Aw: Trip to Mars would turn astronauts into weaklings

Prolonged exposure to weightlessness could cause astronauts to lose more than 40 percent of their muscle strength even with regular exercise, researchers said. On a long voyage, a healthy 30- to 50-year-old astronaut could end up with the strength of an 80-year-old.

A 10-month trip to Mars would cause such extreme muscle deterioration that astronauts would find it difficult to perform even routine tasks, let alone move around the Martian surface in spacesuits, according to the study, which was led by Robert Fitts of Marquette University.

Returning to Earth could be even more perilous, the researchers found: The astronauts could be too weak to evacuate their spacecraft if they needed to make an emergency landing.