SpaceX has completed testing of the Falcon 9 rocket's propulsion system as launch preparations get underway at the company's Cape Canaveral launch site for the vehicle's first flight.

The Falcon 9 second stage fires in Texas on Saturday. Credit: SpaceX

The Falcon 9 rocket's second stage was fired for five-and-a-half minutes Saturday at SpaceX's test facility in McGregor, Texas.

"The SpaceX team kicked off 2010 with the successful full duration orbit insertion firing of the Falcon 9 second stage at our Texas test site," SpaceX founder Elon Musk wrote in a posting on the company's Web site.

Powered by a kerosene-fueled Merlin engine modified for use in space, the second stage was the final major piece of the rocket to go through pre-flight testing in Texas.

"This was the final stage firing required for launch, so the second stage will soon be packaged for shipment and should arrive at Cape Canaveral by the end of the month," Musk wrote.

First stage engine testing was finished in October.

SpaceX had reserved a Feb. 9 launch date on the Air Force's Eastern Range, a network of tracking and communications sites for missions from Cape Canaveral. But Musk's update suggests liftoff would likely occur no earlier than March.

"Depending on how well full vehicle integration goes, launch should occur one to three months later," Musk said.

When the second stage arrives in Florida, it will join the Falcon 9's first stage and Dragon payload inside a hangar at Complex 40 on Cape Canaveral Air Force Station. Those components were shipped to the launch site in the last few months.

Engineers have attached the first stage to the carbon composite interstage adapter in the Complex 40 hangar, and SpaceX says propulsion and avionics testing continue at the launch site.

Workers are also finishing wiring inside the interstage in preparation for the integration of the second stage, according to SpaceX.

The Dragon qualification unit is assembled at Cape Canaveral. Credit: SpaceX

The payload for the Falcon 9's maiden flight will be a stripped-down version of SpaceX's Dragon capsule, a vehicle being developed to ferry cargo to the International Space Station.

The Dragon qualification unit will be shot into a 155-mile-high orbit and will send back telemetry, but the spacecraft will not maneuver in space, Musk told Spaceflight Now last fall.

Musk also said the vehicle will not carry a propulsion system or an avionics suite.

Final integration of the Dragon unit has already begun, including the mating of the capsule to the trunk, a service module that will contain spacecraft systems and unpressurized cargo on operational missions.

The second Falcon 9 launch, slated for flight this summer, will send a fully-equipped Dragon vehicle into orbit for a four-and-a-half hour shakedown flight that will end with a parachuted splashdown in the Pacific Ocean.

Launch pad equipment has also been constructed and tested, including the launch mount, helium and nitrogen systems and a payload environmental control system. The sound suppression water system and transporter-erector have also been checked to ensure they are ready for launch.