WASHINGTON -- SpaceX and NASA are in advanced discussions for the private space firm to use Kennedy Space Center's pad 39A, one of the spaceport's Apollo and space shuttle launch sites, as the Florida base for its Falcon Heavy rocket, officials said.

Artist's concept of the Falcon Heavy rocket. Credit: SpaceX
 
NASA and SpaceX are studying how to assemble and launch Falcon Heavy rockets from pad 39A, including adding a facility to horizontally integrate the launcher's core stage, two strap-on boosters and upper stage, according to William Hill, assistant deputy associate administrator for NASA's exploration systems division.

With 28 liquid-fueled core, booster and upper stage engines, the Falcon Heavy rocket is a behemoth booster designed to launch human and robotic exploration missions, massive U.S. military satellites, and huge payloads for commercial clients at competitive prices. Its first demonstration launch from California is scheduled for 2013.

SpaceX plans to piece the rocket together on its side, then roll it to the launch pad and lift it vertical before liftoff. Fully fueled and assembled for launch, the Falcon Heavy will weigh 3.1 million pounds and stand 227 feet tall, according to SpaceX.

"KSC did an assessment of options for SpaceX to consider relative to their non-exclusive use of pad 39A," said Michael Braukus, a NASA spokesperson, in an email to Spaceflight Now. "KSC is currently in a second round of more detailed discussion; however, no decisions have been made by either NASA or SpaceX at this time."

The space agency has been looking to turn over some of its mothballed shuttle infrastructure to commercial programs, and one of the space center's three orbiter hangars will be home of final assembly and testing for a Boeing crew capsule bidding to ferry astronauts to the International Space Station.

Part of the Vehicle Assembly Building, the shuttle's mobile launch platforms, and the KSC runway are also available to commercial entities.

Artist's concept of the Falcon Heavy rocket. Credit: SpaceX
 
Kirstin Grantham, a SpaceX spokesperson, said pad 39A was one of the launch sites being considered for the Falcon Heavy. Grantham did not say what other sites were being evaluated.

According to Braukus, NASA is not currently in discussions with any other company regarding the use of launch pad 39A.

The Falcon Heavy's first launch will be from Vandenberg Air Force Base, Calif. SpaceX is modifying Space Launch Complex 4-East at Vandenberg to host missions of the firm's medium-lift Falcon 9 rocket beginning as soon as late 2012.

SpaceX says the Falcon Heavy's first flight from Vandenberg, a demonstration mission, is set for 2013.

There are no Falcon Heavy flights on SpaceX's manifest from Florida, but the company will need an East Coast launch site for interplanetary missions. SpaceX has not announced a contract for further Falcon Heavy launches beyond the 2013 test flight.

Complex 40, SpaceX's Cape Canaveral pad for its Falcon 9 booster, is not configured today for the Falcon Heavy, which will thunder off the launch pad on the power of 27 kerosene-burning Merlin engines, cumulatively generating 3.8 million pounds of thrust.

File photo of a space shuttle on launch pad 39A. Credit: NASA/KSC
 
Since the final space shuttle launch from pad 39A in July 2011, NASA has kept the facility in its current configuration to await a decision on its future.

The fixed and rotating service structures at pad 39B, the space center's other shuttle launch complex, were demolished to make way for NASA's government-run heavy-lifter, which will haul more than 154,000 pounds into low Earth orbit in its basic version.

The Space Launch System's first test flight from pad 39B is expected by the end of 2017. NASA is developing the monstrous 32-story rocket to launch human expeditions to asteroids, the moon, the vicinity of Mars, and other destinations in deep space.

SpaceX's Falcon Heavy rocket has a payload capacity of 117,000 pounds to low Earth orbit, more than twice the lift capability of any other existing launch vehicle, but still less than NASA's Space Launch System.

SpaceX claims each flight of the Falcon Heavy will cost between $80 million and $125 million. There are no NASA cost estimates for a single Space Launch System mission, but officials expect it may be about $1 billion.