Plans for docking the private unmanned SpaceX Dragon at the International Space Station are running behind.
The Dragon is now set to hook up with the International Space Station later this morning, becoming the first commercial visit to do so.
The space station will capture the Dragon capsule with a robot arm.

Connecting to the space station Friday will require NASA's approval in a staged approach that the statement called "the most difficult aspects of the mission."

Only after a series of maneuvers and tests are successful would the Dragon craft be allowed to approach the space station, and astronauts would "grapple Dragon with the space station's robotic arm" to complete the attachment, the statement said.

If the connection goes as planned, the space station crew will open Dragon's hatch Saturday, it said.

Under the mission plan, Dragon will remain attached to the space station for two weeks before it plummets back into the atmosphere and splashes into the Pacific Ocean off the California coast, according to SpaceX.

Tuesday's launch marked the culmination of six years of preparation to bring commercial flights to the space station after the retirement of NASA's space shuttle fleet last year. It's backed by entrepreneur Elon Musk, the founder of PayPal.

The Falcon 9 rocket that carried Dragon into orbit launched without a hitch Tuesday following a flawless countdown that came three days after a faulty valve on one of the rocket's engines forced a last-second postponement.

At 180 feet tall and 12 feet in diameter, the Falcon 9 rocket is tiny in comparison to the football-field-long Saturn V rockets that carried Apollo spacecraft into orbit.

The cargo manifest for the trip included 674 pounds of food, clothing and miscellaneous supplies, 46 pounds of supplies for use in science experiments, 271 pounds of cargo bags for use in future flights and 22 pounds of computer equipment.

It will return with science experiments, hardware and used gear.

Cremated human remains were placed in the second stage of the Falcon and will orbit the Earth. Celestis Inc. charges families $2,995 to launch 1 gram of remains in this type of memorial spaceflight.

NASA's Internet tool SkyWatch is providing information about viewing the Dragon from Earth.

The launch is an important step for NASA and the United States, which currently has no means of independently reaching space. NASA relies on the Russian space agency to ferry U.S. astronauts to orbit.

"What's really important is not control, as much as it is the fact that the United States will once again be in the lead, will be providing our own vehicles to take our own astronauts and cargo to the International Space Station," Bolden said. "It's fine to rely on partners, but that's not where the greatest nation in the world wants to be."

SpaceX is conducting the flight as part of a contract that could be worth as much as $396 million, according to company spokeswoman Kirstin Brost Grantham. The company has completed 37 of the 40 milestones in the contract and has received $381 million so far, she said.

Musk likened the significance of the launch to the growth of the commercial Internet -- from its underpinnings as a government initiative to the technological, economic and cultural engine it is today.

"I think we're at a similar inflection point for space," he said. "I hope and I believe that this mission will be historic in marking that turning point towards a rapid advancement in space transportation technology."

The first attempt to launch the rocket was halted Saturday when a flight computer detected high pressure in an engine combustion chamber. Workers replaced the valve Saturday, SpaceX said.

The company plans 11 more flights to the space station.

One of a handful of private companies receiving funds from NASA to develop a space taxi system, SpaceX hopes the experience with the cargo flights will help the company reach its goal of carrying astronauts aboard the Dragon.

The company is developing a heavy-lift rocket with twice the cargo capability of the space shuttle, and also dreams of building a spacecraft that could carry a crew to Mars.