NASA Predicts People on Mars Within 25 Years

US space agency NASA believes it can put humans on Mars within 25 years but the technological and medical hurdles are immense, reported Aljazeera.

Deadly radiation from the cosmos, potential vision loss, and atrophying bones are just some of the challenges scientists must overcome before any future astronaut can set foot on the Red Planet, top NASA officials said on Tuesday.

"The cost of solving those means that under current budgets, or slightly expanded budgets, it's going to take about 25 years to solve those," said former NASA astronaut Tom Jones, who flew on four space shuttle missions before retiring in 2001.

At an average distance of about 225-million kilometres, Mars poses scientific problems an order of magnitude greater than anything encountered by the Apollo lunar missions.

With today's rocket technology, it would take an astronaut up to nine months to reach Mars - the physical toll of floating that long in zero gravity would be huge.

For instance, scientists think prolonged weightlessness can cause irreversible changes to blood vessels in the retina, leading to vision degradation. And after a while in zero gravity, the skeleton starts to leach calcium and bone mass.

With gravity only one-third of Earth's, scientists don't yet know the effects of a presumed one-year mission to the surface of Mars.

One way to reduce wear and tear on the human body is to dramatically cut down on travel time to Mars.

Jones called for nuclear propulsion systems that would have the added benefit of producing electricity on flights.

"If we start now, in 25 years we might have these technologies available to help us and protect us from these long transit times," he said.

Under current conditions, just an outbound trip...