Why Has The World Not Built A Moon Base In All The Years They Have Traveled To Outer Space/the Moon?

In a word,  'MONEY'. Building a base on the moon may be technically feasible, and doing it may bring some short-lived sense of achievement, but these days, unless there are sound economic reasons for doing so, it just 'ain't gonna happen !

The moon landings have to be placed in their historical context. The USSR had already won the race to produce the 1st satellite (Sputnik 1 - 1957) and the 1st man in space (Yuri Gagarin - 1961). Following JFK's famous speech ("We choose to do these things ..." etc) , it became imperative for the USA's national pride that they be the first to put a man on the moon. Once that was achieved, interest kind of tailed off (watch the movie CAPRICORN 1 to see what I mean), and honour having been satisfied, the moon then took a back seat in favour of other space projects.

This is a very complex question, however being a contributor to the Space & Technology section of New Scientist I think I am qualified to answer this query.

In 2006, NASA had laid out plans to build a permanent Moon base. The agency's deputy administrator at the time, Shana Dale, was quoted as saying that NASA would put fourth the effort to develop rockets, landers, and the accompanying technology to land people on the Moon and establish a rudimentary manned outpost. The plan was to then allow other countries and private interests to expand on this outpost and develop the resources, sciences, and infrastructure to take advantage of their particular interests. Something Similar to the ISS, but not quite seeing as how they would allow private entities to take part. Said base would be established at one of the lunar poles, which would allow for year round sunlight, allotting for solar power production to be had 24/7. At the time, the projected start date for this would be ~2020, and by 2024 the manned portion of the base would go from housing astronauts for 180 days to permanently. Furthermore, by 2027, there would be pressurized transports available to take the base occupants on expeditions around the lunar surface. Of course, this all was projected to be rather costly @ roughly 17 billion US dollars per year.

Now, as of April 2009, NASA's new administrator Chris Scoles stated that they are talking about scrapping these plans. Instead, he stated that NASA will be focusing on other space missions such as a manned landing on Mars and/or some near-Earth asteroid. This isn't to say that NASA *WONT* go back to the Moon, but as it stands they are looking at much shorter trips (still by 2020 however). They are currently working on a pressurized lunar rover (something in which astronauts can drive around in without the aid of space suits) which will act as a mobile base for lunar explorers, allowing them to extend their stay for a week or longer without needing to return to earth. This in and of it self is a great leap forward from the previous manned moon missions.

Of course all of this hinges on NASA's future budgets. Something which looks promising given the Obama Administrations renewed interest in supporting out space programs. Then again, HOW that money is spent will be up to the people in charge at NASA. As states, some administrators think a permanent moon base would be a good thing. A stepping stone for missions to Mars or beyond, and good practice for visiting another planet. Yet others think that the money would be better spent on actually going to those destinations.

Money mostly. And materials. Each shuttle flight alone costs about $1.5 billion dollars. And it would take many, many trips to bring enough materials to the Moon to construct a working base. Another factor is construction. How do you build something that massive when you are confined in a space suit? How do you find enough construction workers? The base itself would have to sustain human life, another daunting task. Where would you get all of the air from? What about water, food, plants, livestock? It just isn't economically or physically viable at this time, or for a while for that matter.

Indeed I will. But EVERYONE should go see this movie:

www.moonmovie.com science-fiction at its BEST. It has REAL science and is fiction, but based in reality. It does NOT have robots and CGI cities being blown up, but what it does have is an actual story, a basis in science, and a look at humanism and our future.

How, When, and What changes every 4 years!