These days ''small is beautiful'' even in outer space.
Caught between federal budget reductions and start-up costs of the space shuttle, the National Aeronautics and Space Administration (NASA) is pinning the immediate future of its planetary exploration program on efforts to radically reduce mission costs.
''We have a mind-set for reduced costs now,'' says Jessie Moore, director of NASA's Earth and Planetary Exploration Division.
This represents a radical departure from the space agency's past philosophy, and one which it has found difficult to accept. Over the past decade NASA's planetary budget has steadily shrunk. Its 1983 request of $155 million is only 47 percent of its 1973 budget, and this does not take inflation into account.
But until a year ago, the agency continued to propose ever larger, more elaborate, and more expensive missions. Its last forays into the solar system, while returning spectacular pictures of, and invaluable scientific information on, such natural wonders as the rings of Saturn, also had price tags that mounted above the $500 million range. As economic conditions worsened at home, these pricey planetary projects became harder and harder to sell to Congress and the administration. The result has been to choke off the flow of new missions.
''We haven't been too successful with the high cost approach recently,'' Mr. Moore says ruefully.
Having finally accepted the inevitable, the space agency has turned to ''cost reduction'' with its characteristic technological aggressiveness. Studies are under way at a number of NASA laboratories. Guiding this effort is an advisory group called the Solar System Exploration Committee, which has been meeting regularly since last summer.
Charles Barth, director of the University of Colorado's Laboratory of Atmospheric and Space Physics, is a member of this committee. The lanky, soft-spoken scientist has been an active proponent of lower-cost planetary missions for some time.