High Risks, Profound Challenges : Mars Mission Gathers Growing Support

A manned expedition to Mars would usher in a new era of high risks and profound challenges, and it cannot be said at this point that such a rigorous journey is within the scope of human endurance.

Yet scientists throughout the country and around the world have joined a groundswell of support for a Mars mission, convinced that the risks are worth taking and that the conquest of space is the essence of human destiny.

A manned mission to Mars is one of four primary goals recommended by a NASA panel headed by astronaut Sally K. Ride, but the space agency has not yet formally embraced the proposals. Mars has gained considerable support in recent months among scientists who believe that such a mission could give the nation’s space program the kind of direction many officials believe it lacks.

The hurdles that must be leaped, and the dangers that must be faced, however, are staggering.

Most experts believe that a round trip to Mars would take about three years, and at times the spacecraft would be so far from Earth that ground controllers could not warn the crew of immediate dangers, including the potential catastrophic failure of life-support systems.

The length of the voyage would increase the chances that a meteor could rip through the spacecraft, causing rapid decompression that would kill the crew within seconds. And it is unclear at this point whether the crew could be adequately protected from fatal doses of radiation emitted by solar storms.

Three years in isolation also would pose psychological problems so severe that some members of the crew might have to be sedated at times. As one scientist observed, “How would you like to spend the next three years in a motel room?” Problems that seem trivial on Earth would be magnified enormously, and medical specialists in the crew would have to be equipped to deal with any emergency, including major surgery.

Soviet cosmonauts have spent up to eight months in orbit around the Earth, giving the Soviet Union by far the greatest experience in prolonged exposure to space. That experience has revealed that long missions challenge human endurance in every arena and can lead to physiological and emotional problems.

“Our volume of information is insufficient to determine whether men will be able to travel to Mars,” Oleg Gazenko, a top scientist in the Soviet space program, said last week. That statement is significant because it is widely believed that the Soviets hope to carry out such an expedition around the turn of the century, after completing a series of unmanned missions throughout the next decade.

Many hazards would be intensified by the length of the trip. One scientist noted during a Mars conference at the University of Colorado last week that it takes only about a day and a half to reach the moon, so if anything goes wrong “you can whip around the moon and come back,” as the crew of Apollo 13 proved in 1970 after an explosion in an oxygen tank created one of the most harrowing space flights of all time.

Such rapid turnaround would not be possible on a trip to Mars because once the spacecraft was sent on its way it would have to reach Mars--a journey that would probably take a minimum of a year--before it could head back. The spacecraft would need the gravitational field of Mars to reverse its direction.

“There’s no way you can shortcut it, or you just blow up spaceships,” said Jesco von Puttkamer, one of NASA’s senior executives.

Communications Delay

Barney Roberts of NASA’s Johnson Space Center in Houston noted that when the spacecraft is in the vicinity of Mars, the communications delay will be up to 30 minutes because it will take that long for electromagnetic waves to carry messages between the spacecraft and Earth.

“So you cannot have real-time communications with the crew,” he said.

By contrast, when the shuttle is flying, “1,000 people on the ground” monitor every event, Roberts said. When problems arise, they are usually detected by people on the ground long before they show up aboard the shuttle.

As one scientist pointed out, the crew aboard a Mars-bound spacecraft cannot be forewarned by “a hundred screams from a hundred eagles” at Mission Control when peril looms.

“So this will have to be a truly autonomous spaceship that must survive from 360 to 1,000 days,” he said.

Most current planning is based on a trip of about three years, a long time for the crew to be exposed to unprecedented dangers, including meteor showers, equipment failures and radiation.

“You are living on the brink of death any time you are in space,” said Benton Clark, a radiation expert with Martin Marietta.

Solar Storms

One concern is over radiation emitted by the sun during solar storms. Earth’s atmosphere shields the planet from most of that radiation, but in space that protection is lost. That does not pose as serious a problem during lunar missions or the flight of the shuttle because the storms usually can be predicted within a few days, but that would not be much help on a three-year voyage.

Roberts, who outlined the level of difficulty of a Mars mission during a presentation at the Boulder conference, was asked by one scientist how much radiation the crew would have to endure in a “worst-case scenario.” The scientist was concerned about massive radiation that would be unleashed during a prolonged solar flare, the solar equivalent to a hundred-year flood on Earth.

“It could be 800 to 1,000 rems (a measurement of radiation) over a 24-hour period,” Roberts said. Noticing that some in the crowd seemed puzzled by the estimate, he blurted: “I mean the crew is dead.”

It is not considered feasible to build a protective shield around the spacecraft because it would be too heavy, and that has led scientists like Clark to suggest that the crew could be protected by “radiation storm shelters” aboard the spacecraft. The shelters could consist of areas in the spacecraft that are surrounded by fluids--possibly the crew’s drinking water--that would absorb cosmic rays.

Radiation Dosage

As Clark described it, when sensors aboard the spacecraft sounded a warning that the ship was being bombarded by radiation, the crew would take refuge in the nearest shelter. But even if everything worked as planned, the crew would probably be subjected to about 200 rems of radiation during a round-trip voyage. Federal regulations set the lifetime limit for any individual at 300 rems.

Clark believes that other dangers are more threatening to a Mars mission than radiation.

He said that if the spacecraft were somehow punctured and the cabin suddenly lost its pressure, becoming a vacuum chamber, crewmen would have little time to take whatever action they could because many bodily functions, including the heart, would stop.

