(Photo: NASA / HANDOUT EPA)

Now, a group of former NASA executives is trying to make it back to the moon, and some space experts say they've got the brains and the business plan to do it.

Startup Golden Spike on Thursday announced its plans to fly spacecraft to the moon by 2020. The price tag: $1.5 billion roundtrip for two people.

The two men in charge of it have lofty resumes. Gerry Griffin, the Chairman of the Board, is a former director of the Johnson Space Center in Houston. President and CEO Alan Stern is a former head of NASA's science mission directorate.

Stern told Today in the Sky that the Colorado-chartered venture should be able to start operations with about $8 billion. To keep costs down, the company plans to partner with other private companies that have already developed rockets and capsules. All they have to come up with is a lunar lander and spacesuits.

Rather than target wealthy individuals who want to go to the moon, Golden Spike is going after nations that can't develop their own spacecraft to get there.

"The news here is, wow, we can go back to the moon, and American industry is coming up with ways to the moon a lot sooner than we thought," said James Muncy, president of the space policy consulting firm PoliSpace in Alexandria, Va.

NASA relinquished its near- monopoly on U.S. space transportation by retiring the Space Shuttle program last year. Since then, at least a dozen private companies have emerged to build spaceships to replace the shuttle's duties.

Last Spring, private firm SpaceX came the closest when its Dragon spacecraft made a successful cargo flight to the International Space Station.

But no company has set out to send humans into space until Golden Spike, whose name refers to the gold spike that completed the transcontinental railroad in 1869.

"The time is right," Stern said. "Five years ago, even three years ago, we didn't have the private space capsule and rockets to make this work … And I think five years from now we will be in catch-up mode with our competition."

Muncy said the technology already exists to make trips to the moon. Private companies have developed rockets and spacecraft that can make it to the moon with some adjustments, he said.

Much of that has been done with NASA funding, said Jonathan Card, executive director of the Space Frontier Foundation.

"The pieces have all been built largely with various aspects of NASA money, as part of NASA contracts," he said. "The pieces are already in place."

At a press conference, Golden Spike said getting to the moon would require four separate launches. During the first two, existing rockets would propel spacecraft and the lander into the moon's orbit. The second two launches would deliver the people to the lander.

David Livingston, host of popular Internet radio program The Space Show, said he had confidence in Golden Spike's leaders. "They're really tops of the tops," he said.

Still, they face significant challenges, Livingston said.

For one, the rockets and capsules they will rely on to get them to the moon, such as United Launch Alliance's Atlas V and SpaceX's Falcon Heavy, are still being tested and developed.

Secondly, they are raising money for the venture in a weak domestic and global economy.

Lastly, they don't know what regulatory hurdles they could face from the U.S. Congress. "The regulatory world for space is still a little bit of an unknown," Livingston said. "They're really braving a new world here."

Muncy said the other unknown factor is how big the company's clientele will be. "The question is will the countries actually sign up?" he said.

But Stern said he wasn't worried. "We're very confident in our numbers," he said. "I've been doing this my entire life and we have the best people in the world."