Buzz Aldrin walks on the surface of the moon during his historic 1969 mission. (Neil Armstrong/NASA via Associated Press)

Question for Buzz Aldrin: Weren’t you scared, in that little spacecraft, descending to the surface of the moon and not knowing for sure that you’d ever make it back to Earth?

“Fighter pilots have ice in their veins,” Aldrin answers. “Fear is a disabling emotion. It prevents you from thinking clearly.”

Sunday will mark the 45th anniversary of the moment the world heard those amazing words from Aldrin’s Apollo 11 crewmate, the late Neil Armstrong — “Tranquility Base here. The Eagle has landed.” — that marked the first lunar landing.

Aldrin, now 84, is making much of the anniversary. In a telephone interview, he said he hopes to drop into the White House and also hopes President Obama will use the anniversary to announce new ambitions for NASA and human spaceflight. Aldrin wants to see humans travel to Mars — and stay, permanently, something he thinks the U.S. government could accomplish in an international partnership that could include China.

He’d like Obama’s successor to use the 50th anniversary of the landing — July 20, 2019 — to say something Kennedyesque, such as, “I believe that this nation should commit itself within two decades to leading international permanence on the planet Mars.”

American astronaut Neil Armstrong became the first man to walk on the moon 45 years ago, as part of NASA's Apollo 11 mission. Here's a look back at six compelling moments from America's successful manned moon missions—from a lightning strike to golf balls in space. (Jason Aldag/The Washington Post)

Not for a billionaire

Could someone like SpaceX’s Elon Musk — who has said he’d like to go to Mars — pull off a Mars mission to the Red Planet? “I don’t think it’s going to be a multibillionaire who does this,” Aldrin says. It’s too expensive even for a tycoon, he suggested.

The people who go must be prepared for it to be a one-way trip, living out their lives on Mars, he said. That’s more doable than round trips and would keep funding flowing to Mars exploration, unlike a flags-and-footprints stunt. “If we go and come back, and go and come back, I’m sure Congress will say, ‘Oh, we know how to do that, let’s spend the money somewhere else.’ And everything we will have invested will be sloughed aside,” he said.

Aldrin has launched a social media campaign featuring a YouTube video in which celebrities and scientists relay their memories of Apollo 11. “I feel we need to remind the world about the Apollo missions and that we can still do impossible things,” Aldrin says in the video. “The whole world celebrated our moon landing, but we missed the whole thing, because we were out of town.”

Aldrin has spent the past 45 years as a living legend, and he creates a stir wherever he goes. His long-time assistant, Christina Korp, who used to work in the music industry, says, “I took this job to have a boring, quiet job. I had no idea what I was getting into. No rock star can hold a candle to Buzz Aldrin and his energy.”

In his book “Mission to Mars: My Vision for Space Exploration,” Aldrin recalls that his Mars ambitions weren’t shared by Armstrong, who thought the United States should focus on returning to the moon for longer-duration missions. (Armstrong, though taciturn by nature, became vocal in his final years about NASA strategy, and once sent me an on-background e-mail taking issue with a blog item in which I had been skeptical about a lunar return.)

Aldrin writes about past visits to the White House with his crewmates: “Conversation in some cases turned to where the next step into the future should lie: Return to the moon or on to Mars? For me, Mars. Neil disagreed. He thought that the moon had more to teach us before we pressed onward to other challenges.”

In his Mars book, Aldrin laments the passing of Armstrong and alludes to the obvious fact that the second man on the moon will never be as famous as the first: “My friend Neil took the small step but giant leap that changed the world, and he will forever be remembered as the person that represented a seminal moment in human history.”

Of NASA, Aldrin told me, “I believe that we are — in other people’s terminology — adrift right now. We cannot take our own people to the space station. We invested $100 billion.” (NASA pays Russia to launch American astronauts to the International Space Station.) “I am extremely concerned as a patriotic Cold War veteran and Korean War veteran that we remain Number 1,” he said. “We are adrift.”

Aldrin’s longtime friend, aerospace executive Norm Augustine, recalls being with Aldrin when he testified on Capitol Hill in favor of one-way missions to Mars.

 “Who would ever want to do that?” Augustine asked.

To which Aldrin quickly responded: “Did you ever hear of the Pilgrims?”