For as long as humankind has been capable of wonder, men and women have looked to the stars and dreamed. For centuries, they had to be content with just that. Only a mere half century ago, we first escaped the Earth's atmosphere; a decade later an American astronaut lowered himself to the lunar surface. That landing and the few more that followed are the high point of humankind's attempt to leave this planet as the costs of space travel -- both human and financial -- have mounted.

Dreams of exploring worlds beyond our own have been rekindled with reports that U.S. President George W. Bush will announce a new space initiative this week. According to the leaks, the president will propose establishing a permanent science base on the moon for astronauts, from which, more than a decade from now, they will be used for manned trips to Mars or asteroids. In the meantime, the United States will gradually terminate its involvement in the International Space Station, or ISS, and retire the trouble-plagued space shuttle, replacing it with a new spacecraft, the crew exploration vehicle.

There are a number of reasons for Mr. Bush's new initiative. In practical terms, the troubles with the space shuttle have forced the U.S. to rely on the Russians to make progress in space and the Russians have not performed as promised. Establishing a base on the moon would facilitate space exploration since the gravity there is one-sixth that of the Earth, making it easier to launch vehicles. It would also provide a better environment for testing equipment and procedures.