One of the last surviving men to walk on the moon has left this world for the last time.

Al Bean, the fourth man to set foot on the moon and a resident of America’s first space station, made a second career out of an interesting hobby. He became the only artist who ever painted pictures based upon his experiences and personal observations of another world.

Bean’s passing over the Memorial Day weekend -- a day before that of another astronaut, Don Peterson -- reminds us that only four of the dozen men who’ve set foot on the moon still walk among us on Earth. It also reminds us how dramatically America’s approach to space exploration has changed. Instead of giving us astronaut heroes like Bean, our government’s space policy now promotes eccentric tycoons like Elon Musk.

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Musk is best known for leading both Tesla, an electric car company, and SpaceX, a company that sells transportation to low-Earth orbit on its line of Falcon rockets. But he’s picked up a bewildering array of side gigs, everything from initiatives on artificial intelligence to brain-computer interfaces to his own line of flamethrowers. He also recently announced he’s “building a cyborg dragon.”

Musk is certainly entertaining. But his activities seem a bit less comical when one considers the immense responsibilities the people of the United States have entrusted to him through government subsidies and federal contracts. And unlike Al Bean’s artistic pursuits, Musk’s second career is underwritten with taxpayer dollars — an estimated $4.9 billion according to the Los Angeles Times.

Musk is at the leading edge of a trend in national space policy emphasizing the private sector. The thinking goes that NASA, long starved of sufficient resources to conduct manned exploration of space, ought to yield a bit to entrepreneurs like Musk. SpaceX and similar companies will take over activities in low-Earth orbit so NASA can focus on truly aspirational missions, such as a mission to Mars.

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It is a model that these pages have supported in the past in hope that, with the private sector taking over routine missions, NASA would be free to explore deeper into space.

SpaceX has indeed done amazing things, and it has generally performed well. Its reusable boosters are a genuine innovation, and the company’s plan to launch rockets from Brownsville is an exciting prospect for Texas.

But time has started to show us the limits of this approach. The highest expectations of the turn to commercial space exploration do not appear to be coming to pass, and it has not been a boon for Houston.

NASA appears just as starved of resources as before, despite the omnipresent talk among politicians of returning America to the moon and beyond. It’s just that now, some of the funding goes to SpaceX and to Musk. That money may well help Musk build a thriving business that helps humanity in other ways, but the space agency itself is still stuck in low gear. Musk would like to help solve that problem, representatives of SpaceX recently told Congress, by securing more public money for the company to fund missions beyond Earth and canceling NASA’s future rocket platform. In other words, SpaceX has made clear that its plan is to supplant NASA, not aid it.

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It’s a plan that Texas’ own politicians, like Senator Ted Cruz, seem to support — he convened the hearing at which SpaceX made its pitch.

There are arguments to be made for and against the proposition that NASA’s core responsibilities should be privatized, but Houston’s interest is clear. For more than 50 years, the Johnson Space Center has been the city’s guarantor of glory, one of its greatest assets. When it arrived, Houston was reborn. The Colt .45s became the Astros and the city stepped into the future. Now the Astrodome is a shell, the generation of astronauts who walked on the moon is dying, and the memories of the Apollo program are fading.

We’re at an inflection point. The nation can preserve the idea of a people’s space program, piloted by men and women like Bean, with Houston at its center. Or it can relinquish the nation’s space heritage to billionaires like Musk.