Of all the events of 1980/81, which will be considered memorable and significant by historians a thousand years from now? Among the struggles for minor political advantage and the fluctuations in global impoverishment and oppression, which events provided a major aperture to a hopeful future?

If we survive, I think 1980 will be remembered at least in part because of the unmanned American spacecraft, Voyager 1. In middle November, the immense cloud-bound planet Saturn, its exquisite rings and tantalizing moons, floated into our consciousness, as the coastal cities of India did for the sailors of Vasco da Gama in the spring of 1948. In colorful worlds named Tethys and Rhea, Iapetus and Titan, we have glimpsed our future ports of call.

More worldwide attention was directed to Voyager 1 than to any American scientific venture in more than a decade. This was exploration on behalf, not of any one nation or small group of scientists, but rather for all peoples of the Earth. Many pictures arrived on home TV screens at the same moment as on the monitors at the Jet Propulsion Laboratory. Voyager represents not just the pursuit of pure science but also an enterprise of great practical merit. These moons and planets, evolving under different conditions elsewhere in the solar system, represent natural experiments on the destinies of worlds. Out there are lessons on what else is possible.

Voyager is at the forefront of robotics technology -- complex, self-checking, self-repairing autonomous systems that can be reprogrammed on human command. There are no maintenance men in the Saturn system, a billion miles from home. For ships like these to work, they must be almost flawless. And they have been, repeatedly surpassing even the expectations of their designers, functioning in the stifling, broiling inferno of Venus or in the frigid vacuum beyond Saturn. They are testaments to the excellence of our technology. The potential value of the next generation of such robots -- for undersea mining, say, or in Earth orbit -- is inestimable.

And unmanned planetary exploration speaks to us on an almost mythic level about our place in the universe, about origins and ends, about our responsibility for our small blue world. The rings of Saturn hold clues on the accretion of the Earth; the organic clouds of Titan, on the chemical steps that led here, 4 billion years ago, to the origin of life. These spacecraft provide nourishment for the spirit and the soul -- and civilization are not judged on what they provide for the body alone.

Planetary missions are, compared to other activities we support, inexpensive. Voyagers 1 and 2, over their three years of encounters with the Jupiter and Saturn systems (1979-1981), cost every American annually less than a nickel a world. There are few better bargains. (Voyager 2 will encounter Saturn this August, and, if we are very lucky, will return data from the system of the planet Uranus in 1986.)

The exploration of the planets is recognized throughout the world as an area of unchallenged American leadership in a benign high technology. The United States has been first to orbit another planet, first to explore Mercury, Venus, Mars, Jupiter and Saturn by spacecraft, and the first to land humans on another world. The Soviet Union, which continues a vigorous planetary program, was first to see the far side of the moon, first to land on the moon and first to land on another planet. But ships of the U.S.S.R. have so far never ventured beyond Mars or Venus and no other nation has sent its craft even as far as the moon next door.

This situation is, however, changing. No comet has ever been examined, close-up, by a spacecraft. But in 1986, when Halley's Comet returns to the inner solar system, it will be greeted by at least three ships from Earth; Giotto, launched by a consortium of European nations; Planet A, launched by Japan; and a joint Soviet-French mission which will encounter the comet after dropping ships off in the clouds and on the surface of Venus. However, the United States, with the capability to fly closer to and obtain superior data from the enigmatic nucleus of the comet, has not approved a Halley mission.

The Reagan administration's new budget asks not only for no new comet mission, but only lukewarm support for the Galileo mission and indefinite postponement of VOIR. Galileo would be the first spacecraft to orbit Jupiter and to drop an entry probe into its atmosphere. It was resoundingly approved by more than 2-to-1 in an unusual vote on the House floor in summer l977. VOIR, Venus Orbital Imaging Radar, would be a spaceship to orbit Venus and map with radar its cloud-covered and otherwise invisible surface. It is an item submitted in the last Carter administration budget, but still to be approved by the Congress.

With the proposed new budget, there is the ominous and very real prospect that American leadership in planetary exploration will come to an abrupt end, that there will be no new missions for more than a decade and that one of the premier centers of precision engineering on the planet Earth, NASA's Jet Propulsion Laboratory, will deteriorate. And yet the amounts of money involved are relatively small. For example, the cost of a single nuclear aircraft carried could pay for all of the following: the Halley Comet mission, Galileo to Jupiter, VOIR to Venus and significant initial work on a MARS roving vehicle, a Titan entry probe and a manned mission to a carbonaceous asteroid.

These planetary missions are ventures we can be proud of. They cost relatively little. They are a credit to our nation, our species and our epoch. As fundamental science and frontier technology, they ease our entry into the future. They are adventures of historic proportions. And they help understand the nature of excellence, what else we may be capable of, where we have come from and who we are.

The short-term economy of canceling planetary exploration would be dramatically outweighed by the longterm loss.