in the 1970s NASA shelved the mighty Saturn V launcher, along with the lunar module, lander and return capsule - and with this we lost the capability to send people beyond Earth orbit.
Credit: NASA
Forty years later, the sad truth is this: today, we do not venture beyond our own backyard. Our travelling horizon lies no farther than the International Space Station (ISS), some 350 km above us.
The two pioneers of manned space flight, Russia and America, have been joined by China, but so far it has done no more than replicate their brief low-orbital trips of nearly half a century ago.
While robots do all the real exploration of space, humans are stuck in a rut, says Francis Rocard, an astrophysicist in charge of Solar System exploration at France's National Centre for Space Studies (CNES).
"There is a deep disinterest around the world for manned flight today, including in the United States," he says. "There's boredom with the flights to the ISS, which nobody finds interesting, neither the media nor the public."
1969 was styled as the 'giant leap' that would take us to other worlds. But, in retrospect, was it the year when we peaked? Experts say there are several reasons why our expectations have slowly deflated like a wrinkled balloon.
The biggest, is that there is no longer any rivalry between superpowers – and without it the almost limitless cash for manned spaceflight has dried up.
Fearing Moscow's domination of space, the U.S. pumped more than 5% of its federal budget into NASA in the mid-Sixties. At the program's peak, more than 400,000 people worked on the Apollo program.
"We didn't go to the Moon for Teflon pans or lunar rocks. We went to the Moon to beat the 'dirty commies'," is how Bill Anders, Apollo 8 astronaut, has described it. After America won the lunar race, public interest waned – along with NASA's budget.
The last three Apollo missions were axed, leaving Apollo 17, in December 1972, to close this golden age of achievement.
With it came a crossroads decision on where to go next. Other worlds, even nearby Mars, were just too far away. Using slow, chemical rockets, it would be too dangerous and too expensive to send people there, and there was little point in building an outpost on the lifeless, waterless Moon.
So NASA shelved the mighty Saturn V launcher, along with the lunar module, lander and return capsule.
In their stead came the space shuttle, based on the notion – which proved horribly wrong – of providing a cheap, reliable form of reusable transport for a hefty payload.
But the shuttle had nowhere to go but loop around Earth, a few hundred kilometres from home. Just as Nature abhors a vacuum, so do space budgets: the ISS handily emerged to give the craft a new role.
The tandem programs have been badly hit by budget overruns and delays, however. The loss of two shuttles prompted the plan to retire the fleet of vehicles next year, leaving the U.S. with no manned spaceflight capability until perhaps 2015.
These problems help explain the caution that today surrounds project Constellation; former U.S. president George W. Bush's goal of returning to the Moon by 2020 and thereafter venturing to Mars.
Unless President Barack Obama opens up an Apollo-style spigot, NASA will be 100 billion dollars light on how to achieve the 2020 target, says Rocard.
The space agency faces surging budget demands to build a rocket-and-capsule successor to the shuttle and extend the operational life of the ISS beyond 2015. Europe, its fingers burned by the ISS experience, is lukewarm about contributing.
Mike Griffin, who stepped down as NASA boss this year, bitterly regrets the crossroads decision of the 1970s.
Had the Apollo technology been retained and nurtured, the U.S. could be carrying out six manned flights each year, two of them to the Moon, and building a low-cost ISS by adding to the Skylab orbital station, all for 6.3 billion dollars a year, Griffin calculates.
"If we had done all this, we would be on Mars today," he said in an essay published in Aviation Week in March 2007. "We would have decades of experience operating long-duration space systems in Earth orbit, and similar decades of experience in exploring and learning to utilise the Moon."
Jacques Arnould, a French researcher, says going beyond low Earth orbit requires international cooperation to help share costs that are beyond that of a single nation, however rich.
"Making it work is not as easy as it sounds," he cautions. "But it would be the sign of something we need, of cooperation between humans rather than rivalry."
Richard Ingham is a writer for the AFP news agency, based in Paris.
