U.S.-Soviet Mars Mission Called Risky : Space: Committee instead recommends “a graceful path” of coordinated but independent exploration.

Joint missions to Mars by the United States and the Soviet Union are too risky now, a panel said today, recommending instead that the two nations follow “a graceful path” of coordinated but independent exploration.

“The United States and U.S.S.R. have no prior experience with the degree of cooperation necessary to carry out a technical project of this complexity or magnitude,” said a committee of the National Research Council.

The committee said it was concerned “about relying on the consistency of the relationship over a period of a decade or more into the future.”

The panel’s report appeared to chill the idea frequently expressed by many experts that Mars would be explored jointly by the Soviets and Americans, doing together what would be too expensive for either nation to do alone.

The United States and the Soviets have cooperated in space in the past, most notably in 1975 when three Apollo astronauts joined their spacecraft with a Soviet Soyuz and exchanged bear hugs in orbit with two cosmonauts.

The committee was commissioned by NASA to look into undertaking missions with international partners to use robots to gather rocks and soil from Mars and bring them to Earth for analysis. The committee concentrated its study on efforts by the United States and the Soviets because “they are the only nations presently in a position to take on the lead role in a major Mars program.”

The Soviets have said they intend to explore Mars with robotic rovers, with orbiting space probes and by returned samples. A scenario often mentioned is that one nation would build a lander and a sample-return vehicle while the other would develop a roving vehicle for collecting samples and analyzing them.

The committee said it reached the conclusions after considering these three levels of U.S. participation with the Soviets in a Mars venture:

* Each country conducting programs independently. The cost would be too high, the returns would be less than maximum, U.S. technology would benefit greatly and there would be no additional risk of transferring technology to the Soviets, the report said.

* Split responsibilities and joint technical operations. Such a venture would allow the nations to share costs while increasing returns and to take advantage of the best of both nations’ space programs, such as the Soviets’ lead in heavy-lift launch capability. But a mission highly dependent on cooperative efforts would be a “potential hostage to political events that might disrupt communications and interaction between the two nations,” the committee said.

* A highly coordinated exploration program. “The two sides would work together at all stages,” the report said. “However, the two sides would conduct their own self-contained and independently designed missions.”