; it came down off Mexico's Baja California coast.
NASA is paying SpaceX and Virginia-based Orbital Sciences Corp. to make station deliveries. Orbital is next up, next month. Russia, Europe and Japan also make occasional shipments.
SpaceX also is competing for the right to ferry station astronauts, perhaps as early as 2017.
The Dragon rocketed to the space station on April 18 with a full load and arrived at the orbiting lab two days later.
Following Sunday's splashdown, a ship is to carry the Dragon to a port near Los Angeles, and then it will go to a SpaceX factory in McGregor, Texas. Critical science samples will be hustled off at the port for quick return to NASA.