MOSCOW — Soviet scientists revealed plans Wednesday to land humans on Mars by the year 2010, in what would be the culmination of the most ambitious series of planetary expeditions ever attempted by the Soviet Union.
As outlined by officials, the manned landing on Mars is so challenging that some scientists attending a symposium here said they doubt the Soviets will try it that soon.
Nonetheless, unmanned flights to Mars are scheduled to begin tonight with a launch of a robotic spacecraft to a tiny Martian moon called Phobos, and unmanned expeditions will continue through the end of the century, paving the way for a manned expedition. The trip to Phobos will take about 200 days.
A manned mission to Mars, which some scientists believe may be beyond human endurance, has been discussed by various nations, including the United States, but the Soviet Union on Wednesday gave it a special thrust. The U.S. National Aeronautics and Space Administration has gone only so far as to conclude that a mission to Mars should be considered in its long-range planning.
Calling interplanetary travel "a logical expansion of human development," Leonid A. Gorshkov, of the Soviet space agency Glavkosmos, said the Soviet Union is now aiming at "around 2010, but sometimes we think we are a bit optimistic."
Although many scientists have suspected for some time that the Soviet program was aimed in that direction, "that's the first time they have ever given it a date," said Lou Friedman, executive director of the Pasadena-based Planetary Society. Friedman is one of several dozen scientists from around the world who are taking part in a series of meetings here on the Soviet Mars program.
Soviet scientists apparently have decided that it will not be necessary to provide artificial gravity for a manned mission to Mars--a decision that could save many years in preparations. Gravity can be simulated by slowly rotating the spacecraft, and some medical experts believe that this may be necessary to reduce the damage to muscles and bones that occurs during prolonged exposure to weightlessness.
But the Soviets have more experience in space endurance than anyone else, and Gorshkov is believed to have played a key role in the development of the vehicle that gave them that experience--the Soviet space station Mir. Schematics that he showed scientists here Wednesday did not depict the kind of large, rotating structure that could create artificial gravity.
Friedman said he was told by Soviet officials that their research shows artificial gravity will not be required.
Internal Politics Seen
Like its counterpart in the United States, however, the Soviet space program is a many-faceted creature with competing interests, and some scientists attending the session speculated that the announcement of the manned expedition amounted to little more than jockeying for position within the program.
"I would be very skeptical," said Tom Heinsheimer, vice president of Titan Systems of Gardena. Heinsheimer is part of an international team that is designing balloons to be released into the Mars atmosphere by a Soviet spacecraft toward the end of the decade. The balloons will drift around the planet, collecting and transmitting data back to Earth.
Heinsheimer said the Soviets have a powerful new rocket system, called the Energia, and now they are trying to justify it.
"Like the shuttle, we build this big rocket that has no mission," he said of the Soviets. "So you run around and sell a mission to Mars."
That is the same process, he said, that got NASA in trouble--building hardware and then trying to find something to use it for.
"What we see here is the start of a classic process," he said.
Yet some Soviet scientists, while not fully embracing the Mars mission, indicated that it is inevitable.
"It's impossible to stop development of an idea," noted Wiatcheslav Linkin, director of the atmospheric sciences laboratory at Moscow's Space Research Institute.
The scientific meeting, which began Wednesday and will continue through next week, revealed a Soviet space program that is clearly set on Mars, although open to disagreement and divided over whether to use the powerful new Energia or the reliable old Proton rocket. Soviet scientists repeatedly cross-examined their counterparts at Wednesday's session.
"That kind of lateral communications in this country is new," Friedman said.
"It's a very healthy process," Heinsheimer added.
The decision to plan a manned expedition to Mars should have a dramatic impact on the unmanned Soviet missions between now and then, several scientists noted. Rather than simply being scientific missions, they will become precursors to a manned expedition--and thus, the demands will be much greater.
And before any attempt can be made to send humans to Mars, profound questions must be answered that deal directly with human survivability. In announcing the plans, for example, Gorshkov said flatly that the crew would survive intense bursts of radiation from the sun, although they would receive a lifetime dosage in just one mission, meaning they could not be expected to make the journey again. But he brushed aside questions from other scientists who saw nothing in his presentation to convince them that the problem had been solved.
"They underestimate the problem of radiation," said Jacques Blamont, a senior scientist with the French space agency.