Washington  - The Apollo 11 command module sits amid artefacts at a museum in Washington, a relic of the past that continues to draw tourists, including many too young to remember the date man first landed on the moon - July 20, 1969.

Forty years later, the National Aeronautics and Space Administration (NASA) hopes that moon landings will move out of the history books to become part of the United States' future.

The US space agency is well on its way to putting man back on our nearest celestial neighbour - if political will and funding hold out.

Much has changed since those first iconic images were beamed back to Earth. The US is no longer locked in a fierce space race with what was then the Soviet Union. US astronauts live full time aboard the International Space Station alongside their colleagues from Russia, Japan, Europe and Canada.

But the moon continues to fascinate NASA and space buffs who hope a return is imminent, even as President Barack Obama has ordered an independent review of all manned space flight, including plans to return to the moon, with results expected later this summer.

As the Earth's nearest celestial neighbour, scientists see the moon providing clues about our own past as well as a trying grounds for future exploration of the universe.

"I can remember how excited people were when Neil and Buzz walked on the moon and Mike circled the moon and what a shock it gave the nation at a time when it really needed it," said Norman Augustine, who is leading Obama's independent panel to reassess human space flight.

"And as I travel abroad and talk to young people in this country I think there's still a lot of excitement."

NASA is three years into the development of the Constellation programme of next-generation spacecraft set into motion by former president George W Bush.

This summer, NASA plans to conduct its first tests of the Ares I-X rocket and have a preliminary design review of the Orion, the next- generation spacecraft that will replace the ageing space shuttle and enable moon travel, said Doug Cooke of the Constellation programme.

NASA hopes to have it fully operational by 2015 and again on the moon by 2020, 51 years after man first set foot there.

Not everyone thinks a return to the moon is prudent.

"I don't think there's a purpose to back," said Bill Whitton, a Missouri resident who had just finished telling his 10-year-old son about the historic event while viewing the capsule at the Washington museum that carried the Apollo 11 astronauts to the moon. "It would just be for entertainment reasons."

Even some big names in space flight have raised a critical voice. Edwin "Buzz" Aldrin, who along with Neil Armstrong landed on the moon for the first time 40 years ago, recently told the New York Times he thinks there is little further value in the moon, and that NASA should instead focus on Mars.

The moon "is not promising for commercial activities. It's got science, it may have strategic values but I don't believe it's a requirement for Americans to be present to take advantage of the resources. Their viability can be determined by robots," he said.

As NASA presses forward, one of the first public manifestations of the new focus on the moon was the launch last month of two satellites to send data back to NASA to help scientists find the best location for a spacecraft landing.

The Lunar Reconnaissance Orbiter (LRO) is circling the moon, taking the most detailed images yet of the lunar surface, creating three-dimensional maps that are accurate to within one metre, showing details as small as boulder.

The Lunar Crater Observation and Sensing Satellite (LCROSS) will focus on determining whether water could be hidden in the shadowy craters of the moon near its poles. An earlier lunar satellite found high levels of hydrogen in the atmosphere near the poles, a hint that water could be present.

But NASA doesn't want to stop where it's already been. It hopes to establish long-term lunar bases on the moon's poles, where humans have never set foot, for a launching place to even further afield - perhaps Mars.

The red planet was at the back of everyone's mind when designers drafted the Orion spacecraft, which was destined not only for the moon but eventually for Mars, the programme's Jeff Hanley told the review panel at a public meeting last month.

Orion is a throwback to the Apollo missions with a capsule boosted aloft either on an Ares I or Ares V rocket, unlike the space shuttle, which is more similar to an airplane in its design.

A key consideration in designing Orion is safety - a constant problem for the shuttle after two tragic accidents in 1986 and 2003.

The Orion will also be more robust than Apollo with more lift power than any previous craft and the ability to carry more astronauts to the moon for longer durations, Hanley said.

The challenges of the next trip to the moon aren't just technological. First, it must overcome Obama's review. Budget constraints amid the ongoing economic turmoil can hamper the kind of massive spending space flight relies on.

Obama's current budget requests would decrease funding for the Constellation programme by 3.4 billion dollars over four years. But that request could be increased after the independent review results are published and presented to Congress in August.

Despite the questions, the administration says the president is commited to space exlporation.

As the US examines its manned space flight programme, review chairman Augustine notes the monumental financial challenges that must be taken into account, but still says it has the power to inspire future generations.

"My two small grandchildren, the things that excite them the most are space and dinosaurs - and we're very short on dinosaurs," he said. (dpa)