Four decades ago, NASA's Launch Complex 39A was at the center of the Cold War race to the moon.

Now the mothballed launchpad at the Kennedy Space Center in Florida, which dispatched Neil Armstrong and his crew on their historic Apollo 11 mission in 1969, is the focus of a battle of another sort, between two billionaire techies seeking to dominate a new era of private space flight.

NASA had hoped to turn over maintenance of the pad to a private company by October 1, saving itself $100,000 a month in maintenance costs, according toNASA spokeswoman Tracy Young.

Instead, fierce competition for control of the pad by digital entrepreneurs Elon Musk and Jeff Bezos has led to a government probe and congressional lobbying, delaying NASA's choice of a partner.

Musk's 11-year-old Space Exploration Technologies, known as SpaceX, already has two U.S. launch sites for its Falcon rockets at Florida's Cape Canaveral Air Force Station and California's Vandenberg Air Force bases.

Musk, the co-founder of Paypal and chief executive of electric car maker Tesla Motors Inc, also plans to build a site, probably in Texas, for commercial launches and wants Pad 39A for Falcon rocket launches to ferry cargo and possibly astronauts to the International Space Station for NASA.

Blue Origin, the company formed in 2000 by Amazon.com Inc. founder Bezos, is working on a suborbital reusable spaceship called New Shepard. A smaller test vehicle made a debut flight in 2006 from a company-owned site in west Texas. A second test vehicle flew in 2011.

Last October, Blue Origin tested a crew capsule developed in part with NASA funding.

Two weeks ago, Blue Origin, based in Kent, Washington, filed a protest with the U.S. Government Accountability Office over the NASA solicitation for Pad 39A proposals. The GAO is scheduled to rule on the dispute by December 12.

SpaceX told NASA it had no problem with other companies using the launchpad if SpaceX was awarded a five-year lease. However, Musk says SpaceX is light-years ahead of the competition.

"I think it's kind of moot whether or not SpaceX gets exclusive or non-exclusive rights for the next five years. I don't see anyone else using that pad for the next five years," Musk told Reuters.

"I think it's a bit silly because Blue Origin hasn't even done a suborbital flight to space, let alone an orbital one. If one were to extrapolate their progress, they might reach orbit in five years, but that seems unlikely," he said.

SpaceX Falcon 9 rockets have flown six times, including a test flight on Sunday of an upgraded booster designed to deliver heavier payloads into orbit. They are being developed to fly back to the launch site for re-use.

SpaceX has a backlog of more than 50 customers for Falcon rocket launches, including 10 more cargo runs to the International Space Station for NASA and satellite launches for commercial firms and foreign governments. The company also has two U.S. Air Force launches that are considered trial runs toward potential bigger contracts.

Blue Origin plans to evolve its rockets and spaceships for orbital flight as well and has proposed running Launch Complex 39A for multiple users while it continues to develop its technology.

"Blue Origin has been looking at various sites for our orbital launch operations for a number of years. We started talking to NASA Kennedy Space Center in 2008," company President Rob Meyerson told Reuters.

The company would modify 39A for other users as early as 2015, with plans to fly it own rockets from there in 2018, he said.

Among the firms backing Blue Origin's proposal is United Launch Alliance, a partnership of Lockheed Martin and Boeing whose monopoly on flying U.S. military satellites is threatened by upstart SpaceX.

Each bidder has sought congressional support. Blue Origin's plan has the backing of Frank Wolf, a Virginia Republican who chairs the House subcommittee overseeing NASA funding. Wolf and other legislators including Senator Patty Murray, a Democrat from Blue Origin's home state of Washington, and Representative Robert Aderholt, an Alabama Republican, warned NASA about granting an exclusive use agreement for the launchpad.

Florida's bipartisan congressional delegation countered with a letter to NASA Administrator Charles Bolden encouraging the space agency to ignore outside pressure in selecting a proposal.

Launch Complex 39A is one of two launchpads built by NASA in the 1960s for the Apollo moon program and later modified for the now-retired space shuttles. The U.S. space agency is keeping a sister launchpad, 39B, for a planned heavy-lift rocket known as the Space Launch System.

NASA spokeswoman Young says the agency can't comment on the bids. (Reuters)