“It’s not just a matter of holding your breath,” he said, because the brain would cease to function within about 30 seconds.

John Billingham, who directs much of the research on life sciences at NASA’s Ames Research Center in Mountain View, said the astronauts would not even have that much time.

“Probably about 10 seconds,” Billingham said.

If the astronauts reached Mars, they would face additional dangers, including the need to regulate temperatures in an environment where the thermometer ranges from below freezing to near boiling.

“You could literally stew in your own juices,” Clark said.

No Paramedics

And there won’t be any paramedics on hand when they land, so the astronauts will need to be healthy when they climb out of their spacecraft.

“We want the people who get there and are the first to stare at Mars face to face to be in good condition,” said John D. Rummel of NASA headquarters.

That could be difficult if the astronauts have spent more than a year in a weightless environment getting to the Red Planet. NASA chief James C. Fletcher told the Boulder conference, “We’ve cited muscular and skeletal deterioration after three months,” which is the longest time any American astronauts have spent in space. No permanent damage has been reported, however.

It may turn out that further research will convince scientists that it is not possible for humans to spend two or three years in a weightless environment, and some research suggests that if astronauts are successful in adapting to zero gravity over such a long period, they may not be able to readjust to gravity upon their return.

If that turns out to be the case, it will be necessary to develop artificial gravity, which could be done by slowly spinning the spacecraft, but there is no research about what physiological effects that might have because it has never been tried.

Troubling Results

Soviet cosmonauts have spent the longest periods in space, because only the Soviet Union has a permanent space station, and the results there have been somewhat troubling. Some cosmonauts exposed to long periods of weightlessness have experienced psychological trauma, and others have been hospitalized for brief periods, primarily because of exhaustion and depression.

Jack Stuster of Anacapa Sciences Inc. of Santa Barbara, who has studied the effects of isolation and zero gravity under a contract with NASA, said one cosmonaut told him that he had suffered from “what he called an irrational fear” of a toothache that made it nearly impossible for him to complete his work.

Concern over such traumas has led the Soviet Union to establish a “psychological engineering” program to try to sort out problems among orbiting cosmonauts before they become too serious, according to Yvonne Clearwater of Ames Research Center.

Clearwater said psychological teams on the ground continuously monitor cosmonauts through such things as voice stress analysis and facial contortions.

“If they see you are getting irritable, they assist you in getting out of it” through counseling with ground personnel, she said.

The program has such high priority that 25 out of every 90 minutes of communications time is allotted to the psychological effort, she said.

Sheer Isolation

Part of the problem is the sheer isolation of the environment, plus the cramped quarters and the need to get along with a handful of people under difficult circumstances for a very long time.

Stuster has looked at a wide range of similar experiences, including tours aboard submarines, undersea laboratories, Antarctica and Skylab.

“Trivial issues are exaggerated in an isolated environment,” he said. “Group interaction is the most important of all,” and experience has shown that the behavior of some team members may not always be anticipated.

“It is essential to have a way to sedate people who become extremely disturbed,” he said.

The limits on creature comforts can also lead to serious problems. Noting that the toilet has rarely worked right aboard the space shuttle, Stuster said: “Some astronauts stopped eating so they wouldn’t have to use the bathroom. It’s criminal what they have had to endure.”

Nearly all of these problems could be reduced if the length of the journey could be shortened, a possibility that has intrigued Ride.

Ride, America’s first woman in space, maintains that it would be possible to fly to Mars--and back--in a little over a year, although Fletcher told the Boulder conference that such a mission “doesn’t look like a good possibility.”

Shortcut Idea

To shorten the journey, either the spacecraft would have to be lightened or more powerful rockets than those currently envisioned would have to be provided.

Ride is pushing a concept that originated with a group of students at the University of Texas and Texas A&M.; The students suggested sending many of the expendables, including the return fuel, to Mars aboard a slower unmanned cargo ship. After the freighter reaches the planet, a much lighter spacecraft could carry the crew to Mars in about six months.

Fletcher seemed cool to that proposal, indicating that a “split mission” could prove too costly. Others see problems with sending a crew to Mars with no certainty that when they arrive, the previously dispatched supplies--including the fuel to get home on--would be usable.

However the mission is eventually carried out, the first people to set foot on Mars will mark the beginning of a new era.

Manned exploration of Mars is “the great adventure of mankind for the coming decades,” said Thomas O. Paine, former head of NASA and chief architect of the blueprint for the future of the nation’s space program.

Crops on Mars?

Mars is the only other planet in the solar system that could sustain human life, albeit under austere conditions. Humans could mine Mars for the fuel they need to power their rockets, and research by Amos Banin of the Hebrew University in Israel suggests that it should be possible to grow crops on Mars if the carbon dioxide atmosphere could be enriched slightly with oxygen.

That sort of thinking has led dreamers to envision human colonies on Mars, growing food under giant plastic bubbles, embarking on the exploration of the universe.

It took a Soviet scientist to find the bottom line during the satellite conference in Boulder, which was sponsored by the Planetary Society of Pasadena.

“We cannot rule out the possibility of the time coming when man will be forced to another planet,” he said, without elaborating.

So despite the hardships and challenges that lay ahead, support for such an endeavor is growing.

The fact that it is so challenging is what makes the mission so intoxicating to scientists, like Cornell University’s Carl Sagan.

“Can we afford to send human beings to Mars?” he asked rhetorically. “Can we afford not to?”