When I was very young, I witnessed the manned landings on the Moon and I thought it was the start of the future.
By Dr David Whitehouse
BBC News Online science editor
I was growing up reading Arthur C Clarke's science fiction novels and watching Star Trek and 2001:A Space Odyssey.
I believed that man would stay on the Moon, build a base there, construct vast wheel-shaped space stations where interplanetary ships could dock, and I expected planetfall on Mars not many years hence.
When I grew older and these things did not happen, when presidents were threatened with impeachment and the planet was being polluted, I realised that the science fiction gurus were too optimistic.
Their vision of the future may well be right 1,000 years hence, but they were wildly wrong about the near-term.
But perhaps the future needed to catch up with them, and perhaps it is starting anew.
More than science
In his speech at Nasa President George W Bush said: "Human beings are headed out into the cosmos," and it may be true this time.
The first President Bush made the same commitment in 1989, but his initiative was so costly, so ill-thought-out, that it folded under its own financial projections.
His son seems to have made a better job of sorting out the money. But even so, money will be a key problem.
The increased funding Nasa will be getting to put the new vision into place will not be great. It will have $86bn over the next five years - an increase certainly, but not a dramatic one.
Nasa will have to find billions from within itself by cutting research programmes that do not contribute to astronauts travelling and working in space. Consequently, there are many worried scientists who see their research in jeopardy.
Indeed, many scientists lambast manned spaceflight saying that unmanned probes do better science far more cheaply. But in doing so, they fail to recognise that what is being proposed here is bigger than science.
It is important that we explore and strive, and for humankind to become a multi-planet species. Our Earth will not be safe forever and, as the Americans have shown us all, leaving home revitalises and renews the human spirit. But back to the money.
The sum of all things
Should not the money be spent on earthly things, such as really exploiting the genetic knowledge in the human genome so that we can truly conquer disease and possibly the aging process?
Yes. But we should do it as well and not instead of. We have the money we need if we spend it wisely. Indeed, our return to the Moon and the voyage to Mars will only really mean something if we solve our problems on Earth as well.
Space exploration is only part of the sum of all things we must do.
I suspect that given a free rein, the Americans would immediately start scaling down the International Space Station (ISS) but instead they say they will honour their international obligations for the next few years but declare it built by 2010 and then retire the space shuttle.
This will mean that for four to five years, between 2010-2015, until Nasa's next manned spacecraft comes online, only the Russians and the Chinese will be able to put astronauts into space.
It is even possible that Nasa would take a back seat regarding the ISS after 2010. That will save a lot of money.
So it is from about 2008 onwards, with new missions to the Moon, and the development of a new manned spacecraft, that things will really start to seem different.
President Bush says he wants a Moonbase by 2020. Because the techniques and technology for a manned Mars mission are to be tested on the Moon, this has pushed the Mars mission to near 2030, I expect.
Most engineers believe that a Moonbase is technologically possible, especially if it is sited at one of the lunar poles where the ice in the soil would be a valuable resource for drinking water and rocket fuel.
There are also craters there that are in permanent shadow and could be used to protect crews from solar radiation flares.
And what an inspiration it would be. Imagine schoolchildren all over the world logging on to the Moonbase website for a lesson in science, or to view the long shadows and bright mountains of the lunar polelands on various webcams
- live from the Moon.
A generation has grown up since humans left the Moon; a generation that has never known a time when mankind went somewhere in space.
Perhaps, if this all works, future generations will not be so deprived, and the future many young minds have dreamed they were entering may actually come to pass.