When Neil Armstrong took his “one small step” on July 20, 1969, the future of manned space exploration seemed bright — yet the moon has spun untrampled by humans since Apollo 17 blasted off in December 1972.

Fifty years after Apollo 11’s triumph, however, a new space race is ramping up to put boots back on the moon.

“The current directive that’s been given to NASA is to return to the moon by 2024,” said Vahe Peroomian, associate professor of physics and astronomy at the University of Southern California. “I don’t know if 2024 is doable, but within the decade is definitely doable, at least by the US.”

But while America may have pole position in the new space race, she’s facing far more competition now than in the ’50s and ’60s, when the Soviets were the only other serious competitor.

A crowded field of nations is funneling funding into space exploration with an interest not seen since manned missions were scaled back beginning in the ’70s due to hand-wringing over sky-high price tags and dangers to astronauts.

Japan earlier this year inked a contract with auto giant Toyota to develop a six-wheeled lunar rover for eventual use in manned moon missions.

The Israel Space Agency, bankrolled by private funding and working in collaboration with NASA, attempted to land a robotic probe on the moon in April, but the craft crash-landed on the lunar surface when a gyroscope failed.

As recently as July 15, India was poised to launch its second unmanned mission to the moon, only to abort the launch less than an hour before liftoff due to a “technical snag.”

The biggest threat to America’s exclusive hold on the mantle of manned missions to the moon, however, is China.

“They are pouring money into their space program like there’s no tomorrow,” said Peroomian, noting that China recently completed construction of the world’s largest radio telescope. “If we do not ramp up things to go to the moon, they may actually beat us.”

Whichever nation next sets foot on the moon, they will likely have eyes on staying.

“The current US plans call for a station to be built on the moon,” said Peroomian.

A permanent foothold would facilitate more in-depth scientific study, while also serving as a way station for the next stop: Mars.

“The spaceship that will take us to Mars will either be built on the moon or in orbit,” said Peroomian.

A manned Mars mission had long been viewed as the natural encore to the lunar landing — Vice President Spiro Agnew called for a flight to the Red Planet even as Apollo 11 was en route to the moon — but the proposal quickly became another casualty of waning public and government interest.

“We’ve had plans to send astronauts to Mars for 40 years,” said Peroomian. “But the willingness hasn’t been there.”

If — or when — the Mars mission comes, it could be a joint venture between a nation and a private company, such as Elon Musk’s SpaceX or Amazon mogul Jeff Bezos’ Blue Origin, according to Peroomian.

Regardless of where it comes from, a new giant leap in space exploration is needed to spark the imagination of a world now a half-century removed from Apollo 11, said Peroomian, who formerly worked with NASA.

“I was inspired by the Apollo moon landings,” he said. “I don’t see my kids inspired by events that are happening in that arena.

“And I’d like to see them inspired.”

With Post wires