"We need to get started now on some key technologies," said NASA astronaut Tom Jones.
Lethal radiation from the cosmos, potential loss of vision and atrophying legs are just some of the challenges that researchers must overcome before any future astronaut can set foot on Mars, experts and top NASA officials said Tuesday.
The US Space Agency believes it can put people on the red planet within 25 years, but the technical and medical obstacles are huge.
"The cost of solving them means that under the current budgets or in some extended budgets, it will take about 25 years to solve them," said former NASA astronaut Tom Jones, who flew on four space mission missions before retiring in 2001.
"We need to get started now on some important technologies," he told reporters in Washington.
At an average distance of approximately 140 million miles (225 million kilometers), Mars's scientific problems constitute an order of magnitude greater than that of Apollo Lunar missions.
With today's rocket technology, it would take an astronaut of up to nine months to reach Mars – the physical pathway for fluctuations that were long in zero gravity would be huge.
For example, researchers believe that long-term weight loss can cause irreversible changes in the blood vessel in the retina, leading to synapse.
And after a while at zero G, the skeleton begins to leak calcium and bone mass.
With gravity only one third of the earth, scientists do not yet know the effects of a supposed one-year mission to Mars.
One way to reduce the wear of the human body is to dramatically cut down on travel time to Mars.
Jones demanded nuclear power plants that would have the added benefit of producing electricity on airplanes.
"If we start now, in 25 years, maybe we have this technology available to help us and protect us from these long transit times," he said.
Under current conditions, only one outgoing trip to Mars would take so long that any astronaut would receive the same amount of radiation that would normally be considered safe for a whole career.
"We do not have the solution when it comes to shielding, when it comes to protecting you from cosmic rays and sunspots that you experience during this transit time," Jones said.
Aerospace experts have identified several technologies that require rapid development, including spacecraft that can survive the difficult entry into Mars and land enough softness, as well as the ability to lift people from the surface and return to the ground.
NASA currently has a new robotic landlord called InSight Zooming to Mars, due to land on November 26th after leaving California on May 5th.
The $ 993 million project aims at expanding human knowledge of internal conditions on Mars, informing efforts to send investigators there and revealing how rocky planets the Earth formed billions years ago.
Jim Garvin, chief researcher at NASA Goddard Space Flight Center, said InSight would fill "critical unknowns" and help build an important understanding of Mars.
By 2020, another mission will be to see NASA send a rover to Mars, which aims to determine the habitat of the martian environment, look for signs of old life and assess natural resources and dangers of future human explorers.
In addition, private companies like SpaceX and a host of other nation building technologies can be used on future Mars missions.
Some experts see new moon exploration as the key to a future mission to Mars, as astronauts can learn about extracting water or using technology and apply these lessons to future Mars missions.
(With the exception of the title, this story has not been edited by NDTV staff and published from a syndicated feed.)