A serious look at a trip to Mars. Some say a joint manned flight could aid US-Soviet ties

Around the world, long-range manned spaceflight planners are seriously considering an expedition to Mars. No one has yet established a permanently manned space station, nor have astronauts returned to the moon. Many experts say these feats should precede a visit to the Red Planet.

A Mars expedition, however, appears to be technically feasible as an early 21st-century project. More important, it is beginning to be perceived as a politically feasible way for the United States and the Soviet Union to work together, because a Mars expedition would almost certainly be a global project.

The desire for such cooperation dominated a day-long meeting on Mars exploration held Tuesday at the US National Academy of Sciences by the Planetary Society.

Society president Carl Sagan said he sensed ``a hunger, a longing'' in the audience for such a joint enterprise. He added that he believes people around the world ``wish the major technological nations on the planet would do something together on behalf of all mankind.''

The conference had a symbolism that transcended the technical discussions. It was held to commemorate the 10th anniversary of the US-Soviet joint spaceflight, when an Apollo craft linked with a Soyuz spaceship to orbit Earth. Soviet mission commander Alexei Leonov and crew member Valery Kubasov joined their former American colleagues Thomas Stafford, Donald Slayton, and Vance Brand to celebrate that historic event.

But July 16 was also the 40th anniversary of the first nuclear-weapons test. The technologies both of destruction and of the outward expansion of civilization into the solar system thus formed a background for the meeting.

Dr. Sagan reflected several speakers' comments when he observed that these technologies had brought humanity to a major branch point in its development.

He added that it would be hard to imagine ``a more dramatic symbol'' of the US and USSR doing something on behalf of the human species at this transitional time than to lead a first human landing on another planet.

A study commissioned by the Planetary Society projects a cost of about $25-$30 billion -- no more than the cost of the Apollo mission in terms of inflation-adjusted dollars. Spread among a number of nations, such a cost is well within reason, said James Beggs, administrator of the US National Aeronautics and Space Administration (NASA).

To encourage wider space cooperation, Sen. Spark M. Matsunaga (D) of Hawaii introduced a congressional resolution Wednesday urging organization of an International Space Year.

It would begin in 1992 -- the 500th anniversary of Columbus's first voyage to America -- and run through 1995. It would pool world resources in a major space-research effort.

But cooperation in space isn't cut-and-dried. A Congressional Office of Technology Assessment memorandum on the issue, released Wednesday, outlined several considerations that affect decisions on whether to embark on such projects: the scientific and practical benefits; the potential for transfer of militarily sensitive technology; and the effect of such cooperation on US foreign policy in general and US-Soviet relations in particular. -- 30 --