SpaceX is poised to take a giant leap with the biggest rocket since the Saturn V carried men to the moon, and it could blast off by early 2013.

Elon Musk's private space startup announced Tuesday that the 22-story Falcon Heavy will carry more than 117,000 pounds into low Earth orbit, giving it twice the lift capability of the space shuttle or the Delta IV heavy rocket built by Boeing–Lockheed Martin. Musk says it'll be far cheaper, too.

"It's more capability than any vehicle in history apart from the Saturn V," Musk told reporters. "It opens up a range of possibilities for government and commercial space missions that simply aren't present with the current lifting capacity."

Musk, the CEO of Space Exploration Technologies, says the first launch will happen soon after the Falcon Heavy arrives at the company's launch complex at Vandenberg Air Force Base, California, late next year.

He estimates launching the 227-foot-tall rocket at $80 to $125 million, less than one-third the cost of the Delta IV and roughly one-tenth that of the space shuttle. If SpaceX stays within that cost, the Falcon Heavy will deliver payloads at the $1,000-per-pound benchmark long sought by the space industry.

"It's not so mythical anymore," Musk told reporters in Washington, D.C. He believes SpaceX will find customers eager to use the rocket. Analysts say he may be right.

"SpaceX has established credibility in the commercial market and with NASA," Tim Farrar, president of consulting and research firm Telecom, Media & Finance Associates, told the Los Angeles Times. "The Falcon Heavy is going to open more markets."

The cost savings comes as budgets for NASA and the Pentagon face increasing pressure and the government increasingly looks to the private sector to assist its space programs. SpaceX already has contracts with NASA to use the Falcon 9 rocket and Dragon spacecraft to deliver cargo to the International Space Station as early as the end of this year.

It's also another big step forward for Musk and SpaceX. The Falcon 9 became the first commercial vehicle to launch a spacecraft into orbit and have it return to Earth safely.

SpaceX also has contracts to deliver commercial satellites to orbit – including a $492 million deal with telecommunications firm Iridium Communications – but does not have any military contracts yet. So far, the military relies solely on United Launch Alliance, a collaboration between Boeing and Lockheed Martin.

The relatively cheap cost of the Falcon 9 and Falcon Heavy may help SpaceX break that monopoly. Musk has said the Air Force is interested in having SpaceX delivering payloads to orbit.

"There's no point in matching the competition," Musk said. "We want to steamroll them. We're trying to make this a complete no-brainer."

The Falcon Heavy will be used for cargo missions at first, but Musk said it is designed to meet NASA's human-rating standards – opening the door to missions to the moon or even Mars.

It is also being designed with reliability in mind. The first stage consists of three nine-engine cores. They are the same cores used to power the Falcon 9. The 27 engines will provide 3.8 million pounds of thrust at liftoff, and the mission can continue even if multiple engines fail.

The Saturn V that delivered 12 men to the moon – and another 15 to lunar orbit – could carry 262,000 pounds to low Earth orbit. Musk noted a mission to the moon could be staged with a pair of Falcon Heavy launches.

After an initial launch at Vandenberg, SpaceX says the Falcon Heavy should make its first launches from Cape Canaveral in late 2013 or early 2014.

Images: SpaceX