A lunar base could be built if NASA or another space agency launched several modules to the moon and managed to land them safely there in very close proximity to each other. Then a manned or robotic crew could go and assemble the structure, but it would be much more difficult to do because of the moon's gravity. And its a quater million miles away so if something was broken or damaged, its not like you could just fedex a replacement overnight.
I'm sure a lunar base will be constructed at some point but probably not within the next 20 - 30 years.
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