Since Galileo noticed the mountains on the moon in the seventeenth century, people have been eager to go there.
When the Apollo mission made it a reality in 1969, the US space program began to anticipate a complex future on the moon. In 1984, a NASA symposium on this topic was convened after its organizers "realized that the space transportation technology of 2000 was able to regularly deliver payloads to the moon" and decided that they should start planning ahead.
Unfortunately, no nation on Earth possessed space transport technologies capable of regularly visiting the moon by the year 2000. Moreover, we knew little about the true nature of the lunar surface.