Credit: iStockPhoto
PARIS: If a human ever sets foot on Mars, will it be a giant step or an exhausted shuffle?
Long-term space flight so weakens fitness that an astronaut heading to the Red Planet may lose up to half the power in key muscles in the course of the mission, scientists have found.
The loss - equivalent to a crew member aged between 30 and 50 returning home with the muscles of an 80-year-old - would add a major danger to a trip already laden with peril, they said.
Muscles weaken at zero gravity
Researchers led by Robert Fitts of Marquette University, Wisconsin, took tiny samples of tissue from the calf muscles of nine U.S. and Russian astronauts who spent around six months on the International Space Station (ISS).
The biopsies, taken 45 days before launch and on the day of return, showed dramatically how muscles atrophy in zero gravity.
The losses in fibre mass, force and power translated into a decline of more than 40% in the capacity for physical work, Fitts reported.
Biggest muscles suffered the most
Ironically, beefing up before the trip had no impact on muscle loss. In fact, crew members who began with the biggest muscles turned out to have the biggest decline in muscle fitness.
Under one NASA scenario, a return trip to Mars using current rocket technology would take around three years, if a one-year stay on the planet is factored in.
If so, the decline in the most-affected muscles such as the calf could approach 50 percent, said Fitts.
Too weak to evacuate
Astronauts would tire faster doing even routine tasks, especially if they donned a space suit, and on returning to terrestrial gravity they could be so weak they might be unable to evacuate their spacecraft quickly in an emergency.
The paper has been published online by The Journal of Physiology, and will appear in print next month.
Muscle loss is a well-researched area in space medicine, but this is the first to include specific analysis of muscle cells on long-duration missions.
Far, too far?
With all respect to our modern space travelling. As long as we depend on ballistic space travelling, we may have to realize, that we are not on the right track yet...
How do you expect to overcome the large distances, when you start your trip orbiting? And then slowly accelarate to escape gravity!
Regards, Manfred