Called Crew Dragon, the vehicle landed in the Atlantic Ocean on Friday, following a six-day mission in orbit.
Pending the analysis of flight data, everything indicated that SpaceX - founded in 2002 by Elon Musk - had passed its test from beginning to end, a result that drew widespread praise.
Another goal of the USA is to stop their dependence on Russian "Soyuz" rockets and since the success of SpaceX's "Crew Dragon", NASA has awarded SpaceX and Boeing Co a total of $US6.8 billion to build a competing rocket and capsule system. Instead, the experimental Demo-1 mission carried a crash-test dummy and a plush toy Earth doll. The mission began March 2, when the Crew Dragon launched from NASA's Kennedy Space Center in Florida, and racked up a number of "firsts" in less than a week.
It is the first commercially-built and operated American crew spacecraft to dock with the ISS.
The Crew Dragon capsule has gone through a successful docking test with the International Space Station and subsequently spent a week with the astronauts on it, after it had delivered a sensor-packed dummy- named Ripley after the iconic Alien franchise heroine- around 450lbs worth of cargo and a Little Earth plush toy that acted as a zero-g indicator. The Dragon linked with the station autonomously, being the first American spacecraft ever to do so in this manner.
First autonomous docking of a USA spacecraft to the International Space Station.
Even though the capsule came back to Earth looking like a "toasted marshmallow" - in the words of SpaceX engineer Kate Tice - the heat shield held. "It was handsome", said Benji Reed, director of crew mission management at SpaceX. However, NASA described the mission as "absolutely critical" in its effort to replace the space shuttle (which retired in July 2011).
"He's going to welcome us aboard, probably, when we get there", Behnken said Friday during a NASA TV broadcast. "It's not just for our own astronauts from NASA, but it's also going to carry up crew members from Canada, Europe, Japan and even Russian Federation".
Live footage from NASA showed the capsule's main parachutes opened without a hitch, and it splashed down at 8:45 am (1345 GMT), completing a mission to demonstrate that it could reliably and safely carry astronauts to the International Space Station (ISS). Worried about his other fellow astronauts, inanimate or not, he added he is "personally, very anxious to hear how Ripley is feeling after they pull her out of the capsule and get her onto the recovery vehicle".