Astronauts not ready for Marswalk as yet

Another space medic fears bones might be the “show-stopper” to Mars.An astronaut, sports medicine specialist and triathlete all rolled into one, Jerry Linenger figured people lost bone strength in space because they exercised wrong or skipped workouts.

So he exercised like mad during his four months on Mir, putting in two muscle-straining, feet-burning hours a day on the Russian space station treadmills to counter the sapping effects of weightlessness. And what happened? Like everyone else, Linenger returned to earth with weakened, injury-prone bones.

“That was disturbing, discouraging I guess is the word,” says Linenger, 42, who’s been back now for two months. “I really see the bone loss thing as the big thing we need to overcome.”

Just recently, a National Research Council Committee criticised NASA for not doing enough to address the physiological and psychological factors associated with human missions beyond earth orbit. What’s more, the work that is being done is poorly organised, the committee noted in its NASA-funded study.

From a technical standpoint, NASA doesn’t expect to send anyone to Mars before 2010 and that’s only if not-yet-approved funds start to flow. Robots, like the Sojourner Rover, will pave the perilous way over the next decade.

That gives Nicogossian and his team enough time, hopefully, to overcome all the medical hurdles to Mars, some of which could be fatal.

Space radiation could cause cancer. Weightlessness-induced calcium depletion could lead to excruciating kidney stones and, once the crew lands on the red planet, to broken bones or injured joints. And without an infirmary, Mars-bound astronauts would be unable to treat heart attacks, bleeding ulcers, tumours and other medical emergencies including the most hush-hush one of all-pregnancy.

“You cannot do telemedicine like we do, or abort (the mission), on the way to Mars,” explains Nicogossian.

Mir commander Vasily Tsibliyev, for instance, could be back on earth within several hours via the soyuz capsule that’s attached to the Russian space station if his heart condition worsened. His complaints of irregular heartbeats forced flight controllers to postpone crucial repairs to the battered station last week. Nicogossian, head of NASA’s Life and Microgravity Sciences office, has asked researchers to develop computer models for what he calls `space bioman 21′ and `space biowoman 21′. These profiles would represent the average man and woman flying in space in the 21st century.

He wants a better grasp of health issues based on gender and age.“We need to accumulate that data if we are going to go and open the space frontier for everybody,” Nicogossian says.

NASA’s favoured Mars itinerary: Six months to get there, one and a half years on the surface and six more months to return. The target price tag: $ 20-25 billion dollars.