Space Exploration Technologies Inc. (SpaceX) has literally opened the door for routine commercial operations to the International Space Station, with an almost perfect demonstration mission that wrapped up May 31 with the splashdown of the Dragon vehicle off the coast of Mexico's Baja California.

The flight and ocean recovery of the spacecraft, with almost 1,400 lb. of “down-mass” cargo, marks the last of the nine-day mission's 33 objectives. Dragon flew under the banner of NASA's Commercial Orbital Transportation Services (COTS) program, initiated six years ago with the goal of turning responsibility for transportation to low Earth orbit over to the private sector, in lieu of a government-led effort to replace the space shuttle.

Although NASA's formal post-flight report is several weeks away, “at this point, it looks like a 100% success,” says Alan Lindenmoyer, NASA's COTS program manager.

The milestone mission triggers transfer of the final installment of $396 million in COTS assistance to the Hawthorne, Calif.-based SpaceX, founded a decade ago by PayPal co-creator Elon Musk. The flight also marks the start of a $1.6 billion, 12-mission space station resupply agreement NASA awarded to SpaceX late in 2008. Two of the missions are tentatively scheduled for this year.

Four companies, including SpaceX, are working with NASA under the Commercial Crew Development initiative to nurture at least two commercial crew transport services to the ISS by 2017. Orbital Sciences Corp., NASA's second COTS participant, plans a similar test flight of its Cygnus cargo carrier this year. However, the Cygnus will provide only “up-mass” delivery, burning up on reentry.