Billionaire entrepreneur Elon Musk has ambitious plans to set up bases on the Red Planet, and recently suggested he could have an outpost up and running in just ten years.
But Jennifer Ngo-Anh, SciSpacE Team Leader with the European Space Agency (ESA) said the challenges were enormous.
Mrs Ngo-Anh, who was not commenting specifically about Mr Musk’s plans, said the problem arose because of the huge amount of radiation which emanates from the Sun in the form of solar particles as a result of coronal mass ejections (CMEs) and other solar activity.
She explained: “Cosmic radiation and its effects on the human body have been identified as one of the main showstoppers for human exploration and colonisation of the solar system.
“Crewmembers on long-duration exploration missions will be exposed to significant ionising radiation doses from Galactic Cosmic Radiation as well as from Solar Particle Events.
“Also secondary particles from the interaction of this radiation with spacecraft materials, planetary surfaces or a planetary atmosphere have to be considered.
“Possible health risks include cancer, damage to the central nervous system, cataracts, risk of acute radiation sickness, and cumulative, hereditary effects.
On Earth, people are shielded from the various rays which bombard the planet by a combination of the atmosphere and magnetosphere.
Together they block 99.9 percent of the harmful radiation from the Sun and deep space – but in space there is no such protection.
She added: “On Earth we are exposed to roughly 3 millisieverts of radiation per year.
“On the International Space Station astronauts, who typically stay there for an average of six months (like Tim Peake) are exposed to roughly 100 millisieverts of radiation.
“A roundtrip mission to Mars, not including time for exploration of the planet, would expose potential Martian astronauts to 662 millisieverts of radiation, which is scary considering in an astronaut’s career their cap is supposed to be 1,000 milliseverts!”
In order for a crew of astronauts to operate successfully on a base on the Moon, Mars or another planet, it was crucial to develop some type of shielding to protect them.
Mrs Ngo-Anh explained: “Unfortunately – to date – we do not yet have good, practical and efficient countermeasures or radiation protection strategies at hand.
“That is why since 2005 we have been cooperating with the GSI Helmholtz Center for Heavy Ion Research in Darmstadt within the so-called IBER programme (Investigations into the Biological Effects of Space Radiation) trying to advance our space radiation knowledge.”
Starting last year, the ESA has made five European radiation research facilities located in Germany, France, Italy and the Netherlands available to scientists trying to develop possible solutions to the problem, Mrs Ngo-Anh said.
Speaking in 2016, Mr Musk told the International Astronautical Federation (IAC) in Guadalajara, Mexico he was not particularly concerned about the threat posed by radiation.
He explained: “There’s going to be some risk of radiation, but it’s not deadly.
“There will be some slightly increased risk of cancer, but I think it’s relatively minor.
“The radiation thing is often brought up, but I think it’s not too big of a deal.”