SpaceX continues to plan to debut the new Falcon 9 rocket by the end of this year, but company engineers are still qualifying some parts of the vehicle for the rigors of launch.

"We're not down to an exact date, but we are targeting the end of the year. And so far, so good," said Tim Buzza, SpaceX's vice president of launch operations.

The Falcon 9 rocket's first stage and interstage undergo testing in McGregor, Texas. Credit: SpaceX

Buzza said last week most of the 180-foot-tall launcher has passed qualification testing. A handful of components, including the second stage's Merlin vacuum engine, must still complete the extensive checks.

Everything should be qualified for flight in about two months, Buzza said.

"Between September and October, we'll have all of our hardware through. This is down to the detailed boxes, avionics boxes, primary structure, engines, all that stuff," Buzza said.

Space Exploration Technologies Corp., founded by Internet mogul Elon Musk in 2002, has conducted back-to-back successful flights of its small satellite launcher, the Falcon 1.

Those successes came after three consecutive launch failures to begin the program.

Company officials are careful to point out the Falcon 9 uses similar technology, but the new launcher is more than twice as tall and 25 times more powerful than anything SpaceX has flown before.

Pieces of the first Falcon 9 are stopping at the company's Texas test facility on the trek from California to the launch site in Florida.

"We're focusing on those first two flights and getting all that hardware moving from Hawthorne through Texas to the Cape," Buzza said.

The first stage tagged for the rocket's maiden flight is already in Texas after proof testing earlier this summer. The stage's aft section, which contains the Falcon 9's nine Merlin engines, will soon arrive in Texas for a series of ignition tests.

"We will mate those two together, and then we're going up on our large test stand for a series of static fire tests in a full flight configuration," Buzza said.

Officials hope to ship the flight-ready first stage to Cape Canaveral by the end of September. The second stage could join it by late October after completing its own round of tests, according to Buzza, who will serve as launch director for the inaugural mission.

When the first launch will occur is still unknown, but Buzza stressed SpaceX is still counting on flying by the end of this year.

"The first stage hotfire in Texas and the second stage hotfire in Texas are clearly the two big systems tests that get us to launch. As we pass through those successfully, that will dictate our launch date," Buzza said.

Workers will assemble the rocket inside a new horizontal integration building and lift the Falcon 9 on the launch pad for a fueling and countdown demonstration before continuing with the final launch campaign. The wet dress rehearsal will culminate in a static engine test at Complex 40.

SpaceX first shipped components of the Falcon 9 to Florida in late 2008, an exercise that gave officials practice in handling the booster, which is much larger than the company's Falcon 1 rocket.

Although some of that hardware was flight-rated, SpaceX transported the equipment back to California and Texas after several weeks of configuration checks.

Since then, engineers have been transforming the pad from abandoned real estate into a working launch complex.

Besides constructing the assembly hangar, SpaceX has outfitted the rocket's transporter and erector system with a network of electrical and fluid lines.

Kerosene and liquid oxygen tanks at the pad are already being filled with propellant and gaseous helium and nitrogen plumbing is currently being added to the launch mount.

"We're heading toward the finish line very quickly," Buzza said.