The whole planet watched 40 years ago today, as two Americans became the first humans to set boots on the dusty, desolate surface of the moon.
Today, amid much celebration and remembrance of that achievement, it's easy to overlook something: We intend to go back. And maybe beyond.
NASA is deep into plans to return astronauts to the moon, and may send them to a destination that once was simply the realm of science fiction — Mars.
But while the 1969 moon shot was a national imperative, the new moon program elicits far more ambivalence, even from astronauts. A chorus of former astronauts and other experts is pushing the Obama administration to downplay those plans and focus more on getting humans to Mars.
Buzz Aldrin, who set foot on the moon 40 years ago, entered the debate last week as he strode into a celebratory news conference at the Kennedy Space Center with seven other astronauts from his era.
Aldrin reflected that it had taken only 66 years for humans to go from the first flight at Kitty Hawk to the first successful moon landing at a location called "Tranquility Base."
"Let's add 66 years to Tranquility Base and that's 2035. I certainly think we ought to have footsteps on Mars by that time," Aldrin said, sitting at a table with an Apollo capsule behind him. Aldrin said NASA's current plans of returning to the moon are "going back and doing what we did before. And to me that is not U.S. global space leadership."
He said going to Mars is difficult but not impossible. And Aldrin, 79, said so with a phrase reminiscent of 1969:
"It's not that gigantic a leap," he said.
After the glory days of Apollo, NASA's space shuttle era began in 1981. The shuttles fly astronauts into orbit, where they have performed countless experiments, released satellites, repaired the Hubble Space Telescope and spent years constructing the International Space Station. After the early years, the shuttles generally have failed to command the public's attention like some of the classic moon launches.
The Bush administration changed gears five years ago by preparing a new "Vision for Space Exploration," which called for sending astronauts back to the moon and on to Mars.
And it's under way. The space shuttle is scheduled to be retired in 2010 or 2011. A newly designed rocket called Ares will be flight-tested at Cape Canaveral this year. The prototype of a new spacecraft called Orion already is under development. Unlike the space shuttle, which glides back to Earth like an airplane, the new spacecraft will be an Apollo-like capsule that will parachute back to Earth, possibly coming to rest on land instead of in the sea.
In short, on this anniversary of the shining moment of the American space program, the United States is gearing up again to send astronauts beyond Earth's orbit, for the first time since Apollo.
But everything is different.
The new moon mission comes without the urgency of the Cold War that pitted the United States against the Soviet Union for space pre-eminence.
Also, with a faltering economy and looming national debt, there is no guarantee the new rockets will ever fire up.
And although the moon-to-Mars program remains official policy, the Obama administration recently named a panel to review the whole human space flight program.
Sen. Bill Nelson, D-Fla., is among those saying the United States should return astronauts to the moon. But he said such a mission should be a step along the way to the more important goal of sending humans to Mars.
After the review panel finishes its work, Nelson said the time would be right for President Obama to make his signature statement on the future of human space flight, "a clarion call like President Kennedy giving the vision and the goal and pointing out why that vision and that goal is important for the American people, and for the human race."
The space shuttle was designed as a kind of space truck, ferrying people and payloads into orbit.
The moon and Mars program is designed for exploration. A new journey to the moon, possibly as early as 2020, would enable astronauts to set up a lunar base for long visits, and also to look for possible ice on the moon's south pole.
"I would like to see us go back to the moon," former Apollo 16 astronaut Charlie Duke, a graduate of St. Petersburg's Admiral Farragut Academy, said in the news conference. "It's a place where we can start understanding long-duration space."
Howard McCurdy, a space policy expert and professor at American University, said the next journey to the moon would be designed as a first step, not a final step. "The moon now is like a base camp for a higher summit," he said.
There is plenty of work to be done developing technology and studying human physiology on a lunar base, to prepare astronauts for what could be a three-year round trip to Mars.
"We know how to get to the moon," McCurdy said. "That's easy, more or less. What's hard is going beyond the moon."
But that's what NASA should do, said Louis Friedman, who co-founded the "space advocacy" group the Planetary Society, along with Carl Sagan. He said he would like to see NASA take its current plan and "retool it so it's less of a moon program and more of a Mars program." His group wants to see astronauts go farther into space than ever before, to asteroids, and ultimately to establish a "human outpost" on Mars.
Nearly four decades have passed since Americans' last trip to another planetary body, in 1972, so not everyone is optimistic.
Norman Thagard, a former astronaut who logged 140 days in space on five missions, said "when I came to NASA in 1978, I really did think that before the end of my career we might send a mission to Mars."
Now Thagard, 66, who is associate dean at the FAMU-Florida State University College of Engineering, says "I don't see it happening in my lifetime, honestly. I wish it would."
Curtis Krueger can be reached at firstname.lastname@example.org or (727) 893-8232.