The new American spacecraft capable of carrying astronauts and built by SpaceX gently splashed down in the Atlantic Ocean on Friday morning, ending a successful demonstration trip.

“This is an amazing achievement in American history,” Jim Bridenstine, the NASA administrator, said on NASA Television afterward.

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The mission, even though there were no astronauts aboard, was a milestone in NASA’s strategy of turning to private companies to provide trips to orbit for its astronauts. Instead of building its own vehicles, like the space shuttles that were retired in 2011, the space agency hired SpaceX and Boeing to develop commercial space systems.

Last Saturday, SpaceX was the first to launch its spacecraft, an upgraded version of the Dragon capsule that has carried cargo to the space station for years. The Crew Dragon capsule docked with the International Space Station a day later. Early on Friday, it left and after a couple of orbits of Earth, it fired its thrusters to allow Earth’s gravity to pull it down.