- You're an astronaut on the way to Mars in the year 2034.
Your mission is to fulfill the American goal laid out three decades earlier
by President George Bush when he called for the United States to return
to the moon and then venture on to the Red Planet.
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- "Mankind is drawn to the heavens," Bush had
said back then. "We choose to explore space because doing so improves
our lives and lifts our national spirit."
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- So now you're living with five other astronauts in the
small cabin of a spacecraft that left Earth orbit three months ago. Your
home planet is a tiny pinpoint of light in space, millions of kilometres
behind you, and Mars is still three months ahead.
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- Outside, space crackles with radiation. High-energy particles
stream through the spacecraft hull and zap your body, leaving an unseen,
potentially damaging wake. A sudden burst of harmful radiation from the
Sun could force you into a reinforced safe room, a place you call the "storm
shelter".
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- Your crewmates are beginning to get on your nerves. You
see the same people, every day, all day. You eat together, work together,
depend on each other for survival. You've heard the same stories, over
and over. There are no more secrets.
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- You're alone only in the unconsciousness of sleep, and
that's sometimes hard to find, because the whirring, buzzing, clanking
din of machinery never stops inside your home among the stars.
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- You feel isolated and alone, and yearn for home, ache
for a loving contact with family. You know them now only as video images
occasionally beamed from Earth. Your three-year-old will be six by the
time you get back.
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- Conversation with your children is difficult, because
the words take so many frustrating minutes to make the long radio journey.
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- Weightlessness is doing its best to destroy your body
- weakening bones and reducing muscle mass.
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- Even the food tastes different. You exercise hard on
special machines two hours a day just to maintain muscle tone and keep
your heart strong. But still your bones grow more brittle.
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- You live with stress, because there's always danger.
Millions of things could go wrong with your complex spacecraft, and any
one of them could kill you. Just beyond the window there is a vacuum and
deep, deep cold. In an instant you could become a lifeless bit of space
debris, ever drifting, never to return.
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- And Mission Control is always on your back. Every day
they send long lists of chores to maintain the craft and to get ready for
the Mars landing. They just don't understand what you're going through
and you're not sure any more that they even care. Your crewmates grouse
constantly, and you join the chorus of discontent.
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- The scenario above is an illustration of just some of
the complex human problems Nasa must overcome before the agency is ready
to send people on three-year trips to Mars, on what will be the most hazardous
voyage yet undertaken.
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- Guy Fogleman, head of Nasa bioastronautics research,
said the four toughest problems to be solved were space radiation, bone
loss from weightlessness, the psychology of long-term spaceflight, and
developing technologies for remote medical diagnosis and treatment.
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- "There is a wide range of things we have to look
at and they all have to be managed if we minimise the risk," Fogleman
said last week after Bush sketched his vision of Nasa's future.
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- Radiation, particularly from cosmic rays, poses a big
health risk in deep space, so much so that Nasa has established a radiation
laboratory that uses high-energy beams to study the effects of heavy ion
particles on biological specimens.
-
- Walter Shimmerling, a Nasa radiation expert, said high-energy
particles from supernovae that exploded in our galaxy permeate interplanetary
space.
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- "They are considered to be much more destructive
biologically than common X-rays or gamma rays," Shimmerling said.
"The particle acts like a very tiny bullet going through a living
cell."
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- It can damage DNA and cause a cell to die or turn cancerous.
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- Scientists also worry about solar flares that can spray
nearby space with extremely energetic and destructive particles. To guard
against these infrequent events, solar-observing satellites will be posted
to give automatic warnings, allowing Mars-bound astronauts to move to a
safe room shielded from the radiation.
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- Nasa has been studying the phenomenon of bone loss in
astronauts since early in the space age, but no real solution has been
found. People in space tend to lose about 1% of their bone mass every month
in orbit. All countermeasures, so far, have failed to correct this problem.
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- Muscles can be kept toned by exercise, but even this
is not a solution. If muscles were stronger than bone, said one expert,
then a flexed muscle could actually pull away a sliver of brittle bone.
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- The psychological effects of spaceflight are still being
explored.
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- Studies of people confined in tight quarters, such as
in Antarctica, show that even the most dedicated and determined tire of
their companions, become withdrawn, and feel lonely and isolated.
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- Often crew redirect their anger toward headquarters,
or, during space missions, toward Mission Control. On some long-term flights
in the past, mild-mannered astronauts turned mean and ugly, railing at
Mission Control, scolding engineers and complaining about work assignments.
And that was after only a few weeks.
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- Dr Jeffrey Sutton, head of the National Space Biomedical
Research Institute, said solving the potential psychological problems of
a Mars flight was critical to mission success.
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- At this point, Nasa is not sure what would make up an
ideal Mars crew. Should it be men and women? Should parents with young
children be included? What skill mixes are needed? Should there be a doctor
on board? What is the ideal number?
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- ©2004 The Cape Argus. All rights reserved.
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- http://capeargus.co.za/index.php?fArticleId=328569
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