Somebody has their terminology screwed up. "Libration" refers to an effect caused by the apparent wobble of the Moon as it orbits the Earth. The Moon always keeps the same side toward the Earth, but due to libration, 59% of the Moon's surface can be seen over a period of time. What they were trying to say was "Lagrange Point".
Lagrange Point
French mathematician and astronomer Joseph Louis Lagrange showed that three bodies could lie at the apexes of an equilateral triangle which rotates in its plane. If one of the bodies is sufficiently massive compared with the other two, then the triangular configuration is apparently stable. Such bodies are sometimes referred to as Trojans. The leading apex of the triangle is known as the leading Lagrange point or L4; the trailing apex is the trailing Lagrange point or L5.
Easy mistake to make (both words begin with "L") but they mean entirely different things. If we are ever to move permanently into space and commercialize the asteroid belt, we will need to build a large base at one of the Lagrange points. The best way to do that would be to start with a base on the Moon, use solar power to produce building materials for the Lagrange station from Moon rock and ship it to the assembly point with a mass driver.
If the Earth is going to survive population pressure we need to begin moving permanently into near space and then progress further as technology develops. We are made of "star-stuff", it's time to go home.
Regards,
GtG
PS A mass driver on the Moon would make an excellent way to launch kinetic weapons (rods of God?) back at Earth should the need arise.
Lyndon Johnson: And as I was sayin', whoever controls the high ground of space controls the world. The Roman Empire controlled the world because it could build roads. Later, the British Empire was dominant because they had ships. In the Air Stage, we were powerful because we had the airplane. And now the Communists have established a foothold in outer space. Pretty soon they'll have damned space platforms so they can drop nuclear bombs on us, like rocks from a highway overpass. Now HOW IN THE HELL did they ever get ahead of us?
I was an early member of the L-5 Society. The plan was to disband the organization with an all-member meeting aboard an L-5 domicile. That plan hasn't quite worked out (yet) and the Society has since merged with the former National Space Institute to form the present National Space Society L-5 Society