ALL RIGHT NOW, are you ready for a serious discussion of whether the resources of the moon and other celestial bodies should be developed under an American-style free enterprise system or under an international socialist regime? You may not be, but you should know that your fellow citizens in the L-5 Society regard that as Meaningful Topic No. 1. The L is for libration, a point at which the gravitational pulls of earth, moon and sun are equalized. L-5 is the fifth libration point, where you'd park a space platform to manufacture, say, the perfect ball bearing. The L-5 Society wants to turn back what it sees as the chief threat on the space horizon, the moon treaty with its "common heritage" core.

The early international legislation of the space age spawned one treaty to denationalize and demilitarize outer space and a second to provide for the rescue of astronauts in distress.But meanwhile, up at the United Nations' Committee on the Peaceful Uses of Outer Space, the lawyers have been cooking up yet another treaty to regulate exploitation of the resources of space. It's not as crazy as it sounds. The world's drive for development virtually assures that these resources will be sought when the technology, markets and costs are in line. That's way off but not way off: the United States, after all, is about to launch the space shuttle envisioned as the way to get back and forth to factories in the sky.

The one-man, one-vote nature of the United Nations has assured, however, that any international approach to space resources would follow the United Nations' collectivist approach to the resources of the deep seabed. At the law of the sea talks, the United States may yet conceivably swallow articles putting into effect the notion that seabed resources are the "common heritage" of mankind. It would do so chiefly to ensure that other nations agree to other articles of special American interest -- in particular, freedom of navigation. But should space resources, in which American technology is even more commanding, also be designated as the "common heritage"?

A moon treaty draft may soon pop out of the United Nations toaster. Fortunately, there's no need for hasty action on it. Space mining and manufacturing remain distant enough to let the parties see first what common heritage means when applied to seabed resources, which are much closer to being exploited. And certainly there's no need to indulge the would-be space colonists and others who, for a variety of personal and ideological reasons, want space declared a preserve for private American exploitation. Like, man, far out.