Deadly cosmic radiation, potential loss of vision and atrophy bones are just a few of the challenges that scientists must overcome before any future astronaut can walk to Mars, experts and top NASA officials said Tuesday.
The US space agency believes it can divert people to the Red Planet within 25 years, but the technological and medical barriers are huge.
"The cost of solving these problems means that it will take about 25 years to solve this problem, due to the current budget or somewhat expanded budget," said former NASA astronaut Tom Jones, who was flying in four space shuttle missions before the holidays in 2001.
"We have to start certain key technologies now," he told journalists in Washington, DC.
In about 225 million kilometers, Mars creates scientific problems that go well beyond what Apollo moon visits are.
With today's rocket technology to reach Mars, the astronaut should take nine months – the physical load that would be long in zero gravity would be enormous.
For example, scientists believe that prolonged weightlessness can lead to irreversible changes in the blood vessels in the retina, leading to visual degradation. And after the time zero is G, the skeleton starts to leak calcium and bone mass.
With a gravity of just one-third of the Earth, scientists are still unaware of the possible impact of the one-year mission on the surface of Mars.
One way to reduce the wear and tear of a human body is to significantly reduce travel time on Mars.
Johns called for nuclear-propulsion systems that would have the added advantage of generating electricity on flights.
"If we start now, after 25 years we will probably use these technologies to help us protect us from these long transit times," he said.
In the current circumstances, only an outbound trip to Mars so long as any astronaut will receive the same amount of radiation than is usually considered safe throughout the course of the career.
"At the moment, we do not have a shielding solution to protect you from cosmic rays and solar radiation sources that you experience during this transit," said John.
Aerospace experts have identified a number of technologies that require rapid development, including a spacecraft that can survive on the harsh route and in dry peace, as well as the ability to lift people from the surface and return to Earth.
NASA currently has a new robotic aircraft called InSight, which moves to Mars, due to land on November 26, after taking off from California on May 5th.
The $ 993 million project aims to expand human knowledge of the internal conditions on Mars, to inform efforts to send researchers and discover how planets like the planet, such as Earth, have been developing billions of years ago.
Chief Scientist Jim Garvin, NASA's Goddard Space Flight Center, said InSight could fill out "critical unknown" elements and help shape Mars's core awareness.
In 2020, another mission will see that NASA sends a Mars route aimed at identifying Mars's environmental habitat, looking for signs of ancient life, and assessing natural resources and threats for future researchers.
In addition, private companies such as SpaceX and many other countries are developing technologies that could be used for future Mars missions.
Some experts believe that the study of the new Moon is the mainstay of the future mission to Mars, as astronauts could learn about water extraction or technology use and use this lesson for future Mars missions.