The unmanned Dragon capsule from Elon Musk’s SpaceX has splashed down after a short stay at the International Space Station.
It is the first time a commercial space system built for humans has been successfully flight tested by NASA.
The capsule – containing a dummy called Ripley – reached hypersonic speeds after detaching from the ISS and splashed down off Florida at 8.45am local time.
Its descent was slowed by four parachutes and recovery boats raced to intercept it about 200 miles off the Atlantic coast.
Benjamin Reed, SpaceX’s director of crew mission management, said: “Everything happened just perfectly, right on time the way that we expected it to.”
Dragon launched from Kennedy Space Center on a rocket last Saturday, in a major step towards reviving America’s human spaceflight programme.
The 16ft spacecraft was set to be lifted out of the water by crane by a boat in the Atlantic. It will be carried back to land by Sunday.
The rocket made 18 orbits of the Earth, before Dragon docked with the International Space Station on Sunday morning.
Space X’s billionaire founder Elon Musk tweeted a picture of Ripley inside the capsule.
The company said the dummy had sensors around its head, neck and spine to monitor how a flight would feel for a human.
Dragon carried around 400 pounds (181kg) of supplies and gear.
The space station crew has spent the last five days running tests on the capsule to see if it is safe to carry humans.
Canadian ISS astronaut David Saint-Jacques said it was “very slick” and called it business class.
A flight carrying astronauts Bob Behnken and Doug Hurley is pencilled in for June.
NASA awarded SpaceX and Boeing $6.8bn (£5.2bn) to build competing rocket and capsule systems in a bid to launch astronauts for the first time since the space shuttle was retired in 2011.
It is aimed at ending reliance on Russian rockets for rides to the ISS, which costs about $80m (£60.6m) per ticket.
Boeing plans to launch its unmanned Starliner capsule as early as next month, with a crewed mission possible in August.