Key parts of the article...

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"I think long term -- and whether this is 10 years, 40 years or 100 years -- human exploration and presence in space way beyond Earth orbit is very achievable for everyone," said Dave Lavery, NASA's Mars Exploration Rover program director.

But, said NASA space architect Gary Martin, "We want to retire as much risk as possible before sending someone on a three-year mission."

(Risk retirement is where the Mars Society activiteis comes in--CV)

The health risks alone are daunting.

During a three-year mission, astronauts would be exposed to their lifetime limit of radiation, according to results from the Odyssey probe currently orbiting Mars. In those three years -- most of which would be spent in an aluminum spacecraft -- every cell of the astronaut's body would be penetrated by galactic rays, Martin said.

"There is probably no system that is going to be spared in terms of the need to address the physiological changes which occur," said Jeffrey Sutton, director of the National Space Biomedical Research Institute.

...

Yet, the space agency doesn't have an official manned mission to Mars on in its plans.

A human mission would have to follow the last robotic mission now planned, in 11 years. That mission would bring a sample of Martian soil and rocks back to Earth.

"I think that 10 to 15 years is a target that is not unreasonable to aim for," Sutton said. "I think that we should be bold and ambitious. There's a lot of momentum." ***

http://www.floridatoday.com/news/space/stories/2003b/060703marsA1852A.htm