The Dragon capsule floating in the Pacific Ocean as it waits for recovery. (Michael Altenhofen/SpaceX/May 31, 2012)

After becoming the first-ever private spacecraft to berth to the International Space Station last week, SpaceX's Dragon safely returned to Earth on Thursday, landing in the waters a few hundred miles west of Southern California. 

In partnership with NASA, the capsule delivered more than 1,000 pounds of supplies to the space station, mainly food and noncritical crew items. It carried back an estimated 1,400 pounds of cargo, the bulk of it hardware. 

A barge will carry Dragon to a port near Los Angeles, where some cargo will be returned to NASA within 48 hours. The capsule will then be transported to McGregor, Texas, for remaining cargo unloading and processing. 

This first test flight to the space station is part of NASA's Commercial Orbital Transportation Services (COTS) program, begun in 2006 to create a commercial cargo-carrying capability for access to and from the space station and other low-Earth orbit destinations.  

NASA will spend the next several weeks evaluating mission results, said COTS Program Manager Alan Lindenmoyer during a post-splashdown press conference at SpaceX headquarters in Hawthorne, Calif., but “it looks like 100 percent success at this point.”

"A grand-slam,” added SpaceX CEO and Chief Designer Elon Musk, who founded the firm in 2002.

Reflecting on the company's early years of financial hardship in a tough economy, Musk said, “We would've died if it weren't for NASA."

Since the retirement of NASA's space shuttle fleet last July, the agency has lacked a follow-on transportation system and needed to completely rely on Russia, Japan and Europe for crew and cargo access to and from the space station, which will remain in operation through at least 2020. Two Americans, one Dutch and three Russians are presently living and working onboard the orbiting complex.

Unlike the foreign-provided vehicles, Dragon is the only spacecraft capable of returning a significant amount of cargo from the space station. 

With NASA's approval, the company may start hauling cargo to and from the space station this year as part of a 2008 contract for a minimum of 12 flights through 2015. The company also plans to use the reusable Dragon capsules to ferry crew to and from the space station, but that effort is part of another ongoing NASA multi-phase competition.

Orbital Sciences is also a COTS partner. Its demonstration mission to the space station is expected later this year. The company has a contract with NASA for eight routine cargo missions to the space station through 2015.

NASA is transferring the role of crew and cargo transportation to the space station over to the American private sector so the agency can focus on developing spacecraft to take astronauts farther into space, including to an asteroid and Mars. 

Musk said President Obama as well as lawmakers from both sides of Congress, many of whom who have continuously expressed doubt toward the nascent commercial spaceflight industry, have extended 'congratulations' throughout the mission.

Dragon launched from Cape Canaveral, Fla., last Tuesday atop SpaceX's two-stage Falcon 9 rocket.

There are no definitive post-mission plans yet for this particular capsule, Musk said, but a countrywide tour is a possibility.

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Reach senior staff reporter Len Ly here; find her on Twitter here.