KENNEDY SPACE CENTER, Fla. - Dr. Tamarack Czarnik drove to Florida to watch the space shuttle launch, but his view is different from the average space
fan's.   The Huber Heights resident is a medical doctor halfway through Wright
State University's aerospace medicine program, which trains physicians for
aviation- and space-related medical work. Besides coming down to watch Endeavour lift off, Czarnik is observing NASA's flight surgeons and taking in lectures onbiomedical space research.
  

Czarnik, 38, is a child of the Apollo era. He grew up in the 1960s when
many people thought the moon landings would lead quickly to a moon base and
expeditions to Mars.  Czarnik said he dreamed of being a doctor, but he also dreamed about space. In fact, he said, he had `a rather naive dream of being the first doctor on Mars.'
  

More than a quarter-century after the last Apollo moon flight, there's no
moon base and no Mars expedition on the space agency's timetable. Most of
NASA's efforts over the next six years will focus on building the International Space Station, an orbiting laboratory where scientist astronauts will probe the frontiers of science, but not the solar system.
  

But Czarnik hasn't given up his dream. He's just modified it to fit
reality - and is striving to modify reality to fit his dream.   `I've come to accept the fact that I will probably never go in space myself, much less be the first doctor on Mars, just because my vision is so terrible. I'm tremendously nearsighted,' he said. `I would still like very, very much to see other people go. And I wanted to be able to say at the end of my life, 'Yes, I contributed to that.''
  

So Czarnik is aiming at a career in aerospace medical research, to
develop medical procedures needed to treat illnesses and injuries on long flights
millions of miles from the nearest hospital.
  

He is also involved in a grassroots movement to prompt NASA to make a
Mars expedition a high priority. He has organized a 30-member Ohio chapter of the Colorado-based Mars society, which was founded in August.    Czarnik said the society doesn't advocate rushing to Mars.   `Mars is roughly 1,000 times more distant than the moon,' he said. `If we sent a mission to Mars tomorrow, I don't believe that we would make it. The thrust of the Mars Society is that if we directed an initiative at Mars starting now ... challenging us to make it to Mars by the end of the (next) decade, I believe then we could do it.'
  

Some Mars advocates claim the space station program siphons billions of
dollars from research needed to mount a Mars expedition. Czarnik agrees more
money should be spent on Mars research, but he believes the space station is
an essential step.   `There are certain problems with long-duration space flight we really haven't worked out yet,' he said. Ohio Sen. John Glenn spotlighted several
with his return to space, which he said was aimed at comparing the effects
of aging with similar effects astronauts experience in the absence of gravity.
   One of the `real show-stoppers' to a Mars expedition is the gradual weakening of bones in microgravity, he said    The rate of bone loss varies unpredictably but doesn't seem to stop, he said.   Biomedical research on the space station will seek to learn how to counter bone loss and other problems in space flight.    `There's a tremendous amount of research (on the station) that will benefit a mission to Mars,' Czarnik said.