The moon, a thin crescent, hovered in the western sky like a crystal bowl ready to catch a falling star. Cheers filled the air as Newt Gingrich’s campaign bus eased out of the parking lot of the Holiday Inn Express. He had just made an astonishing vow: By the end of his second term as president, the U.S. flag would once again be planted on the moon. America, he said, would have a permanent lunar base.

Gingrich’s speech Wednesday created big headlines Thursday on the Space Coast. People here have been eager to hear some launchin’ words.

The question is whether this is science fiction.

“I think it’s an aggressive mission,” said Robert Whelan, an aerospace executive with Harris Corp. That was his polite way of saying that building a lunar base by January 2021 — or even putting a single human bootprint on lunar soil — would be difficult to achieve.

Gingrich proposed doing this without increasing NASA’s budget. Instead, he’d transform the agency’s culture, rely heavily on private industry and leverage American ingenuity. He said he’d use 10 percent of the NASA budget — which would amount to nearly $2 billion a year — to create prizes, incentives for entrepreneurs to achieve spaceflight milestones.

Edward Ellegood, a space policy analyst at Embry-Riddle Aeronautical University, agreed with Whelan: “It’s very, very aggressive.” He said the prize-money strategy probably wouldn’t work for such an ambitious mission. “Prizes at that scale don’t work very well,” he said.

Mitt Romney blasted Gingrich’s moon base idea during the presidential debate Thursday night, saying, “That’s an enormous expense,” and suggesting Gingrich has been pandering to voters by making budget-busting promises at every campaign stop. He added, “It may be a big idea, but it’s not a good idea.”

Rick Santorum echoed that sentiment: “To go out there and promise new programs and big ideas, it’s a great thing to maybe get votes, but it’s not a responsible thing.”

Gingrich stuck to his guns, saying his program would be “90 percent private sector” and he’d like to see space flight become so common that there would be “six or seven launches a day.” He added: “I’d like to have an American on the moon before the Chinese get there.”

This has been a painful period for the Space Coast. People here launch spaceships — or at least they did until last summer, when the space shuttle was retired after 30 years of service. Unmanned rockets still blast off from the Air Force base at Cape Canaveral, but the end of the shuttle program has meant a dramatic reduction in highly specialized engineering and technical jobs.

President Obama killed NASA’s Constellation program, created during the Bush years as a successor to the shuttle program.

Instead, the administration placed a bet that commercial spacecraft will, in a few years, carry astronauts to the international space station.

Gingrich frequently attacks Obama in his stump speeches, but in the space talk he didn’t mention him. Gingrich has been a vocal supporter of the president’s efforts to privatize elements of the space program. The Gingrich strategy essentially takes the Obama approach and runs with it.

“You could call it the Obama-Gingrich model if you want. Gingrich is doubling down on Obama,” said Charles Miller, a space industry consultant who until recently was a NASA official working on commercial spaceflight.

Obama has endorsed a manned mission to a near-Earth asteroid, with Mars remaining, as ever, the long-term objective of human spaceflight. But the president has not made space a major element of his political agenda.

Congress has insisted that the administration speed up efforts to build a new, heavy-lift rocket for deep-space exploration. That is still years away. In the meantime, no one’s going anywhere, at least not in this part of the world. U.S. astronauts can get into orbit only when NASA purchases seats for them on a Russian spacecraft.

With NASA in this awkward transition, there’s a market for a big-idea candidate who has a passion for space. But small-government advocates may see a Gingrich-style moon mission as another example of big-government overreach.

People in the audience Wednesday night liked what they heard. Gingrich spoke without notes, throwing in personal history (how he read Isaac Asimov novels and Missiles and Rockets magazine as a kid), and bluntly declaring his disappointment with what’s happened to the Space Age dream.

“I come at space from a standpoint of a romantic belief that it really is part of our destiny. And it has been tragic to see what has happened to our space program over the last 30 years,” said Gingrich.

His vision of a moon base is distinctly American, even though space missions in recent decades have often involved international collaboration. Gingrich went so far as to bring up a proposal he made when he was a young congressman to create a “Northwest Ordinance” for space in which, as soon as 13,000 Americans lived on the moon, they could petition to become a state.

“Probably the best speech I’ve heard in this political season so far. Visionary,” said John Weiler, 67, a retired shuttle worker.

“What they blame Obama for is not having a vision,” said David McLaughlin, 53, a NASA technician.

About 700 people showed up for the speech, with many forced to wait outside, listening over loudspeakers. Gingrich provided a lesson in American progress and associated himself with some of the great names of American leadership and innovation. He spoke of Abraham Lincoln standing on the bank of the Missouri River in Council Bluffs, Iowa, in 1859, endorsing the construction of an intercontinental railroad. Lincoln, Gingrich said, had advocated railroad construction since long before he ever saw a train.

“I would just want you to note: Lincoln standing at Council Bluffs was grandiose. The Wright Brothers standing at Kitty Hawk were grandiose. John F. Kennedy was grandiose. I accept the charge that I am grandiose and that Americans are instinctively grandiose,” he said.

As he closed his speech, he hinted that historians would note what was said here on January 25, 2012, at the Holiday Inn Express off I-95 in Cocoa, Fla.

Someday, he told his supporters, they’d be able to say that they’d been there “at the beginning of the second great launch of the adventure that John F. Kennedy started.”